Study On Mechanical And Thermal Properties Of Low-grade Magnesite Concrete Hollow Block Masonry

In recent years,blocks have become a substitute material for clay bricks and have been widely used in practical engineering.Low-grade magnesite concrete hollow block is not only a new type of wall material,but also a multi-purpose new building material.Especially for saving resources,protecting the environment,and promoting sustainable economic development it has far-reaching significance.Firstly,the deformation characteristics and failure mechanism of low-grade magnesite concrete block masonry under compression are mastered through the experimental study of two groups(totally 12)of axial compression specimens.After calculation,it is known that the utilization ratio of blocks in this experiment is 54.03% and 66.48% respectively,and the average compressive strength of compressive specimens is larger than the theoretical value..Therefore,the normal formula can be used to calculate the average compressive strength of such masonry.In addition,the failure characteristics and mechanism of low-grade magnesite concrete block masonry are analyzed through the experimental study of two groups(totally 12)shear specimens.The test results show that the average values of shear strength of low-grade magnesite concrete block masonry under two different strength mortars are 1.019 and 1.046 times the theoretical calculations respectively.It can be seen that the coincidence is good and the standard calculation formula is safe.Then,the finite element simulation software ANSYS is used to simulate and analyze the mechanical properties of low-grade magnesite concrete block masonry under axial pressure.The finite element analysis model of 590 mm × 190 mm × 1000 mm(length × width × height)is established.Then in the finite element analysis,appropriate assumptions are adopted,and the stress distribution map,deformation map,etc.of the masonry are calculated and analyzed.Through the finite element analysis,the weak part of masonry stress is at the top of masonry,At the same time,the error between simulation results and experimental results is 5.5% and 3.2%,which can provide some references for the improvement of masonry.Finally,the thermal calculation model of low-grade magnesite concrete block masonry is established,and the heat transfer coefficient of the masonry is tested.At the same time,the thermal inertia index of the wall is calculated theoretically.The test results of heat transfer coefficient of the masonry show that it meets the current standard of 65% energy saving in buildings and has the promotion value.