Study On The Basic Strength Properties And Deformation Of Plastic Fiber Reinforced Concrete Rubber

Waste rubber is a macromolecular elastic material, and it is hard to decompose under thenatural conditions. When abandoned and accumulated, it not only breeds bacteria, but pollutesthe environment. Studies have shown that the concrete with rubber has the characteristics oflight weight, high toughness, good ductility, good impact resistance and good dampingresistance, while the strength decreases. Plastic fiber is a new type of organic polymer, andwhen used in rubber concrete, the physical and mechanical properties of rubber concretewould be improved greatly. The experimental study and theoretical analysis on theworkability, the cube compressive strength，the flexural strength and constitutive relationabout the different water-binder ratio of plastic fiber reinforced rubber concrete, and get theconstitutive equation. The main research contents and conclusions are as follows．Putting rubber particles with diameter of5-10mesh into concrete, and the mixingamount is15%of the fine aggregate volume according to the experimental results. Whilejoining the length of30to40mm plastic fiber of2kg/m3,4kg/m3,6kg/m3,8kg/m3,10kg/m3in the water-binder ratio of0.35,0.4,0.45. The experimental results showed twoaspects. Firstly, when fixed the same ratio of water to cementations materials, with the plasticfiber dosage increased, the fluidity of rubber concrete decreased; the cubic compressivestrength overall remain the same. At the same time, the flexural strength reduced after raisedand appeared the optimal dosage; when the rubber concrete with the proper plastic fiber, thecracks were tiny after it was compressed, the expansion speed were slowed relatively, and thespecimens could be more completed together after unloading. Secondly, when fixed the sameamount plastic fiber content, with the water-binder ratio reduced, the fluidity of rubberconcrete was decreased; the strength of plastic fiber for the cube compressive and flexuralincreased. At the same time, the integrity of low water-binder ratio concrete block wasrelatively better after compression. The study on the stress-strain curves with the different water-binder ratio of plastic fiberreinforced rubber concrete found a series of characteristic parameters, such as elastic modulus,poisson’s ratio, peak stress,peak strain and specimen deformation.Based on the stress-strain curves, and referenced to the uniaxial onlinear materialconstitution model of Guo zhenhai, it was proposed constitutive relations containingparameters A, B with the rubber concrete in this paper. Through the nonlinear least squares onthe data of stress-strain curves to put forward the mathematical expression about theconstitutive parameters and parameters a, b of rubber concrete. Then determined therelationships between the constitutive parameters A, B and the cube compressive strength, therubber concrete constitutive parameters and plastic fiber characteristic parameters, finallygot the constitutive equation，and lay a theoretical foundationfor study of constitutive relationof plastic fiber rubber concrete.