Experimental Study On Mechanical Properties Of The Matrix Material Of Autoclaved Aerated Concrete Under High Speed Impact And Triaxial Stress

Autoclaved aerated concrete(AAC)has the advantages of light weight,thermal insulation,sound insulation and so on,which is widely used as filler wall and external insulation wall of buildings.At the same time,the load caused by explosion wave has the characteristics of high amplitude and obvious impact effect.The building components in the explosion wave are subjected to strong dynamic load,which makes the building materials in a complex stress state.In order to obtain accurate and efficient material model of autoclaved aerated concrete(AAC)and to quantitatively analyze the damage characteristics of autoclaved aerated concrete masonry structure under various explosions,it is necessary to obtain the material model of autoclaved aerated concrete matrix first.However,there is a lack of research on the mechanical properties of autoclaved aerated concrete.Therefore,in this paper,the mechanical properties of autoclaved aerated concrete matrix materials under high-speed impact and threedimensional stress state are studied.The research is carried out from the following four aspects:(1)Preparation and dimension design of autoclaved aerated concrete matrix material.(2)The static compression test,elastic modulus and poisson’s ratio measurement and splitting test of the matrix material of autoclaved aerated concrete are carried out.The failure mode and stress-strain curve of the material are analyzed,and the mechanical performance parameters of the matrix material of autoclaved aerated concrete are given.(3)The high-speed impact test of autoclaved aerated concrete matrix material is carried out.The mechanical properties and failure mode of the material under dynamic load are studied.The failure mode and stress-strain curve of the material under different strain rates are analyzed.The mechanism of strain rate sensitivity of compressive strength and splitting tensile strength of autoclaved aerated concrete matrix material is revealed.The compression and tension of materials are given The fitting formula of dynamic magnification factor is given.(4)The effect of confining pressure on the strength and deformation of autoclaved aerated concrete matrix materials was studied by conventional triaxial compression tests.The failure modes and stress-strain curves of materials under different confining pressures were analyzed,and the compression meridian and state equation fitting formula of materials were given.