2. EQUIPMENTS FOR COMPACTION
Compaction is the process where by material particles
are constrained to pack more closely together through
a reduction of air void content generally by mechanical
means
3. Types of compactors
static smooth wheeled rollers
sheep foot or pad foot rollers
pneumatic tyred rollers
vibratory rollers
Tamper and vibrating plates
4.
5. Static smooth wheeled rollers
Rollers used with or without ballast
Not effective on uniformly graded sand, gravel or silt
and on over moist cohesive soil.
Rely on weight alone to compact the material over
which they pass
The unit of 80 to 10 tonnes imparting pressure of 20 to
40 kg per linear cm are generally used.
Lighter rollers of weight up to 1 ton are also available.
6. Sheepfoot or padfoot rollers
Self driven or tractor driven
Suitable on cohesive soils specially when water
content is on the higher side.
Higher degree of compaction at faster rate.
8. Pneumatic-tyred rollers
Used for both in earthwork and bituminous road
construction.
Produce more even compaction across the rolling
width than wide steel wheel smooth rollers
Eliminate surface cracking and material crushing on
bituminous wear courses
Produce an almost sealed finish
Weigthts ranging 6-30 tonnes with 500-4000 kg per
tyre
Tyre pressure 2-8 kg/sq.cm
10. Vibratory rollers
Eccentric weights within the rolls produce vibration
Particles of material brought closer together as air
voids eliminated
Very effective on free draining type soil and granular
base course
Not effective on uniformly graded sand, gravel or silt.
Effective pressure around twice the static weight of the
roller.
11. Tamper and vibrating plates
Used to tamp footing, trench bottom, position posts,
lay paving slabs or in any small areas.
Operational weights fall approximately 80kg for
tamper 300 for vibrating plates.
Deliver 800-4500 blow per min.
2.5-12.5 H.P powered engine
12. Static compaction equipment
towed static smooth compactors
static sheep foot or pad foot compactors
static three wheel self propelled compactors
static tandem compactors
three axle static compactors
14. Vibratory compaction equipments
a)
Tandem vibratory compactors
b)
Towed vibratory compactors
c)
Towed sheep foot and tamping foot vibratory
compactors
d)
Self propelled vibratory compactors
e)
Hand guided vibratory compactors
15. Tandem vibratory compactors
Dual dive or single axle dive
Available in two type:
•
Sngle drum vibrating
•
Both drum vibrating
double drum vibrator have 80% increased output than to
single drum vibrator
16. Towed vibratory compactor
Used for compaction of cohesive soils fine and coarse
grained mixed soil, and rocky materials.
Heavy towed vibratory compactors are used for the
compaction of extremely thick layers(in dam or
embankment construction)
17. Towed sheepfoot or tamping foot vibratory compactors
Used for compaction of highly cohesive soil
Kneading and crushing effect improves the compaction
performance.
Depending on the shape of foot: sheepfoot vibrator or
tamping foot vibrator
Sheepfoot rolls: cylindrical shape foot, small contact area
Tamping foot rolls: larger contact area
18. Self propelled vibratory compactors
Large varieties available
8-12 tons dead weight
Some of job condition :
• Large vibratory steel roll in the front and two rubber
tyres in the rear. The rubber tyres may either be smooth
one for bituminous work or having thread for earth
compaction work. Front roll (drum ) may be smooth,
padded, sheep foot or rubber coated.
• Vibratory steel roll in the front and two static steel rolls
in the rear for multipurpose work.
19. Handguided vibratory compactor
These may be either,
•
•
Single drum: vibrate with operator guiding behind
Duplex drum: one or both drum vibrating
Less than 1m width
Excellent gradability and cross-country mobility
Used for : trenches, slopes, parking lots, small repair jobs,
sport centres, inside building and other confined spaces, and
preparing foot and bicycle paths
20. Erecting equipments
Operation of lifting a weight from one location and
moving it to another location which is at a reasonable
distance and then dumping it.
22. Cranes can classified into following classes
1.
2.
3.
4.
5.
6.
Derrick cranes
Mobile cranes
Hydraulic cranes
Overhead cranes
Traveller cranes
Tower cranes
23. Derrick cranes
Consist of :
•
•
•
•
a mast,
a boom,
bull wheel on which it rotates
Supporting membrane
Used : construction projects, plant erection, loading and
unloading of cargoes, ship building etc.
Boom can revolve through 360ᵒ
Bullwheel attach mast and rotate
Operated by diesel engine or by electric motor
24. Some time mounted on rail wagon for quick transport
and are known as whirler
Capacities 40tones with 25m boom length and 15m
work radius
25. Mobile cranes
Either crawler mounted or wheel mounted
Crawler mounted:
-ability to operate unmade ground
-low ground bearing pressure
-move slowly
- used in tough terrain
-economically used where ground conditions are
poor and operate in a limited area
26. Wheel mounted crane:
-high mobility
-can travel upto 70-75km per hr
-designed for long distance travel
-operate on firm ground
Mobile cranes have four motions: hoisting, dericking,
slewing and traveling.
27. Hydraulic cranes
Operation are hydraulically powered including
extension
Retraction of out-riggers, extension and shortening of
boom
Power generated by rotary oil pumps
Quick change of boom length and easy and quick
change of angle
Beside operation of hoisting slewing and derricking
can be performed simultaneously
28. Overhead ( gantry) crane
Used for handling loads over a long rectangular area
Supported on tram wheel and can move on gantry rails
These are widely used in erection
Consist of two main part bridge and crab
Crab consist of hoisting gear mounted on a frame
Frame mounted on another set of wheels and capablw of
moving across the main girder
29. Traveller (or goliath) cranes
Crabs moving on girders supported on legs
Legs moves on tracks laid on floor
Useful as docksite crane
30. Tower crane
Mounted on steel tower
Used in various construction projects
Its constructed for work and then dismantled
Truss structure
Ladders are provided inside the whole height
Operation cabin is provided
Saddle moves horizontally and controlled from the hook
block