On the basis of the test results of nine steel-fiber high-strength concrete corbel specimens subjected to a vertical load, the influence of the steel fiber content on the shear performance of corbels was analyzed. The softened strut-and-tie model (SSTM) was used to analyze the shear strength of steel-fiber high-strength concrete corbels, taking into consideration the shear contribution of steel fibers. A calculation model for the shear strength of steel-fiber high-strength concrete corbels is proposed, and a database for 26 steel-fiber high-strength concrete corbels was created by using the model. The results obtained according to the codes ACI318-19, EC2, CSA A23.3-19 and the softened strut-and-tie model were compared with the experimental values to verify the rationality of the model. The findings showed that steel fiber can effectively limit the crack width and improve the crack morphology. The overall average value of the ratio between the experimental and the predicted strengths of the model was 1.082, and the variance was 0.004. The values predicted with the proposed calculation model were closer to the experimental values than those calculated according to the codes. This study provides a definite mechanical model that can reveal the shear mechanism of steel-fiber high-strength concrete. It can reasonably predict the shear strength of steel-fiber high-strength concrete corbels.

As short cantilever members, corbels are mainly used to transfer eccentric loads to columns. Because of the discontinuity of load and geometric structure, corbels cannot be analyzed and designed using the method based on beam theory. Nine steel-fiber-reinforced high-strength concrete (SFRHSC) corbels were tested. The width of the corbels was 200 mm, the cross-section height of the corbel column was 450 mm, and the cantilever end height was 200 mm. The shear span/depth ratios considered were 0.2, 0.3, and 0.4; the longitudinal reinforcement ratios were 0.55%, 0.75%, and 0.98%; the stirrup reinforcement ratios were 0.39%, 0.52%, and 0.785%; and the steel fiber volume ratios were 0, 0.75%, and 1.5%. According to the test results, this paper discusses the failure process and failure mode of corbel specimens with a small shear span/depth ratio and analyzes the effects of variables such as shear span/depth ratio, longitudinal reinforcement ratio, stirrup reinforcement ratio, and steel fiber volume content on the shear capacity of corbels. The shear capacity of corbels is significantly affected by the shear span/depth ratio, followed by the longitudinal reinforcement ratio and the stirrup reinforcement ratio. Moreover, it is shown that steel fibers have little impact on the failure mode and ultimate load of corbels, but can enhance the crack resistance of corbels. In addition, the bearing capacities of these corbels were calculated by Chinese code GB 50010-2010 and further compared with ACI 318-19 code, EN 1992-1-1:2004 code, and CSA A23.3-19 code, which adopt the strut-and-tie model. The results indicate that the calculation results by the empirical formula in the Chinese code are close to the corresponding test results, while the calculation method based on the strut-and-tie model of a clear mechanical concept yields conservative results, and hence the related parameter values must be further modified.