The 2019 World Congress on Advances in Structural Engineering and Mechanics (ASEM19) Jeju Island, Korea, September 17 - 21, 2019 Flexural behavior of bolted beam-to-column connections of steel storage racks * Nattawut Asawasongkram 1) ,Prakit Chomchuen 1) and Prakit Premthamkorn 1) 1) Department of Civil Engineering, Mahanakorn University of Technology, Bangkok, Thailand 1) nattawutcivil@gmail.com ABSTRACT This paper presents an experimental investigation of bolted beam-to-column connections of steel storage racks. The conventional beam-to-column connections with and without additional bolts are experimentally tested using the standard cantilever test in order to evaluate the flexural behavior of the connection. Moment-rotation curves of rack’s connections obtained from the experiment show a great benefit of additional bolts in terms of moment resistant and ductility. The experimental results show that the strength of bolted beam-to-column connections is higher than the conventional beam- to-column connections by up to 76%. The ductility of the bolted beam-to-column connection is also increased by up to 22%. The study shows that the additional bolts can be applied for the strengthening of beam-to-column connections of steel storage racks. 1. INTRODUCTION Steel storage racks are wildly used in industry and large public warehouses for storing products. This type of structure has become a common feature in several countries. A structural system of steel storage racks is composed of a perforated thin wall cold-formed open section column, a box beam and beam end connectors. A beam end connector, welded into the ends of the beam, provides a means of connecting the beams and the column together. Steel tabs are often used as connectors. Steel tabs are the hooks in the beam end connector that are engaged into the perorated column at optional heights. Many experimental studies (Markazi et al. 1997: Bernuzzi and Castiglioni 2001; Bajoria and Talikoti 2006) have found that this type of connection has a low of strength which can be classified as a semi-rigid connection. The failure mode is usually the tearing of an outermost steel tab, which is a brittle failure mode. For practical reasons, it has been found that some of the conventional beam-to- column connections use additional bolts to avoid the accidental unlocking of the 1) Lecturer