Properties of Self-Consolidating Concrete for Prestressed Members

Abstract

This paper evaluates self-consolidating concrete (SCC) mixtures for use in prestressed concrete applications. In the laboratory, 21 SCC mixtures are created with varying water-to-cementitious materials ratios, sand-to-total aggregate ratios, and cementitious material combinations (e.g., Type III cement, Class C fly ash, ground-granular blast-furnace slag, silica fume). Prestress transfer compressive strengths of between 5470 and 9530 psi (38 and 66 MPa) are shown for the SCC mixtures. The authors note that the moduli of elasticity of the SCC mixtures show reasonable agreement with the elastic stiffness assumed to be present in the design of conventional slump concrete structures. Also noted is that long-term drying shrinkage strain for all the SCC mixtures show approximately the same or less shrinkage strain than those measured for the control mixtures. Moreover, long-term drying shrinkage is not significantly affected by a change in sand-to-total aggregate ratio. And, at later ages of 56 and 112 days, measured drying shrinkage corresponds reasonably well to drying shrinkage predicted by the American Concrete Institute (ACI) Committee 209 procedure.