Experimental Study on Mechanics and Pressure Sensitivity of Carbon Fiber RPC

To study the mechanical properties and conductivity enhancement effect of carbon fiber (CF) on reactive powder concrete (RPC), this work systematically investigated the changes in the compressive strength, elastic modulus, Poisson’s ratio, and pressure sensitivity of RPC under standard curing system. With age, CF content, and pressure sensitivity as parameters, the micro-method for scanning mechanism was used to study the effect mechanism of CF content on RPC. The experimental results showed that with the increase of carbon fiber content, poisson's ratio and compressive strength of carbon fiber RPC tended to increase first and then decrease. The elastic modulus decreased first and then increased, and 0.75% was the turning point of fiber content. With the increase of carbon fiber content, the resistivity decreases gradually, while the resistivity change rate (FCR) shows a trend of increasing and decreasing first, and there is a strong corresponding relationship between strain and FCR.When the CF content is 0.75%, the maximum FCR is 38.8%, which is increased by 33%. the CF RPC with a CF content of 0.75% is the highest stress and strain sensitivity group, reaching 2.05%/Mpa and 513.7, respectively.

Keywords:
Reactive powder concrete; Smart concrete; Carbon fiber; Pressure sensitivity; Mechanical properties