Meso-analysis Of Recycled Coarse Aggregate Self-compacting Concrete Based On Random Aggregate Model

At present,with the acceleration of urbanization,the accompanying construction waste is increasing,which not only seriously pollutes the environment,but also leaves many hidden dangers.After the construction waste is crushed and treated as coarse and fine aggregates in the concrete,it is recycled again,which not only effectively solves the problem of construction waste pollution,but also creates very considerable economic benefits.There are still many problems that cannot be solved through the macroscopic test and qualitative analysis of recycled concrete.Therefore,this article uses a meso-scale numerical simulation to analyze the basic mechanics of Recycle Coarse Aggregates Self-Compacting Concrete(RCASCC).Research and analysis of performance and mechanical properties of simply supported beams under bending,the specific content and conclusions are as follows:(1)Based on the shape and distribution of the coarse aggregate of the RCASCC specimen section,the random number is generated by Monte Carlo method,and the random distribution of the coarse aggregate in the three-dimensional space is transformed into the random distribution in the two-dimensional plane with the help of the Valavin formula.A statistically similar RCASCC random aggregate model;(2)Based on the RCASCC random aggregate model established by the above method,using ABAQUS finite element analysis software,the accuracy of the meso-scale numerical model is verified by simulating the prism compression test when the replacement rate of recycled coarse aggregate is 25%.The results show that the numerical results are consistent.The test results are similar,which confirms the reliability of the modeling method.The principle of this modeling method can be used to simulate and analyze other subsequent samples.The uniaxial compression test of RCASCC is simulated,and the change rule of the replacement rate of recycled coarse aggregate on the macro performance of RCASCC is analyzed.The analysis result shows that the failure form of RCASCC is similar to that of ordinary concrete,and as the replacement rate of recycled coarse aggregate increases,the strength The indicators generally show a downward trend.Among the replacement rates of 25%,50%,75%,and 100%,the basic mechanical properties of the recycled aggregate specimens with a replacement rate of 50% perform best;and are compared with the constitutive equation of ordinary concrete.Fitting,the control parameter value a is 0.9,b is 11;(3)Introduce the constitutive equation obtained from meso-level numerical simulation into macro-mechanical analysis,use finite element analysis software,and select the extended finite element method in numerical simulation to perform numerical simulation on the whole cracking process of test beams of the same specification to obtain the crack propagation Evolutionary process.Through numerical simulation,the evolution process and law of crack distribution during the failure process of RCASCC beam are gradually revealed,and the simulation results basically accord with the experimental results.