冻融-干湿耦合循环下粉煤灰混凝土损伤度分析

探讨不同掺量的粉煤灰混凝土分别在冻融循环损伤或干湿循环损伤单一因素作用下,以及冻融-干湿循环耦合作用下动弹模量及质量损失率的变化,分析冻融-干湿耦合循环效应与单一因素作用下的损伤关系.在此基础上,建立以动弹模量损失为指标的损伤度的概念,量化研究粉煤灰混凝土在不同的损伤方式下的损伤程度.研究结果表明:当混凝土的动弹模量达到相同的损伤度时,冻融-干湿循环损伤速率最快,是冻融循环的1.21倍,是干湿循环的3.58倍。

Analysis on the damage degree of fly ash concrete under freeze-thaw-dry-wet coupling cycle

The change of dynamic elastic modulus and mass loss rate of fly ash concrete with different fly ash content under the single factor of freezing-thawing cycle or drying-wetting cycle damage and the coupling between the freezing-thawing and drying-wetting cycle damage are discussed.On this basis,the concept of damage degree with dynamic modulus loss as index is established to quantify the damage degree of fly ash concrete under different damage mechanisms.The result shows that when the dynamic elastic modulus of concrete reaches to the same damage degree,the damage rate of coupling effect is the fastest,which is 1.21 times of freezing-thawing cycle and 3.58 times of drying-wetting cycle.