粉煤灰混凝土早期热膨胀系数试验研究及预测模型构建

Experimental Study and Prediction Model Construction for Thermal Expansion Coefficient of Fly Ash at Early Ages

热膨胀系数是混凝土结构早龄期开裂计算的重要热学参数,对不同粉煤灰掺量混凝土早期热膨胀系数进行了试验研究,得到了混凝土早期热膨胀系数的变化规律,分析了粉煤灰掺量变化的影响机理,提出了考虑粉煤灰掺量变化的混凝土早期热膨胀系数预测模型。研究表明:粉煤灰掺量增加,混凝土早期热膨胀系数先增大后减小,且在掺量为30%时有最大值。研究结果可为混凝土结构早期开裂计算提供试验依据和参数选取。

Thermal expansion coefficient(TEC)is an important thermal parameter in cracking computing of concrete structures at early age.The TEC of concrete with different contents of fly ash at early age is studied by experiments.The change law of concrete's TEC is obtained.The influence mechanism of the fly ash contents on TEC of concrete is analyzed.The calculation model which considering fly ash contents of concrete’s TEC at early age is suggested.The results show that the early TEC of concrete increases first and then decreases when the fly ash content increased.It has a maximum value when the fly ash content is 30%.The results can provide experimental basis and parameter selection for the calculation of concrete structure cracking at early age.