Research On Electrical Properties Of Carbon Fiber Reinforced Concrete Containing Coarse Aggregate

Concrete used as the basic material of civil engineering in the field of buildingstructure, the intelligent research and development has become the focus of attentionof many experts and scholars. Carbon fiber reinforced concrete is a kind ofcomposite material by uniformly admixing short carbon fibers toconcrete.Compared with ordinary concrete, the strength and toughness of carbonfiber reinforced concrete can be improved, and conductivity also can be improvedsignificantly, and also its volume resistivity change with external conditions andproduce a corresponding change, derived the functional properties such asresistivity-temperature characteristics, pressure-sensitive, heat, electromagneticshielding and then. This paper combined with Zhengzhou technological leadingtalents project: Study on the properties of carbon fiber reinforced concrete and itsapplication in structural health monitoring(131TLJRC674）, through experiment,study the electrical properties and resistivity-temperature and others of CFRC. Themain contents include as follows:(1) When measuring voltage is10V, resistivity test result performs consistently; withthe increase of volume fraction of carbon fiber, matrix and the electrode contactresistance decreases; Different matrix of CFRC block, the compressive strengthdecreases differently after admixing carbon fibers, and S/C=1.08the amplitudereduces t the smallest.(2) When carbon fiber content is the cement quality of2%, sand cement ratio is1.47,and the carbon fiber length was12mm, the optimal CFRC conductive ability wasobtained.(3)Resistivity-temperature characteristic presents negative temperature coefficienteffect; with the increase of volume fraction of carbon fiber, the materialtemperature sensitivity coefficient decreases; as the temperature sensor, carbonfiber volume content is0.3%.(4) CFRC in the axial compressive loading, the relative resistance and relativerelationship among stress, strain can be present in various stages of stress condition clearly.(5) The curve of stress-strain block was studied on different carbon fiber volumecontent of prism specimens, and gives the calculating formula.