橡胶混凝土弯曲疲劳性能研究

Flexural Fatigue Performance of Rubber Concrete

为研究橡胶混凝土的弯曲疲劳性能,将粒径为0.54 mm的橡胶颗粒以不同掺量掺入混凝土中,制成橡胶混凝土试件进行轴压试验与轴拉试验,测其应力-应变曲线,计算出弹性模量和泊松比。进行四点弯曲静载试验及ABAQUS数值模拟,得到极限荷载、峰值挠度和荷载-挠度曲线,试验结果与数值模拟结果较接近,验证了数值模型的可靠性。使用疲劳软件Fe-safe分析等幅及变幅加载下橡胶混凝土弯曲疲劳寿命,结果表明:无论是普通混凝土还是橡胶混凝土,在等幅循环荷载下,应力水平越高,弯曲疲劳寿命越低;各掺量下橡胶混凝土的弯曲疲劳寿命都比普通混凝土的大,且橡胶掺量越多弯曲疲劳寿命越大;在变幅荷载作用下,随着橡胶掺量的增大,混凝土的弯曲疲劳寿命也越大;随着变幅等级增多,各掺量下橡胶混凝土的弯曲疲劳寿命均降低,且变幅等级越多,弯曲疲劳寿命越低。

In the aim of investigating the flexural fatigue performance of rubber concrete,we prepared rubber concrete specimens by mixing different dosages of rubber particles(particle size 0.54 mm)into concrete,and carried out axial compression test and axial tension test.According to the measured stress-strain curve we calculated the elastic modulus and Poisson’s ratio.Furthermore,we acquired the ultimate load,peak deflection and load-deflection curves via four-point bending static load test and ABAQUS numerical simulation.The test results were close to the numerical simulation results,verifying the reliability of the numerical model.Moreover,we analyzed the flexural fatigue life expectancy of rubber concrete under constant-amplitude loading and variable-amplitude loading by using software Fe-safe.Our findings demonstrated that both ordinary concrete and rubber concrete had a shorter flexural fatigue life expectancy at higher stress level under constant-amplitude cyclic loading.The flexural fatigue life of rubber concrete with any rubber dosage was longer than that of ordinary concrete,and the more rubber content,the longer the flexural fatigue life.Under variable amplitude load,the flexural fatigue life of concrete extended with the rising of rubber content;with the increase of the amplitude grade,the flexural fatigue life of rubber concrete shortened with the increase of amplitude grade.