Experimental Study On The Test Of Masonry Walls Strengthened With CFRP Under Lowcyclic Loads

The brick masonry building due to its low cost is widely used in China’s industrial and civil construction and some masonry buildings is of high historical and heritage value. The shear, tensile and flexural strength of brick is low that reduce seismic performance. In the previous earthquake, the masonry structures’damage rate is very high, and the failure is serious consequences. In Wenchuan earthquake, the loss of lives and propety are stricking. Therefore the seismic strengthening of masonry structures research has great significance. CFRP as a newly arisen material construction material has been widely used in the reinforcement works. The theory and calculation method of masonry structures reinforced with remain unclear.According to the test of five brick masonry walls reinforced with CFRP under Low Cyclic loads,the ductility and the lateral-load-carrying capacity of brick masonry are investigated.The test result shows that the craccking loads,ultimate loads and deformabilities of the reinforced walls are improved and Hysteresis curves of the strengthened masonry walls are regular.The main factors and failure mode in effect of strengthening include the area location of CFRP and anchor conditions.The CFRP which is anchored by layering CFRP,its work permormance is improved and debonding failure is smothered.The strain distribution of CFRP shows that the stres of CFRP is an uniforn distrubution,the stress of CFRP which is nearer the crack is much higher than others.In the past, we think then the aspect ratio of brick masonry wall is less than1,the moment effect could be ingnined.However the failure modes proved the moment effects couldn’t be ingnined,if CFRP improved the ultimate loads of reinforced walls.This paper will try to put forward some views on some disputs in the current theory.The definitions of application limit to the current theories are inadequate and the current theories didn’t find the major infloencing factor to the stress of CFRP.The defined formula of the coefficient of CFRP stress is not given,neglecting the influences of the destroy forms on the stress of CFRP.Based on experimental and theoretical study, an analytical model and computing menthod is provided.The computing method concerned may be tentatively used in the reinforced design of masonry walls. The concept of reasonable computational model simulates the actual situation and the calculated result is in accord with experment.