Numerical simulation of temperature rise of highstrength concrete incorporating silica fume and superplasticiser

Abstract

A numerical model is proposed to predict the process of adiabatic temperature rise of high-strength concrete (HSC) incorporating silica fume (SF) and superplasticisers. On the basis of predicting the exothermic hydration process of plain concrete, the proposed numerical model takes the retardation caused by the superplasticisers and the effect caused by the SF into consideration. The verification of the proposed model is carried out with several groups of experimental data on concrete at different water to cementitious material ratios and initial temperatures. This numerical model is able to predict the adiabatic temperature history of HSC with SF and superplasticiser. The computing model requires the following relevant material parameters, namely, the mineral composition of Portland cement, the amount of SF, the dosage of superplasticiser, mix proportions and initial placing temperature of concrete. The model is useful in the prediction of heat of hydration, temperature distribution in mass concrete providing useful information on de-moulding at early ages and on controlling the potential thermal cracking.

Hydration of Binary Portland Cement Blends Containing Silica Fume: A Decoupling Method to Estimate Degrees of Hydration and Pozzolanic Reaction

“…In this study, it is assumed that the pozzolanic reaction of SF takes place according to Equation (11). This assumption has been adopted successfully in many simulations and calculations involving SF (Bentz, 2000;Bentz et al, 2000;Swaddiwudhipong et al, 2003;Yajun and Cahyadi, 2004).…”

“…To express hydration kinetics of the blended binders, the reaction kinetics of SF also need to be known. Rather than through separated fittings, the degree of reaction of SF (α SF ) is tied to the degree of hydration of cement (α) in the same blended paste through a reasonably established relation, shown in Equation 21, which is modified from Swaddiwudhipong et al's work (Swaddiwudhipong et al, 2003). It is assumed that, in a specific cement-SF binary paste at a particular status (or age), the amount of SF that can be reacted depends on the content of CH available for pozzolanic reaction.…”

“…Since hydration of cement and pozzolanic reactions of SCMs are exothermic processes, several models based on direct calorimetry measurements have been developed to describe the hydration of blended cementitious materials (De Schutter and Taerwe, 1995;Swaddiwudhipong et al, 2003;Riding et al, 2013). They are useful in predicting the heat of hydration and semiadiabatic temperature rise in mass concrete, and can be used to broadly estimate the overall degree of hydration of blended cementitious materials (Fanghui et al, 2016;Qiang et al, 2016;Zhang et al, 2016).…”

A Simplified Method for Real-Time Prediction of Temperature in Mass Concrete at Early Age

“…Owing to the related properties assigned to each element, the temperature variations of concrete are simulated more accurately using this method, but the more refined the model is, the longer it takes to calculate. In addition, a number of researchers developed a numerical simulation of the exothermic process of cement hydration according to the chemical reaction of each composition [14][15][16][17], with the microstructure model being established based on molecular dynamics to simulate cement hydration in a certain environment [18]. Alongside the progression of experimental methods and the deepening of applicable research, a series of micromonitoring experiments regarding cement hydration were also performed.…”

Effect of Cementitious Materials Composition on Heat Evolution and Strength of Concrete

“…The hydration heat generated by cementitious materials in massive concrete may results in thermal cracks as it increases the temperature in the center of mass concrete in which the warm state is almost adiabatic. Whereas, the loss of warmth close to the surface to the surrounding climate is simpler [17].…”