混凝土冻融破坏机理分析及寿命预测

为提高高寒地带混凝土的耐久性,对混凝土的冻融破坏机理进行了分析,并对受到冻融破坏后的混凝土寿命预测方法进行了简介。分析表明,目前混凝土冻融破坏应用比较成熟的理论为静水压理论和渗透压理论,静水压理论和渗透压理论的主要区别就在于未冻水的迁移方向。混凝土抗冻性影响因素主要有水胶比、含气量、粗集料和掺合料。每种影响因素作用的机理不同,但都共同影响着混凝上在冻融环境下的耐久性。既有研究建立的混凝土冻融寿命预测方面还仅停留于理论层面,能够指导工程实践应用的寿命预测模型仍有待进一步研究。

Analysis of Concrete Freeze-thaw Failure Mechanism and Lifetime Prediction

In order to improve the durability of concrete in severe cold areas,the freeze-thaw failure mechanism of concrete was analyzed,and the lifetime prediction method of concrete after freeze-thaw failure was introduced.The results show that the most reliable theories currently applied to freeze-thaw failure of concrete are hydrostatic pressure theory and osmotic pressure theory.The main difference between hydrostatic pressure theory and osmotic pressure theory lies in the migration direction of unfrozen water.The main factors affecting the frost resistance of concrete include water-binder ratio,air content,coarse aggregate and admixture.Each of the influencing factors have a different mechanism,but they all affect the durability of the coagulation in a freeze-thaw environment.The freeze-thaw life prediction of existing concrete has only stayed at the theoretical level,and the life prediction model which can be applied in practical engineering needs to be further studied.