| Recycled ceramic coarse aggregate concrete is prepared by using waste ceramic particles instead of natural aggregates,and it is infused into two layers of round steel pipes to form round hollow sandwich steel pipe recycled ceramic concrete compression bending members,and the mechanical properties and working mechanism of these members are systematically studied from both experimental and theoretical aspects.A finite element simulation of this test member is carried out using the intrinsic relationship model of recycled ceramic concrete constrained by steel pipes,and the results are compared with the test results to provide some reference for the design of such members.Specifically,the following areas of work were carried out.(1)The water absorption rate of ceramic particles used in this test was tested,and the proportion of recycled ceramic coarse aggregate concrete prepared by replacing 100%of natural aggregates with ceramic particles was determined by considering the water absorption rate,and the test blocks of recycled ceramic coarse aggregate concrete were prepared and tested for compressive test as well as elastic modulus.(2)The eccentricity,concrete type(recycled ceramic concrete and normal concrete),length to slenderness ratio and hollow ratio were used as the parameter variables to conduct a total of 12 round hollow sandwich steel pipe compression bending members and 4 round hollow sandwich steel pipe compression bending members to analyze the deformation development process,damage pattern and the influence of different factors on the mechanical properties of the compression bending members.(3)The finite element simulations of this specimen were carried out using the principal structure relationship of recycled ceramic concrete constrained by steel pipe proposed by the group,and the results were compared with the experimental results,and the working mechanism of the compression-bending member was analyzed based on the finite element model.In addition,the effects of the two types of principal structure relationship between the normal concrete principal structure relationship model constrained by steel pipe and the recycled ceramic concrete principal structure relationship model constrained by steel pipe on the finite element simulation of the compression-bending members were also analyzed.(4)A parametric analysis of the compression-formed members was conducted to investigate the effects of seven influencing factors,namely ceramic coarse aggregate replacement ratio,length-to-fine ratio,eccentricity,steel content,recycled ceramic concrete strength,steel yield strength and hollow core ratio,on the load-deflection curve and N/N _u-M/M_urelated curves.And The sensitivity analysis of the influencing factors of ultimate bearing capacity is also made.(5)The ultimate bearing capacity of the specimens was calculated by the compression-bending equations proposed in the domestic hollow sandwich steel pipe concrete-related regulations and literature,and the differences between the calculation results of different regulations and literature were evaluated,and the calculation equations with smaller errors were selected to compare the N/Nu-M/Mu relevant curves with the finite element calculations to provide suggestions for the design of compression-bending members of circular hollow sandwich steel pipe recycled ceramic concrete. |
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