On the Strengthening of Pultruded GFRP Connections Using Glass Fiber Sheets: A Study on the Influence of Bolt Diameter

This paper presents a summary of an experimental study aimed at evaluating the effects of glass fiber sheets (GFSs) on the strengthening of pultruded glass fiber reinforced polymer (PGFRP) connections with different bolt diameters under tensile loads. Three types of GFSs (± 45°, 0°/90°, and chopped strand mat (CSM)) were used for the investigation. Three types of bolt diameters were used: 12 mm, 16 mm, and 20 mm. The experimental results indicated that the GFSs remarkably improved the ultimate loads of the PGFRP connections. The strengthening effects were higher for the large-diameter bolts when the same modes of failure were observed for the specimens with the same parameters. Moreover, the CSM GFSs brought better effects on the strengthening of the connections than the ± 45° GFSs and 0°/90° GFSs. A numerical analysis was also used to effectively forecast the ultimate loads of the PGFRP connections. Finally, equations were suggested to calculate the ultimate loads of the PGFRP connections with different failure modes under tensile loads.