Water Retention
Water retention is the ability to resist the forces that push or pull mix water from grout or concrete. Water loss can occur any time the grout or concrete is in contact with porous soil conditions (sand orsandy silt) that allow the movement of water but not aggregate or cementitious particles. Fine sand pulls water from grout or concrete through the process of capillary action. Pressure from pumps or theweight of the material above can squeeze water out. Preventing the loss of mix water is important because it can lead to rapid hardening underground. In augercast piling (CFA or ACIP piling) it can create a false set that prevents reinforcing steel from being dropped completely to the bottom of the pile. In tremie concrete, the premature hardening can interfere with the working time needed for properlymerged concrete flow patterns within a pour.