Interface Shear Tests on FRP Composite Piles: Fid-Bau Portal

Interface Shear Tests on FRP Composite Piles

Pando, Miguel A. / Filz, George M. / Dove, Joseph E. / Hoppe, Edward J.

Problems associated with the use of traditional piling materials in harsh environments include concrete deterioration, steel corrosion, and marine borer attack on timber piles. It has been estimated that the U.S. spends over $1 billion annually in repair and replacement of waterfront piling systems. Such high repair and replacement costs have led several North American highway agencies and researchers to investigate the feasibility of using fiber reinforced polymer (FRP) composite piles, such as concrete-filled FRP piles. These piles, if found viable, could offer advantages such as improved durability and reduced life-cycle costs. However, composite piles have a relatively short track record of performance, and there are few readily accessible, well-documented projects involving use of FRP composite piles. FRP composite materials differ from steel and concrete in properties such as anisotropy, lower stiffness, lower surface hardness, and different surface roughness. Therefore, existing pile design approaches may not be directly applicable to FRP composite piles. The principal focus of this paper is on the skin friction characteristics of FRP composite piles against sand. This paper summarizes the results of sand-to-composite pile interface shear tests on two types of FRP composite piles. The test results are compared with those from sand-to-concrete interface tests. The influence of interface shear strength on pile axial capacity of composite piles is discussed.