Torsional Strength Enhancement of Reinforced SCC Box Beams Using Internal Transverse Steel Bracing Technique

An experimental investigation was conducted, in this paper, to evaluate the torsional strength enhancement of reinforced self-compacting concrete box beams using internal transverse steel bracing technique. Seven beam specimens have dimensions of (2100x300x300mm) for length; width and depth respectively, were poured and tested under pure torsion. Three variables were adopted in the present study; presence or absence of steel bracings, type of steel bracing (X-Type and XW-Type) and a number of steel bracing (1,3 and 5). Accordingly, the tested beams are divided into three groups (based on steel bracing type), the first group consists of one non-strengthened beam specimen (reference), the second group consists of three beams strengthened by X-Type steel bracing; while, the third group consists of three beams strengthened by XW-Type steel bracing. It was found that the ultimate torque moment increased by about (14.4%, 34.3% and 59.2%) for beam specimens containing one, three and five X-Type steel bracing, respectively, in comparison with the reference beam. While, the ultimate torque moment increased by about (21.9%, 41.8% and 71.6%), for beam specimens containing one, three and five XW-Type steel bracing, respectively, in comparison with the reference beam. The paper concludes that the contribution was enhanced using the adopted technique.