Shear capacity of cold-formed light-gauge steel framed shear-wall panels with fiber cement board sheathing

Abstract

Being light in weight, cold-formed steel shear wall panels (SWPs) made with light gauge steel are extensively used in residential and office buildings (low to mid-rise), particularly in structures under seismic loadings. Many design practices involve the use of fiber cement board (FCB) as sheathing material both for hollow and infilled walls. FCB is a preferred choice as cladding material due to many advantages it provides such as water resistance, lower cost, withstand temperature variation, resistance to humidity and termite attack, better acoustic insulation, and superior fire resistance properties. In the absence of design guidelines, based on cold-formed light gauge steel shear walls with FCB sheathing, the designers resolve to use the guideline available for gypsum wall board (GWB) and fiberboard (FB) available in American Iron and Steel Institute Lateral Design. As a pioneer study, an experimental program was designed to investigate the behavior of cold-formed light gauge steel shear walls, both hollow and infilled with expanded polystyrene (EPS) foam concrete, with FCB sheathing on both sides under monotonic loading. The tests were performed according to ASTM E564 standard. Results show that the strength of shear walls with FCB sheathing is much higher than GWB and FB sheathing, suggesting that substitute design practices are highly conservative. Test results can help designers choose desired lateral stiffness and load carrying capacity of light gauge steel SWPs more efficiently, by selecting appropriate framing, infill, and sheathing material.