Structural behavior of jointed precast concrete beams reinforced with GFRP bars

This experimental research aims to reduce the joint length between the precast concrete elements reinforced with GFRP bars. The experimental work was divided into two stages. Stage (I) consists of twelve specimens made from GFRP bars and jointed together using GFRP or steel sleeves filled with epoxy resin. The specimens were tested under tension up to failure to investigate the tensile capacity of splice bars taking into consideration different parameters such as sleeve type, embedment length, bar size, and sleeve radial stiffness. While Stage (II) consists of ten reinforced concrete beams measuring 200 x 350 x 3300 mm. All beams were tested under a four-point bending load up to failure. The connection types for GFRP bars were investigated using two methods; (i) the optimum sleeve connector selected from stage I, (ii) using lap splice with different parameters such as splice length, joint compressive strength, and confinement lap-splice region with GFRP sheets. The test results show that an adequate bar embedment length and sleeve radial stiffness are required to achieve bar tensile strength. Whereas lap splice length can be reduced by increasing confinement of lap splice region with GFRP sheets. Finally, precast elements' joint length can be minimized by using a sleeve connector with adequate radial stiffness and embedment length equal to 15-times bar diameter or by confinement of the lap splice region to minimize its length to 40-times bar diameter.