Wu Fangwen, Tang Wenlong, Xue Chengfeng, Sun Guorui, Feng Yanpeng, Zhang Hao
School of Highway, Chang'an University, Xi'an 710064, China.
School of Civil Engineering, Xijing University, Xi'an 710123, China.
Materials (Basel). 2021 May 22;14(11):2744. doi: 10.3390/ma14112744.
In this research, high strength fiber reinforced concrete (HSFRC) was used to replace the normal strength concrete (NSC) in steel-concrete composite beams to improve their working performance, which might change the static performance of stud connectors. Firstly, push-out tests were conducted to investigation on the static performance of stud connectors in steel-HSFRC composite beams and compared with steel-NSC composite beams. Studs of 8 sizes, 13 mm, 16 mm, 19 mm and 22 mm in diameter and 80 mm and 120 mm in height were adopted to study the influence of stud dimension. The test phenomenon shown that the crack resistance of HSFRC was better than that of NSC, and there were some splitting cracks on NSC slabs whereas no visible cracks on HSFRC slabs when specimens failed. Next, the load-slip curves of studs were analyzed and a typical load-slip curve was proposed which was divided into four stages. In addition, the effects of test parameters were analyzed according to the characteristic points of load-slip curve. Compared with NSC slab, HSFRC slab could provide greater restraining force to the studs, which improved the shear capacity and stiffness of studs while suppressed the ductility of studs. The shear capacity, stiffness and ductility of studs would significantly increase with the increasement of stud diameter and the studs with large diameter were more suitable for steel-HSFRC composite beams. The stud height had no obvious influence on the static performance of studs. Finally, based on the test results, the empirical formulas for load-slip curve and shear capacity of stud connectors embedded in HSFRC were developed which considered the influence factors more comprehensively and had better accuracy and applicability than previous formulas.
在本研究中，采用高强纤维增强混凝土（HSFRC）替代钢-混凝土组合梁中的普通强度混凝土（NSC）以改善其工作性能，这可能会改变栓钉连接件的静力性能。首先，进行推出试验以研究钢-HSFRC组合梁中栓钉连接件的静力性能，并与钢-NSC组合梁进行比较。采用8种尺寸的栓钉，直径分别为13mm、16mm、19mm和22mm，高度分别为80mm和120mm，以研究栓钉尺寸的影响。试验现象表明，HSFRC的抗裂性能优于NSC，试件破坏时，NSC板上出现了一些劈裂裂缝，而HSFRC板上没有可见裂缝。其次，分析了栓钉的荷载-滑移曲线，提出了一条典型的荷载-滑移曲线，该曲线分为四个阶段。此外，根据荷载-滑移曲线的特征点分析了试验参数的影响。与NSC板相比，HSFRC板能为栓钉提供更大的约束作用，提高了栓钉的抗剪承载力和刚度，同时抑制了栓钉的延性。栓钉的抗剪承载力、刚度和延性会随着栓钉直径的增大而显著增加，大直径栓钉更适合钢-HSFRC组合梁。栓钉高度对栓钉的静力性能没有明显影响。最后，基于试验结果，建立了考虑影响因素更全面、比以往公式具有更好精度和适用性的HSFRC中埋入式栓钉连接件荷载-滑移曲线及抗剪承载力的经验公式。
