大体积混凝土施工温度变化规律

Mass Concrete Construction Temperature Change Rule

水泥材料力学特性、外界气温变化和约束条件等多种因素综合影响着混凝土体内外温差,进而控制着大体积混凝土温度裂缝性状产生和发展.为了把握中空箱型截面梁大体积混凝土体内温度变化发展模式,在工地实测资料的基础上,用MATLAB建立数学模型作仿真分析.结果表明,混凝土内部温度随时间的变化规律服从双峰正态分布,在混凝土浇捣后30.3小时和102.8小时分别达到第一和第二个峰值:混凝土内部与表面的温度差随时间变化呈现正态分布模式,在混凝土浇捣后32.5小时混凝土内外温差达到峰值.在综合调查分析实际施工条件、技术和方法的基础上,提出了大体积混凝土施工阶段温度裂缝防范措施.

Mechanical characteristics of cement, ambient temperature variation, structural constraint conditions and other factors affect the temperature difference between the surface and interior of concrete structure that controls the initiation and development of temperature crack in mass concrete under construction. In order to investigate the development mode of temperature inside the mass concrete, basing on the in-situ data of temperature, a numerical analysis model is developed by the tool of Program MATLAB. It is shown from the simulation analysis that the temperature variation inside the mass concrete follows bimodal distribution mode, in which the first and second peak point arrive at 30.3h and 102.8 hours after the pouring of concrete And the temperature difference between the surface and inte- rior of concrete follows normal distribution mode, in which the peak point arrives at 32.5h after the pouring of concrete. Along with the result of in-situ investigation of construction conditions, technologies and methods, the preventive measures against temperature crack of mass concrete under construction are proposed.