Experimental Study On Shear Behaviors Of Steel Fiber Reinforced Full-lightweight Concrete Beams Without Web Reinforcement

Concrete is a kind of large amount building materials applied widely in the constructionof civil engineering. Since the advent of concrete, reducing its weight and increasing itstoughness has been the research focus, which could be well solved by the steel fiberreinforced lightweight aggregate concrete. As for a new material, scholars both at home andabroad mainly focus on the research of the material performance while they did not pay muchmore attention to the research about the behaviors of structural components, especially not tothe shear performance of the component. The experiment in this paper has26steel fiberreinforced full-lightweight concrete beams without web reinforcement. This paper mainlystudies the changesof cracking load and shear bearing capacity of these beams with differentshear-to-span ratio, steel fiber content, longitudinal reinforcement ratio and concrete strength.And then the formula for calculation of shear capacity is proposed.The test results can besummarized as follows:The shear failure modes of steel fiber reinforced full-lightweight concrete beams aresimilar to those of the ordinary reinforced concrete beams, except the different critical valuesdeterming the failure modes. The baroclinic failure occurs when the shear-to-span ratio is lessthan1.5,the diagonal-tensile failure occurs when the shear-to-span is more than3.0,theshear-compressive failure occurs when the shear-to-span ratio is between1.5and3.0. Thesteel fiber can play its reinforcing roles with the content reaching a certain value (0.4%in thispaper), while the cracking and ultimate loads of the test beams increased.The shear capacityof the beam is on the decline with the increase of the shear-to-span ratio,but increases with theincrease of the longitudinal reinforcement ratio.Based on the test data, the suitable formula for calculating the cracking load of the steel fiber reinforced full-lightweight concrete beamis found out, the calculation formula for shearbearing capacity of this beam is proposed by fitness analysis.The test results may offer reference to the future research and engineering application ofsteel fiber reinforced full-lightweight concrete.