Microscopic Numerical Simulation Analysis Of Recycled Concrete

Recycled concrete is generally considered to be composed of five-phase materials,which is more complicated than ordinary concrete.Different numerical models are used and the test conclusions are often different.In order to be more in line with the actual situation,in the paper uses a random aggregate model to examine the plastic damage of recycled concrete and the effects of various phase components on the mechanical properties of recycled concrete from a meso level.This article describes the numerical model theory and plastic damage theory of concrete.The plastic damage of recycled concrete is to study the meso-defects,cracks,and destruction of recycled concrete,which can better study the destruction mechanism of recycled concrete.Through the Python programming language and the script file in Abaqus,the automatic generation of the mesoscopic numerical model of the two-dimensional recycled concrete can be achieved to achieve the randomness of the aggregate model.This article introduces the theory of random generation and interference placement of round,ellipse and convex polygonal aggregates.The search algorithm of elliptical aggregates is used to convert the interference judgment between aggregates to the point-toaggregate distance maximum value problem.The random point method is used to generate random points on the basis of round or elliptical aggregates,and the area invasion method is used to determine the interference of convex polygonal aggregates.The filling rate of convex polygonal aggregates can reach more than 70%.use a transition layer toensure calculation accuracy speed up calculation.The results showed that the aggregate shape of recycled concrete has an effect on the tensile and compressive properties of recycled concrete,plastic damage is first generated at the old interface.Under uniaxial compression load,the shape of the aggregate is closer to round,the compressive strength is greater.New and old mortars have a greater impact on the mechanical properties of recycled concrete,followed by new and old interfaces,and coarse aggregates have little effect.The damage of recycled concrete is mainly distributed in the left and right parts of the aggregate,and the whole presents an inverted V-shaped damage zone.The conclusions obtained by variable parameter analysis are consistent with uniaxial compression.The research conclusions obtained in this paper play a theoretical role in the development and utilization of recycled concrete.