Structural behaviour of concrete filled cold-formed steel channel wall panel under axial loading

Abstract

The Government of Malaysia has promoted the usage of Industrial Building System (IBS) since the early 1960s. However, based on the IBS Roadmap 2003-2010 published by the Construction Industry Development Board Malaysia (CIDB), the factors contributing to the delay of IBS implementation in Malaysia are lack of knowledge among designers and requiring more local researches and developments, technologies and support services. One of the research areas is to develop a new type of load-bearing wall system to overcome the corrosion problem of reinforcement steel in the precast concrete wall panels. The aim of this study is to develop a new type of precast load-bearing wall panel system. The proposed system involved composite cold-formed wall panel (CCFWP) which consists of concrete and cold-formed steel sections, where the steel sections act as reinforcements. The load carrying capacity and the buckling behaviour of individual wall studs, wall frames, and CCFWP were assessed and validated with the relevant code of practices, and data from previous studies. The empirical equation to estimate the load carrying capacity of CCFWP has been proposed. The structural behaviour of individual wall studs, wall frames and CCFWP were investigated using full-scale experiment. Influences of web and flange holes, wall frame arrangements, aspect ratio and slenderness ratio on load carrying capacity of individual wall studs, wall frames, and CCFWP were also studied. It was found that web and flange holes with 150 mm spacing provide adequate compressive strength for the wall studs, and Arrangement 1 with one middle stud is considered as the best arrangement of the wall frame since it yielded higher and consistent results. The increment in ultimate axial strength ratio for CCFWP is 4% when the slenderness ratio of the CCFWP increased from 6 to 13, and the increment in ultimate axial strength ratio is 7.3% when the aspect ratio increased from 1.67 to 3.33. From the validation process, the closest prediction of the ultimate axial load of CCFWP is provided by BS8110. Subsequently, the proposed empirical equation for CCFWP is modified from the empirical equation as in BS 8110 by incorporating the effect of slenderness ratio, aspect ratio, and the contribution of the cold-formed steel.