Flexural strengthening of RC beams using distributed prestressed high strength steel wire rope: theoretical analysis

Abstract

Various strengthening techniques for structural elements using different materials have been investigated. Recently, a new, reliable and cost-effective strengthening technique with distributed prestressed high strength steel wire rope (P-SWR technique) was proposed. This paper mainly focuses on theoretical analysis of the flexural behaviour of reinforced concrete (RC) beams strengthened with the P-SWR strengthening technique. First, mechanical properties of steel wire rope such as ultimate strength, ultimate tensile strain and relaxation were tested. Second, an evaluation method, including the prediction of cracking load and flexural capacity of RC beams strengthened with P-SWR, was proposed. Third, prestressed level of P-SWR, ratio of reinforcement, and bond strength of P-SWR and concrete responsible for short-term cross-sectional stiffness were studied and associated calculation equations are suggested. Finally, according to parametric studies, an entire evaluation system, including a modified Rao & Dilger code calculation method and hypothetical tension method, as well as a simplified method for predicting the maximum crack width, is proposed. All of these analytical procedures are based on experimental studies. A great similarity between the experimental and analytic results suggests that the proposed methods are highly accurate.