Test On Flexural Performance Of Masonry With No Mortar In Vertical Seam And Wall Crack Simulation

With the background of new wall materials developing rapidly,all kinds of new masonry blocks emerge in endlessly,of which there’s a kind of block with the side surface hole rate>50%or the side surface is the mortise and tenon form of the block,such blocks have the advantages of thermal insulation and heat insulation,but the plumpness of the vertical ash slit mortar made of its masonry can not meet the requirements of the standard.In addition,the temperature and dry shrinkage stress are easy to cause wall cracking.Based on this,this paper has carried out the related experiment and simulation research and analysis aiming to provide theoretical basis and engineering application reference for the research of new masonry blocks and wall cracks.The main contents are as follows:(1)The mechanical properties of the aerated concrete block,the special mortar and the basalt fiber grille used in the bending test of masonry are tested.The average tensile strength,splitting tensile strength and splitting pressure ratio of block are obtained,and the average compressive strength of mortar are obtained.The elongation at break of basalt fiber grille and the radial and zonal mechanical properties of basalt fiber grille are also obtained.(2)Respectively with vertical mortar joint with no mortar joints,block section form of vertical ash seam and horizontal mortar seam has no grid as variables,we conduct the flexural bending tensile test of masonry dentiform section.Comparing and analyzing the influence of all variables on the bending bearing capacity of the masonry especially when whether there is mortar at the vertical ash seam being a variable.And by analyzing the test data and combining the existing specifications,the masonry dentiform section flexural capacity calculation coefficient and suggested formula under each variable can be obtained.(3)Respectively with vertical mortar joint with no mortar joints,block section form of vertical ash seam and horizontal mortar seam has no grid as variables,we conduct the flexural tensile test of masonry along the cross section of the masonry.Comparing and analyzing the influence of all variables on the bending bearing capacity of the masonry especially when whether there is mortar at the vertical ash seam being a variable.And by analyzing the test data and combining the existing specifications,the masonry along the cross section flexural capacity calculation coefficient and suggested formula under each variable can be obtained.(4)Based on the idea of separation modeling,the interface contact criterion is introduced and simulated.The finite element software ABAQUS is used to simulate the development of the cracks under the influence of temperature and dry shrinkage stress on the masonry filling wall.The development state and law of wall cracks under the action of temperature and dry shrinkage stress are obtained,and the rationalization proposal for the connection between the masonry filling wall and the frame in the actual project is also put forward.