不同类型混凝土冻融循环超声波损伤模型研究

摘要

For ordinary concrete,steel fiber concrete and steel fiber reinforced concrete with slag and fly ash were fast freeze-thaw experiment,the effects of different types of concrete freeze-thaw damage apparent characteristics,analyzed the mechanism in the process of freezing and thawing of steel fiber and slag fly ash in concrete.By fitting analysis of experimental parameters was established the dynamic elastic modulus and ultrasonic wave velocity as the variables of concrete freeze-thaw damage model.The experimental results show that steel fiber can improve the concrete frost resistance;fly ash can improve the impermeability of concrete,slow in the process of freezing and thawing loss of its quality;by comparing the experimental data analysis the high precision of the damage model with ultrasonic velocity as the variable,the data detection is convenient and quick,and the specific dynamic elastic modulus method is more suitable for the evaluation of freeze-thaw damage in the actual work.%对普通混凝土、钢纤维混凝土和矿渣粉煤灰钢纤维混凝土进行了快速冻融循环试验,研究了不同类型混凝土冻融循环破坏的表观特征,分析了钢纤维和矿渣粉煤灰在混凝土冻融循环过程中的作用机理.对试验参数进行了拟合分析,建立了以动弹性模量和超声波波速为变量的混凝土冻融损伤模型.试验结果表明:钢纤维的掺入可以有效地提高混凝土抗冻融能力;粉煤灰可以改善混凝土抗渗性能,减缓其在冻融过程中的质量损失;通过试验数据对比分析发现,以超声波波速为变量的损伤模型精度高,数据检测方便快捷,比动弹性模量法更适用于实际工作中的冻融损伤评估.