Experimental Study On Seismic Performance Of A New Block Wall Restrained By Assembled Monolithic Structural Columns

In today’s world,in the face of natural disasters,earthquakes can be defined as one of the most destructive natural disasters,especially for villages and towns.At present,the use of the existing cast-in-situ wall type constructional column constraints,to a certain extent,can improve the integrity of the wall and the seismic performance,according to a survey in our country towns and villages in remote regions such as southern xinjiang,nanjiangdue to the remote,the majority of rural buildings are not set the constructional column,even a small amount of set up post,but the reduction of construction quality is very poor,It can not play the role of restraining wall to improve the seismic performance of buildings.Secondly,in recent years,with the implementation of the national "stickiness restriction and consolidation prohibition",the country has paid more and more attention to the research and development of green building materials.In the past,clay bricks were mainly used as load-bearing structures of masonry structures in rural areas,but the use of clay bricks requires a large amount of resources.Therefore,this paper carried out relevant experimental studies by using desert sand autoclaved aerated concrete blocks developed by our research group.Based on the previous research of the research group,a series of studies are carried out in this paper focusing on the assembly of monolithic structural columns to constrain desert sand autoclaved aerated concrete block wall.The research contents are as follows:(1)Study on moisture content and durability of wall materials.In this paper,the water content of B06 grade desert sand autoclaved aerated concrete blocks and the durability of B06 grade desert sand autoclaved aerated concrete blocks coated with ethyl silicate(TEOS)were studied.The results show that: 1)when the water content is below 5%,the slope of the curve between the compressive strength and the water content is relatively high,which reflects that the compressive strength of the test block decreases relatively fast in this stage;When the water content is between 5% and 15%,the slope of the curve is relatively slow,indicating that the strength at this time tends to be stable gradually.When the water content is greater than15%,the compressive strength of the test block gradually stabilties at about 4.5MPa.2)As for the comparative analysis of durability of B06,B07 and B06 test blocks coated with TEOS,among the three types,B07 desert sand autoclaved aerated concrete block has the best durability,and its mass loss and strength loss basically meet the requirements of relevant codes.(2)Study on prefabricated blocks of prefabricated structural columns.In this paper,a new type of building material,gypsum base material,is introduced to fabricate the prefabricated block of structural column.The experimental results show that the prefabricated blocks have good mechanical properties in terms of bulk density and strength.(3)Experimental study on seismic performance of wall.In this paper,the vertical compressive stress and the structural constraints of the wall as the main factors,designed five new block walls with the constraints of monolithic structural columns.Through the test,a series of performance indexes of the wall,such as failure form and hysteresis curve,are obtained.The results show that for the same specimen,with the increase of vertical compressive stress,the bearing capacity of the wall is improved,the number of cracks in the wall is increased and the energy consumption of the wall is also improved,and the ductility coefficient of the wall is gradually reduced.The ultimate bearing capacity of precast concrete blocks is better than that of other walls.However,in terms of stiffness degradation and energy consumption,the WS-2 wall performed better than the other two walls.Secondly,the calculation formula of the shear capacity of the desert sand autoclaved aerated concrete block wall is obtained by using the existing test data,and the coefficient of variation shows that the formula can be used as the calculation formula of the shear capacity of the wall.In addition,the calculation formulas of the shear capacity under the two classical theories are compared and analyzed,and it is concluded that the principal tensile stress theory is more suitable for this kind of wall.(4)The establishment of the wall restoring force model.After the relevant summary,it is found that the three-fold line model is more suitable for the desert sand autoclaved aerated concrete wall.The model takes the vertical compressive stress and the constraint form of constructional column as the main factors,using the existing test data.The expression formula of unloading stiffness of the wall was determined,and the restoring force curve of the skeleton curve was compared with the test curve,and it was found that the two curves were in good agreement.Finally,the hysteresis rules and loading path of the wall are determined.