Short term crack width prediction of CFRP bars reinforced coral concrete

Abstract

In order to study the crack development of CFRP reinforced coral concrete under different bending conditions, experimental study investigation of crack width of steel and CFRP reinforced coral concrete beams were performed. A comparative study of cracking rate, maximum crack height and crack patterns in CFRP bars reinforced coral concrete beams at different stages is made with ordinary steel reinforced coral concrete beams. The results show that under similar reinforcement ratio, the crack width and crack spacing of CFRP reinforced coral concrete beams are larger than that of steel reinforced concrete beams, increasing the reinforcement ratio of test beams can effectively reduce the crack width. The current deign formula from existing design codes overestimates the value of the relative bond characteristic coefficient (vi) and the strain inhomogeneity coefficient (ψ). Therefore, in this paper, the formula for maximum crack width of CFRP bars reinforced beams is developed based on the experimental data, the relative bond characteristic coefficient, the strain inhomogeneity coefficient of the longitudinal reinforcement, the ratio of the maximum crack width to the average crack width (τs) are included in the formula. The formula is validated with test results, the calculated value agrees well with the experimental results. Therefore, can be used for the future design.