This paper presents a method for evaluating the bond behavior of a single carbon yarn embedded in the cementitious matrix. Pullout tests were carried out in which the carbon yarn was progressively pulled out of the matrix. It was found that all pullout specimens with a nominal bond length of 15 mm showed a similar pullout curve that is characterized by an initial ascending part and then a descending part followed by an almost constant part, along with the same failure mode due to the slippage of the carbon yarn out of the matrix. The proposed method was used to evaluate the bond parameters in the trilinear bond slip relationship, which has been demonstrated to be applicable for describing the interface between carbon yarn and the matrix. The reliability of the evaluation method has been substantiated by achieving good agreement between the analytical and the experimental results obtained from a range of pullout tests. For the embedded carbon yarn, an anchorage length can always be found so that the tensile capacity can be attained. Then, a proposed approach was used to directly determine the anchorage length of all the pullout specimens based on the evaluated trilinear bond--slip relationships, and the calculations were verified against the numerical results. In addition, a parametric study was carried out to investigate the effects of the bond parameters on the anchorage length of the embedded carbon yarn and showed that the anchorage length is influenced most by the local bond strength.
|Journal||Construction and Building Materials|
|Publication status||Accepted/In press - 5 Apr 2020|