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BRRDA
width and 20 mm depth by saw cutting to house the joint sealing material.
No emergency joint shall be allowed in less than 2 m distance of any
5.5.
5.6
5.7
preceding or succeeding joint position.
5.4.3 Expansion Joints : These shall be provided only near the bridges and slab
culverts. The expansion joint shall consist of a bitumen impregnated
joint/premoulded synthetic joint filler board about 20 mm thick
complying with IS:1838 and dowel bars as specified in the drawing. The
dowel bars shall be passing through the holes in the board. The filler board
shall be positioned vertically along the line of the joint.
5.4.4 Dowel bars : Dowel bars shall be mild steel bars of 25 mm diameter and
conforming to IS:432 (Part 1) having minimum yield strength 240 N/mm2.
These shall be free from oil, dirt, loose rust, scale, irregularities and
burring. Dowel bars shall be positioned at mid depth of the slab within a
tolerance of (±) 20 mm. All bars in a joint shall be within (±) 5 mm in length
of bar, normally 500 mm long and spaced 250 mm c/c or as specified. They
shall be parallel to the longitudinal axis of the pavement.
5.4.5 Premoulded Joint Filler : Bitumen impregnated filler board/premoulded
synthetic joint filler board for expansion joints shall be 20 mm thick within
a tolerance of (±) 1.5 mm and of a firm compressible material in conformity
with the requirements of IS:1838.
5.4.6 Joint Sealing Compound : Joint sealing compound shall be hot poured
sealing compound type having flexibility, resistance to age hardening and
durability and shall conform IS:1834.
Surface Levels : The tolerance in surface level of cement concrete pavement shall
be (+) 5mm or (-) 6mm which may not exceed (-) 8mm at 0-300mm from the
edges.
Surface Regularity : The maxm allowable difference between the pavement
surface and a 3 m straight edge/profile plate shall not exceed 6mm for the
longitudinal profile/cross profile.
Acceptance criteria for Cracked Concrete Slabs (One panel)
(i)
The length of single crack in any panel shall not be more than 750 mm,
even though its depth is less than half of the slab depth.
(ii)
The cumulative length of cracks with depth of crack less than half the
depth of slab in a panel shall not be more than 1250 mm.
(iii) Slabs with cracks which are penetrating to more than half of the slab
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BRRDA
depths shall not be accepted.
Do’s
1. Back fill properly, surface trenches and soft
spots in the sub-grade and compact the
same. Remove all organic and extraneous
material from sub grade.
2. Saw cutting of joints should be done when
concrete is neither too soft nor too hard.
3. Ensure that side forms are sufficiently
robust and rigid to support the weight and
pressure caused by paving equipment.
4. Do make provisions to maintain sufficient
supply of tarpaulin or other water proof
cloth during placement of concrete when
rain is expected.
5. The Coarse aggregate shall be free from
dirt, flint, chalecedony or other silica.
6. Use fine aggregate free from soft particles
of clay, shale, loam cemented particles,
mica and other foreign matter.
7. Ensure sufficiency and accuracy of material,
plant and equipment and methods of
construction.
8. Measure workability of the concrete at the
time of placing with slump cone Test.
9. Provide proper construction joint if
concreting is suspended for more than 30
minutes. Use bulk head to retain the
concrete.
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Don’ts
1. Do not lay sub-base on a sub grade
softened by rain
2. Do not expose concrete slab for a period
of more than half an hour for saw
cutting of joints.
3. Do not provide any vertical step
between the adjacent side forms greater
than 3 mm
4. Do not carry out concreting work when
concrete temperature is more than 300C
or less than 50 C at the point of placing
and ambient temperature is greater than
350C
5. Do not use disintegrated, soft, flaky,
elongated, highly angular or splintery
coarse aggregate.
6. Do not vibrate concrete excessively to
prevent flow of mortar to the top.
7. Do not allow concreting without
approval of mix design of concrete.
8. Do not walk on freshly laid concrete to
place covering for curing.
9. Do not allow any traffic, including
construction vehicles on the finished
surface of concrete pavement till the
joints are permanently sealed.
10. Do not drop concrete into place freely
from a height exceeding 1.5m.