SHEAR TESTS OF PLAIN CHLOROPRENE RUBBER BEARINGS OF HIGHWAY BRIDGE UNDER FREEZE-THAW CYCLE CONDITION

The impact of climate is more serious to highway bridge rubber bearings than building rubber bearings. In order to study the change on the shear properties of plain chloroprene rubber bearings of a highway bridge affected by climate change, the changes of low-temperature climate are simulated by using a standard freeze-thaw chamber. The plain chloroprene rubber bearings are processed 25, 50, 75, 100 times, then the shear tests are carried. The shear carrying capacity, ultimate shear strength, horizontal equivalent stiffness, and elastic modulus of shear of plain chloroprene rubber bearings of a highway bridge under a freeze-thaw cycle condition are studied through the contrastive analysis. The results show that the plain chloroprene rubber bearings are more to failure under a freeze-thaw cycle than the standard sample. The exposure of a steel plate and cracks destructive phenomenon are more serious. The shear carrying capacity, ultimate shear strength, horizontal equivalent stiffness, and elastic modulus of shear of plain chloroprene rubber bearings decreased with freezing and thawing increasing. The decay curve and attenuation formula in 50 years of ultimate shear strength and the elastic shear modulus of plain chloroprene rubber bearings are developed by the least square method, and decay trends of ultimate shear strength and elastic shear modulus are approximately according with power function.