Experimental Research On Tensile Performance Of Gravel Reactive Powder Concrete

Reactive Powder Concret (RPC), is a new kind of high performance cement composite materials, which is high strength, high toughness and durability.The RPC is a promising new material in Civil engineering field. Because the cost of RPC is ten times expensive than the ordinary concrete, so is hard to promote this new materials in engineering field. At present there still cannot find a more cheap fiber materials instead of steel fiber, through the rubble to substitute partly mixing quartz sand to reduce the cost of RPC become necessary. This article is to explain the flexural and axis tensile process experimental study for the mechanical properties of mixed gravel of RPC. The main work done and conclusions are as follows:(1) Summarized the experimental research achievements of axial at domestic and overseas, Finished the axial tensile process experiment of mixed gravel of RPC.In the trials I using the cross-section arc transition dumbbell specimens and cooperate with variable thickness copper gaskets.This methods solved the promblem of folder type specimens easly concentrat stress at the tso.This test is easy and reliable.(2) Did the experiment about the flexural performance of mixed gravel of RPC.This experiment showed,the materials mixed with gravel which the flexural strength showed increased after reducing trend with the increasing of gravel.And the flexural strength is linked with the quantity of cementitious materials.With the reducing of cementitious materials,the flexural strength could increasing slowly.When the RPC mixed with gravel for 30%or 40%,the increasing of flexural stength is the most which about 19%.In the 16 groups,the most stength of flexural is 18.59 MPa,and the minimum is 14.34 MPa.(3) Did the experiment about the axis tensile process of mixed gravel of RPC.The axis tensile of strength is increasing with the adding of steel fiber.When the steel fiber added from 1%to 2%,the axis tensile of strength is increasing from 6.5MPa to 9.8MPa.(4) This article is to explain the influence law for the axis tensile stress-strain curve of RPC when the cementitious materials is 766kg/m3 and the gravel content is 40%,and respectively the steel fiber volume content is 1%,1.5%and 2%.The RPC is began to fractureing when the smaller volume ratio of steel fiber with the maximum stress,which with a steep decline.With the increasing of steel fiber volume content,the stress-strain curve flattens out all the decline.The fractured RPC could bearing a high pressure and having a good toughness.(5) This article also combined with other classmates group of compressive performance, and analyses the relationship between the axial compression strength, flexural strength and axis tensile strength.