Shear Strength Of Masoniy Mortar In-situ Pull-out Method Research

Masonry is a combination of brick and mortar, mortar strength directly affectsthe overall strength of the masonry, so the detection of mortar strength plays animportant role in the assessment of the quality of structural masonry construction,housing inspection, reinforcement and reconstruction. Herein, we comprehensivelystudy the status and the development trend of the basic theory of masonry structure, toanalyze the pros and cons of existing masonry strength detection method, alsoconsidering the project needs, based on the strength of the existing detection theory,and through improvements of existing methods, proposed a new method for the shearstrength of the mortar in-situ extraction method, in addition, we put forward a newmethod for the detection of low-intensity mortar, and summarizes the characteristicsof the method as well as the applicable conditions. Then propose the appropriate stepsand conversion formula of mortar shear strength test for the method. According to theexperimental requirements, we design and produce a set of in-situ extraction devicethat can visually detect mortar shear strength. UsingANSYS software for the finiteelement analysis of gear bearing parts, to prevent the device damage caused by excessload.The in situ extraction method in this paper proposes a combination of in situdouble shear method and launch method, using the theory of the in situ double shearmethod that dig the mortar joint to release additional stress suffered by the point. Todetermine the specific relationship between the hollowed-out mortar joint andpressure stress. This paper, based on the failure modes of masonry structure andmaterial properties, to divide the masonry into masonry units, mortar joint units aswell as the connecting unit, then set up separately limited element model. And toestablish the constitutive relation and failure criteria based on different attributes ofeach material. Then on the basis of the established separate model, to do the finiteelement analysis for the emptied masonry mortar joint after a certain length by usingtheANSYS software, then the finite element results compared with the test.At last, combination with the practical engineering error concluded the length of mortar jointsthat should be emptying within the range of different intensity.To make it easier to meet the engineering need, this paper finally optimize theexisting pull-out device design, mainly optimized for the below three parts--shape ofequipment support, cross section area and the jack, the purpose is to reduce the overallweight of the equipment as soon as possible under the allowable stress of work. Thepurpose is that in the guarantee of under the allowable stress of work, as soon aspossible to reduce overall weight.Finally, for the mortar joint intractable problem,re-propose a new program, that is below the fourth floor stairwell window opening atselect brick specimens and analyzed by software vertical stress, given the appropriatecorrection factor calculated shear mortar capacity.