冻融条件下矩形板式天然橡胶支座轴压性能

Compression performance of rectangle plate natural rubber bearings under the alternate freezing and thawing environment

为研究矩形板式天然橡胶支座在不同冻融循环次数情况下的轴压性能,利用冻融试验箱,首先对5个试件分别进行25次、50次、75次、100次和150次高低温交变冻融循环,然后对冻融循环后的试件进行轴压性能试验,对试验后的试件外观、极限承载力、极限抗压强度、竖向刚度和抗压弹性模量进行对比分析.实验结果表明:随着冻融循环次数的增多,矩形板式天然橡胶支座试件的变形越大,橡胶层开裂现象越严重,极限抗压强度和抗压弹性模量下降越快.利用试验结果和最小二乘法给出的极限抗压强度及抗压弹性模量的衰减模型基本符合指数函数规律.

The objective of this paper is to study the compression performance of plate natural rubber bearings for bridges under the alternate freezing and thawing environment. The five specimens are dealt with respectively in high-low alternating heat chamber for 25, 50, 75, 100 and 150 times and then conduct the axial compression tests on the five treated rubber bearings. The ultimate bearing capacity, ultimate compressive strength, vertical stiffness and compressive elastic modulus are analyzed. The results of tests show that the more times the specimens are dealt, the larger the deformation of the rectangle plate natural rubber bearing and the more serious the cracking phenomenon of rubber layer. The ultimate compressive strength and the compressive elastic modulus decreased seriously when the dealt cycle times of the rubber bearing specimen increase. The attenuation model of ultimate compressive strength and compressive elastic modulus given by using the experiment results and the least square method basically agree with exponential laws respectively.