观音岩大坝碾压混凝土2种设计龄期的温控特性比较

A Comparison between the Temperature Control Characteristics of Two Design Ages of Roller Compacted Concrete on Guanyinyan Dam

碾压混凝土设计龄期的选择对其后期强度、水化热温升具有重要影响。基于室内混凝土力学和热学试验数据,对90及180 d设计龄期的碾压混凝土特性进行了对比分析;研究制定了2种设计龄期混凝土的温度及应力控制标准。基于有限元单元法采用ANSYS对观音岩碾压混凝土重力坝施工期的温度场及应力场进行了仿真分析;对比了90和180 d设计龄期下坝体内部温度场以及应力场的分布状况;通过对坝体抗裂安全系数、最高温度和应力状况的分析,比较了2种混凝土设计龄期的温控特性,从温控的角度探讨了采用180 d设计龄期混凝土的合理性,为相关工程采用180 d设计龄期提供了重要参考和依据。

The long-term strength and temperature rising of hydration heat for the roller compacted concrete （RCC） are influenced by its design age. The RCC properties with 90 d and 180 d design age are compared based on mechanical and thermal experimental data. The temperature controlled standard and the stress controlled standard of RCC are proposed. The temperature field and the stress field of Guanyinyan RCC gravity dam are simulated by using ANSYS based on the finite element method, and the distributions of the temperature field and the stress field of 90 d and 180 d design age are contrasted. The safety factor of crack-resistance, the maximum temperature and the stress situation of dam are analyzed to compare the temperature control characteristics of the two design ages. The rationality of application of 180 d design age in RCC is discussed in the terms of temperature control, which has laid an important foundation for the adoption of the 180 d design age in relevant projects.