Got a RFI from the contractor requesting if he can use lean concrete instead of 6" compacted CA-6 under a new slab on grade. My initial reaction was no, because I am worried about water in wet concrete. They probably would want to put vapor barrier within 7 days, so that would mean a lot of trapped water. The reason being that this is a slab replacement within an existing building and I guess its easier for the contractor to supply concrete via a chute thru a window as opposed to wheel-berrowing in gravel.
Has anyone run into this situation before?
Has anyone run into this situation before?
