水泥混凝土路面板固化温差对翘曲和应力的影响

Effect of built-in temperature difference on curling and stresses in cement concrete slabs

实测硬化中水泥混凝土路面板内的温度分布,确定混凝土的终凝时间,提出固化温差及有效温差的计算方法,并计算两种施工环境条件下路面板的固化温差和有效温差,进行固化温差对板的翘曲和应力影响分析计算。研究结果表明:春季和秋季施工在水泥混凝土路面板中产生负的固化温差,将会导致路面板在1d中的大部分时间处于板中脱空的状态,在板中临界荷位处板底产生拉应力,而采用小尺寸板,相比较大尺寸板更能降低路面板翘曲及耦合应力,降低疲劳破坏。

The temperature distributions were measured in hardening concrete slabs, determining final set time of concrete; the calculation methods of built-in temperature difference and the effective temperature difference were provided to determine the corresponding values of the slabs constructed during spring and fall, respectively. Finally, the influence of built-in temperature difference on slab curling and stress were evaluated based on finite element analysis. The results show that negative built-in temperature differences were found in both spring and fall construction which will lead to loss of slab support in the mid-slab position during the most time of a day, and larger tensile stress generates at the slab bottom. However, small size slab will minimize this negative effect from built-in temperature difference and at the same time reduce fatigue damage.