Experimental Study On Seismic Behavior Of Prestressed Small-sized Concrete Hollow Block Masonry

The basic national policy of "Protecting the land resource and the farmland" has been executed in our country in recent years.so the small-sized concrete hollow block has replaced the clay block gradually.and become one of the predominant materials in the reformation of wall material.The small-sized concrete hollow block is widely used in domestic construction.For the shearing-resistance of the block masonry is relatively low,it is a question for discussion that how to improve the cracking-resistance and earthquake-resistance of block masonry by effective ways.Prestressing the block masonry structure can not only change its material property,improve its cracking-resistance,shearing-resistance and earthquake-resistance, but also expand its application range.fulfill its development for tall-buildings,anti seismic and environmental protection.Based on foreign and domestic researches,this paper summarizes the research about cracking-resistance and earthquake-resistance of prestressed and non-prestressed small-sized conrete hollow block masonry walls under vertical upper load. The following is the primary content of the research:Design three walls to simulate the ones of the bottom floor of a building,and add low frequency cyclic static load to the 2 pieces of prestressed small-sized hollow block masonry walls and the 1 non-prestressed one. The experimental results show that prestressing the walls can greatly improve the cracking-resistance and earthquake-resistance of them. Some questions such as characteristic of resilience,skeleton curve,ductility,energy consumption are studied.The test results also indicate that the shearing-resistance,behavior of deformation and ductility of the prestressed walls are increased.and the prestressed walls are forced more uniformly while the material property are completely developed.Cracks are more slight and more dense,and will close after being unloaded while the prestressed walls will not fall apart with cracks.All these show clearly that the prestressed walls retain the entirety well and have good resistance for collapse.Adopt the finite element analysis software.and carry out the nonlinear finite element analysis of the prestressed and non-prestressed masonry walls under vertical upped load.The results indicate that the cracking-resistance of the prestressed walls are greatly improved.The failure mechanism and the pattern of damage are analyzed in this paper.Based on the test results and the theoretical analysis.the formulas of cracking-resistance capability and ultimate shearing-resistance capability of prestressed small-sized concrete hollow block wall are advanced.The paper also simply introduces some recommendations of design method and construction details of the prestressed masonry structure.