Experimental Study On Mechanical Properties Of Recycled Concrete Considering The Effect Of Aggregate Erosion Degree And Loading Parameters

With the rapid development of China's social economy,a large number of buildings demolition caused serious environmental pollution and waste of resources.Recycled concrete from construction waste is of great significance in alleviating waste pollution.Since recycled concrete and ordinary concrete have essential differences in mechanical properties,dynamic properties and physical properties,it is necessary to carry out further mechlanical properties tests of recycled concrete.This article applies the method of indoor test,the basic performance test of recycled coarse aggregate and recycled concrete under uniaxial compression test and triaxial compression test,mainly studies the aggregate erosion degree and the load parameters(including the confining pressure and strain rate)on the recycled concrete mechanics performance(including peak axial compressive strength,axial strain and the stress-strain curve).The research results show that:(1)Under the condition of uniaxial compression test,when the replacement rate of recycled aggregate is the uniform,reduced resistance to pressure of recycled concrete,the peak strain increases,the slope of the rising section of stress-strain curve decreases gradually,and the slope of the falling section is almost equal with the deepening of aggregate erosion;when the aggregate erosion degree is the same,the slope of recycled concrete increases with the replacement rate of recycled coarse aggregate.The compressive strength and peak strain decrease first and then increase.(2)Under triaxial compression test,when the water cement ratio is the same,the lateral pressure is incremental,both the strength and peak deformation is also incremental,the slope of the rising section of stress-strain curve remains unchanged,and the slope of the falling section decreases.When the confining pressure is the same,the water cement ratio is incremental,the peak deformation is also incremental,but the the strength is reduced.(3)Under the condition of dynamic triaxial compression test,when confining pressure is the same,the rate at which the load is incremental,the strength is also incremental,but the peak deformation does not change much,and the slope of the rising and falling sections of stress-strain curve does not change significantly;when the strain rate is the same,the lateral pressure is incremental,both the strength and peak deformation is also incremental.The research results in this paper can provide a theoretical basis for the application and promotion of recycled concrete,and have a certain reference value for future scholars to do similar research.