水工混凝土早期日照辐射吸热特性及结构施工期日照辐射响应研究

Solar radiation has a significant impact on temperature field of hydraulic concrete structure during construction. Especially in high altitude area, intense radiation is one of the main challenges for concrete crack prevention. Traditional research usually concern on solar radiation absorbing characteristics of mature concrete, and corresponding solar absorptivity model couldn’t reflect the influence of early-age concrete changing surface characteristics. In addition, conventional solar radiation responding simulation method ignores changes of the surface properties, and just relies on the temperature field calculation, which needs to be improved urgently. As a result of insufficient basic research, structure responding to solar radiation during construction is quite inadequate, and the quality of crack prevention in strong radiation areas is affected. Therefore, experiment of solar absorptivity of early-age concrete concerning on the reflection of surface humidity, age, roughness of surface will be implemented. A solar absorptivity model specifically for short-age concrete will be established and applied in the simulation of coupled temperature and Moisture of concrete, then a simulation algorithm for concrete structure responding to solar radiation during construction considering the changes of surface characteristics will be proposed. Basing on the practical engineering projects data, profound study about hydraulic concrete structure temperature field responding to solar radiation during construction will be made, and temperature control theory for concrete structure construction period will be improved, aiming at improving the construction quantity of hydraulic concrete structure in radiation area.

日照辐射对施工期水工混凝土结构温度场有重要影响，尤其在高海拔地区，强辐射是施工期水工防裂工作所面临的重要挑战。传统研究只关注长龄期混凝土日照辐射吸热特性，所建立的辐射吸收率模型无法体现混凝土早期表面特性变化的影响，且常规的结构施工期日照辐射响应仿真忽略表面特性变化、仅依赖温度场计算，亟待改进；上述基础研究的不足，导致混凝土结构施工期日照辐射响应特性研究不够深入，影响了强日照辐射地区防裂工作质量。为此，本项目拟从混凝土早期表面日照辐射吸收率试验入手，研究表面相对湿度、龄期、表面类型对日照辐射吸收率的影响，建立混凝土早期日照辐射吸收率模型，并将其引入温湿耦合仿真计算中，提出考虑表面特性变化的结构施工期日照辐射响应仿真算法。结合实际工程资料，通过全过程、多工况对比仿真，探究水工混凝土结构施工期温度场日照辐射响应特性，完善水工混凝土施工期温控理论，为强日照辐射地区水工温控防裂工作夯实基础。

日照辐射对施工期水工混凝土结构温度场有重要影响，尤其在高海拔地区，强辐射是施工期水工防裂工作所面临的重要挑战。传统研究只关注长龄期混凝土日照辐射吸热特性，所建立的辐射吸收率模型无法体现混凝土早期表面特性变化的影响，且常规施工期日照辐射响应仿真忽略表面特性变化、仅依赖温度场计算，亟待改进；上述基础研究的不足，导致施工期温度场日照辐射响应特性研究不够深入，影响了强辐射地区防裂工作质量。为此，本项目从混凝土早期表面日照辐射吸收率试验入手，研究表面相对湿度、表面类型等因素对日照辐射吸收率的影响，初步建立了混凝土早期日照辐射吸收率模型，并将其引入温湿耦合仿真计算中，提出考虑表面特性变化的结构施工期温度场日照辐射响应仿真算法。结合高海拔地区实际工程混凝土墩墙资料，通过全过程、多工况对比仿真，探究水工混凝土结构施工期温度场日照辐射响应特性，完善水工混凝土施工期温控理论，为强辐射地区水工温控防裂工作夯实基础。