冲击荷载下橡胶混凝土道面应变响应研究

A study on strain response of rubberized concrete pavement under impact loading

为阐明冲击荷载作用下橡胶混凝土道面的应变响应,基于光纤光栅应变计和重型落锤式弯沉仪(heavy weight deflectometer,HWD),设计了一种道面冲击应变响应的测试方法。通过该方法,对比分析了冲击荷载下橡胶混凝土道面与普通混凝土道面的应变响应差异,并通过监测不同尺寸的橡胶混凝土道面,研究道面板尺寸对应变响应的影响。试验结果表明:相较于普通混凝土道面,橡胶颗粒的加入改变了冲击荷载下道面的应变响应分布,使混凝土道面板中的水平应变均减小,而板边、板角的水平纵向应变增加;并且随着板长增加,橡胶混凝土道面板中、板边、板角处最不利应变响应方向的应变逐渐增加,其中板角处纵向应变增加最快,即道面板长增加将使橡胶混凝土道面冲击荷载下的最不利位置和方向从板边横向转移至板角纵向,因此在大尺寸橡胶混凝土道面设计与建造中,板角应变也应被考虑。

To clarify the strain response of rubberized concrete pavement under impact loading,a testing method of strain response under impact loading was designed based on a fiber Bragg grating strain sensor and a heavy weight deflectometer(HWD).With this method,the differences in strain response between rubberized concrete pavement and ordinary concrete pavement under impact loading were compared and analyzed,and the effect of pavement size on the strain response of the pavement under impacting loading was investigated by monitoring different sizes of rubberized concrete pavement.Test results show that the addition of rubber particles changes the strain response distribution of concrete pavement under impact loading compared with ordinary concrete pavement,so that the horizontal strain in the concrete pavement decreases while the horizontal longitudinal strain at the edges and corners increases.Moreover,with the increase of the length of the pavement,the strains in the most unfavorable strain response directions of the rubberized concrete pavement at the center,edge and corner gradually increase,among which the longitudinal strain at the corner of pavement increases the fastest.In other word,the increase of pavement length will transfer the most unfavorable position and direction of rubberized concrete pavement from the transverse direction at the edge of pavement to the longitudinal direction at the corner of the pavement.Therefore,the strain at the corner of the slab should also be considered in the design and construction of large size rubberized concrete pavement.