Experimental Study of Reinforced Concrete T-Beams Strengthened with a Composite of Prestressed Steel Wire Ropes Embedded in Polyurethane Cement (PSWR–PUC)

Abstract

This paper presents the experimental response of reinforced concrete T-beams strengthened with an innovative technique, namely, a composite of prestressed steel wire ropes (PSWRs) embedded in polyurethane cement (PSWR–PUC). The flexural behaviour of the PSWR–PUC-strengthened beams was investigated. One control beam, three PSWR-strengthened beams and five PSWR–PUC-strengthened beams were constructed and tested under four-point bending. The experimental variables included the material into which the wire rope is embedded, the thickness of the PUC, the number of wire ropes, the loading method and the wire rope anchoring type. The test results indicated that relative to PSWR-strengthened beams, PSWR–PUC-strengthened beams had significantly greater yield load, ultimate load and stiffness at the service load, and these enhancements increased significantly with increasing PUC thickness. Relative to using polymer mortar for PSWR strengthening, using PUC increased the durability of the steel wire ropes in the PSWR–PUC-strengthened composite. The cracking load of the PSWR–PUC-strengthened composite mainly depended on the prestressing effect of the wire ropes. However, after cracking, crack constraint in the PSWR–PUC-strengthened beam was dependent on the crack-suppression effect of PUC, especially during the later cracking stage. PSWR–PUC strengthening can effectively ensure secure anchoring by reducing the number of steel wire ropes required. These results indicate that PSWR–PUC strengthening has potential as an external strengthening technique for concrete structures.