Experimental Study of RC Beams Strengthened with Prestressed Steel-Wire BFRP Composite Plate Using a Hybrid Anchorage System

Abstract

Steel wire-basalt fiber reinforced polymer (BFRP) composite plate (SBFCP) is a newly developed plate for strengthening reinforced concrete (RC) structures with both high performance and economy. This paper presents a prestress technique for flexural strengthening RC beams using SBFCPs after investigating mechanical properties of SBFCPs. To achieve higher levels of fiber strength utilization prior to premature debonding failure, a new hybrid anchoring approach that combines adhesive bonding and mechanical fastening is proposed. Six T-beams with 6 m length were tested under four-point bending. The main variable parameters were the composite plate types and prestress levels. The test results demonstrate that the use of SBFCPs for strengthening RC beams is an effective method for improving the flexural performance. Moreover, in comparison with nonprestressed one, prestressed SBFCP technology can further improve the cracking load and overall stiffness with less strain lag, better bonding, and better utilization efficiency of the strengthening material. In comparison with specimens strengthened with carbon-fiber-reinforced polymer materials, prestressed SBFCP technology also has competitive advantages, particularly with respect to their serviceability and performance-cost ratio.