关键词: 低热水泥, 中热水泥, 混凝土, 热学性能, 抗裂

Abstract: The thermal and mechanical properties of low-heat cement and medium-heat cement are compared with the concrete of Baihetan dam as a research object. The compared thermal and mechanical properties include compressive strength, drying shrinkage, autogenous volumetric deformation, and adiabatic thermal rise. Results indicate that given the same water-binder ratio and fly ash content, low-heat cement concrete possesses lower strength, ultimate tension and Young’s elastic modulus at 7 d and 28 d than medium-heat cement concrete does; with the extension of testing age, strength of low-heat cement concrete grows, approaching the strength of medium-heat cement concrete; while at the 180 d age, the strength and ultimate tension of low-heat cement concrete are larger than those of medium-heat cement concrete. No big difference was observed in terms of drying shrinkage, and both concretes exhibited micro-expansion in autogenous volume deformation. The insulated thermal rise of low-heated cement concrete at 28 d age is lower than that of medium-heat cement concrete by 2.0℃-3.5℃. Overall, low-heated cement concrete was rated better than medium-heated cement concrete in terms of crack resistance.

Key words: low-heat cement, medium-heat cement, concrete, thermal property, crack resistance