骨料粒径对早龄期混凝土温度场分布的影响研究

Aggregate Size on Temperature Field Distribution of Early Age Concrete

将混凝土视为由骨料和砂浆组成的两相复合材料,分别建立了散热和绝热边界条件下一、二级配骨料的早龄期混凝土有限元模型,研究骨料粒径对早龄期混凝土温度场分布的影响.结果表明,绝热条件下在骨料含量相同的情况下,骨料粒径并不影响模型最终的温度场分布,但对砂浆和骨料之间热交换速率会产生影响;散热条件下边缘砂浆节点温度下降剧烈,甚至会低于预冷骨料温度升高的极值.因此在混凝土浇筑及养护过程中应做好保温措施,同时应考虑预冷骨料的级配给混凝土温控带来的影响.

In this paper,concrete was considered as a two-phase composite consisting of aggregate and mortar. Finite element models of early-age concrete with different grades of aggregate under adiabatic and heat dissipation boundary conditions were established respectively. We studied the effect of aggregate size on the temperature field distribution of early-age concrete. The results showed that:under adiabatic condition the final temperature field distribution was not affected by the aggregate size when the aggregate content was the same,but the heat exchange rate between the mortar and the aggregate was affected. The temperature of the edge mortar joints was decreased sharply under the condition of heat dissipation boundary,even the temperature was lower than the extreme value of the precooling aggregate temperature. Therefore,insulation measures were taken during the concrete pouring and curing process,and the influence of the gradation of the pre-cooled aggregate on the temperature control of the concrete was considered.