Traffic Control
At first start the work in half width of carriageway and remain opened the rest of width for traffic.
FOR NEW BRIDGES
Leave a cavity during placing the concrete and fill the cavity with sand.
FOR EXISTING BRIDGE
Create such cavity for installing the expansion joint by using chisel or pneumatic equipment. The existing reinforcement of deck slab must not be damaged but to be cleaned, straightened and preserved. Never use jack hammer for this job. Clean the created cavity with brush.
Use bonding agent sikadur-32 lp or (equivalent) to the exposed edges of the concrete, for bondage between concrete.
Use water reducing agent sikament-163 (600 ml / cement bag) along with hardener accelerator as sikarapid-1 (750 ml / bag) or equivalent, for high early strength of concrete. Don’t use low cost admixtures containing chlorides and sulphates.
Use concrete of minimum compressive strength (350 kg / cm2).
Use steel of Grade – 60 requirements.
Don’t place the concrete on plates or formwork heated under sun beyond 32° c.
Complete wet curing for 7 days is must, otherwise prefer using concrete curing compound anticsol-e15 (0.20 kg / m) or equivalent within 6 Hours of concreting and cover the concrete area with opaque / colored plastic sheets.
When the bridge is located over a river / canal / nullah, sealing of joint using backup rod and sikaflex-pro 3ws filler is not required and let
The water flow down to the nullah underneath. But in case of overhead bridges, following additional treatment is required for sealing of joint.
after the installation and curing of the joint, clean the joint gap with wire brush and remove the dust with a blower.
fix the backup rod of specified dimension at a depth of 25 mm from the top.
apply sikaprimer-3 (or equivalent) with paint brush.
apply oil resistant resins sikaflex-pro 3ws (or equivalent) in the upper 25mm cavity in a concave shape, over filling of compound should be avoided.
Indigenous expansion joint is not a propriety item. It can be copied and the joint can be manufactured and placed by any designated.
Temporary steel strips 25x60 thicness 3mm at 500 c/c, welded to top and bottom of vertical plates, have been added to maintain spacing of vertical plates during the construction of the joint, don't forget to remove temporary steel strips within three days of concreting of joints.
Preferably the expansion joint should be manufactured in 2m length or less than 2m and assembled at the site.
