不同种类混凝土冻融循环后双轴压压统一强度准则

针对混凝土遭受冻融循环作用后强度降低导致寒冷地区混凝土结构耐久性和安全性不足的问题,基于已有的大量试验数据,以混凝土冻融损伤后的单轴抗压强度衰减规律为参数,对不同种类混凝土建立了考虑冻融循环次数影响的双轴压压统一强度准则,并与前人试验研究结果做了对比分析。结果表明,本文建立的统一强度准则能较好地预测混凝土冻融循环后的双轴抗压强度,为寒冷地区混凝土结构的安全性分析提供了参考。

Unified Strength Criterion for Different Types of Concretes under Biaxial Compression Subjected to Freezing and Thawing Action

The deterioration of concrete subjected to freezing-thawing action is considered as the major cause for the insufficient durability and safety of concrete structures in cold region. In this paper, on the basis of a large amount of test data, a unified strength criterion for different types of concrete under biaxial compression is developed to account for the damage induced by freezing-thawing. In this criterion, the relationship between uniaxial compressive strength and freezing-thawing action is chosen as a parameter in order to avoid the influence of concrete properties. Therefore, all the test data for different types of concrete can be analyzed together to determine the coefficients in the proposed strength criterion. Compared with the test data, the results show that the unified strength criterion established currently can present an acceptable prediction of concrete biaxial compressive strength after various freezing-thawing action, which provides reference for the safety evaluation of concrete structures in cold region.