Experimental Study On The Mechanical Properties Of Newly Steel Fiber Reinforced Concrete

According to the U.S. standard ASTM C1018-97,this paper, experimental research on the compressive strength, splitting tensile, flexural strength and flexural toughness using different types of steel fiber by 102 cubic specimens' compressive strength, 102 cubic specimens' splitting tensile and 102 small beams' flexural toughness experiments. Fiber content, aspect ratio and fiber pieces/kg have been considered to analyze the influences of steel fiber on the toughness of concrete.Several conclusions are drawn as follows:As concrete incorporation into steel fiber, the compressive strength don't change in any law.While the steel fiber reinforced concrete compared with the same proportion of plain concrete, the compressive strength is improved, the largest increase range for the C30 is 49%, C40 is 30%. Cubic specimens' splitting tensile increases marginally with the fiber content, the increase range is also affected with the steel fiber type and length-diameter ratio.Among them ,the steel fiber FF3 with the aspect ratio 67 is the most significant. When the fiber content is 50Kg/m3,the C30 concrete incorporation into steel fiber FF3 increase 34%,,the C40 concrete incorporation into steel fiber FF3 increase 27%,The flexural strength's influence factors are same as the splitting tensile and improved obviously. Among them, when the steel fiber FF3 content is 50Kg/m3, the C30 concrete increase 26%, the C40 concrete increase 23%. The toughening mechanism of fiber reinforced concrete and the toughening results are different as different types of fiber. As the steel fiber's aspect ratio and unit mass steel-fiber root number larger, the toughening effect of steel fiber reinforced concrete more obvious. As the increase of steel fiber content,the beams' crack curves got smaller decrease and plumper,the the second peak is larger. Within the steel fiber reinforced concrete, the aggregate type and aggregate gradation also affect the toughening effect of steel fiber reinforced concrete. If the match is reasonable, then can use less steel fiber greatly improved the toughness of fiber reinforced concrete.