Modeling of temperature history in the hardening of ultra-high-performance concrete

초록

Ultra-high-performance concrete (UHPC) consists of cement, silica fume (SF), sand, fibers, water andsuperplasticizer. Typical water/binder ratios are 0.15 to 0.20 with 20 to 30% silica fume. In the production of ultra-highperformance concrete, a significant temperature rise at an early age can be observed because of the higher cementcontent per unit mass of concrete. In this paper, by considering the production of calcium hydroxide in cementhydration and its consumption in the pozzolanic reaction, a numerical model is proposed to simulate the hydration ofultra-high performance concrete. The heat evolution rate of UHPC is determined from the contributions of cementhydration and the pozzolanic reaction. Furthermore, by combining a blended-cement hydration model with thefinite-element method, the temperature history in the hardening of UHPC is evaluated using the degree of hydration ofthe cement and the silica fume. The predicted temperature-history curves were compared with experimental data, anda good correlation was found.

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