Mechanism Of Fiber Types Affecting RPC Performance

In order to study the strengthening effect of different curing systems on basalt fiber,carbon fiber,and steel fiber in reactive powder concrete(RPC),natural curing,standard curing,and composite curing were adopted.This paper systematically studies the changes of RPC compression strength and split tensile strength under different curing systems.Using age,three kinds of fiber content,and curing system as parameters,SEM was used to study the influence mechanism of basalt fiber content,carbon fiber content,and steel fiber content on RPC.XRD was used to analyze the micro-component analysis of fiber RPC.Based on the conductive properties of carbon fibers,this paper studies the resistivity changes of carbon fiber RPC in uniaxial compression tests.At the same time,the elastic modulus and Poisson's ratio of carbon fiber RPC and steel fiber RPC were experimentally studied,and the calculation method of RPC strength under different carbon fiber and steel fiber content was also studied.The test results show that: under the same mix ratio and process conditions,the compound curing>standard curing> natural curing.Compared with standard curing,composite curing can increase the early strength of carbon fiber RPC,steel fiber RPC,and basalt RPC,and has little effect on the improvement of later strength.The natural curing intensity is slightly lower than the standard curing,but basically meets the requirements of the project and is beneficial to Engineering practical application.With the prolongation of the age,the composite conservation is better than the standard conservation and natural conservation at the 28-day age intensity.The compression strength and split tensile strength of steel fiber RPC are better than the other two curing methods nomatter whether it is 7d or 28 d.The reinforcing effect of steel fiber on RPC is better than carbon fiber and basalt fiber.Carbon fiber can effectively improve the conductivity of RPC.When the content of carbon fiber in RPC is from 0-0.5%,the resistivity of carbon fiber RPC is significantly reduced by 75.3%.When the carbon fiber content was increased from 0.5% to 0.75%,the resistivity of the carbon fiber RPC decreased by 97.7%,and the resistivity decreased with the increase of the carbon fiber content.