Report on "STRUCTURAL MECHANICAL PERFORMANCE EVALUATION AND HEALTH MONITORING"

STRUCTURAL MECHANICAL
PERFORMANCE EVALUATION AND
HEALTH MONITORING
Student Name: Abdul Majid
Student ID: S32002006W
Teacher Name: 郭轶宏
Submission Date: 2023/05/04

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TABLE OF CONTENTS
Chapter 1 THE SERVICEABILITY LIMIT STATES IN REINFORCED CONCRETE DESIGN ............6
Abstract.....................................................................................................................................................6
Introduction...............................................................................................................................................6
EFFECTS OF CRACKING ON CROSS-SECTIONAL RESPONSE .....................................................6
EFFECTS OF CREEP AND SHRINKAGE ON CROSS-SECTIONAL RESPONSE............................7
MOMENT-CURVATURE RELATIONSHIPS .......................................................................................9
Effects of creep and shrinkage under sustained loads.............................................................................10
Scientific Question?................................................................................................................................11
Answer....................................................................................................................................................11
References...............................................................................................................................................11
Chapter 2 STRUCTURAL HEALTH MONITORING OF A CABLE-SUPPORTED ZHEJIANG
BRIDGE......................................................................................................................................................12
Abstract...................................................................................................................................................12
Introduction.............................................................................................................................................12
Bridge Description..................................................................................................................................13
Bridge Monitoring System......................................................................................................................13
Design and Implementation of the IAS...................................................................................................15
Design and Implementation of the DMS ................................................................................................31
Design and Implementation of the EDS .................................................................................................31
Scientific Question?................................................................................................................................33
Remarks and Conclusion to Questions ...................................................................................................33
References...............................................................................................................................................36
Chapter 3 Study of Mechanical Properties of Concrete Developed Using Metamorphosed Limestone
Powder (MLSP), Burnt Clay Pozzolana (BCP) & Wood Ash (WA) as Partial Replacement of Cement ..38
Abstract...................................................................................................................................................38
INTRODUCTION ..................................................................................................................................39
Properties of Hardened Concrete............................................................................................................40
Pore Size and Porosity ............................................................................................................................40
Drying Shrinkage and Creep...................................................................................................................43
EXPERIMENTAL PROCEDURES.......................................................................................................50
Compressive Strength.............................................................................................................................50
Tensile Strength ......................................................................................................................................63
Flexural Strength.....................................................................................................................................66
Modulus of Elasticity..............................................................................................................................68

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RESULTS ...............................................................................................................................................72
Analysis of Factors .................................................................................................................................74
Scientific Questions? ..............................................................................................................................75
REMARKS AND CONCLUSIONS.......................................................................................................75
REFERENCES .......................................................................................................................................76

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List of Tables
Figure 1 Average moment versus instantaneous curvature relationship.......................................................7
Figure 2 Effects of creep on the strain on a singly reinforced section..........................................................8
Figure 3 Shrinkage-induced deformation and stresses in a singly reinforced beam.....................................9
Figure 4 Average moment vs instantaneous curvature relationship after early shrinkage strain................10
Figure 5Photograph of Zhijiang Bridge......................................................................................................13
Figure 6Overall workflow of the system ....................................................................................................15
Figure 7Layout of sensors on Zhijiang Bridge. ..........................................................................................16
Figure 8Meteorological station...................................................................................................................17
Figure 9Hygrothermograph ........................................................................................................................18
Figure 10GPS sensor...................................................................................................................................19
Figure 11Wind and Structural Monitoring..................................................................................................20
Figure 12Hydrostatic level gauge ...............................................................................................................21
Figure 13Stress and fatigue monitoring points on the box girder...............................................................22
Figure 14Welding crack monitoring points on the box girder....................................................................22
Figure 15Stress and fatigue monitoring points on the steel tower..............................................................23
Figure 16Strain gauges ...............................................................................................................................24
Figure 17Vibration sensor...........................................................................................................................26
Figure 18Acceleration sensor......................................................................................................................27
Figure 19Flowchart of data acquisition and transmission...........................................................................28
Figure 20External environment of the bridge.............................................................................................29
Figure 21Vibration of 4# tower and T7 box girder.....................................................................................29
Figure 22Displacement changes in the box girder......................................................................................30
Figure 23Tower shift...................................................................................................................................30
Figure 24Cable force...................................................................................................................................30
Figure 25Function and composition of the DMS........................................................................................31
Figure 26Flowchart during bridge condition evaluation.............................................................................32
Figure 27 (a) Formation of lime as a byproduct of hydration of Portland cement resulting into a porous
paste. (b) Pozzolanic reaction between lime and mineral admixture to fill the interstitial spaces..............41
Figure 28Effect of FA content and type on the drying shrinkage of FA concrete......................................44
Figure 29Effect of plain and blended GGBS on the drying shrinkage of GGBS concrete.........................45
Figure 30 Effect of plain and blended GGBS on the creep strain of GGBS concrete ................................46
Figure 31 Effect of cement replacement content on the creep strain of SF concrete..................................47
Figure 32Comparison of MK and SF concretes against drying shrinkage .................................................48
Figure 33 Effect of RHA fineness on the drying shrinkage of RHA concrete............................................49
Figure 34: a) Effect of cement replacement () [36], (b) FA types [26], and (c) water binder ratio (and 0.5)
[25] on the compressive strength of FA concrete. ......................................................................................54
Figure 35Effect of plain and blended GGBS on the compressive strength of GGBS concrete..................55
Figure 36Effect of cement replacement on the compressive strength of MK concrete ..............................56
Figure 37Effect of cement replacement on the compressive strength of (a) MK pastes compared to SF and
FA pastes () [12] and (b) MK concrete compared to SF concrete () [30]...................................................57
Figure 38Performance comparison of high strength RHA and SF .............................................................58
Figure 39Effect of grinding timings on the compressive strength of RHA concrete..................................59
Figure 40Effect of RHA imported from (a) USA (on left) and (b) Uruguay (on right) on the compressive
strength........................................................................................................................................................60
Figure 41Effect of volume of cement replacement on the compressive strength of RHA concrete...........61

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Figure 42Effect of Egyptian RHA (EG-RHA) containing low carbon obtained at a different combustion
temperature on the compressive strength of concrete.................................................................................62
Figure 43Effect of (a) FA type [36] (on left) and (b) cement replacement [26] (on right) on the splitting
tensile strength of FA concrete. ..................................................................................................................65
Figure 44Effect of increasing FA content on the flexural strength.............................................................67
Figure 45 Effect of increasing FA content on the elastic modulus of concrete ..........................................69
Figure 46Effect of blended FA on the elastic modulus of concrete............................................................70
Figure 47Effect of cement replacement on the elastic modulus of MK concrete.......................................72
Figure 48Compressive strength of Concrete Cylinder (MPa) under 7 days and 28 days ...........................73
Figure 49Tensile strength of concrete cylinder (MPa) under 7 days and 28 days curing...........................73
Figure 50Flexural strength of concrete cylinder (MPa) under 7 days and 28 days ....................................74
Figure 51: Contour Plot: (a) Comp/Tens Vs Type of Additives (b) Flex/Tens Vs Type............................74

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Chapter 1 THE SERVICEABILITY LIMIT STATES IN
REINFORCED CONCRETE DESIGN
Abstract
This paper provides an overview of the behaviour of reinforced concrete beams and slabs at service
loads and outlines a reliable method for the calculation of deflection. To satisfy the serviceability
limit states, a concrete structure must be serviceable and perform its intended function throughout
its working life. Excessive deflection should not impair the function or be aesthetically
unacceptable, and cracks should not be unsightly or wide enough to lead to durability problems.
Design for the serviceability limit states involves making reliable predictions of the instantaneous
and time-dependent deformation of the structure.
Introduction
The broad design objective for a concrete structure is to satisfy the needs for which it was
contrived. Modern design codes for structures, including AS3600-2009, have adopted the limit
states method of design, whereby a structure must be designed to simultaneously satisfy a number
of different limit states or design requirements. To satisfy the serviceability limit states, a concrete
structure must be serviceable and perform its intended function throughout its working life.
Excessive deflection should not impair the function of the structure or be aesthetically
unacceptable, cracks should not be unsightly or wide enough to lead to durability problems, and
vibration should not cause distress to the structure or discomfort to its occupants. In this paper, the
effects of creep and shrinkage on the deflection and cracking of reinforced concrete beams and
slabs are discussed and quantified. An overview of recent research on the serviceability of
reinforced concrete beams and slabs at the University of New South Wales is also provided.
EFFECTS OF CRACKING ON CROSS-SECTIONAL RESPONSE
The average instantaneous moment-curvature response of a reinforced concrete element subjected
to uniform bending is shown in Figure 1. At moments less than the cracking moment, Mcr, the
element is uncracked and the moment-curvature relationship is linear. When the extreme fibre
tensile stress in the concrete reaches the flexural tensile strength, fct.f, primary cracks form at
reasonably regular centres. At a section containing a crack, the tensile concrete carries little or no
stress, the flexural stiffness drops significantly and the moment-curvature relationship follows the
dashed lines AA’C (when M Mcr). In reality, the flexural rigidity of the fully-cracked cross-
section (EcIcr) underestimates stiffness after cracking because the tensile concrete between
primary cracks carries stress due to bond between the tensile reinforcement and concrete.
The average instantaneous moment-curvature response after cracking follows the solid line AB in
Figure 1. As moment increases, there is a gradual breakdown in the steel-concrete bond and the
average flexural stiffness of the entire member decreases.

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Figure 1 Average moment versus instantaneous curvature relationship.
The upper limit of (=0.6Iuncr) is because the value of Ief is sensitive to the calculated value of
Mcr and for lightly loaded members failure to account for cracking due to unanticipated shrinkage
restraint, temperature gradients or construction loads can result in significant underestimates of
deflection. The term in Equation 1 is used to account for both shrinkage-induced cracking and the
reduction in tension stiffening with time. Early shrinkage in the days and weeks after casting will
cause tension in the concrete and a reduction in the cracking moment. If shrinkage has not occurred
before first loading, the deflection immediately after loading may be calculated with = 1.0. When
calculating the short-term or elastic part of the deflection, = 0.7 is recommended at early ages (less
than 28 days), and = 0.5 is recommended at ages greater than 6 months. For long-term calculations,
when the final deflection is to be estimated, = 0.5 should be used.
EFFECTS OF CREEP AND SHRINKAGE ON CROSS-SECTIONAL
RESPONSE
Effects of Creep
The gradual development of creep strain in the compression zone of a reinforced concrete cross-
section causes an increase of curvature and a consequent increase in deflection of the member. For

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a plain concrete member, the increase in strain at every point on the section is proportional to the
creep coefficient and so too is the increase in curvature. For the uncracked, singly reinforced
section, creep is restrained in the tensile zone by the reinforcement. On the cracked, singly
reinforced beam section, the initial curvature is comparatively large and the cracked tensile
concrete below the neutral axis can be assumed to carry no stress and therefore does not creep.
Creep in the compression zone causes a lowering of the neutral axis and a consequent reduction in
deflection.
Creep is slowed down as the compressive stress reduces, and the increase in curvature is
proportional to a small fraction of the creep coefficient. The relative increase in deflection caused
by creep is greater in an uncracked beam than in a cracked beam, but the total deflection is
significantly greater.
Effects of Shrinkage
Reinforcement embedded in concrete provides restraint to shrinkage, but if not symmetrically
placed on a cross-section, a shrinkage-induced curvature develops. Figure 3a shows a single
reinforced member and a small segment of length, z, showing the shrinkage-induced stresses and
strains on an uncracked and cracked cross-section.
Figure 2 Effects of creep on the strain on a singly reinforced section

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Figure 3 Shrinkage-induced deformation and stresses in a singly reinforced beam.
As the concrete shrinks, it compresses the steel reinforcement and imposes an equal and opposite
tensile force, T, on the concrete. This gradually increasing tensile force produces elastic plus creep
strains and a resulting curvature on the section. The magnitude of T (and hence the shrinkage-
induced curvature) depends on the quantity and position of the reinforcement and on the size of
the (uncracked) concrete part of the cross-section, and this in turn depends on the magnitude of
the applied moment. Although shrinkage strain is independent of stress, it appears that shrinkage
curvature is not independent of the external load. The shrinkage induced curvature on a previously
cracked cross-section (sh)cr is considerably greater than on an uncracked cross-section (sh)uncr,
as can be seen in Figure 3.
MOMENT-CURVATURE RELATIONSHIPS
Effects of shrinkage prior to first loading
The average moment versus instantaneous curvature relationship (OAB in Figure 1 and reproduced
in Figure 4) is significantly affected if shrinkage occurs prior to loading. For example, for a singly
reinforced element, a shrinkage induced curvature (sh)uncr develops on the uncracked cross-
section when the applied moment is still zero (i.e. Ms = 0). The initial curvature due to early

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shrinkage on a fully-cracked cross-section (sh)cr, where the concrete is assumed to carry no
tension, is significantly larger than that of the uncracked member (sh)uncr. Therefore, early
shrinkage before loading causes the dashed line representing the fully-cracked response to move
further to the right, shown as line O′′C′ in Figure 4. The average moment versus instantaneous
curvature relationship (OAB in Figure 1 and reproduced in Figure 4) is significantly affected if
shrinkage occurs prior to loading. For example, for a singly reinforced element, a shrinkage
induced curvature (sh)uncr develops on the uncracked cross-section when the applied moment is
still zero (i.e. Ms = 0). The initial curvature due to early shrinkage on a fully-cracked cross-section
(sh)cr, where the concrete is assumed to carry no tension, is significantly larger than that of the
uncracked member (sh)uncr. Therefore, early shrinkage before loading causes the dashed line
representing the fully-cracked response to move further to the right, shown as line O′′C′ in Figure
4.
Figure 4 Average moment vs instantaneous curvature relationship after early shrinkage strain.
Early shrinkage prior to loading affects the magnitude of tension stiffening under an applied moment Ms >
Mcr, but this is yet to be confirmed. Empirical expressions for the shrinkage-induced curvature on cracked
and uncracked cross-sections have been developed from a refined time analysis using the age-adjusted
effective modulus method (Gilbert & Ranzi, 2010).
Effects of creep and shrinkage under sustained loads
The instantaneous moment versus curvature response of a cross-section subjected to constant
sustained moment over the time period 0 to t is shown as curve OAB in Figure 5. If the cross-
section does not shrink with time, creep causes an increase in curvature with time at all moment

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levels and the time-dependent M- response shifts to curve OA′B′ in Figure 5a. The creep-induced
increase in curvature with time at an applied moment Ms may be expressed as cr(t) = 0 (t,0)/,
where 0 is the instantaneous curvature, (t,0) is the creep coefficient and is a factor that depends
on the amount of cracking and the reinforcement quantity and location. Empirical expressions for
have been developed using the age- adjusted effective modulus method (Gilbert & Ranzi, 2010).
Scientific Question?
We have seen improving of shear, flexural and tension stiffening of concrete using such
techniques. Will Creep and shrinkage be improved by such methods?
Answer
The in-service behavior of reinforced concrete flexural members under sustained service loads has
been discussed and procedures for calculating in-service deflection have been outlined. These
approaches include cracking, tension stiffening, creep and shrinkage, and are ideally suited for
design. They are mathematically tractable and reliable.
References
[1]. Z.S. Sharhan, Master Thesis, Building and Construction Engineering Department,
University of Technology, Baghdad, (2016)
[2]. ACI 318M-14, 2014. Building Code Requirements for Structural concrete ( ACI 318M-
14) and Commentary, USA: American Concrete Institute, (2014)
[3]. BS 8110: part 2, British Standard use of concrete, code of practice for special
circumstances, (1985)
[4]. E. G. Nawy, K. W. Blair, SP-30, American Concrete Institute, Farmington Hills, Mich.,
pp. 1-41, (1971)
[5]. A.W. Beeby, SP-20, American Concrete Institute, Detroit, 1971, pp. 55–75 (cited by
Makhlouf and Malhas (1996)
[6]. BS 8110-1997. Structural use of concrete, Part 1: Code of practice for design and
construction, (1997)

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Chapter 2 STRUCTURAL HEALTH MONITORING OF A
CABLE-SUPPORTED ZHEJIANG BRIDGE
Abstract
The Zhijiang Bridge is a cable-stayed bridge built recently over the Hangzhou Qiantang River. It
has an arched twin-tower space and a twin-cable plane structure. The integrated system of
structural health monitoring and intelligent management for Zhijiang Bridge includes an
information acquisition system, data management system, evaluation and decision-making system,
and application service system. The monitoring components include the working environment of
the bridge and various factors that affect bridge safety. The integrated system also includes a
forecasting and decision-making module for real-time online evaluation, which provides warnings
and makes decisions based on the monitoring information. The monitoring information, evaluation
results, maintenance decisions, and warning information can be input simultaneously into the
bridge monitoring center and traffic emergency center to share the monitoring data. The
installation of long-term structural health monitoring (SHM) systems to long-span cable-supported
bridges has become a trend to monitor loading conditions, assess performance, detect damage, and
guide maintenance. SHM systems can be used to investigate highway loading, railway loading,
wind characteristics, and temperature effects.
Keywords
Cable-Stayed Bridge; Structural Health Monitoring; Intelligent Devices; Monitoring Method
Introduction
In recent years, bridge designs have become more flexible and complex, making it important to
guarantee the safety of these structures. Structural health monitoring (SHM) techniques are
becoming increasingly important for guaranteeing the safety of bridge structures, especially for
large-span bridges. SHM techniques have been developed extensively and various mature
technologies are in use in large-span bridges, making them key research areas in the academic and
engineering domains, including the Hakucho Bridge in Japan [2], Bill Emerson Memorial Bridge
in the USA [3], Jindo Bridge in South Korea [4], Tsing Ma Bridge and Ting Kau Bridge in Hong
Kong [5], and Sutong Bridge and Jiangyin Changjiang River Bridge in China. These systems
guarantee the safe operation of the bridge and the life spans of bridges are extended using various
methods [6–9]. At the same time, through finding the damages of bridge timely, the cost of
maintenance can be reduced considerably and the losses due to traffic closures during active
maintenance can also be avoided [10]. In recent years, the application of devices such as wireless
sensors and GPS [11, 12] to large-span bridge health monitoring has addressed the problem of
inconvenient wired sensor placement and facilitated the construction of SHM systems and the
long-term monitoring of large-span bridges [13–16]. The globalization of the world economy has
increased competition for construction industries, leading to the construction of innovative long-
span cable-supported bridges. SHM technology provides a better solution to bridge problems,
based on a comprehensive sensory system and data processing system. Its main objectives are to
monitor loading conditions, assess performance, verify design rules, detect damage, and guide

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inspection and maintenance. SHM system is used to investigate highway loading, railway loading,
strong wind characteristics, and temperature effects, and to identify time-varying natural
frequencies and modal damping ratio.
A long suspension bridge built in a wind-prone region will suffer buffeting-induced vibration
which can cause fatigue damage to steel structural members. A systematic framework for assessing
buffeting-induced fatigue damage is proposed using the SHM system and integrating
wind/structural components with the continuum damage mechanics (CDM)-based fatigue damage
assessment method.
This study examines the integrated system of structural health monitoring and intelligent
management of Zhijiang Bridge in Hangzhou City, China. It illustrates the four functional sub-
systems used in a SHM: an information acquisition system (IAS), data management system
(DMS), evaluation and decision making system (EDS) and application service system (ASS). This
study provides a reference to facilitate the construction of SHM systems for other bridges.
Bridge Description
Zhijiang Bridge is located in Hangzhou, China, and is a two-arched tower and twin-plane cable-
stayed bridge with a combined span of 478 m. The bridge structure employs a half-floated system,
with the tower being an arched steel structure with an elliptical curve, the central axis having an
elliptical curve, the height of the tower is 90.5 m, the central width of the tower is 44.4 m, and the
width of the pylon in the lateral direction is 3.6 m. The pylon exhibits linear variation up and down
in the vertical direction, with the width at the top of the tower being 4.0 m and the width at the
bottom of the tower being 6.0 m. The beam of the main bridge is a streamlined steel box girder,
with the two sides comprising wind fairs and sideways, the height of the beam is 3.5 m, the full
width is 41.36 m, and the thickness of the top slab is 16 mm. There were 88 cables in the bridge,
which consisted.
Figure 5Photograph of Zhijiang Bridge
Bridge Monitoring System

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Zhijiang Bridge is a two-arched tower and cable-stayed bridge with the largest span, highest steel
arch tower, and widest bridge floor of this type of bridge. It was necessary to build a SHM system
to meet the operational management needs, improve the level of prealarm security, enhance the
efficiency of maintenance management, and facilitate scientific and effective operational
management. The core tasks of the SHM system are to determine the environmental load,
structural response, partial damage, and other information, as well as to obtain security state
information for the traffic and structure based on a comprehensive assessment of this information,
ensuring structural safety and efficient and economic operational decision-making.
The integrated system of structural health monitoring and intelligent management used by Zhijiang
Bridge comprises four functional sub-systems: IAS, DMS, EDS, and ASS. IAS is a lower level
system that includes a data monitoring subsystem and maintenance management subsystem, while
DMS and EDS are middle level systems that include a data management subsystem and a structural
state evaluation subsystem. ASS is the upper level system that includes a user interface subsystem.
Using wired fiber communication and direct inputs, the IAS exchanges data with the DMS
according to acquisition rules. The DMS also provides necessary data support for the EDS, as well
as providing data queries for the ASS. The structural state evaluation subsystem of the EDS
provides analytical results that facilitate decision making and prealarming maintenance
management, while the security prealarming subsystem feeds back to the ASS.
An SHM system was designed to monitor the structural health, safety, and performance of the
bridge. Two categories of phenomena were measured: load-effect monitoring and response
monitoring. An anemoscope and temperature sensors were installed to validate wind parameters
and provide wind load information. Global dynamic properties were determined to calibrate the
bridge theoretical model.
Figure 2 shows the integrated system of Zhijiang Bridge uses the DMS and EDS to interface with
the Expressway Monitoring Advisory System (EMAS) of Hangzhou City. Monitoring
information, evaluation results, maintenance decisions, and warning information related to the
bridge can be input into the monitoring center and Traffic Emergency Command Center of
Hangzhou City, sharing the monitoring data and decisions generated by the system.

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Figure 6Overall workflow of the system
Design and Implementation of the IAS
Sensor Systems
The sensor module design of the SHM system used by Zhijiang Bridge includes work environment
monitoring, structure spatial deformation monitoring, bridge alignment monitoring, section stress
monitoring, fatigue and welding crack monitoring, and vibration monitoring in the steel arch tower
and steel box girder, impact force monitoring in the bridge pier, earthquake response monitoring,
cable force monitoring, and anchor force monitoring in the steel-concrete joint segment. The
numbers of sensors and their layout are shown in Figure 3.

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Figure 7Layout of sensors on Zhijiang Bridge.
Work Environment Monitoring
1) The middle span of Zhijiang Bridge is affected by the wind, so there are monitoring points
for wind load, environmental temperature, humidity, rainfall, and visibility. The monitoring
instrument is fixed to the bridge floor of the steel box girder on the downstream side of the
main span of the main bridge via a stainless steel column located on the outside of a side
guardrail. The SHM system installed in the bridge enabled wind data to be analyzed and
wind characteristics such as mean wind speed, direction, turbulence components, intensities,
integral scales and wind spectra were obtained.
A professional meteorological station (Lufft) is used to monitor atmospheric temperature,
humidity, visibility, wind speed and direction, and rainfall. Figure 4 and Table 1 show
images and technical specifications.
Table 1Meteorological station technical specifications.
Parameter Technical specifications
Wind speed Measurement range: 0–60 m/s; resolution: 0.1 m/s; precision: ±0.3 m/s
Wind direction Measurement range: 0–359°; resolution: 1°; measurement accuracy: < ±3°
Temperature Measurement range: −20°C to 70°C; measurement accuracy: < ±0.2°C
Relative humidity Measurement range: 0–100% RH; measurement accuracy: < ±2% RH
Rainfall Measurable raindrop size range: 0.3–5 mm; resolution: 0.01 mm

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Visibility Measurement range: 10–20000 m; resolution: 0.1 m; precision: +2%
Figure 8Meteorological station.
2) The structural components of the main Zhijiang Bridge are steel box girders and steel arch
towers. A ventilation and dehumidification system is present inside the steel structure,
which can control the temperature and relative humidity inside the steel box girder and steel
arch tower. However, in extreme high temperature or extreme high humidity weather
conditions, or during sudden power failures, the humidity will increase inside the steel
structure, which will affect the durability of the steel structure. Therefore, a temperature and
humidity sensor is placed in an appropriate position inside the steel box girders and steel
arch towers, which monitors the changes in temperature and humidity. Two sections of steel
box girder and four sections of steel arch tower at the junction of steel box girder and steel
arch tower have a hygrothermograph. A networked-edition DSR temperature and humidity
recorder is used to monitor the temperature and humidity of the steel box girder and steel
arch tower, a photograph of which is shown in Figure 5 and the main technical specifications
are presented in Table 2.
Table 2Hygrothermograph technical specifications.
Project Technical specifications
Temperature Measurement range: −20°C to 70°C;
measurement accuracy: < ±0.2°C
Relative humidity Measurement range: 0–100% RH;
measurement accuracy: < ±2% RH

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Figure 9Hygrothermograph
3) The Weigh-in-Motion system is used to monitor vehicle load in real-time and accurately
determine axle loads of passing vehicles. This includes calculating the vehicle weight and
obtaining license plate numbers of overweight vehicles. The bridge is bidirectional with six
lanes, so the system needs to monitor six points in total. WIM stations use two bending path
pads and two magnetic loop detectors to measure vehicle weight and axle numbers.
TDC Systems (UK) manufactures the Weigh-in-Motion system to monitor traffic load, with
the main instrument parameters shown in Table 3.
Table 3Weigh-in-Motion system technical specifications.
Speed range 0~180 km/h
Traffic counting accuracy ±0.1%
Average speed accuracy ±1.5%
Gross vehicle weight accuracy ±3%
Spatial Structure Deformation Monitoring
Finite elements analysis of Zhijiang Bridge showed that the spatial deformation in the top of the
steel arch tower and steel box girder in the middle main span was the largest with different load
combinations. Therefore, a Global Position System (GPS) is used to monitor the spatial

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deformation at these sites. Two GPS sensors are positioned at the top of the east and west steel
towers, and two sensors are located upstream and downstream of the steel box girder in the middle
main span. The same brand of GPS sensor is used to monitor a number of major projects in China,
such as Hangzhou Bay Bridge. The main technical specifications of the GPS sensors are shown in
Table 4.
Table 4Technical specifications of the GPS sensors.
Static long baseline solution
precision
Horizontal: 3 mm + 0.5 ppm
Vertical: 6 mm + 1 ppm
Fast static baseline solution
precision
Horizontal: 5 mm + 0.5 ppm
Dynamic point baseline solution
precision
Horizontal: 10 mm + 1 ppm
Control function
Real-time RTK function, with a maximum sampling
frequency of ≥5 Hz
Transmission performance Real-time automatic collection, 24 h without exception
Working environment
Receiver and terminal: −20°C to 50°C; antenna: −40°C to
50°C
Figure 10GPS sensor.

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Figure 11Wind and Structural Monitoring
Bridge Alignment Monitoring
The positions with the maximum variation in the displacement of the main beam with various load
combinations are the middle main span and the middle side span, and the variation in the
displacement of the quarter-point of the main span is also high. Subsidence points on the pier tops
are also monitored in addition to monitoring the alignment of the main bridge network. The east
approach of Zhijiang Bridge is a continuous beam of 60 + 11 86 + 60 m, and a three-span structure
of the main bridge on the Dongfei navigation channel is used as the key monitoring point. A
hydrostatic level gauge is used for alignment monitoring, and its technical specification is shown
in Table 5.
Table 5Technical specifications of the hydrostatic level gauge.
Measurement range ±300 mm
Measurement accuracy ±0.5% FS
Sensitivity 0.05 FS

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Operating temperature −20°C to 80°C
Protection class IP67
Figure 12Hydrostatic level gauge
Stress, Fatigue, and Welding Crack Monitoring
The high-stress sections on the steel box girders of double-towered, cable-stayed bridges are
generally present in the middle of each span, the juncture of a box girder and a cable tower, and
the load-bearing position. The high-stress sections of the cable tower are generally present at the
bottom of the cable tower and the juncture of the cable tower and steel box girder. The sections in
the middle of each span of the main bridge, the quarter-point of the main span, and the pier tops
are used to monitor the steel box girder stress, fatigue, and welding cracks. The sections at T0, T1,
and T7, the top of the tower, and the steel horizontal beam of the steel arch tower were selected to
monitor stress and welding cracks in the steel arch tower.

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Figure 13Stress and fatigue monitoring points on the box girder.
Figure 14Welding crack monitoring points on the box girder.

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Figure 15Stress and fatigue monitoring points on the steel tower.
The stress on the box girder top slab in the lateral direction is relatively high at the longitudinal
diaphragm and that in the longitudinal direction is relatively high at the web. Monitoring points
were selected based on the layout of the bridge to ensure continuous monitoring. Strain gauges are
used to monitor Strain, the number of sensors in each monitoring position is shown in Table 6 and
the specifications are shown in Table 7.
Table 6Strain sensor arrangement.
Monitoring position Number
Midsection of the main span 12
1/4, 3/4 section of main span 24
Midsection of the side span 24
Section of steel box girder at each pier top 16
T0, T1, and T7 and top section of steel arch tower 56
Section of the lateral steel beam 16
Section of the approach 100

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Table 7Technical specifications of the strain sensor.
Measurement range ±2000 μ ε
Resolution ±1 μ ε
Measurement accuracy ±2-3 μ ε
Strain sensitivity 1.18–1.22 pm/μ ε
Figure 16Strain gauges
Structural Temperature Monitoring
Structural temperature monitoring is used to facilitate temperature compensation during stress
monitoring and determine the temperature ranges of key sections. Optical fiber grating temperature
sensors are used, with a measurement range of 20°C to 70°C and a precision of less than 0.2°C.
The positions and number of monitoring points are shown in Table 8. Temperature variations cause
long suspension bridges to expand and contract in the longitudinal direction and bend in the
vertical plane, causing large forces to develop. This section introduces temperature effects on
displacement responses and provides a basis for real-time monitoring. Temperature sensors
measure ambient and bridge member temperatures along the bridge longitudinal axis.
Table 8Position and number of temperature monitoring points.
Monitoring position Sensor type Number
Midsection of the main span Temperature sensor 2
1/4, 3/4 section of main span Temperature sensor 4
Midsection of the side span Temperature sensor 4
Section of the steel box girder at each pier top Temperature sensor 8

25
T0, T1, and T7, and top section of steel arch tower Temperature sensor 32
Section of the lateral steel beam Temperature sensor 4
Section of the approach Temperature sensor 14
Structural Vibration Monitoring
Structural vibration monitoring involves monitoring vibrations in the steel arch tower and the steel
box girder, as well as the impact force on the bridge pier and earthquake responses. Vibration
sensors are positioned in the middle of each span, the quarter-point of the main span, and the pier
tops on both sides of the main span of the steel box girder. To monitor the impact force on the
bridge pier, the top of the pile cap of each navigable span is used as a vibration monitoring point.
Additionally, a vertical vibration sensor is placed at the same position to monitor the impact force
and earthquake responses. The vibration sensor is shown in Figure 12 and the sensor layout is
shown in Table 9.
Cable-supported bridges are susceptible to vibration caused by wind, rain and support motion. This
can cause undue stresses and fatigue in the cables and in the connections with bridge deck and
towers, and can lead to public confidence in the bridges. To suppress harmful vibration, passive
viscous and viscoelastic dampers have been used.
Table 9Layout of the vibration sensors.
Monitoring position Sensor type Number
T0, T7, and top section of tower
Vibration
sensor
10
Top of the pile cap of each navigable span
Vibration
sensor
8
1/4, 1/2 section of the main-span, 1/2 section of the side-span, and
section of the pier top
Vibration
sensor
8

26
Figure 17Vibration sensor
Acceleration sensors are used to monitor vibrations, impact forces, and earthquake responses. They
have a measurement range of 2 g, a frequency response of zero to 100 Hz, a dynamic range of
>120 dB, and a working temperature range of 20°C to 80°C.
Cable Force Monitoring
The cable is the main component of a cable-stayed bridge, which transfers the weight of the main
girder and the live load on the deck to the main tower. It is important to enhance cable force
monitoring to evaluate the working status of the cable and analyze the stress state of a cable-stayed
bridge. Amplitude monitoring must form the basis of cable tension monitoring, and cables with
the maximum stress under different load combinations and the maximum variation in stress under
live loadings are used for cable tension monitoring.
Acceleration sensors are used to monitor the tension of stayed cables, with a measurement range
of 10 g, a frequency response of zero to 100 Hz, a dynamic range of >80 dB, and a work
temperature of 20°C to 80°C. The positions and numbers of sensors are shown in Table 10.
Table 10Positions and numbers of acceleration sensors.
Monitoring positions Number
1, 1, 11# cables in the side-spans of the east and west sides 12
1, 7, 11# cables in the main-span of the east and west sides 12

27
Figure 18Acceleration sensor.
Anchor Force Monitoring
The reliability of the juncture of the steel tower, concrete bearing, and foundation is key to
guaranteeing the structural safety of the whole bridge. This is because the static disequilibrium of
the steel tower in a horizontal direction, the dynamic response to wind load and earthquake, and
the connection between the steel tower and the bearing would be damaged by a major horizontal
force and bending moment. An anchor is used to connect the main tower and the cap of Zhijiang
Bridge, and the pretightening force of the anchor directly reflects the operational status of the
juncture segment of steel and concrete. It is necessary to monitor the variation in the anchor force
in real-time.
To guarantee the stability and durability of anchor force monitoring at the juncture of steel and
concrete, fiber grating strain sensors are used and the total number of monitoring points is 32.
Data Acquisition and Transmission Module
The data acquisition and transmission module is composed of an acquisition facility, transmission
facility, and data preprocessing and temporary storage facility. The data transmission modes
between the sensor and acquisition facility and the low-level instrument are wireless and wired.
To improve the stability of the data transmission, wired data transmission is used between the
sensor and acquisition facility and the low-level instrument. Two low-level instruments are
positioned in the steel box girder section at the junctures of two steel arch towers and the steel box
girders on the main bridge. Data is transferred between the low-level instruments and the
monitoring center via an embedded optical communication cable.
Figure 14 shows the function flow during data acquisition and transmission. All of the sensors are
connected via an anti-interference shielding line and the corresponding acquisition facility. The

28
acquisition facilities for stress, temperature, and vibration are integrated into the steel box girder
section under the two main towers of the bridge. To ensure highly synchronized vibration
acquisition, the GPS clock is used for clock synchronization between the two acquisition stations
for the stress, temperature, and vibration sensors. The transmission distance is longer than 200 m,
so the GPS clock is used for clock synchronization between the two acquisition stations for the
stress, temperature, and vibration sensors.
Figure 19Flowchart of data acquisition and transmission.
Software System
The design of the system software must meet the needs for data acquisition and transmission
control, maintenance checking data management, data comprehensive management, data analysis
and status evaluation, maintenance decision and safety prealarming, and user management. The
software is divided into data acquisition and transmission software, maintenance management
software, center database software, structural status evaluation software, maintenance decision and
safety prealarming software, user interface software, and other components. The data acquisition
and transmission software includes an acquisition instruction module, parameter setting module,
data preprocessing module, abnormal event log module, software self-repair module, graph display
module, and other components. The system runs on a network and some examples of the results
obtained are shown in Figures 15, 16, 17, 18, and 19.

29
Figure 20External environment of the bridge.
Figure 21Vibration of 4# tower and T7 box girder.

30
Figure 22Displacement changes in the box girder.
Figure 23Tower shift.
Figure 24Cable force.

31
Design and Implementation of the DMS
The SHM system of Zhijiang Bridge uses a data management subsystem to acquire data from the
health monitoring subsystem, maintain data from the maintenance management subsystem,
monitor data from the road floor status, and collect, file, inquire, store, and manage monitored
prestress data.
Figure 25Function and composition of the DMS.
Design and Implementation of the EDS
The structural status evaluation subsystem is the core of the integrated system. It executes various
operations such as calculation analysis, statistics, historical alignment, analysis and trend
forecasting, and fetches key indices that reflect variations in the structural status. The overall data
is integrated to facilitate a comprehensive evaluation of the status of the bridge structure and its
key components.
The structural status evaluation subsystem is divided into two modules: data processing and status
evaluation, which perform the same functions.
1) The data processing module is responsible for filtering, classification, collection, and
statistical analysis of the data, and for fetching the key indices.
2) The status evaluation module is responsible for real-time analysis and evaluating the
structural status.
Data Processing Module
The volume of bridge monitoring data is massive, so they must be finely analyzed in detail to
obtain useful key information. The functions of the data processing module are as follows.
1) The original test values from each sensor are integrated to obtain the primary status of the
bridge health monitoring data.
2) Filtering, classification, collection, and statistical analyses of the monitoring data are
performed to obtain an eigenvalue database of the monitoring data.

32
3) Based on the monitoring results and comparisons with the values in the design document,
the experimental bridge loading values, modified values from simulation calculations, and
the extreme values during the operational process, the variations in the rates of the values
that reflect the structural status can be obtained, which can be analyzed to identify trends
using mathematical model fitting.
4) The degree of deviation and rate of development are calculated based on comparisons with
the threshold values of all the bridge safety prealarming levels.
Status Evaluation Module
The status evaluation module is responsible for damage identification and status evaluation. It
identifies the position, degree, and rate of development of structural damage based on abnormal
data, then evaluates the effects of damage by combining bridge maintenance checking data with
scientific monitoring data. If the user state exceeds the critical condition, the evaluation
information is passed to the maintenance decision and safety prealarming subsystem. The flow
during status evaluation is shown in Figure 21.
Figure 26Flowchart during bridge condition evaluation.
Methods such as module modification, structural fatigue analysis, primary fingerprint comparison,
trends analysis, model state analysis, parameter identification, and reliability evaluation are used
to localize, quantify, and identify damage by monitoring trends and evaluating their effects. These
methods satisfy the structural type, materials, and work environment of Zhijiang Bridge.
Design and Implementation of the ASS
The ASS used by the SHM system of Zhijiang Bridge is an interactive system for bridge
maintenance management users. It provides functions such as monitoring point information
display, monitoring results graphical display, report management, background management, and
user management. The comprehensive management software implemented in the system provides
many functions, such as information management and querying of monitoring points, monitoring

33
and maintenance of data queries, graphical displays, state evaluation result querying, report
management and inquiry, prealarming information management and inquiry, background
management, and user management.
Scientific Question?
(i) What are the damage cases of concern and how is failure defined for them?
(ii) What are the expected future loading conditions on the structure?
(iii) What SHM methods should be used to characterize damage?
(iv) What type of models will be applied to predict the damage propagation in the
structure?
(v) What is the aim of the prognosis?
Remarks and Conclusion to Questions
The core problems and final aims of SHM systems for cable-stayed bridges are damage
identification, module modification, structural safety evaluation, and maintenance decision
making. This study used the integrated system of structural health monitoring and intelligent
management of Zhijiang Bridge as an example to provide a detailed explanation of the components
and model functions employed by a large-scale bridge SHM system. This SHM system generates
time-specific status information such as bridge vibrations, providing data support for bridge
maintenance and decision making. The application of SHM systems to large-scale Chinese bridges
is in the early stage, and new technology and new methods will be beneficial to improving SHM
systems. Wireless communication technology such as microwaves may be an important method in
SHM system networks for bridge structures, which could be applied broadly to health monitoring
and the measurement of bridge structures.
The use of advanced SHM systems allows continuous monitoring and effective management of
large civil engineering structures, such as long span bridges, high-rise buildings, underground
tunnels, high speed railway lines and buried water mains. These monitoring systems include the
wind and SHM system, wireless sensing networks, acoustic emissions and fiber optic sensing
systems. Local monitoring techniques are more likely to locate structural damage in local regions,
while global monitoring methods should be combined with the use of local monitoring techniques
to obtain a better understanding of structural damage. When long-term monitoring data of both
structural responses and operational factors (e.g. loads, temperature, wind, etc.) are available, it is
possible to quantitatively assess the current condition and even predict the future performance of
the existing civil engineering structures using the continuous measurements. For civil engineering
structures, continuous structural monitoring requires the use of robust sensors that can withstand
the damaging effects of the aggressive environments.
These sensors are expected to operate for the service life of the structures, which is often over 50
years. The density of sensors on a civil structure should be sufficient to make an effective global
monitoring approach on a large scale. The structural monitoring systems need to be inexpensive
and easy to deploy, so that the systems can be attached to existing civil structures with little effort.
Further works on SHM of large civil engineering structures are needed, such as advanced sensing
systems with improved and optimized placement of networkable sensors, reliable wireless sensors

34
and data transmission systems, advanced signal processing techniques, software and hardware
integration, effective methods for data interpretations and damage feature extractions, predictive
damage model for a structure and its components, and reliability based and monitoring informed
optimal maintenance strategies.
Sensors are essential elements of structural health monitoring systems. Optical fiber sensors
provide superior structural health monitoring capabilities for civil structures. The primary
advantage of optical fiber sensors is their geometric conformity and capability for sensing of a
variety of perturbations. This article provides a summary of basic principles pertaining to the
structural health monitoring of civil engineering structures with optical fiber sensors. It is possible
to design optical fiber systems for measurements of myriads of perturbations, including strain,
cracks, deformations, accelerations, cable dynamics, etc. Other issues include protection of fibers
against damage by design of proper sensor packaging systems.
Future Trends
Science and technology are driving the development of SHM analysis for condition assessment
and damage detection of cables. However, key challenges remain for further application, such as
the difficulty of estimating cable damage due to health condition and uncertainties such as traffic.
Future trends include data acquisition, development of new monitoring equipment, and recognition
of uncertainties in real bridges. These targets affect the stability of stay cables in the long run.
SHM is becoming increasingly important in civil infrastructure, but there is a lack of understanding
of the needs for a viable system. To address this, steps are suggested to design and implement
vibration-based health monitoring systems for highway bridges:
1) The target structure should be surveyed and studied carefully to establish its baseline
structural and response characteristics. Dynamic responses should be measured at
appropriate locations on the structure during its typical operational conditions. Mobile
instrumentation should be used to investigate as many locations as possible. Acceleration
is usually the preferred type of measurement in terms of dynamic response. The magnitude
and frequency content of the acceleration collected during typical operation conditions will
dictate the type and parameters of the sensors to be used in the health monitoring system.
Capacitive or resistive accelerometers are more suitable for such types of applications. In
cases where the health monitoring system is expected to collect data during extreme events,
predicted response based on finite element models of the structure and past knowledge of
the excitation due to extreme events can be used in place of this data.
2) Modal analysis should be performed to identify the initial modal parameters. Operational
modal analysis can be used for identification when responses caused by ambient excitation
are used. Forced excitation sources such as impact hammers or electromagnetic shakers
can also be utilized. The characteristics of the identified dominant modes should be studied
carefully to determine the number and location of sensors needed to effectively
characterize them. The minimum number of sensors needed to successfully identify a mode
can be determined by Shannon's sampling theorem, but the density of the sensor network
will also be determined by the intended spatial resolution of the damage localization.

35
3) The data acquisition, transmission and archiving system must be designed to accommodate
the type, number and location of the sensors in the sensing system. The sampling rate
should be determined by the frequency range of interest identified in the second step. The
Nyquist frequency should be at least two times the highest frequency of interest. The
amount of data collected is directly proportional to the sample rate and the number of
sensors or channels simultaneously measured. For large civil engineering structures, tens
of thousands of samples may be recorded every second.
4) A baseline finite element model should be updated using modal parameters identified using
sensitivity analysis. The model can represent the pristine state of the structure or its state
at a selected point in time, depending on the modal parameter used. The model updating
process can also be augmented by static response measured during load tests.
5) Operational modal analysis can be used to extract modal parameters from measured
structural response using algorithms.
6) Damage localization should be performed using modal parameters and techniques, and the
baseline finite element model should be updated to record changes in the actual structure.
7) The SHM system can be used to accurately estimate the structural capacity and remaining
life of a structure, making it more effective.
Operational modal analysis is a mature technology, but there is still much work to be done to verify
assumptions, evaluate statistical properties, and compare methods.
Future research should lead to the integration of a statistical framework into the damage
identification process, with operational variability quantified and confidence bounds given, using
extreme value statistics and Bayesian statistical models.
Finite element model updating is an efficient technique for damage diagnostics, but there are
challenges such as non-uniqueness, ill-conditioning, and numerical convergence. Techniques such
as dense sensor networks, dynamic properties, and globally robust optimization algorithms can
help solve or alleviate these issues.
A new multi-level structural health monitoring system integrating global- and local-level
diagnostics is needed to satisfy all end users' requirements. Mission-tailored sensor technologies
such as piezoelectric and fiber-optic sensors with wireless communication capabilities are essential
to reduce system cost and improve efficiency.

36
References
[1] L. I. Hong-Nan, Y. I. Ting-Hua, R. E. N. Liang, L. I. Dong-Sheng, and H. U. O. Lin-Shen,
“Reviews on innovations and applications in structural health monitoring for
infrastructures,” Monitoring and Maintenance, vol. 1, no. 1, pp. 1–45, 2014.
[2] M. Abe, Y. Fujino, M. Yanagihara, and M. Sato, “Monitoring of Hakucho Suspension
Bridge by ambient vibration measurement,” in Nondestructive Evaluation of Highways ,
Utilities, and Pipelines IV, Proceedings of SPIE, pp. 237–244, Newport Beach, Calif, USA,
March 2000.
[3] M. Çelebi, R. Purvis, B. Hartnagel et al., “Seismic instrumentation of the Bill Emerson
Memorial Mississippi River Bridge at Cape Girardeau (MO): a cooperative effort,” in
Proceedings of the 4th International Seismic Highway Conference, Memphis, Tenn, USA,
2004.
[4] S. H. Sim, J. Li, H. Jo et al., “Wireless smart sensor network for automated monitoring of
cable tension,” Smart Materials and Structures, vol. 23, no. 2, 2014.
[5] K. Y. Wong, “Instrumentation and health monitoring of cable-supported bridges,”
Structural Control and Health Monitoring, vol. 11, no. 2, pp. 91–124, 2004.
[6] S. S. Kessler, S. M. Spearing, and C. Soutis, “Damage detection in composite materials
using lamb wave methods,” in Proceedings of the American Society for Composites,
Blacksburg, Va, USA, September 2001.
[7] J. Ma and D. Pines, “The concept of dereverberation and its application to damage
detection in civil structures,” in 7th International Symposium on Smart Structures and
Materials, Proceedings of SPIE, March 2000.
[8] F. K. Chang, “Built-in diagnostic for structural health monitoring,” in Proceedings of the
Grantees Meeting, USJapan Urban Earthquake Disaster Mitigation Research Initiative,
Sonoma, Calif, USA, 1999.
[9] M. W. Lin, A. O. Abatan, and Y. Zhou, “Transverse shear response monitoring of concrete
cylinder using embedded high-sensitivity ETDR sensor,” in Smart Structures and Materials
2000: Smart Systems for Bridges, Structures, and Highways, vol. 3988 of Proceedings of
SPIE, pp. 319–328, Newport Beach, Calif, USA, March 2000.
[10] T.-H. Yi, H.-N. Li, and M. Gu, “Optimal sensor placement for structural health monitoring
based on multiple optimization strategies,” The Structural Design of Tall and Special
Buildings, vol. 20, no. 7, pp. 881–900, 2011.
[11] T.-H. Yi, H.-N. Li, and M. Gu, “Full-scale measurement of dynamic response of a
suspension bridge subjected to environmental loads using GPS technology,” Science
China: Technological Sciences, vol. 53, no. 2, pp. 469–479, 2010.
[12] T.-H. Yi, H.-N. Li, and M. Gu, “Experimental assessment of high-rate GPS receivers for
deformation monitoring of bridge,” Measurement, vol. 46, no. 1, pp. 420–432, 2013.
[13] J. P. Lynch, Y. Wang, K. J. Loh, J. H. Yi, and C. B. Yun, “Performance monitoring of the
geumdang bridge using a dense network of high-resolution wireless sensors,” Smart
Materials and Structures, vol. 15, no. 6, article 008, pp. 1561–1575, 2006.

37
[14] T. Nagayama and B. F. Spencer Jr., “Structural health monitoring using smart sensors,”
Newmark Structural Engineering Laboratory Report Series 001, 2007,
http://hdl.handle.net/2142/3521.
[15] S. Kim, S. Pakzad, D. Culler et al., “Health monitoring of civil infrastructures using
wireless sensor networks,” in Proceedings of the 6th International Symposium on
Information Processing in Sensor Networks (IPSN '07), pp. 254–263, April 2007.
[16] S. Jang, J. A. Rice, J. Li, H. Jo, B. F. Spencer Jr., and Z. Wang, “Structural monitoring of
a historic truss bridge using a wireless sensor network,” in Proceedings of the Asia-Pacific
Workshop on Structural Health Monitoring, 2009.

38
Chapter 3 Study of Mechanical Properties of Concrete
Developed Using Metamorphosed Limestone Powder
(MLSP), Burnt Clay Pozzolana (BCP) & Wood Ash (WA) as
Partial Replacement of Cement
Abstract
This text discusses the analysis of concrete and reinforced-concrete structures with in-service
defects and evaluates the efficiency of injection technologies. It proposes numerous injection
composite materials with high technological characteristics based on polyurethane and
polyethylene. The efficiency of these materials is confirmed by testing of laboratory specimens
with filled stress concentrators. Additionally, corrosion protection of uncoated steel reinforcement
can be achieved by adding corrosion inhibitors to the injection compositions, and hardening of
damaged structures can be achieved by filling detected defects. This paper provides an overview
of the behavior of reinforced concrete beams and slabs at service loads and outlines a reliable
method for the calculation of deflection. To satisfy the serviceability limit states, a concrete
structure must be serviceable and perform its intended function throughout its working life.
Excessive deflection should not impair the function or be aesthetically unacceptable, and cracks
should not be unsightly or wide enough to lead to durability problems. Design for the serviceability
limit states involves making reliable predictions of the instantaneous and time-dependent
deformation of the structure. The most important details in this text are that concrete has become
one of the most utilized construction materials across the globe, and that waste materials are now
being used to develop eco-friendly products. Stone slurry and solid marble waste are two of the
most produced waste materials of the Metamorphosed limestone industry. Researches are being
made to replace expensive materials with low cost or waste materials in order to achieve eco-
friendly yet cost-effective materials. In this paper, cement is being replaced by metamorphosed
limestone powder, burnt clay pozzolana, and wood ash. The tests are carried out for concrete
developed in combination with the replacement of 0, 5, 10, 15 and 20% cement by metamorphosed
limestone powder, burnt clay pozzolana, and wood ash. The main focus of the current study is to
effectively identify the optimum range of percentage replacement that can be practically useful to
achieve high-performance mechanical properties of concrete.
Keywords: Concrete; Waste Materials, Cement; Mechanical Properties; Strength

39
INTRODUCTION
Concrete is an amalgamated material prepared with cement, sand, aggregates, admixtures or super
plasticizers and water. It is used as a binder to hold the aggregates, while fine aggregate (sand) acts
as a filler material to increase the density of concrete and water is used to hydrate the cement.
Research has been conducted on the use of waste materials to enhance the properties of concrete,
such as silica fume, fly ash, blast furnace slag, burnt clay pozzolana, metamorphosed limestone
powder, wood ash and waste construction materials. These waste materials are used to improvise
the strength of concrete, workability behaviours, increase the water tightness, and reduce the heat
of hydration and significant thermal shrinkage. The civil engineers are primarily concentrating to
develop advanced concrete to enhance the properties of concrete.
The purpose of this study is to study the suitability of metamorphosed limestone powder, burnt
clay pozzolana and wood ash as pozzolanic materials to replace the cement by weight up to a
certain amount in concrete. It is anticipated that the employ of metamorphosed limestone powder,
burnt clay pozzolana and wood ash in concrete improves the base mechanical properties of
ordinary concrete. Mineral Additives are also known as Pozzolanic Materials, which are the natural
residues of different processes and can be replaced with chemical admixtures. Pozzolanic materials
are:
(i) Natural Pozzolanas (Shales and Clay, Cherts, Diatomaceous Earth and Pumicites and
Volcanic Tuffs) and
(ii) (ii) Artificially existing Pozzolanas (Metamorphosed limestone powder, Burnt clay
pozzolana, Wood Ash, Slag (GGBFS), Fumes of silica, Rice Husk and commonly
available Metakaolin).
These materials improve numerous characteristics of concrete, such as reduce the warmth of
hydration and warm shrinkage, increase the water snugness impact, reduces the plane soluble base
total response, improvises the protection from assault by sulphate soils and ocean water, elevates
the potential extensibility, lowers the defenselessness ability towards the disintegration and
filtering, improvises efficient workability and lowers the gross costs.
Researchers have tested three different waste materials for strength performance of concrete as a
replacement of cement. This study is designed to utilize sustainable waste management in the field
of construction materials.
Researchers have made significant efforts to improve the performance of concrete, especially
permeability and durability. The use of mineral admixtures has reduced the porosity of concrete,
leading to increased demand for blended cement. These admixtures enable concrete to exhibit
greater resistance against harmful solutions, freezing and thawing, chloride ion penetration,
sulphate attack and carbonation, and so forth, and are important contributors for sustainable
environment. Cement companies have started manufacturing fly ash cement, which is a partial
replacement of fine aggregate and has been recommended for structural use.
The most commonly used mineral admixtures are fly ash (FA), silica fume (SF), ground granulated
blast furnace slag (GGBS), metakaolin (MK), and rice husk ash (RHA). Researchers have

40
reviewed the properties of mortar and/or concrete containing different mineral admixtures, such
as MK. Additionally, researchers have compared the properties of few mineral admixtures, such
as SF and GGBS, Justice et al. and Poon et al. compared SF and MK, and Nehdi et al. compared
SF and rice husk ash (RHA). However, a combined review and comparison among pozzolanic
concretes partially containing FA, SF, GGBS, MK, and RHA is needed.
Properties of Hardened Concrete
The performance of concrete is evaluated from mechanical properties such as shrinkage and creep,
compressive strength, tensile strength, flexural strength, and modulus of elasticity. Compressive
strength is the most important characteristic and an improvement in it will improve its mechanical
properties. However, in concrete in which cement is partially replaced by mineral admixtures, all
mechanical properties are not directly associated with compressive strength and the effects of
different minerals on the mechanical properties of hardened concrete are not the same.
Pore Size and Porosity
The mechanical properties of concrete are closely related to its porosity and pore dispersion. It is
reported that the addition of mineral admixture significantly refines the pore configuration by
reducing the pore size and porosity. After initial hydration of cement, hydrated limes (Ca(OH)2)
form. If moisture is available, mineral admixture reacts with lime to form tricalcium silicate which
refines the pore configuration of the cement matrix. To attain good results, silica in mineral
admixture should be amorphous, glassy, or reactive. The parameters representing the pore
configuration, such as pore size and porosity, are significantly different for each partially replaced
cement pastes with different mineral admixtures, even if the amount of cement replacement and
water binder ratio is the constant.

41
Figure 27 (a) Formation of lime as a byproduct of hydration of Portland cement resulting into a
porous paste. (b) Pozzolanic reaction between lime and mineral admixture to fill the interstitial
spaces.
In hydrated cement research, mercury intrusion porosimetry (MIP) has been used to quantify the
distribution of pore sizes in cement pastes. Table 1 shows significant reduction in the pore diameter
with the increasing curing age, showing the effectiveness of FA, MK, SF, and GGBS as partial
cement replacing materials. Chindaprasirt et al. [15] experimentally investigated the influence of
inclusion of class F FA on the porosity and pore size distribution of hardened cement pastes by
replacing 0, 20, and 40% cement content. Ramezanianpour and Malhotra [16] investigated the
performance of SF, FA, and slag concretes under four different curing procedures and reported
that through continuous moist curing, lowest porosity can be achieved. It is also found that use of
slag produces a very low permeable slag concrete, but it is more sensitive to the curing regime and
slag content.
Authors
Mineral
admixture
w/c
or
w/b
ratio
%
content
Average pore diameter (nm)
Remark
3
days
7
days
28
days
60
days
90
days
Chindaprasirt
et al. [15]
Control 0.35 0 — — 23 19 15 Results
estimated
from
Figure 2 of
[15]. OFA
had median
Original fly
ash (OFA)
0.35
20 — — 22.5 18.75 13.75
40 — — 20 17.5 13
0.35 20 — — 19 13.75 11.25

42
Classified
fly ash
(CFA)
40 — — 18 13 9.5
particle size
of 19.1 µm
and CFA
had 6.4 µm.
Poon et al.
[12]
Control 0.3 0 38 37.1 36.2 — 34.8
Results are
borrowed
from
Table 3 of
[12]
Metakaolin 0.3
5 35.7 27.9 25.7 — 24.3
10 28.7 25.1 19.7 — 18.6
20 20.4 14.3 12.2 — 11.4
Silica fume 0.3
5 36.6 37 36.7 — 34.9
10 35.3 34.1 32.5 — 30.6
Fly ash 0.3 20 36.8 35.6 34.7 — 33.9
Collins and
Sanjayan [20]
Control 0.5 0 74.7 48.7 34.9 26.4* — Results are
for pore
radius,
taken from
Table 5 of
[20]
Alkali
activated
Slag
0.5 100 38.1 12.4 8.7 3.9* —
Reported results are for 56 days.
Poon et al. [12] presented the results of pore diameter and total porosity for MK, SF, and FA
concrete and found that improved pore configuration can be achieved by using MK in comparison
to the SF. At 20% replacement, pore diameter and porosity of MK paste were remarkably lesser
than FA cement pastes, and at 5% and 10% replacement, pore diameter and porosity of cement
paste containing MK are lesser than those with SF. Khatib and Wild [17] presented the results of
pore structure of the cement pastes in which 5, 10, and 15% cement content were replaced by MK;
however water binder ratio of 0.55 was kept constant. Results of pore structure of the pastes cured
for 3 to 365 days were examined through mercury intrusion porosimetry (MIP). The largest pore
radii have been reported as larger than 0.02 m, but pore radii were observed to be decreased for
those specimens in which MK content was higher and they were cured for the longer period.
Kostuch et al. [18] and Bredy et al. [19] examined the microstructure and pore size distribution of
mortar specimens cast by adding 20% MK which significantly reduced the average pore size and
water absorption rate. Collins and Sanjayan [20] verified that alkali-activated slag paste (AASP)
contains higher numbers of small size pores as compared to OPC paste. The addition of RHA in

43
concrete reduces the porosity of concrete, but the interfacial zone porosity of the RHA composite
was observed to be higher than that of the SF composite. El-Dakroury and Gasser [22] and Ganesan
et al. [5] suggested the optimum replacement content of cement by RHA as 30% and that the use
of RHA higher than 30% adversely affects the permeability and strength of concrete.
Drying Shrinkage and Creep
The drying shrinkage property of pastes and/or concrete is usually associated with the loss of
adsorbed water from the material. This property is especially significant in porous concrete,
especially aerated concrete due to higher total porosity and specific surface of pores (around 30
m2/g). Decrease in the pore radius results in a higher percentage of pores and increases shrinkage.
Higher temperature and lower humidity significantly influence shrinkage. Mineral admixture
reduces the creep and drying shrinkage of concrete, but the mechanism and behavior of FA and
OPC concrete are the same.
Almusallam reported lower drying shrinkage in the hardened FA concrete with 20% cement
content as compared to the OPC concrete when specimens were exposed to 10% humidity
condition at 50°C temperature. The early age shrinkage in FA and OPC specimens was similar,
but later ages (i.e., 14 to 98 days) were observed to be lower for FA concrete specimens. The
comparison of FA and OPC concrete at 50% humidity and 23°C (i.e., at room temperature) showed
higher amount of shrinkage in FA concrete. Naik et al. [26] reported the results of FA concrete in
which class C and class F fly ashes were used together in varying proportions. The comparison of
both studies showed that the drying shrinkage of concrete increases with time with or without use
of FA and water/cement ratio is a significant parameter to reduce the drying shrinkage.
Additionally, the cement paste, in which 75% class C and 25% class F fly ashes were used, has an
equivalent shrinkage to that containing 50% class C and 50% class F fly ashes. However, inclusion
of GGBS does not significantly influence the drying shrinkage of concrete. However, ultrafine
GGBS was examined alone and along with SF by Jianyong and Yan [9], and it was found that
ultrafine GGBS caused a maximum reduction in drying shrinkage in comparison of ordinary
concrete and concrete with GGBS and SF. On the contrary, the rate of creep is lower in comparison
to ordinary concrete; while the combination of GGBS and SF caused the lowest creep. In the
literature, it has been reported that, at the replacement level of more than 70 percent GGBS, the
reduction.
Chung and Mazloom et al. [28] reported that the addition of untreated and treated SF in cement
pastes reduces drying shrinkage and creep rate, but the performance of treated SF is far better than
plain and untreated SF concrete. Mazloom et al. [29] investigated the effect of 0, 6, 10, and 15
percent cement replacement by SF on the drying shrinkage and specific creep of high strength
concrete. They reported that percentage of the replacement does not significantly influence the
total shrinkage, but the autogenous shrinkage increases and drying shrinkage decreases with the
percent increase in the replacement content. Additionally, they reported an equivalent rate of
decrease in total and basic creep of SF concrete with the increase in the SF replacement level and
reported negligible change in the drying creep.

44
Figure 28Effect of FA content and type on the drying shrinkage of FA concrete

45
Figure 29Effect of plain and blended GGBS on the drying shrinkage of GGBS concrete

46
Figure 30 Effect of plain and blended GGBS on the creep strain of GGBS concrete

47
Figure 31 Effect of cement replacement content on the creep strain of SF concrete

48
Figure 32Comparison of MK and SF concretes against drying shrinkage

49
Figure 33 Effect of RHA fineness on the drying shrinkage of RHA concrete
Zhang and Malhotra [30] and Brooks and Johari [31] found that 10% replaced MK concrete had
lowered the drying shrinkage than SF concrete and ordinary Portland concrete. Wild et al. [32]
replaced cement by 0, 5, 10, 15, 20, and 25% of MK to investigate the chemical shrinkage and
autogenous shrinkage. Their results showed that chemical shrinkage increased in the specimens
containing 0 and 15% MK; however, above 15% MK content, chemical shrinkage decreased. On
the other hand, to reduce the autogenous shrinkage, the amount of MK replacement varied between
0 and 10 percent and, beyond 15% replacement, autogenous shrinkage increased.

50
EXPERIMENTAL PROCEDURES
Mechanism
The use of different wastes in concrete and enhancing the base mechanical properties of concrete
helps to produce eco-friendly yet efficient structures. Marble powder, wood ash, and burnt clay
pozzolana were explored as an aspect of strength improvisation. Cement was tested to be by using
M25 grade concrete in combination with the replacement of 0, 5, 10, 15 and 20% cement by
metamorphosed limestone powder, burnt clay pozzolana, and wood ash. Pozzolana clay allowed
better binding properties to prevail leading to higher strengths and low cracking concerns. Wood
ash was finely ground to powder in order to achieve required consistency to be utilized in concrete.
After the development of concrete, the mechanical properties of concrete were tested to understand
the strength behaviour of concrete.
Materials
Pakistan generates large volumes of metamorphosed limestone powder, burnt clay pozzolana and
wood ash that go untreated into river waters or landfills. Brick production also produces tons of
wastages per day. Wood ash is an efficient improvisation in concrete that renders finely reliable
characters. All materials were analyzed for detailed properties and their respective behaviors. All
these materials were analyzed for detailed properties and their respective behaviors as shown in
Table.1.
Testing
This paper presented the use of metamorphosed limestone powder, burnt clay pozzolana and waste
wood ash in the production of concrete. Waste materials were analysed for their base properties
such as consistency measures, fineness, and sieve analysis. Three major mechanical properties
were tested to understand the impact of cement replacement with these materials on concrete
strength.
Compressive Strength
The compressive strength of concrete using burnt clay pozzolana, metamorphosed limestone
powder, burnt clay pozzolana, and wood ash at different proportions was significantly greater than
the normal compressive strength achieved by ordinary concrete. However, the compressive
strength of concrete using metamorphosed limestone powder, burnt clay pozzolana, and wood ash
at different proportions was less than the effective compressive strength of normal concrete.
Compressive strength of concrete is an important property as concrete is designed to carry

51
compressive loadings. Almusallam and Mehta and Gjrv found that inclusion of FA results in higher
compressive strength on later ages. Pala et al. confirmed the decrease in the early compressive
strength and increase in long-term compressive strength of fly ash concrete. Naik et al. evaluated
the effects on the compressive strength by using mixed ASTM class C and class F FA on the
mechanical and durability related properties of concrete. They reported that performance of mixed
ASTM class C and class F FA concrete is comparatively better than the concrete without FA or
only containing ASTM class C FA. Siddique showed that, at a higher cement replacement level
with FA, compressive strength is reduced. Jianyong and Yan compared the results of plain
concrete, GGBS concrete, and blended concrete incorporating GGBS and SF, and found that the
highest compressive strength was achieved with blended concrete. This is due to the slow
hydration process and higher slag content, but the long-term strength is higher if moisture remains
available for further reaction between Ca(OH)2 and GGBS. The compressive strength of concrete
has been reported to increase if concrete contains SF between 30 and 100. Pala et al. and Bágel
showed that addition of SF produces highest increase in the early compressive strength in
comparison with all concrete containing different amounts of FA content due to higher pozzolanic
nature. Khatib and Hibbert investigated the effect of incorporating GGBS and MK on the strength
of concrete and concluded that the incorporation of MK increases the strength due to fast reactive
nature, especially during the early ages of curing. Qian and Li reported an increase of 51% in
compressive strength when cement content was replaced by 15% MK and specimens were cured
for 3 days. Thus, the addition of MK has a prominent influence on early strength. Poon et al. [12]
achieved the best performance of cement pastes in terms of compressive strength at young age,
using 10% MK content. Zhang and Malhotra [30] reported lesser compressive strength gain after
28 days, but confirmed the faster rate of strength development in MK concrete than concrete at
young age. Givi et al. reported the optimum amount of cement that can be replaced with RHA of
10 to 30% in order to improve the compressive strength of RHA concrete and achieve maximum
long-term strength. Other researchers suggested the contents of RHA by weight of the total
cementitious material. Mahmud et al. reported the results of high strength concrete with 10% of
RHA giving 80 MPa compressive strength at 28 days. Zhang et al. reported higher compressive
strength with reduced porosity, reduced calcium hydroxide content, and reduced width of the
interfacial zone between the paste and the aggregate. Habeeb and Fayyadh reported that finer RHA
showed higher strength of the concrete as compared to the coarser RHA due to the fact that finer
RHA reacts more with Ca(OH)2 resulting in higher production of calcium silicate hydrate (C–S–
H).
Rodrguez de Sensale (40), Alvarez (41), Ganesan et al. (5), El-Dakroury and Gasser (22), and
Nehdi et al. (13) have all found that replacing 10 and 20% of cement with Rice husk Ash (RHA)
has a positive effect on the compressive strength of concrete up to 91 days. Nehdi et al. (13)
reported a higher compressive strength of RHA concrete as compared to SF concrete having
similar proportion (refer to Figure 16). Rice husk ash is a highly reactive pozzolan and produces
high strength concrete, but it requires a higher quantity of superplasticizer than OPC and SF
concrete.

54
(c)
Figure 34: a) Effect of cement replacement () [36], (b) FA types [26], and (c) water binder ratio
(and 0.5) [25] on the compressive strength of FA concrete.

55
Figure 35Effect of plain and blended GGBS on the compressive strength of GGBS concrete

56
Figure 36Effect of cement replacement on the compressive strength of MK concrete

57
Figure 37Effect of cement replacement on the compressive strength of (a) MK pastes compared
to SF and FA pastes () [12] and (b) MK concrete compared to SF concrete () [30].

58
Figure 38Performance comparison of high strength RHA and SF

59
Figure 39Effect of grinding timings on the compressive strength of RHA concrete

60
Figure 40Effect of RHA imported from (a) USA (on left) and (b) Uruguay (on right) on the
compressive strength

61
Figure 41Effect of volume of cement replacement on the compressive strength of RHA concrete

62
Figure 42Effect of Egyptian RHA (EG-RHA) containing low carbon obtained at a different
combustion temperature on the compressive strength of concrete
Compressive strength is evaluated by using the following formula:
Compressive Strength (MPa) = P/A

63
Where,
P = compressive load at failure (N)
A = cross-sectional area of cylinder, (mm²)
Tensile Strength
The 7- and 28-days tensile strength of concrete (ASTM C 496) using burnt clay pozzolana at 10%
by weight was greater than normal concrete. In all other cases, the effective tensile strength of
modified concrete using metamorphosed limestone powder, burnt clay pozzolana, and wood ash
was lesser than normal concrete. In general, the tensile strength of the cylinder is 10% of its
compressive strength. Splitting tensile strength is the measure of tensile strength of concrete which
is determined by splitting the cylinder across its diameter. Siddique reported a decrease in the
splitting tensile strength of FA concrete when content of cement was replaced as 40, 45, and 50%;
however, at all replacement level, compressive strength of FA concrete was higher than ordinary
concrete. Naik et al. presented the results of tensile strength of FA concrete in which class C and
class F types were used together in varying proportions. The comparison of both studies has been
shown in Figure 17. According to Figure 17, irrespective of the type and proportioning of FA and
content of cement replacement, splitting strength of concrete increases with time, but not more
than OPC at a young age.
Therefore, it may be assumed that the addition of different types of fly ashes in different variations
negatively influences the splitting tensile strength of concrete; however, replacement of fine
aggregate by FA increases the tensile strength of concrete at replacement levels from 10–50% at
all ages. The rate of increase in tensile strength with age decreases with the increase in replacement.
The tensile strength of GGBS concrete is slightly higher than that of ordinary Portland concrete,
while SF significantly increases the tensile strength of concrete. According to Zhang and Malhotra,
the splitting tensile strength of high strength concrete incorporating SF is equivalent to high
performance concrete, but lesser than RHA concrete at cement replacement level of 10% and water
binder ratio of 0.4. Splitting tensile strength of MK concrete is increased with the increase in MK
content as cement replacing material. The splitting tensile strength of high strength concrete
incorporating RHA is comparable to high performance plain concrete, but Alvarez observed that
28-day splitting tensile strength with 10% RHA is higher than normal concrete. Ganesan et al.
reported the 28-day splitting tensile strength of concrete with 0 to 35% of RHA with 5% variation.
Habeeb and Fayyadh reported that later age tensile strength of RHA concrete at 90 and 180 days
is higher in comparison to concrete without RHA.

65
(b)
Figure 43Effect of (a) FA type [36] (on left) and (b) cement replacement [26] (on right) on the
splitting tensile strength of FA concrete.
The effective tensile strength of concrete can be evaluated by the following formula:
Tensile Strength (MPa) = 2P/πDL,
Where,
P = compressive load at failure (N)
L = length of the cylinder (mm)

66
D = diameter of the cylinder (mm)
Flexural Strength
The flexural strength of concrete (ASTM C 78) using metamorphosed limestone powder, burnt
clay pozzolana, and wood ash was higher than normal concrete when cement was replaced by
weight up to 15%, but was reduced by adding further metamorphosed limestone powder, burnt
clay pozzolana, and wood ash. Siddique observed a decrease in flexural strength when cement is
replaced with 40, 45, and 50% of FA. However, replacing fine aggregate by FA increases the
flexural strength from 10 to 50%. Flexural strength of concrete incorporating GGBS as the cement
replacing material has not been found in the literature. The flexural strength of SF concrete is
dependent on compressive strength and the young age curing method. Zhang and Malhotra
reported that the flexural strength of high performance concrete containing SF is comparable to
RHA at 10% level of cement replacement and constant water to binder ratio, but the flexural
strength of both SF and RHA concrete was higher than that of the plain high strength concrete.
Justice et al. reported a higher flexural strength of MK concrete and SF concrete than ordinary
concrete. The addition of RHA does not cause a positive effect on the flexural strength of concrete
at 28 days, but the gain flexural strength is higher at 90 and 180 days in comparison to concrete
without RHA. Alvarez reported that the flexural strength of concrete containing 10% RHA is
higher than normal concrete.

67
Figure 44Effect of increasing FA content on the flexural strength
The flexural strength is computed by the following formula:
Flexural Strength (MPa) = 3Pl/bd2,
Where,
= total load at failure point (N)
= effective beam span between supports (mm)
= total width of beam (mm), = measured depth of beam
Flexural strength can also be computed as:
flexural strength (MPa) = 0.7√fc´,

68
Modulus of Elasticity
Modulus of elasticity is an important property to assess the resistance of concrete against freezing
and thawing. Ghosh and Timusk reported that concrete containing good quality FA had equivalent
modulus of elasticity value as that of normal concrete; however, decrease in modulus of elasticity
was observed at the replacement level of 40, 45, and 50%. Naik et al. presented the effect of
blended FA concrete containing class C and class F FA in different proportions. At the age of 1
day, the elastic modulus results of OPC (i.e., control) concrete were the optimum, but, on later age,
the difference in the elastic modulus of OPC and blended concrete reduced as the pozzolanic
reactivity of FA increases with age; therefore, after 28 days, blended concrete showed higher
results than the control. Almusallam analyzed the effect of w/b ratio on the initial and secant
modulus of OPC and FA concrete. Results showed that the modulus of elasticity increases with
age, and the difference between the initial and secant elastic modulus for OPC is higher than FA
concrete at w/c of 0.48 and 0.5. GGBS slightly increases elastic modulus for a given compressive
strength, while SF does not follow the same trend. Table 4 shows a slight increase in elastic
modulus, and HSC results show that at 10% SF, elastic modulus of SF concrete improves with
decreasing water to cement ratio. Zhang and Malhotra and Qian and Li reported that MK concrete
has a higher modulus of elasticity than plain concrete and SF concrete for a w/c ratio of 0.38. Qian
and Li also reported a small increase in the tensile and compressive modulus of elasticity with an
increase in MK content using a w/c ratio of 0.4. The results of both studies are shown in Figure
21. Habeeb and Fayyadh found that the static modulus of elasticity of concrete marginally
increases with higher dosage of superplasticizer, while Zhang and Malhotra found comparable
results for concrete with and without RHA.

69
Figure 45 Effect of increasing FA content on the elastic modulus of concrete

70
Figure 46Effect of blended FA on the elastic modulus of concrete
Concrete type Elastic modulus (GPa) w/c or w/b ratio
Days
7 14 28 90
OPC
Initial
26.7 36.5 28.2 44.6
20% FA 0.48 29.3 27.5 26.4 38.8

71
OPC
Secant
23.9 28.9 26.4 35.1
20% FA 22.2 21.8 23.9 32.8
OPC
Initial
25.9 25.4 30.9 33.1
20% FA
0.5
23.2 22.7 25.3 38.1
OPC
Secant
21.9 22.5 26.6 28.9
20% FA 19.0 19.8 24.0 30.9

72
Figure 47Effect of cement replacement on the elastic modulus of MK concrete
RESULTS
Performance Analysis
The most important details in this text are the results of an evaluation of mechanical properties.
The maximum compressive strength was achieved at 7 days for 10% replacement level of burnt
clay pozzolana with cement, while the effective compressive strength was achieved at 28 days for
10% replacement level of burnt clay pozzolana with cement. The tensile strength of cylinder
specimens cured at 7 days was 1.165 MPa at the control mix, while the tensile strength of cylinder
specimens cured at 28 days was 1.58 MPa at the control mix. For the flexural strength of beams,
the maximum 7 days strength was achieved for 5% replacement level of burnt clay pozzolana with
cement, while the flexural strength of beam specimen at control mix was 2.62 MPa. For the

73
effective flexural strength parameter of casted beams at 28 days of curing, the maximum strength
was achieved for 5% replacement level of metamorphosed limestone powder with cement, while
the flexural strength of beam specimen at control mix was 3.38 MPa.
Figure 48Compressive strength of Concrete Cylinder (MPa) under 7 days and 28 days
Figure 49Tensile strength of concrete cylinder (MPa) under 7 days and 28 days curing

74
Figure 50Flexural strength of concrete cylinder (MPa) under 7 days and 28 days
Analysis of Factors
The main focus of the analysis was to find a replacement material for cement, as it is a costly
material and industrial wastes are available raw materials. To further investigate the impact of the
change of additive and replacing it with cement, a relationship has been built between ratios.
Compressive/Tensile strength ratios and Flexural/Tensile strength ratios have been plotted against
the types of additives, and the highest strengths are with cement, but only additive 3 (i.e. BCP) is
the true alternative. Similarly, in Plot (Fig.4.b) again clear dominance can be observed by additive
3(i.e. BCP).
(a) (b)
Figure 51: Contour Plot: (a) Comp/Tens Vs Type of Additives (b) Flex/Tens Vs Type

75
Scientific Questions?
i. Are the mechanical properties of concrete highly influenced by its density?
ii. What affects the mechanical properties of concrete?
REMARKS AND CONCLUSIONS
Concrete is one of the most used materials in construction, consisting of cement, sand, aggregates,
and water. Research has been conducted to test its mechanical, physical, fresh, and hardened
properties. This research focused on replacing cement with metamorphosed limestone powder
(MLP), burnt clay pozzolana (BCP), and wood ash (WA). The maximum strength of the cylinder
specimen at 28 days was achieved for 10% replacement level of BCP, while the maximum tensile
strength was 1.67 MPa at 10% replacement level of BCP. The maximum flexural strength
parameter of casted beams at 28 days of curing was achieved for 5% replacement level of MLP
with cement. This study can help in the construction of concrete structures like rigid pavements
which are saved and need rough construction pattern. This review aims to understand the role of
different mineral admixtures on the mechanical characteristics of concrete. It is important to note
that these conclusions are general and purely based on the studies reported in this paper, and may
vary in different circumstances.
The following conclusions are drawn:
1. Different mineral admixtures affect the mechanical characteristics of concrete;
2. Different admixtures affect the mechanical characteristics of concrete;
3. 3.Different admixtures affect the mechanical characteristics of concrete;
7. Different admixtures affect the mechanical characteristics of concrete.
Addition of mineral admixtures reduces pore size with increasing pore size distribution, which in
turn reduces porosity, permeability, shrinkage, and creep. The reduction of average pore diameter
is highly and oppositely dependent on volume of cement replacement and age of concrete or paste.
Drying shrinkage and creep strains increase with the increasing age and volume of cement
replacement, and the rate of increase in these strains is observed to be lower in pozzolanic
concretes. Inclusion of mineral admixtures improves compressive strength of concrete, but FA and
GGBS are those mineral admixtures which enhance the later age compressive strength instead of
early age due to their slow pozzolanic reactivity and/or lesser surface area. Alongside compressive
strength, addition of mineral admixtures slightly improves tensile strength, flexural strength, and
modulus of elasticity of concrete with the increase in replacement level. However, the case of FA
is different from other mineral admixtures, as the reported tensile and flexural strength of FA
containing concrete is lesser due to slow compressive strength gain.

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