Experimental Research On Seismic Behavior Of Masonry Wall With New Self-thermal Insulation Concrete Blocks

In cold northeast region, the thickness of masonry wall usually reaches 490mm or more to meet the requirement of comfort. Previous research invented a new kind of self-thermal insulation concrete block which has five rows with EPS insulation board and of which the thickness is 280mm. The heat transfer coefficient of the block is 0.31W/(m2·K) and 0.39 W/(m2·K) which its strength grade is MU3.5 and MU5.0. The new block not only meets the need of current building energy conservation in cold northeast region, but also extremely reduces the thickness of the wall, which can save materials and increase the use area of building. Therefore, this new block has great developing prospect and great economic value.A series of experimental and theoretical studies is presented in this paper. which contributes to the promotion of the new blocks.The experiment of 4 full scale specimens under cyclic loading was carried out in order to study the seismic performance of the new block masonry wall. The main factors are constructional column and window. It turns out that constructional columns can effectively delay the development of cracks and make the crack distribution more uniform and fine, while the cracks in the wall with window are more concentrated and show a certain brittle failure. In addition, constructional columns not only greatly improve the cracking loads and the ultimate loads of the wall, but also improve the seismic performance of walls, such as deformation, ductility, energy consumption, stiffness degradation and so on, while the window obviously weakens the shear capacity and seismic performance of walls.Based on the previous study, since the presence of holes in the new block, mortar strength should be adapted to the concrete base material strength of blocks. Experimental results show that when the strength of mortar is improved from 5MPa to 10MPa to adapt to the strength of 5MPa of the new block, the shear capacity formula of specification is applicable to the new block masonry walls as well and greatly improves the shear capacity of masonry walls which provides a reliable basis for specification to amend.The shear capacity of the two-story masonry structure with the new self-thermal insulation concrete blocks without constructional columns can meet the requirements of seismic capacity when the seismic intensity is not higher than seven degree (0.1 Og). The constructional columns should be set up as L-shaped concrete blocks for constructional column template when the seismic intensity is seven degree (0.15g) and eight degree (0.2g). In practical projects, constructional columns are suggested to be set up in new self-thermal insulation concrete block masonry wall to improve the seismic its performance such as ductility, energy consumption and so on.