Experimental study on the mechanical performance of angle shear connectors with and without concrete gaps

Because it is difficult for the flow, vibration and gas exhaust of concrete, gaps may exist near the welded regions of angle shear connectors. Based on the engineering practice and standard provisions, a test on nine groups of full-scale push-out specimens of three different gap depths (0, 10 mm and 20 mm) was conducted. To reduce the discreteness, there were three duplicate specimens in each group. All specimens failed in concrete crushing in the test. Compared with the specimens without a gap, the crushing area was smaller and the deformation of the angle steel was larger in the specimens with a gap. The concrete gap had a significant influence on the strength and stiffness of the angle shear connectors. Compared with that of the specimens without a gap, the strength was decreased by 16.5% and 37.5% and the stiffness was decreased by 48.4% and 70.6% for the specimens with a gap of 10 mm and 20 mm, respectively. Different formulas in the literature were verified based on 62 groups of specimens in other papers and 3 groups of specimens in the current test. The formula proposed by Kiyomiya and Kimura was found to have good accuracy and small discreteness, while the formula proposed by 《Design Code for Steel-Concrete Sandwich Structures》in Japan was conservative. A new shear strength empirical formula was proposed based on the existing experimental data, which showed better accuracy and applicability. Based on the new shear strength formula and a mechanical model considering the concrete gap, a shear strength corrected formula for angle shear connectors with concrete gaps was proposed. The proposed corrected formula was verified based on 3 groups of specimens in other papers and 6 groups of specimens in the current test and was found to have good accuracy and small discreteness. Copyright ©2020 Engineering Mechanics. All rights reserved.