非规则再生骨料建模及再生骨料混凝土数值模拟OACSTPCD

Traditional recycled aggregate concrete(RAC)models mostly use basic geometries to represent recycled aggregate(RA)structures,which is quite different from the actual situation.In this paper,a real two-dimensional aggregate database was constructed by combining digital image technology and Fourier descriptor method,and a new method for random generation of RA based on aggregate overlap method was proposed.A new rapid placement algorithm suitable for Fourier reconstituted aggregate was proposed based on the coarse determination of the outer rectangular box/inscribed circle and the fine determination based on the overlap box.And the construction of RAC meso-structure with different RA substitution rates and RA residual mortar content was realized.Based on the cohesive zone model,a numerical model was established based on the meso-structure of randomly generated RAC,and the effects of RA substitution rate and RA residual mortar content on the uniaxial tensile performance of RAC were studied.The results show that the tensile strength and elastic modulus of RAC decrease with the increase of RA substitution rate and RA residual mortar content,but the peak strain does not change much.The RA model is more realistic,and the content and distribution of adhesion mortar can be adjusted independently.