| Fiber-reinforced plastic (FRP) composites are being used for reinforcement of wood, concrete, and steel. The objective of this study is to develop a qualification program to evaluate the service performance and fracture of composite/wood bonded interfaces. The proposed method is used for two types of FRP wood interface: FRP strips (plates) bonded to wood (used commercially for glulam timber beams) and wood cores wrapped with FRP by filament winding (being investigated for reinforced railroad wood crossties and utility wood poles). First, the service performance and durability of FRP-wood interface bond is evaluated using a modified ASTM delamination test. Second, the apparent shear strengths of interface bond under both dry and wet conditions are obtained from modified ASTM block shear tests. Finally, a simplified design of an innovative contoured double cantilever beam (CDCB) specimen is developed, and this specimen is used to evaluate Mode-I fracture of interface bonds; interface fracture toughness data are experimentally obtained for dry, wet and 3-cycle aging conditions. (Abstract shortened by UMI.)... |
