大体积混凝土季节性温控措施有限元分析

Finite element analysis of seasonal temperature control measures for mass concrete

为探究大体积混凝土夏冬季浇筑时保温措施,以某筏板基础大体积混凝土施工项目为依托,通过建立精细化有限元模型,探讨夏季与冬季两种季节下的温控措施(外保温材料、混凝土入模温度)对大体积混凝土温度场的影响。结果表明:1)浇筑时环境温度的变高会使混凝土放热量增加并延长放热时长,其中夏季使用3 cm厚挤塑式聚苯乙烯板板保温,混凝土入模温度为25℃时其峰值温度和所需时间为66.8℃、114.7 h;2)两种季节的环境温度下,外保温性能与里表温差都呈线性降低趋势,与核心温度呈线性增加关系;3)不同保温措施会推迟核心温度出现时间,且保温性能越好,温度梯度越小;4)随着入模温度的增加,混凝土核心温度随之增大,且使其出现时间提前。本文成果可为同类型筏板基础大体积混凝土施工提供一点借鉴。

In order to explore the insulation measures of large-volume concrete during summer and winter pouring,based on a raft foundation large-volume concrete construction project,the influence of temperature control measures(external insulation material and concrete mold temperature)on the temperature field of large-volume concrete in summer and winter is explored by establishing a refined finite element model.The results show that:1)The increase of the ambient temperature during pouring would increase the heat release of the concrete and prolong the heat release time,in summer,3 cm thick extruded polystyrene board is used for insulation,and the peak temperature and required time are 66.8℃and 114.7 h when the concrete mold temperature is 25℃.2)Under the ambient temperature of the two seasons,the variation between the external thermal insulation performance and the inner surface temperature is decreased linearly,and the relationship with the core temperature is increased linearly.3)Different insulation measures will delay the occurrence time of core temperature,and the better the insulation performance,the smaller the temperature gradient.4)With the increase of mold temperature,the core temperature of concrete increases,and the occurrence time is advanced.The results can provide references for the construction of large-volume concrete for the same type of raft foundation.