Feasibility of specialty cement possessing improved bond properties

Abstract

Reported attempts to develop specialty cement possessing improved bond and tensile properties resulting from inter-grinding elastomeric styrene–butadiene rubber (SBR) latexes during clinker processing are limited. Such types of ready-to-use cement would be of particular interest for repair and precast applications as well as for adhesive and protective cementitious materials requiring enhanced bond to existing substrates. The test results obtained in this work showed that cement processed in the presence of SBR is characterised by higher workability and improved flexural and pull-off bond strengths, but exhibits reduced efficiency of clinker grindability and compressive strength development. For SBR addition rates of less than 0·3%, the incorporation of an alkanolamine-based grinding aid (GA) was found to compensate for grindability and compressive strength losses while maintaining cement properties to ASTM C 465 requirements. The increases in flexural and pull-off strengths of cement inter-ground with combinations of SBR and alkanolamine-based GAs were higher than those achieved when the same SBR concentration was added as a post-addition to the cement.