Experimental Research on Tensile Performance of Chemical Anchor Bolt Groups under Repeated Loading after Freeze-Thaw Cycles

In order to analyse the tensile performance of chemical anchor bolt groups under repeated loading after freeze-thaw cycles, 4 groups of 12 chemical anchor bolt groups specimens were designed and fabricated, and the chemical anchor bolt groups specimens subjected to different freeze-thaw cycles tensile test under repeated load,we analyze its failure form, load-displacement curve, skeleton curve and stiffness degradation curve. The test results show that freeze-thaw cycles will cause damage to the concrete of the test block, and repeated loading will damage the bonding surface of the chemical glue and concrete; due to the repeated load, the load-displacement curve of the test piece will appear dense first and then sparse; the number of freeze-thaw cycles increases from 50 to 100, chemical anchoring The peak load of the bolt group anchor specimens decreased by 9.36%; the number of repetitive loads increased from 10 to 20 times, and the peak load of the chemical anchor bolt group specimens decreased by 10.78%; compared with the chemical anchor groups test without freeze-thaw cycles Compared with the test pieces, the initial stiffness of the chemical anchor groups after 50 freeze-thaw cycles decreased by 7.79%, and the initial stiffness of the chemical anchor groups after 100 freeze-thaw cycles decreased by 14.71%; the initial stiffness of the effect of melting cycle on the tensile performance of chemical anchor bolt groups is greater than repeated loading.