Precast piles for Route 40 bridge in Virginia using concrete filled FRP tubes

This paper summarizes the construction details and findings of laboratory and field tests of a new generation of precast composite piles used for the first time in the construction of the substructure of the Route 40 highway bridge over the Nottoway River in Virginia. The piles consisted of 24.6 in. (625 mm) diameter concrete-filled glass fiber reinforced polymer (GFRP) circular tubes, with a 0.21 in. (5.3 mm) wall thickness. The composite piles extended above the ground level and were directly embedded into the reinforced concrete cap beam supporting the superstructure. Laboratory tests included two full-scale composite piles loaded to failure using four-point bending configuration. Field testing included a full-scale precast composite pile and a conventional 20 in. (508 mm) square concrete pile prestressed with fourteen 1/2 in. (12.7 mm) diameter strands. This paper presents details of the construction and driving of the piles, comparisons between the behavior of the composite and prestressed concrete piles under axial and lateral loading, the observed failure modes, and the details of the connection between the piles and the reinforced concrete cap beam.