1.  
Dr. ir. Eva Lantsoght
10/28/2016
1

2.  General overview of
work/research since
graduating from VUB
 Current research line:
(proof) load testing
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3.  2003-2008: burgerlijk
ingenieur bouwkunde
 2008-2009: M.S. in structural
engineering, Georgia Institute
of Technology
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4.  2009-2013: PhD in Civil
Engineering
 Concrete Structures research
group
 Promotor: Joost Walraven
 Co-Promotor: Cor van der Veen
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5.  Experiments
o Shear in reinforced concrete slabs
o 156 experiments
 Analytical work
o Extended Strip Model – plastic
analysis method for shear in slabs
o Probability-based improvement for EC
shear formula based on experiments
 Practical application
o Quick Scan for Rijkswaterstaat
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6.  2013 – …
 B.Sc. level, 5-year program
 Teaching (3 courses/semester):
o Reinforced Concrete I
o Reinforced Concrete II
o Construction Materials Lab
o Design of Pavements
o Structural Analysis I
 Research with students for
“Trabajo de Titulacion”
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7.  2013-2016: Profesor auxiliar
 2016 (?) - … : Profesor
Investigador Principal Titular
after concurso de
merecimientos y oposiciones
=> reduction of teaching,
more research
 ACI student chapter
 ASCE student chapter
 2013 – 2016: Starting ICV-Lab
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8.  Research:
o Publications of PhD research
o Analysis existing bridge Tambura
o Torsion in slabs
o Digital Image Correlation with
cheap tools
o Chancellor Grant 2015: Extended
Strip Model
o Chancellor Grant 2016: Stop
criteria load testing (research line
TU Delft)
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9.  Research lines:
o Difficulties:
• contact with Ministry of Public Works?
• Infomation (structural plans?)
• Mentality: no interest in existing structures
• Limited facilities
• No research group
o Approach:
• Desk research
• Presentations about existing structures and
maintenance
• Cooperation through international committees
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10.  2013 – now: 0,2 fte
 Short projects
 Summer 2013:
o Quick Scan spreadsheets for
Rijkswaterstaat
 Summer 2014:
o Fatigue of high-strenght concrete:
proposal for Dutch code
o Ruytenschildt Bridge collapse test
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11.  Summer 2015:
o Effect of ASR on shear- and
bending moment capacity
o Proof load test viaduct Zijlweg
o Support for research line proof
load testing
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12.  Summer 2016
o Research line proof load testing
o Beam tests + analysis of results
o Analysis results of proof load test
viaduct De Beek
o Literature review
o Overview previous proof load tests
in NL
o First draft guideline
o Vechtbrug: last week – collapse
test
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13.  ACI-ASCE 421: Design of reinforced concrete slabs
 ACI-ASCE 445: Shear & Torsion
 ACI-DAfStB 445-D: Shear Databases
 ACI 342: Evaluation of Concrete Bridges and Bridge
Elements
 TRB AFF30: Concrete Bridges
 TRB AFF40: Testing and Evaluation of Transportation
Structures
 IABMAS, IALCCE, IABSE, fib
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14.  Advanced structural
engineering
 2 junior engineers
 Bridges: La Armenia, Los
Pajaros (ILM), Villorita
 Buildings
 Project on concrete masonry
houses (EQ-resistant) for
coast of Ecuador
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15.  Introduction
o Why proof loading?
o Stop criteria?
 Overview of existing guidelines
 Past proof load tests by TU Delft
 Recommendations
o Preparation of proof load tests
o Execution of proof load tests
 Summary and conclusions
Slab shear experiments, TU Delft
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16. Bridges from 60s and 70s
The Hague in 1959
Increased live loads
common heavy and long truck (600 kN)
End of service life + larger loads
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17. 10/28/2016 17

18. Diagnostic load testing Proof load testing
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Barcza ridge, Poland (Olaszek et
al., 2012)
Delaware (Jones, 2011)

19. Diagnostic load testing
 Calibration of FEM
 Strain gages over girder
height
 Low load levels
 Rating with updated FEM
Proof load testing
 Directly demonstrate that
bridge fulfils criteria
 Higher load levels
 Larger involved risk
 Follow measurements
 Stop criteria
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20.  Safety philosophy
 Stop criteria:
o Further loading not permitted
o Failure near
o Irreversible damage near
MSc Thesis W. Vos
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21.  Apply predetermined load
to bridge
o Information lacking
o Damage due to ASR, …
 Proof load testing
o Immediate approval of
bridge
o Recalculate updated β
o RC slab bridges
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22.  Europe: DAfStB Richtlinie
 Stop criteria
o Concrete strain
o Steel strain
o Crack width and residual
crack width (new & existing
cracks)
o Residual deflection
 For flexure
 Structures with large existing
cracking?
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23.  North America:
o Buildings: ACI 437.2M-13
o Bridges: Manual of Bridge
Rating Through Load Testing
(1998)
 ACI 437.2M-13 stop criteria:
o Residual deflection
o Permanency ratio
o Deviation from Linearity Index
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24.  Guideline for proof loading of existing bridges for the
Netherlands
 Flexure + shear
 Stop criteria?
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25.  Proof load tests:
o Heidijk 2007
o Medemblik 2009
o Vlijmen-Oost 2013
o Halvemaans Bridge 2014
o Ruytenschildt Bridge 2014
o Viaduct in the Zijlweg 2015
o Viaduct De Beek 2015
o Vecht Bridge 2016 Load test to failure of Ruytenschildt Bridge, summer 2014
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26.  Heidijk
o RC slab bridge
o ASR-induced damage
o Loading frame
o RWS + TNO
 Medemblik
o Girder bridge
o BELFA
o RWS + TNO + ifem
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27.  Video
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28.  BELFA
 Viaduct with ASR-damage
 Viaduct remained open to
traffic
 Disturbs AE measurements
 TU Delft + ifem:
measurements
 Bridge approved
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29.  System with load spreader
beam
 Bending moment capacity
 1 night closure of bridge
 TU Delft: measurements
 Bridge from 1930s
 Approved with proof load test
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30.  Existing reinforced concrete slab
bridge (1962)
 Test to failure in two spans
 4 concentrated load – one tandem
 Cyclic loading protocol
 Failure only achieved in span 2
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31. Existing bridge Partial demolition and building new bridge
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32. 10/28/2016 32

33.  Proof load test for bending
moment and shear
 Bridge closed for 1 week
 Viaduct over highway
 ASR-induced damage
 Approved thanks to proof
load test
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34.  No material damage
 Extensive cracking
 Proof load test on Span 1
 Span 2 over highway
 Shear and flexure position
 Bridge approved if 7% plastic
redistribution in Span 2 is OK
 Check for durability/corrosion
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35.  Video
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36.  Determination of dimensions
 Live load: EN 1991-2:2003
 RBK load levels
o Different β
o Different load factors
 In FEM model
o mx over 3 m
o v over 4d
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37.  Critical position
o Bending moment: largest
moment
o Shear: 2.5d from Support
 Required proof load
o Same shear or bending
moment as with load
combination
o Value → considered safety
level
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38.  Cyclic loading scheme
o Acoustic emission measurements
o Check linearity and reproducibility of measurements
o Check residual deformations
 Stop criteria
o Evaluated during tests
o Research in progress
o Criteria for shear failure need to be developed
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39.  Beams from Ruytenschildt Bridge
o Cyclic loading protocol
o Tests: Failure in shear and flexure
o Measurements:
• Lasers: deflection of beam
• LVDTs: crack opening
• Acoustic emission sensors
Beams RSB01 after failure (Yang, 2015)
Yang, Y. (2015). "Experimental Studies on the Structural Behaviours of Beams from Ruytenschildt Bridge,"
Stevin Report 25.5-15-09, Delft University of Technology, Delft, 76 pp.
Beams RSB02B after failure (Yang, 2015)
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40. RSB 01F 02A 02B 03F 03A
d (mm) 503 515.5 520 521 515
Ac (m2) 0.290 0.297 0.307 0.596 0.537
Rebar 4Ø22
4Ø19
4Ø22
4Ø19
4Ø22
5Ø19
9Ø22
8Ø19
7Ø22
8Ø19
ρl 0.91% 0.89% 0.96% 0.95% 0.92%
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41.  Analysis of stop criteria ACI 437.2M-13 and DAfStB
Richtlinie for RSB03F – Flexure test
ACI 437.2M-13
Criterion
Load (kN) DAfStB
Criterion
Load (kN)
Δr 340 Δr 150
Ipr >Pu w new crack 300
IDL 250 Strain -
PACI,st 250 PDA,st 150
Pu 606.6 Pu 606.6
PACI,st/Pu 0.41 PDA,st/Pu 0.25
Tersteeg, R. H. D. (2015). "Proefbelastingen op betonnen bruggen," B.Sc. Thesis,
Delft University of Technology, Delft, The Netherlands, pp. 69.
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42.  Analysis of stop criteria ACI 437.2M-13 and DAfStB
Richtlinie for RSB03A – Shear test
ACI 437.2M-13
Criterion
Load (kN) DAfStB
Criterion
Load (kN)
Δr >Pu Δr >Pu
Ipr >Pu w new crack 690
IDL 390 Strain -
PACI,st 390 PDA,st 690
Pu 706.7 Pu 706.7
PACI,st/Pu 0.55 PDA,st/Pu 0.98
Tersteeg, R. H. D. (2015). "Proefbelastingen op betonnen bruggen," B.Sc. Thesis,
Delft University of Technology, Delft, The Netherlands, pp. 69.
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43.  Use cyclic load protocol
o Study linearity and repeatability of results
 Flexure: Stop criteria exceeded long before failure
o Suitable stop criteria
• Crack width criterion from DAfStB + add lower bound
• Residual deflection DAfStB / ACI 437.2M-13 + minimum load level
• Deviation from Linearity ACI 437.2M-13: consistent performance except for
retested beam
• BUT: Deviation from Linearity and Permanency Ratio depend on applied loading
protocol
 Shear:
o Need to develop stop criteria
o Research on acoustic emission measurements
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44.  Controlled experiments in
laboratory
 Heavily instrumented beams
 Beams: part of series of
shear tests
 Study of stop criteria and
loading protocol
o Interrelated!
 First proposal for stop criteria
for guideline
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45. Previously cracked in bending moment or not?
Failure mechanism Uncracked Cracked
Flexural failure Concrete strains
wmax ≤ 0.5 mm
wres ≤ 0.1 mm
Stiffness reduction ≤ 25
%
Deformation profiles
Load-displacement graph
Concrete strains
wmax ≤ 0.5 mm
wres ≤ 0.1 mm
Stiffness reduction ≤ 5 %
Deformation profiles
Load-displacement graph
Shear failure Concrete strains
wmax ≤ 0.3 mm
Stiffness reduction ≤ 5 %
Deformation profiles
Load-displacement graph
Concrete strains
Stiffness reduction ≤ 5 %
Deformation profiles
Load-displacement graph
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46. 10/28/2016 46

47.  Proof loading to approve existing
bridges
 Existing guidelines:
o Only flexure
o Cracked structures?
 Research on stop criteria
 Determination of maximum proof
load
o LFEA
o Different safety levels
 Execution
o Cyclic loading protocol
o Safely applying large loads
Viaduct Zijlweg, tested in summer 2015
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48. Contact:
Eva Lantsoght
elantsoght@usfq.edu.ec // E.O.L.Lantsoght@tudelft.nl
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