Research On The Effect Of Prestress For Behaviors Of Composite Masonry Walls Which Are Eccentrically Compressed

Composite wall, also known as "encrypted column masonry", is a centralized reinforced masonry generated from confined masonry. It is extensively applied in urban and rural construction as one type of "composite masonry". In current project,entire cast to columns and beams will necessarily intensify the eccentric compression of exit plane of composite walls. Chongqing University has studied on the eccentric compression of exit plane of single and multi-layer composite walls, including several test parameters which are: whether there are upper load and downward evenly transferring load, open-hole conditions and structural column spacing and so on. In addition, pre-stressing masonry has generally been utilized to improve the seismic performance of masonry structures, and is also applied in engineering. This paper introduces "centralized pre-stressing" method of pre-stressing tendons arranged inside of the structural columns proposed by Professor Luo Wankang, also combines pre-stressing force with compression of exit plans of composite walls based on previous studies, which has certain engineering significance. Through comparisons of four composite walls applied with different degrees of pre-stressing force, the paper studies its influence to eccentric compression performance of exit planes of composite walls ,including the following contents:①Introduced the development and research of composite walls, and expounded the purpose and content of this paper;②Making an introduction to the design, production, test equipment and loading program offour different pre-stressing composite walls in two models and carring out corresponding calculation of the test pre-stage;③Recording and describing the emergence and development of structural cracks, the deformation and failure modes of walls and other basic experimental phenomena;④With the analysis on the strain, deflection and displacement curve, probing into the influence of pre-stressing force wall to eccentric compression performance of exit planes of composite walls.⑤According to pre-stressing force transfer of eccentric compression of exit planes of composite walls, re-distribution and the ultimate failure mechanism in this test, adopting multi-frame models for calculation, taking the stiffness of section of composite walls based on the elastic modulus ratio of masonry and concrete into account, and also considering values of the width of section of composite walls on the basis of distribution relationship between the T-eccentric compression column flange and web pressure;⑥According to the test analysis and calculations of the tset, made a conclusions and recommendations of design.