Experimental analysis of bolts employed as shear connectors in circular concrete-filled tube columns

Abstract

This paper presents experimental and theoretical analysis of bolts employed as shear connectors in circular concrete-filled steel tube columns (CFTs). The theoretical results, obtained from ABNT NBR 16239:2013 formulations, were compared with the experimental results. A series of push-out tests were carried out, where the diameter and length of the bolts, the number of connectors and the concrete strength were varied. From the experimental results, it was observed that the equations from ABNT NBR 16239:2013 are conservative. Therefore, it is proposed an adjustment to the formulations in order to consider the concrete confinement. It was also verified that increments in the diameter and the length of the bolt increase the load capacity of the connector. However, the variation of the quantity of bolts and the concrete strength did not interfere in the load capacity.

Development of a numerical model to simulate the behavior of plate shear connectors applied to slender cross-section concrete-filled steel tube

“…Prates [11] studied the behavior of bolted shear connectors, when used as shear connectors in columns composed of cold formed steel tubes filled with concrete, a simple and innovative solution for this type of connection, eliminating welding. The load transfer in the CFST by bolted shear connectors was also the study object of Ribeiro and Sarmanho [12] and Xavier et al [13] Younes et al [14] and Tao et al [15], who evaluated the load transferred using bolted connectors in CFST columns subjected to axial and cyclical loads, respectively. Although the way in which force is applied is different, Younes et al [14] as for Tao et al [15] also corroborated the efficiency of this type of tool as shear connector in CFST columns.…”