Experimental And Explicit Fe Simulation Study On Size Effect Of Shear Strength Of Plain Recycled Concrete Beams

As more and more old buildings are being demolished,more and more waste concrete materials are being used.With the increasing awareness of recycling of building materials,more and more researchers in the field of construction engineering are paying attention to the research of recycled concrete components.In the building structure,the beam is a very common component,and the shear strength of the beam is a basic kind of mechanical performance,but it has a size effect.An in-depth study of this effect is conducive to the construction of the shear capacity formula of recycled concrete beams.In this paper,the size effect of shear strength of unreinforced recycled concrete beam with 100% coarse aggregate replacement rate was tested and simulated.In this paper,the static tests of six different sizes of recycled concrete beams were completed,of which four beams had a shear-span ratio of 2.45 and two beams had a shearspan ratio of 2.00.During the test,crack recording,deflection recording,and strain measurement were also carried out.First,it was found that the laws of crack development,deflection change,and strain change were similar to those of a general concrete beam.Secondly,the shear strength presented a significant size effect,which has a decreasing rule with increasing beam height.This paper completed the finite element simulation of the above-mentioned six test beams.In the simulation,the concrete used a kind of solid elements and the steel bars used truss element;the concrete used a kind of damaged plastic constitutive embedded in the Abaqus code model and the steel bars used elastic constitutive model;to avoid the nonconvergence of the implicit algorithm caused by concrete cracking or crushing,the explicit algorithm was chosen to capture the peak load points.The simulation results were in good agreement with the experimental results.In short,through the above research work,it was clear that the shear strength of recycled concrete beams without web reinforcement had a size effect,and the 3D explicit finite element method can better simulate the size effect of shear strength.