基于Logistic模型的混凝土冻融损伤演化规律

Evolution Law of Freeze-thaw Damage of Concrete Based on Logistic Model

为了更准确地描述混凝土在冻融循环破坏中的真实演化过程,首次将Logistic函数引入到混凝土的冻融损伤研究中,进行了不同水灰比下的混凝土、不同纤维的纤维混凝土的冻融循环试验。利用Logistic函数定量刻画两种混凝土的质量损失与相对动弹性模量的变化规律,并将理论分析与试验结果、现有文献进行对比,吻合较好。研究结果表明:不同水灰比、纤维类型和纤维掺量的混凝土的冻融破坏演化规律均符合Logistic函数所描述的发展规律,该模型能够对混凝土冻融破坏的演化规律进行准确预测。

For describing the damage process of concrete during freeze-thaw cycles,a new model based on the Logistic Function was introduced.Freeze-thaw cycle tests on concrete and fiber reinforced concrete were conducted to evaluate the influence of different water-cement ratios and fibers.The Logistic function quantitatively characterized the variation of mass loss and relative dynamic elastic modulus of concrete.Comparing theoretical analysis with experimental results and references,it was in good agreement.The results show that the freeze-thaw damage of concrete with different water-cement ratios,fiber types as well as fiber content is conformed to the law described by Logistic Function and the model can make an adequate prediction for the deterioration of concrete.