Elasto-plastic Damage Analysis Of Partially Leached Concrete Structures

Concrete structures immersed in a soft water environment for a long time are subjected to leaching damage,causing deterioration in the mechanical properties of concrete or even failure.This seriously affects the durability and safety of concrete structures.Therefore,it is of great theoretical significance and practical value to study the mechanical properties of partially leached concrete structures.According to concrete damage theory and elasto-plastic mechanics,two damage variables are selected to define concrete damage.Based on the irreversible thermodynamic constitutive model of concrete and the experimental results on the mechanical properties of leached concrete,an elasto-plastic damage constitutive model of partially leached concrete is constructed.Finally,by combining the Fortran language with the finite element software ABAQUS,the mechanical properties of ordinary concrete and partially leached concrete structures are simulated.From this study,the main conclusions can be made as follows:(1)In discussing the constitutive model of concrete,the coupling effect between the plastic deformation and damage is considered.The shear and tensile damage variables are introduced to define two different types modes of failure of concrete,which can better describe the mechanisms of plastic deformation and damage and meet the basic framework of thermodynamics.(2)The elasto-plastic damage constitutive model of concrete is applied to the mechanical analysis of concrete under uniaxial compression,uniaxial tension,and biaxial stresses.The simulation results are in good agreement with experimental results,which shows the validity of the model.The model is further applied to the mechanical analysis of a reinforced concrete column under compression and a shear wall.The simulation results are in good agreement with experimental results and the model can better describe the softenning characteristics of concrete structures.(3)Deterioration models of elastic modulus,compressive strength,and tensile strength of partially leached concrete are proposed.Numerical simulations show that the mechanical properties of partially leached concrete,such as elastic modulus,compressive strength,and tensile strength,are correlated linearly to the degree of leaching damage.(4)The model has few parameters and quicker convergence.It can more accurately describe the stress-strain relationships of concrete under uniaxial compression,uniaxial tension,and triaxial compression before and after calcium leaching,which provides a reference for the analysis of leached concrete structures.(5)Compared with ordinary concrete,partially leached concrete under various stresses exhibits a decreased strength and an improved deformation capacity,and with the increase of degree of leaching,the load-deformation curve of concrete becomes more and more flat.