Carbon Fiber Gradient Distribution Of Thermal Stress Distribution In Cement-based Materials

Cement base material is the maximum and most widely used man-made building material in nowadays. It is easy damaged by the environment reason and over load. Especially the concrete used in highway, which is often face with the salt to melt snow. Carbon fiber reinforced cement material is the new way to melt snow, as the electrothermal it have, and is quickly developing technology in these years. However, the thermal stress caused by the joint between heating layer and no-heating layer would crack the bond and descend durability. In this paper, the concept of FGM is firstly applied in cement-based materials to study the effect of carbon fiber gradient distribution in cement-based materials on mechanical property, conductive property and thermal stress distribution.(1) The cement based material's mechanical property is improved if carbon fiber gradient distribution. In this paper, we found that, the carbon fiber distribution in gradient have clearly higher flexural strength than distribution in uniform, but the compressive strength have not changed much. As the number of carbon fiber increased in the cement based material, its modulus of elasticity decrease, and poisson ratio raised.(2) The cement based material's conductive property is improved if carbon fiber gradient distribution. When the usage of carbon fiber get to 0.3% and 0.4%, the carbon fiber gradient distribution on the cement material have obvious higher conductive property than the uniform one, but the conductive will keep the same level when the usage get to 0.8%. the research on thermal property indicated that, as the number of carbon fiber increased in the cement based material, its coefficient of thermal expansion decrease, same with coefficient of thermal conduction.(3)The cement based material's thermal stress distribution is released if carbon fiber gradient. In this part, we use the software of finite element analysis, called ansys9.0, to imitation the field of stress caused by energized heat in the carbon fiber gradient distribution and uniform distribution on the cement based materials.