Experimental Study On Basic Properties Of Recycled Concrete With Recycled Fine Aggregate Rich In Brick Particles

In this paper,in view of the lack of natural river sand and the reuse of brick-rich construction waste,some or all of the reclaimed fine aggregate prepared from waste concrete with natural river sand will be replaced,and the recycled coarse aggregate prepared by brick construction waste will replace the natural coarse.Aggregate,research on the basic mechanical properties of recycled fine aggregates rich in brick recycled concrete.The content of the thesis is combined with the study of the environment in Hebei Province,which promotes the comprehensive utilization of construction waste and is of great significance for sustainable development and the creation of civilization.The result of this paper provide favorable support for the further application of the field of recycled concrete in the region.Based on the research on the preparation and physical properties of the reclaimed coarse aggregates rich in bricks and recycled concrete,and the blending ratio of recycled fine aggregates rich in brick concrete,the paper uses recycled coarse aggregates and regenerated fine sets.Three kinds of water-to-binder ratio recycled concrete cubes and prisms were prepared,and the compressive strength test,static elastic modulus test,stress-strain test and ultrasonic damage detection of the recycled concrete under uniaxial compression were carried out.According to the results of the research and analysis,combined with the relevant domestic and foreign related materials,the practical engineering application suggestions are put forward.Main research content:(1)Through the compressive strength test of recycled concrete cubes and prisms,the failure characteristics of the test block under this condition are analyzed,and the influence of the change of the replacement rate of the recycled fine aggregate on the strength is studied.Based on the test,The relationship model among them is established.(2)The elastic modulus of recycled concrete is tested by standard method,simple method and ultrasonic non-destructive testing method.It studied the influence of the replacement rate of regenerated fine aggregate on the elastic modulus of recycled concrete,and the corresponding elasticity with the replacement rate of regenerated fine aggregate as the variable factor was obtained.Comparing the elasticmodulus calculation models obtained by the three test methods,the standard test method is slightly better than the other two test methods.(3)Studying the effect of the replacement rate of recycled fine aggregate on the constitutive relationship and Poisson's ratio of recycled concrete,Through the test results analysis,the stress-strain curve of recycled concrete under different replacement rates of regenerated fine aggregates was drawn.These studies have obtained the relationship between peak stress and peak strain and the replacement rate of regenerated fine aggregates.It proposes a stress-strain full curve equation considering the influence of the replacement rate of regenerated fine aggregates,and analyzes the variation law between the Poisson's ratio and the dimensionless stress of recycled concrete.(4)Introducing the test results of ultrasonic non-destructive testing,and analyzing the damage inside the recycled concrete with the increase of pressure,The variation of ultrasonic wave velocity under the action of compressive stress is studied.This study has obtained the damage model of recycled concrete.