Experimental Study On Strength And Toughness Characteristics Of Steel-Synthetic Fiber Reinforced Concrete

Steel fiber reinforced high strength concrete(SFRHSC) and Hybrid fiber concrete(HFC) are two promising approaches within the study of fiber concrete. Steel fiber can turn high strength concrete into high performance concrete while hybrid fiber is conducive to combine the benefits of different fibers with proper mix proportion and reduce costs.This paper, with reference to the test standard CECS13:89, studies the compression behavior of High strength steel fiber reinforced concrete and toughness of Hybrid fiber concrete. The study specifically covers: the investigation of the compressive strength of High strength steel fiber reinforced concrete by employing standard cubic and prism specimens with the height/width ratio 2 and 3; After the measurement of the uniaxial compression strain-stress curve of SFRHSC, It calculates and analyses its value of stress peak, peak strain, Young's modulus and compression toughness according to the steel fiber volume fraction, and simulates the curves with proper equations based on the analysis of test data.This paper also presents the experimental results of bending, splitting and shear behavior of hybrid steel-polyacrylonitrile fiber concrete and hybrid steel-polypropylene fiber concrete. Taking benefits of Germany DBV standards, It studies the hybrid effects of flexural strength and toughness of steel-synthetic fiber, so does the splitting strength and toughness. It develops the primary analysis of the shear toughness of HFC in energy approach.The results show that the peak strain of SFRHSC has a linear relationship with the steel fiber volume fraction. The equations selected correlated quite well with the test data. The steel-synthetic hybrid fiber can substantially improve the flexural, splitting and shear behavior of concrete. Compared to steel-polypropylene hybrid fiber, the steel-polyacrylonitrile hybrid fiber presents better hybrid effect on the flexural behavior of concrete.This paper also observes and analyzes the failure mode of SFRHSC and HFC in different load pattern and probes into the working mechanism of fiber.