不同粗骨料混凝土早期热膨胀系数试验研究

Experimental Study on Thermal Expansion Coefficient of Different Type Coarse Aggregates Concrete at Early Ages

混凝土早期热膨胀系数是影响混凝土早期开裂的重要参数。进行了不同粗骨料混凝土早期热膨胀系数试验研究,得到了混凝土早期热膨胀系数随龄期变化规律。试验结果表明,混凝土的早期热膨胀系数在实际初凝至实际终凝时快速下降,而后缓慢回升并逐渐趋于稳定;混凝土的热膨胀系数随着其骨料热膨胀系数的增大而线性增大。提出了考虑粗骨料种类影响的混凝土早期热膨胀系数计算方法,可供混凝土早期相关计算使用。

Thermal expansion coefficient（CET） of concrete at early ages is an important parameter in concrete cracking at early ages.In this paper,experimental study on CET of different type aggregates concrete at early ages was carried out,and then rules of change about CET and age were analysed.Test results indicate that the coefficient falls down quickly between actual initial setting and actual finally setting,and then the CET arises slowly and keeps stable at last.Test results also indicate that the CET of concrete increases when the CET of its corresponding aggregate increases,and there is a linear relationship between them.The calculation method about CET of concrete at early ages was proposed considering the influence of coarse aggregate type,which can be used for concrete calculation at early ages.