Concrete-Filled Double Skin Steel Tubular Columns Exposed to ASTM E-119 Fire Curve for 60 and 90 Minutes of FireSharifah Salwa Mohd Zuki, Shahiron Shahidan, Choong Kok Keong, J. Jayaprakash and Noorwirdawati AliMATEC Web Conf., 103 (2017) 02009DOI: https://doi.org/10.1051/matecconf/201710302009