Finite Element Analysis Of Compressive Properties Of Small Single-Row Hollow Block Masonry Wall Of Recycled Coarse Aggregate Concrete

Masonry structure has been widely used in China,but the traditional concrete materials can not meet the requirements of environmental protection,energy saving and carbon reduction.Therefore,the implementation of the innovation policy of block masonry materials and the development of new green wall materials with economic benefits and social effects are responding to the national concept of green social development in the new era of "green water and green mountains are golden mountains and silver mountains".Among them,recycled concrete materials have the advantages of simple materials,wide sources and relatively low cost.At the same time,it can process and recycle waste construction waste to achieve the social goal of green environmental protection and emission reduction.Therefore,it has gradually become one of the emerging green wall materials.It is of great value and significance to study the application of recycled concrete in masonry structure.In this paper,the finite element model of the reclaimed coarse aggregate concrete block wall was established by using ABAQUS software,and the compressive performance of the reclaimed coarse aggregate concrete block wall with the block strength grade of MU10 was studied.The main research conclusions are as follows:(1)The finite element models of Ordinary Concrete Hollow Block Masonry(OCHBM)and recycled coarse aggregate concrete hollow masonry are established respectively,and the simulation results are compared with the experimental results.The results show that: The failure morphology of OCHBM finite element model is consistent with the experimental results,and the constitutive curve is well fitted.(2)Simulation of Recycled Aggregate Concrete Hollow Block Masonry(hereinafter referred to as RACHBM)under axial compression.Combined with the damage cloud map of masonry and the distribution of plastic strain,the representative working conditions of RACHBM under axial load in the whole time period were analyzed,and finally the load-displacement curves of RACHBM with different regenerated coarse aggregate inclusion(RAC)were obtained.The simulation results show that the displacement-load curve of masonry under axial compression is also composed of ascending and descending sections,similar to that of ordinary masonry.Its failure mode is different from that of common masonry with crack development,but all of them show strength failure.If other factors remain unchanged,the bearing capacity of masonry will weaken with the increase of RAC.Compared with OCHBM,the bearing capacity of RACHBM will decrease by 28% at most,which proves that the compressive strength of blocks is the most important factor affecting the compressive performance of masonry to a certain extent.Finally,the axial compression capacity of all replaced masonry is verified by the relevant formula of the national code.The results show that the bearing stability of RACHBM meets the requirements of the national code standard.(3)Simulation of RACHBM under eccentric load.The simulation results show that RACBM is brittle without warning under eccentric load in long axis direction.The eccentric compression in the short axis direction will greatly reduce the eccentric bearing capacity,which is unfavorable to the application of the block.The differences and similarities between RACHBM and OCHBM under eccentric load were analyzed by using the deflection load curve.The results show that the vertical deformation compression side of the eccentric compression specimen is greater than that of the tension side during the whole load process,and the compression amount of the upper part is smaller than that of the lower part.The displacement value of the compression side increases with the increase of RAC.It shows that with the increase of RAC,the tensile strength of recycled concrete is weakened more seriously than that of compressive strength,which makes the tensile stress resistance of all replaced concrete weak.Always the concrete on the tensile side is pulled apart first,and then the concrete on the compressive side is crushed.