METHODS FOR IMPROVED RHEOLOGICAL CONTROL IN CEMENTITIOUS SYSTEMS

摘要

A microbial polysaccharide having the features characteristic of S-657effectively improves the rheological properties of a varietyof cementitious systems. The addition of S-657 to such cementitious systems asportland cement, self-leveling grouts, fresh or saltwateroil well cement slurries, microfine cements, gives rise to substantialimprovements in such properties as bleed, flow resistance, fluid losscontrol, and the like. In addition, S-657 provides a number of advantages,including improved free water and sedimentation control, reducedfines loss during underwater placement, enhanced stability of highly dilutedmicrofine cementitious systems, enhanced flow and workabilityof superworkable and self-leveling pastes, enhanced color delivery inpigmented concrete and stabilized bubble entrapment in foamed orcellular cement systems. In sprayable cementitious systems, S-657 reducesrebound and sag.