Effect of fly ash on the kinetics of Portland cement hydration at different curing temperatures

Mongkhon Narmluk, Toyoharu Nawa
Cement and Concrete Research, Volume 41, Issue 6, June 2011

Abstract

This paper describes the effect of fly ash on the hydration kinetics of cement in low water to binder (w/b) fly ash-cement at different curing temperatures. The modified shrinking-core model was used to quantify the kinetic coefficients of the various hydration processes. The results show that the effect of fly ash on the hydration kinetics of cement depends on fly ash replacement ratios and curing temperatures. It was found that, at 20 °C and 35 °C, the fly ash retards the hydration of cement in the early period and accelerates the hydration of cement in the later period. Higher the fly ash replacement ratios lead to stronger effects. However, at 50 °C, the fly ash retards the hydration of the cement at later ages when it is used at high replacement ratios. This is because the pozzolanic reaction of the large volumes of fly ash is strongly accelerated from early in the aging, impeding the hydration of the cement.

Go to Journal

Check Also

Strain yy at residual strength on plane cutting through central section of the rock specimen under different intermediate principal stresses σ2: (a) σ2=10MPa; (b) σ2=30MPa; and (c) σ2=100MPa. - Advances Engineering

Numerical Investigation of Hard Rock Strength and Fracturing under Polyaxial Compression Based on Mogi-Coulomb Failure Criterion