Retarder

[pinki]

The top slab with webs of a box girder is to be poured over prepoured concrete slab in such a way that the whole concreting for this 52 m span bridge supported over truss type scaffolding spanning between the piers is completed before any concrete starts setting to avoid putting any stress in the concrete.

The estimated pouring time for the concrete is about 8 hours and the setting time is 4.15 hours.

Some type of retarder can be used. Please advise the right type of retarder or some alternative method to keep the poured concrete green until all concrete is poured in about 8 hours.

 

[merbas]

if you are in Europe consult

http://www.pieri.com

or in america

http://www.apchem.com

they have an experience special retarder, I used to XL TARD or XL STAB

best regards

 

[Riz]

Pinki,
Sika-Retarder is a set retarding concrete admixture available in either powder or liquid form. U need to contact your local Sika agent ( depending on where u r ) for expert details as a prestigious project is under implementation.
I have used Sika products extensively and applaud its usage.
Sika-Retarder dosage is between 0.2 to 2% of cement weight. At 30 degrees centigrade u need about 1% if cement content is 300kg/m3. Initial set time will be extended by 8 hours.