Abstract
•Three types of swaged steel couplers, four splice lengths, and three surface deformations for GFRP bars were studied to investigate the feasibility of splicing No.4 GFRP reinforcing bars (13 mm bar diameter).•The ultimate strength of the spliced GFRP bars, the coupler’s strength, and failure modes were determined by conducting pull-out tests.•The test results showed that spliced No.4 GFRP bars achieved up to 97% of the guaranteed tensile strength (0.97 Ffu*min) as per ASTM D7957 when a 102-mm long low-carbon steel coupler was used, and a pressure of 20 MPa was applied for swaging.•Based on the pull-out test results, three failure modes were observed: (a) GFRP bar breaking when applying a swage pressure greater than 20 MPa; (b) fracture of steel coupler because of using low-ductility steel coupler (i.e., high carbon steel); and, (c) steel yielding of coupler due to the low tensile strength of the steel coupler.•The FEM results showed that No.4 GFRP bars could reach more than 125% of the GFRP guaranteed ultimate tensile load (1.25Ffu*min) per ASTM D7957 when the coupler’s length is more than 203 mm (16db).
Fiber-reinforced polymer (FRP) reinforcing bars are used as reinforcement in concrete structures mainly due to their non-corrosive property. FRP bars are anisotropic and use a thermoset resin as a matrix to embed the fibers. Lap splicing is the conventional method for connecting or splicing FRP bars; however, it may result in significant construction challenges due to the long development length requirements of FRP reinforcement. Mechanical splices are alternatives where lap splicing is not practical or causes congestion. The lack of an efficient mechanical splice for FRP bars is a limitation for the full deployment of the composite reinforcement in concrete construction. This paper focuses on an experimental investigation conducted on splicing No. 4 (13 mm nominal bar diameter) Glass FRP (GFRP) bars using swaged steel couplers. The investigation only addressed short-term strength and did not cover the durability performance of the coupler. Three types of swaged steel couplers, four splice lengths, and three surface deformations for GFRP bars were studied. The ultimate strength of the spliced GFRP bars, the coupler’s strength, and failure modes were determined by conducting pull-out tests. The test results showed that spliced GFRP bars could achieve up to 97% of the guaranteed tensile strength as per ASTM D7957 when a 102 mm long low-carbon steel coupler is used and a pressure less than 20 MPa is applied for swaging.
