Influence of high early temperatures on properties of PFA concrete

Abstract

The paper presents results of a laboratory investigation using temperature matched curing (TMC) to study the effects of high early temperatures (65-85°C) on properties of concrete made with both ordinary Portland cement (OPC) and blends of OPC and fly ash. TMC is a technique in which test specimens are cured under the temperature regime similar to that which would occur at a chosen point of a pour, particularly for a thick section. Concrete mixes with three different total cementitious contents were studied with PFA replacement of cement at 0%, 15% or 30% by weight. Strength of each concrete mix was monitored for ages from one day to one year. The properties investigated were peak temperature rise, compressive and tensile strength development. The results show that for the case of massive structures in hot climate, partial replacement with PFA lends itself as one of the most effective techniques for reducing the potential loss of strength due to high early temperatures. © 1990.