The Research On The Dynamic Behavior Of Rubberized Concrete By Using Split Hopkinson Pressure Bar

Due to the crumb rubber as the elastomer in rubber modified concrete can prevent micro-cracks emergence and development, and absorp the strain energy, thus improving the impact resistance of concrete,increasing the seismic performance of concrete and durability. This modified concrete is low-cost, and technology is simple,having broad application prospects.In this paper,dynamic behavior of Rubberized Concrete (RC) was studied by using the split Hopkinson pressure ba(rSHPB).Under different strain rate stress-strain curves and toughness index were obtained, and dynamic compressive strength was compared with static compressive strength. From test results, dynamic compressive behavior of rubberized concrete containing different sizes,volumetric contents and grading was discussed.At last, the paper summarized the strain-rate effect of rubberized concrete, and factors that affected dynamic compressive behavior of rubberized concrete.At frist, this paper introduced the research status of rubberized concrete at home and abroad and the basic principles of SHPB test equipment . According to this paper studies, to determine the raw materials, the mixture ratio, and the test methods. Dynamic behavior of the 70mm diameter cylinder specimens was studied by using the split hopkinson pressure bar. Research found that the rubberized concrete having strain rate enhancement effects. Under the same rubber mixture, as the size of crumb rubber increases, the static and dynamic compressive strength decreases, the elasticity modulus decreases.However, it does not affect toughness of concrete obviously. But the finer rubber is, the less the toughness increases. Generally speaking, mixture of fine crumb rubber can bring better mechanic behavior than mixture of coarse crumb rubber into concrete. As the rubber mixture increase, the static and dynamic compressive strength decreases,the elasticity modulus decreases,but dynamic increase factor and toughness increase. Mixture of grading crumb rubber does not improve strength of rubberized concrete obviously, but it could further increases toughness of concrete, comparing with other three types rubberized concrete which just added one size of crumb rubber. So mixture of grading crumb rubber can decrease the quantity of rubber mixture when satisfying the same toughness, and therefore improves strength of rubberized concrete.