Papers by Keyword: Carbon Fiber Reinforced Concrete

Abstract: The relationship between electrical resistivity and temperature of carbon fiber reinforced concrete ( CFRC) road ma-terial are studied, from which the temperature sensibility of carbon fiber reinforced concrete is discovered, the electrical resistivity of CFRC decreases with increasing temperature and increases with decreasing temperature. The function mechanisms of the tem-perature are also analyzed. Using this property , carbonfiber reinforced concrete can be used as a kind of temperature sensor and self-diagnose the temperature of airfield runways or bridge deck.

Abstract: The strength and deformation properties of carbon fiber reinforced concrete under different fiber volume loadings under impact loading were studied by using the ɸ100 mm split Hopkinson pressure bar (SHPB) test system. The results show that after the carbon fiber is added, the stress-strain curve of the specimen shows the platform section at the peak stress. The strength and peak strain of the concrete under the impact load increase first and then decrease with the increase of the carbon fiber volume. Trend, when the carbon fiber volume is 0.2%, the impact mechanical properties of concrete are significantly improved.

Abstract: Based on the test results of conductive properties of carbon fiber reinforced concrete, the main influence on content of carbon fiber, content of coarse aggregate, and carbon fiber length are discussed and analyzed. The test results show that when CF content reach the amount of 0.8%~1.2% by mass of cement, the factors have no significant effect on the fractional change in resistance under 0.5% of the significance levels. But when CF content reach the amount of 1.2%~2.0% by mass of cement, the factors show significant effect on the fractional change in resistance under 0.5% of the significance levels. The CFRC resistance can be taken the minimum only when the sand-cement ratio is 1.47, the CF nominal length is equal to 12mm and the CF content is accounted for 2.0% by weight of cement.

Abstract: In order to further investigate the stress-strain curve of carbon fiber reinforced concrete, the curve of stress-strain is used segmentation tabulators on the basis of the existing tests. Based on the axial compression experiments of 9 carbon fiber concrete reinforced samples filled with different carbon fiber admixture amounts, the theoretical calculating formula of the stress-strain curve with different admixture amounts was proposed, and the theoretical formula of calculation parameters and carbon fiber volume fraction was putted forward. The experimental results show that the calculation parameters of the stress-strain curve increases with the increase of the carbon fiber admixture amounts. The theoretical calculating formula of the peak strain and carbon fiber volume fraction, the compressive strength, and the calculated results agreed well with the experimental results.

Abstract: The carbon fiber reinforced concrete has good pressure-sensitivity and compatibility with the surroundings and can be used as a sensor in the double yellow lines monitoring system. Combined with other electric appliances, this system can monitor the traffic violation effectively. The relationships of the electrical resistivity with the hydration time, carbon fiber content, conductive fillers and pressure-sensitivity on the load are studied in the paper. The smart control system designed in the paper can record the illegal drive automatically, overcome the shortcoming of the present methods and reduce the workload of staff effectively. It will play an important role in the road safety monitoring.

Abstract: Rebar corrosion test of Carbon Fiber Reinforced Polymer (CFRP) concrete was did. Carbon fiber in concrete improved the compression strength of the concrete, but width and number of concrete cracks was not reduced, carbon fiber has not obvious act for improving concrete corrosion crack behavior. CFRP concrete Corrosion potential was a little high than common concrete, carbon fiber has not obvious act for improving concrete behavior in protecting steel beyond corrosion. The porosity of the carbon fiber reinforced polymer concrete was twice of the common concrete, carbon fiber added to concrete lead to increase porosity and maybe decrease concrete behavior in protecting the embedded steel in corrosion.

Abstract: This paper analyzed the cracking behavior of carbon fiber reinforced concrete beam under static load using the finite element numerical analysis. By the way of finite element numerical simulation and the method of increasing the load gradually to analyze the carbon fiber content influence on the beam cracking, crack developing, beam deflection and beam average crack spacing. By comparing with the simulation result of common reinforced concrete beam test piece, it turned out that the carbon fiber reinforced concrete beam has a good cracking and deformation behavior under the same ratio of reinforcement. Under the same load, both the carbon fiber reinforced concrete beam and the common reinforced concrete beam have a small deformation, but the carbon fiber reinforced concrete beam showed a better resistance to deformation as the load increasing, its deflection increasing extent showed an obvious decrease compared with that of the common reinforced concrete beams. Its crack width can be revised by the common reinforced concrete beam rules.

Abstract: An increasing trend towards the demand for resisting to Freeze/thaw exposure has led to fibers being incorporated into concrete. This paper addresses the freeze/thaw durability of carbon fiber reinforced concrete by using a paired comparison test based upon relative dynamic elastic modulus and the rate of loss mass. The carbon fiber reinforced concrete was found to be more durable than plain concrete probably due to the high elastic modulus of carbon fiber. Durability is an important material property and carbon fiber reinforced concrete needs to be widely tested to gain confidence for use within the industry and this work shows future possibilities.

Abstract: Carbon fiber-reinforced polymer (CFRP) sheets have recently become popular for use as repair or rehabilitation material for deteriorated carbon fiber reinforced concrete structures. Carbon fiber reinforced concrete beams were analyzed by finite element software ANASYS. Through the finite element analysis, the results showed that using bonded CFRP to strengthen R. C. beams can significantly increase their load carrying capacity. However, the beams with prestressed CFRP can withstand larger ultimate loads than beams with bonded CFRP. Using bonded CFRP to strengthen R. C. beams can obviously reduce the ultimate deflection.

Abstract: Carbon fiber reinforced concrete (CFRC) structures exhibit both strain sensibility and temperature sensibility, which are coupled with each other when used in traffic or health monitoring for concrete structures. This coupling property results in inaccurateness of measured deformation. In this paper Four-probe Difference Method is used to detach the above two effects according to loaded conditions of structures and different characteristics of the two effects. The theoretical and experimental results indicate that the method is feasible and effective.