Peng Kai, Liu Laijun, Wu Fangwen, Wang Ruizheng, Lei Song, Zhang Xiaoyu
School of Highway, Chang'an University, Xi'an 710064, China.
Gansu Province Transportation Planning, Survey & Design Institute Co., Ltd., Lanzhou 730010, China.
Materials (Basel). 2022 Jul 2;15(13):4665. doi: 10.3390/ma15134665.
To investigate the shear performance and failure mechanism of stud shear connectors in steel fiber-reinforced cementitious composite (SFRCC) beams, six steel-SFRCC and six steel-normal strength concrete (NC) push-out specimens with two heights (80 mm, 120 mm) and three diameters (14 mm, 18 mm, 22 mm) of stud connectors were prepared. The experimental results revealed that the stud shearing failure was the main failure mode of all push-out specimens. In comparison to the steel-NC specimens, the development of cracks in the SFRCC beams was efficiently restrained due to the existence of high-strength steel fibers added to the normal concrete. The shear resistance and stiffness of studs in the steel-SFRCC beams were, respectively, 22.3% and 15.1% greater than those in the steel-NC specimens; however, their ductility was reduced, and the stud shear connectors failed in advance. The finite element (FE) model was developed and verified by push-out test results. FE analysis results indicated that the shear resistance of stud shear connectors was significantly improved with the increase in the concrete compressive strength, the stud diameter and tensile strength, whereas the aspect ratio of studs had a small impact on the ultimate resistance of stud shear connectors. Based on the as-obtained push-out experiment and FE analysis results, empirical formulas were presented to predict the load-slip curves and ultimate shear resistance of stud shear connectors in the steel-SFRCC specimens, and higher accuracy and a wider application range were obtained than with previous formulas.
为研究钢纤维增强水泥基复合材料（SFRCC）梁中栓钉抗剪连接件的抗剪性能和破坏机理，制备了六个钢-SFRCC和六个钢-普通强度混凝土（NC）推出试件，栓钉连接件有两种高度（80mm、120mm）和三种直径（14mm、18mm、22mm）。试验结果表明，栓钉剪切破坏是所有推出试件的主要破坏模式。与钢-NC试件相比，由于在普通混凝土中添加了高强度钢纤维，SFRCC梁中裂缝的发展得到有效抑制。钢-SFRCC梁中栓钉的抗剪强度和刚度分别比钢-NC试件高22.3%和15.1%；然而，其延性降低，栓钉抗剪连接件提前破坏。建立了有限元（FE）模型，并通过推出试验结果进行了验证。有限元分析结果表明，随着混凝土抗压强度、栓钉直径和抗拉强度的增加，栓钉抗剪连接件的抗剪强度显著提高，而栓钉的长径比对栓钉抗剪连接件的极限抗剪强度影响较小。基于所获得的推出试验和有限元分析结果，提出了经验公式来预测钢-SFRCC试件中栓钉抗剪连接件的荷载-滑移曲线和极限抗剪强度，与以前的公式相比，具有更高的精度和更广泛的应用范围。
