Experimental Study On Seismic Performance And Seismic Vulnerability Analysis Of Regenerated Concrete Brick Composite Wall Under Acid Atmospheric Environment

Masonry structure is a building structure which has a long history. It has a very wide range of applications in our country and even in the world. Since the reform and opening up, with China’s rapid economic development, environmental pollution inevitably results in the problem of acid rain, and acid rain on the building damage has become one of the arch-criminal premature retirement of buildings in china. With acid rain’s deep corrosion degree for masonry structure, the overall structure’s bearing capacity declines and its use function reduces, which seriously affects the durability of masonry structure. Therefore, study on the degradation performance of masonry structure under acid rain is imperative.This paper designed and produced 8 kinds of recycled concrete composite walls under different degrees of acid rain corrosion experiments with manual simulation method. Then studyed the effect of acid rain on the seismic performance of recycled concrete brick composite wall through the cyclic loading experiments of the walls under different acid rain corrosions. The compare result of the experiment shows that with the increase of the test pieces by the extent of corrosion of acid rain, the cracking load and ultimate load of the test pieces showing a downward trend in the overall, and the cracking displacement and ultimate displacement showing a generally increasing trend.The initial stiffness, ductility and energy dissipation capacity of the test pieces become worsen. Then, this paper analysis the masonry walls performance degradation principlein the micro and macro aspects. From the micro point of view, with the erosion of acid rain, the density of the continuous strengthening of mortar and brick expands until it reaches saturation damage and produce micro cracks, reducing the strength of the mortar and brick. From the macro point of view, the acid rain makes the cement surface of mortar and bricks more prone to micro-cracks, and even dissociate the adhesive surface, making its shear strength decline.On the basis of experiments, this paper modified the ultimate load calculation formula of the masonry walls with structural columns, and the test values of this paper and other domestic literature were compared. The compare result shows that the formulas in this paper have good accuracy. After that, this paper introduced Lu-Qu restoring force model and its provisions on the parameters of masonry structures and correct some parameters. Then, build the damage restoring force model of masonry structure based on damage theory. Utilizing three spring elements model finite element simulation with MARC Finite element software. The material degradation characteristics of masonry structures can be considered in Lu-Qu restoring force model based on damage theory,and three spring element simulation the behavior of masonry members have a good degree of accuracy.At last, this paper select a typical in-service masonry structure building and structural finite element modeling software. After that, the Finite element model of different pieces of the wall were classified, and fed into the Lu-Qu restoring force model based on damage theory for all the walls. Then, select 12 seismic wave based on the principle of select seismic wave and conducted IDA analysis for the structure. Finally, the seismic vulnerability curve of structure under different damage state were conducted.The vulnerability analysis result shows that with the increase in the degree of structural damage, the exceedance probability in each limit damage state increases. The results can provide a theoretical basis for the structure seismic performance evaluation of existing masonry.