膨胀混凝土延迟膨胀损伤模型

Damage model for delayed-expansion of expansive concrete

以钙矾石为膨胀源的膨胀混凝土的延迟钙矾石在很大程度上影响混凝土耐久性。当得到充足水分和硫酸盐时,延迟钙矾石迅速生成,导致混凝土损伤。对该情形下的延迟钙矾石行为进行分析研究。根据膨胀混凝土延迟膨胀的特点,利用时间标志将膨胀混凝土延迟钙矾石损伤理论分段讨论。在此基础上,利用Fick扩散定律、损伤力学理论建立损伤模型,同时利用损伤力学及弹性力学对时间标志进行推定。

The delayed ettringite formation in the expansive concrete with ettringite as the expansive source has great impact on the durability of the expansive concrete.When there is plenty of water and sulfate,the delayed ettringite formation is rapidly generated,resulting in the damage of concrete.The behaviors of the delayed ettringite formation under the above situation were studied.According to the properties of delayed expansion of the expansive concrete,the damage procedure of the concrete owing to the delayed ettringite formation was separated into different stages by using time marks.On such a basis,a damage model was established by means of the Fick＇s diffusion law and the damage mechanics.The time marks were calculated based on the damage mechanics and the elastic mechanics.