Experimental Study And Analysis On Shear Strength Of The Self-insulating Structural Wall With Inner Frame

With the in-depth conduction of wall material reformation, solid clay brick gradually retreats from the constructional materials market. Concrete hollow blocks gain much attention, especially are widely used in the new rural construction for these advantages, easing to use local materials, low cost, energy conservation and waste utilization. The block masonry structure will have been the main structural style of town construction for a long time. However, the stipulation about the reinforced masonry members subjected to local compression in the existing code for design of masonry structures is established on the basis of the solid clay brick. While in such development background of the widely-used of multi-hole energy-efficient building blocks, and the universally setting of larger bays and big openings in the town buildings, the study on reinforced masonry members subjected to local compression of new-style concrete hollow block masonry has the significant epochal character and necessity.Through the application of experimental verification method, theoretical derivation method and numerical simulation method of finite element analysis, this paper mainly studies the following key subjects on the local compression test of energy-saving and load-bearing block masonry, the load carrying mechanism, the failure pattern, the stress diffusion, and the transformation law of bearing capacity of wall which is at the end of beam under the multi-factors conditions, and further improves the system of self-insulating structural wall with inner frame.Summarized as follows:First of all, through the compressive strength experiment of energy-saving and load-bearing block masonry, this study has revealed the compressive stress mechanism and the failure law of block masonry. And at the same time, combining with the given calculating formulas for compressive bearing capacity by the code and the test results, this study also gives a good account of the calculating formula for compressive strength of the grouted block masonry and the non-grouted block masonry, to meet the engineering requirements, and further meets the demand of engineering.Furthermore, by means of carrying out the experimental study on partial uniform compression of energy-saving and load-bearing block masonry, this paper discloses the three stages of the destruction of local compression, and the failure pattern. Moreover, combining with the failure process and the structure characteristics of the energy-saving and load-bearing blocks, this study has explained the working mechanism of the local compression of masonry which locates in the edge of the wall from the aspects of the transitive function of stress distribution and the stress diffusion. According to the measured data of the experiment, the cracking load and the ultimate load of the blocks which are compressed locally are figured out. By means of the model which is about the increase coefficient of local compression bearing capacity, the calculating formula is achieved by matching the regression curve. Compared with the coefficient of 0.35 in the code, the fitting formula adopts 0.2, which can be regarded as a security coefficient for guiding the engineering application. And then through drawing the curve of load-strain relationship which concerns the local compression position and the non-local compression position, at the same time analyzing the deformation results and the strain regularity, the deformation characteristics and laws of energy-saving and load-bearing blocks with the impact of vertical load. In addition, due to the energy-saving and load-bearing blocks are the multi-hole blocks whose internal holes are inconsecutive, so the built-in thermal insulation materials- straw compressed block can increase the area of the horizontal mortar joint, have a very good connective effect, and to some extents enhance the local compressive strength. But for the practical engineering which demand the high reliability of structure, the holes in the position of local compression still need to be filled in full, to ensure the safety of the project.Finally, the conduction of study on local non-uniform compression of the wall that locates on the edge of the beam through applying the finite element software ABAQUS, has figured out that different core column distance has different impacts on the change rule of the bearing capacity of the wall and the stress diffusion. Reveal the presence of beam end constraints, different core column spacing and floor load on the bearing capacity of the wall change rule and the influence of stress diffusion. Through model analysis of stress nephogram, beam end wall around the edge contact position easy to appear the phenomenon of stress concentration, the maximum stress and strain have appeared in this area, with the increase of the depth of the wall spread weakened gradually, until the steady, stress and displacement in force in the process of diffusion model, down along the arc to pass before they spread. So strengthen the density of the core column distance can effectively support upper transfer stress, and further improves the bearing capacity of the wall significantly. In addition, it can be found that the increase of the local compression of energy-saving and load-bearing blocks which is caused by the uniform compression stress of the upper beam under the function of "unloading arch" is not obvious. Therefore, when calculating the local compressive strength of the beam, its beneficial effects can be ignored.With the financially support of Shandong Province Science and Technology Development Program(2012GNC11401), this research carries out the study from the local uniform pressure experiment of energy-saving and load-bearing blocks to the non-uniform compression numerical simulation experiment of the wall which locates in the end of the beam. And combining with the previous thermal insulation properties testing of self-insulating structural wall with inner frame, the axial compression test of wall, and the numerical investigation of anti-seismic property and so on, the present study has provided the theoretical basis and safety instruction for the popularization and applications of self-insulating structural wall with inner frame system.