Experimental And Theoretical Study On The Mechanical Behaviors Of Carbon Fiber Reinforced Concrete

The carbon fiber reinforced concrete, shorten as CFRC, is multifunctional compositematerials filled with carbon fibers of a certain dosage and length. With the rapid developmentof China’s construction structure, a higher requirement of building materials needed. CFRCattract more and more attention due to the good mechanical properties, excellentelectromechanical effect and pressure sensitivity, furthermore, carbon fibers can postpone theemergence of concrete cracks. CFRC have been used for the project in some developedcountries (Baghdad, America), but China’s scientific research and engineering applicationsrelatively late. Therefore in this article some research on basic mechanical properties,stress-strain curve, flexural behavior of CFRC beam and axial compressive performance havebeen implemented by experimental study, theoretical analysis and finite element simulation.The article mainly covers the following fields:Experiments of concrete sample with different dosage of carbon fiber under axialcompression are carried out to investigate the failure mode, ultimate load, axial deformationand the optimum mix amount. According to relevant data, formulas used for expressingrelationship of splitting tensile strength, carbon fiber content and compressive strength areproposed.The concrete constitutive relation of CFRC concrete is established based on the axialcompression test of concrete at different additive of carbon fiber. And then the relationship ofstress-strain curve model coefficients, peak strain and carbon fiber content are studied. Basedon the analysis of the experiment, the stress-strain curves upward section under differentdosage of carbon fiber are established. The stress-strain curves descent stages under differentdosage of carbon fiber are established based on the previous studies. Then to fitting therelationship between carbon fiber additive and the curve coefficients, taking the restricted conditions of this model.Experiments of CFRC beams under flexural behavior are carried out to investigate themechanical properties, failure mode, mid-span deflection, plane-section hypothesis etc.According to comparise and analyze on different length carbon fiber, different stirrup ratio,the experimental results showed that carbon fiber can delay the cracking of concrete, andimprove span deflection value of concrete beam. Based on the experiment, the formulas usedfor predicting the cracking-carrying capacity of CFRC beam are deduced. The whole stressingprocess and the cracking process of beam are simulated using large-scale finite elementsoftware ANSYS, and get the load–deformation curves of concrete beam.Experiments of the CFRC column under axial compression are carried to investigate themechanical properties of working feature, failure mode, axial deformation, transverse strain,the effect length of the carbon fiber on cracking load of concrete columns, strain change curveof the different positions etc. The experimental results showed that carbon fiber can delay thecracking of concrete column, and the resistance on cracking enhance at first and then decreaseslowly with the increase of carbon fiber length. The Whole stressing process and the crackingprocess of concrete column are simulated using large-scale finite element software ANSYS,and get the load–longitudinal deformation curves of concrete column.