Experimental study and modelling of heat evolution of blended cements

TY - JOUR

T1 - Experimental study and modelling of heat evolution of blended cements

AU - Paine, K. A.

AU - Zheng, L.

AU - Dhir, R. K.

N1 - dc.publisher: Institution of Civil Engineers

PY - 2005

Y1 - 2005

N2 - The advisability of controlling the temperature rise and fall in concrete at early age is well recognised, and the choice of an appropriate, low-heat cement with suitable heat of hydration characteristics can assist in this control. This is particularly pertinent with respect to water-retaining and massive concrete structures where the need to prevent early-age thermal cracking is paramount. Portland cement/ground granulated blast furnace slag (PC/ggbs) or PC/fly ash cements are often used in these structures due to their low heat hydration properties. This paper presents the results of isothermal conduction calorimetry tests carried out on PC/ggbs and PC/fly ash cements and describes a model that uses these results to simulate the heat evolution processes in hydration concrete sections at early ages. The tests covered a range up to 90% ggbs and up to 65% fly ash content by mass of cement, at temperatures from 5° to 60°C. For PC/ggbs cements, the total heat of hydration can be considered as a composition of three components, that is heats from an initial Portland cement reaction, a latent ggbs hydraulic reaction and co-reactivity effects of PC and ggbs; whereas for PC/fly ash cements, the initial PC reaction dominated with a small co-reactivity effect.

AB - The advisability of controlling the temperature rise and fall in concrete at early age is well recognised, and the choice of an appropriate, low-heat cement with suitable heat of hydration characteristics can assist in this control. This is particularly pertinent with respect to water-retaining and massive concrete structures where the need to prevent early-age thermal cracking is paramount. Portland cement/ground granulated blast furnace slag (PC/ggbs) or PC/fly ash cements are often used in these structures due to their low heat hydration properties. This paper presents the results of isothermal conduction calorimetry tests carried out on PC/ggbs and PC/fly ash cements and describes a model that uses these results to simulate the heat evolution processes in hydration concrete sections at early ages. The tests covered a range up to 90% ggbs and up to 65% fly ash content by mass of cement, at temperatures from 5° to 60°C. For PC/ggbs cements, the total heat of hydration can be considered as a composition of three components, that is heats from an initial Portland cement reaction, a latent ggbs hydraulic reaction and co-reactivity effects of PC and ggbs; whereas for PC/fly ash cements, the initial PC reaction dominated with a small co-reactivity effect.

U2 - 10.1680/adcr.2005.17.3.121

DO - 10.1680/adcr.2005.17.3.121

M3 - Article

SN - 0951-7197

VL - 17

SP - 121

EP - 132

JO - Advances in Cement Research

JF - Advances in Cement Research

IS - 3

ER -