Prediction Of The Elastic Modulus Of Recycled Concrete

In recent years,the use of recycled concrete has,to a certain extent,relieved the increasingly serious environmental problems in our country.The elastic modulus is an important mechanical index for the design concrete structures.Further study of the elastic modulus of recycled concrete will help to promote the practical application of recycled concrete.The prediction of the elastic modulus of recycled concrete through theoretical methods can not only save a lot of manpower and material resources,but also reduce the influence of the laboratory environment and human factors.Based on two methods: theoretical analysis and numerical simulation,this paper discusses the quantitative relationship between the macro sacopical performance and mesostructure of recycled aggregate concrete,which provides a theoretical basis for the optimization design of recycled concrete.First,based on the mesostructural characteristics of recycled concrete,a five-phase composite circle model is construted.By considering the content and mechanical properties of each phase and the interaction among various phases,an analytical solution of the elastic modulus of recycled concrete is derived based on the theory of elasticity.The analytical solution is compared with the experimental and numerical simulations obtained from the literature,and it is confirmed that the analytical solution is of higher accuracy.Second,based on the simulation of the distribution of polygonal aggregates in recycled concrete,the equal-distance pixels are selected on the reconstructed recycled concrete model.Combined with the FFT algorithm,a numerical method is discussed for predicting the elastic modulus of heterogeneous materials and the elastic modulus of recycled concrete is evaluated.Through comparison with the analytical solution and experimental results obtained from the literature,the validity of the numerical method is verified.Finally,based on the analytical solution and numerical results,the main factors that affect the elastic modulus of recycled concrete are discussed.