合江二桥承台大体积混凝土水化热仿真分析

Analysis of Cap Massive Concrete of Second Bridge of Hejiang

采用减缩型聚羧酸减水剂及大掺量粉煤灰,设计出承台C50低温升高抗裂大体积混凝土,取消预埋冷却水。利用ANSYS分别对配合比优化后的混凝土以及普通大体积混凝土的浇注过程进行有限元模拟分析,得出配合比优化设计后混凝土最高温升控制在60℃以内,内外温差控制在25℃以内,温度应力小于混凝土各龄期的劈裂抗拉强度,能有效避免温度裂缝的产生。采用该文提出的优化配合比,进行合江二桥承台大体积混凝土施工未见裂缝产生。

C50 low temperature rise high anti-crack massive concrete for cap was designed by using reduced-type PC and high volume fly ash,so the embedded cooling water can be cancelled.Using ANSYS to optimize the mixture ratio of concrete and anglicizing the pouring process of ordinary mass concrete by FEM,finally the maximum temperature rise of concrete can be controlled below 60 ℃ after the optimum design,and the range of temperature below 25 ℃,the temperature stress of concrete is smaller than the splitting tensile strength of all ages,so it can prevent temperature cracks effectively.With the proposed optimal mixture ratio,the construction of mass concrete have no cracks.