Research On Properties Of Reactive Powder Concrete With Polymer And Fiber

Concrete which has high strength,high performance and good durability,has become the main development trend.Reactive powder concrete(RPC)is a new kind of super high strength cement-based material.which has a grate adaptability.As an ultra-high strength cement-based material,reactive powder concrete(RPC)has good adaptability.As a new type of cement based composite material,the toughness of the cement based material has been obviously improved.Shrinkage is the inherent time-dependent property of concrete materials.It refers to the reduction of the volume of specimens under non loading.Greater shrinkage will lead to safety problems of concrete structures.In order to improve the toughness of reactive powder concrete,reduce the shrinkage of polymer powder and the basalt fiber,the mechanical properties of reactive powder concrete and shrinkage effects,first selection of reactive powder concrete can improve the polymer,and the optimum dosage of polymer and fiber.On the basis of the research on the different curing system on the properties of polymer fiber reactive powder concrete mechanics and shrinkage effect and feasibility study of limestone powder and fly ash preparation of reactive powder concrete were substituted quartz powder and silica fume.In order to reduce the cost of reactive powder concrete,so that the application range is more broad.The experimental results show that the use of two kinds of polymer powder(PVA and VAE)improved the working properties of reactive powder concrete remarkably the polymer powder can improve the flexural strength,the compressive strength ratio of reactive powder concrete,but its compressive strength decreased.Among them,the effect of polymer PVA powder on the reactive powder concrete is better,the best yield is 0.6%,the flexural strength is 19.7MPa.The addition of suitable amount of basalt fiber in the polymer modified reactive powder concrete can improve the flexural strength and flexibility of the reactive powder concrete,and the compressive strength is also increased slightly.When the dosage of PVA is 0.6%,the basalt fiber content is 1%,the comprehensive mechanical properties of fiber reinforced concrete polymer reactive powder best;polymer PVA doped with basalt fiber composite admixture can effectively reduce the reactive powder concrete shrinkage and shrinkage test,decreases with the increase of polymer and fiber content of dry hot water;maintenance can effectively improve the mechanical properties of the specimen,reduce its shrinkage and mechanical properties of specimens and shrinkage with increasing temperature and curing time were gradually increased and decreased.90 ℃ hot water curing 2d specimens,compressive strength of 7d age can reach 122.4MPa,the flexural strength of 24.5MPa;the suitable dosage of lime powder can effectively inhibit the sample shrinkage,under standard curing conditions of limestone powder content greater than 20% inhibition of shrinkage effect is more obvious,the hot water curing condition of limestone powder dosage should not exceed 40%.