Experimental Study On Mechanics Properties Of Plastics-Steel Fiber And Steel Fiber Reinforced Light-Weight Aggregate Concrete

Although light aggregate concrete has significant advantage than ordinary concretein seismic performance, economy, ecological environmental protection and so on, thedefects that elastic modulus is low, easy to brittle and its big creep and shrinkage makethe widespread application of it in civil engineering seriously restricted. Currentresearch shows that light weight aggregate concrete mixed with steel fiber haseffectively improved mechanical properties, and plastics-steel fiber which is similarwith steel fiber in appearance, and has advantages such as low density, low cost, noteasy to rust and so on is more suitable for the light weight structure characteristics oflight weight aggregate concrete. Therefore, it is of profound significance for thepromotion of light weight aggregate concrete in civil engineering structure to study themechanics performance of light weight aggregate concrete reinforced by plastics-steelfiber.It is deeply researched that the differences of the three specimens in compressivestrength, flexural strength, impact resistance strength and flexural toughness through thespecimens’ mechanical property test of the light weight aggregate concrete without fiber,the lightweight aggregate concrete with steel fiber (volume dosage rate were0.5%,1.0%,1.5%,2.0%,2.5%), and the lightweight aggregate concrete with plastics-steelfiber (volume dosage rate were0.5%,0.7%,0.9%,1.1%,1.3%). Then the results showthat,(1) Both of plastics-steel fiber and steel fiber have unapparent enhanced effect forLC30of light aggregate concrete compressive strength.(2) Steel fiber has apparent enhanced effect of light aggregate concrete flexuralstrength while plastics-steel fiber has unapparent improvement of the flexural strength.When the plastics-steel fiber volume ratio mixing content is0.5%~1.1%, the enhancedeffect of light aggregate concrete’s equivalent bending strength is similar with that ofsteel fiber, when the volume ratio is1.3%, the enhanced effect is weaker than that ofsteel fiber.(3) The initial crack and damage energy consumption of light weight aggregateconcrete improved gradually with the increasing of steel fiber volume ratio underimpact loading. When the volume ratio of mixing amount is less than1.1%, theenhanced effect of the initial crack energy consumption of light weight aggregate concrete produced by plastics-steel fiber is similar with that of steel fiber, and theenhanced effect of the destruction energy consumption of light weight aggregateconcrete is stronger than that of steel fiber. When the volume ratio is1.3%, theenhanced effect of the initial crack energy consumption of light weight aggregateconcrete produced by plastics-steel fiber is lower than that of steel fiber, but theenhanced effect of the destruction energy consumption produced by plastics-steel fiberis still stronger than steel fiber.(4) The addition of plastics-steel fiber and steel fiber can both slow down thedeformation speed and improve the failure characteristics of lightweight aggregateconcrete while being loaded, and makes the brittle destruction of lightweight aggregateconcrete to be destructions with certain plastic processes.The influence rule of the mechanical property of plastics-steel fiber and steel fiberto lightweight aggregate concrete shows that the plastics-steel fiber has similarmechanics performance effect with steel fiber to the light weight aggregate concretewhile maintaining the light quality characteristics of the concrete. The study lays thefoundation of the widely using of lightweight aggregate concrete in load-carryingmembers, and has far-reaching significance in the development of lightweight aggregateconcrete structure.