Geotechnical Behavior of Concrete- filled gfrp piles

Glass-fiber reinforced polymer pipes (GFRP) have been recently usedas permanent casings in the construction of foundations piles. Benefits ofGFRP composite piles, as compared to conventional concrete-filled steelcasing piles, include long term durability, high strength, low maintenancecosts, and long expected service life especially when used in marineapplications and other corrosive environments.In this study locally manufactured GFRP pipes are filled with concreteto produce composite GFRP-concrete piles. The main objective of thisresearch is to study the behavior of the composite GFRP-concrete pilesembedded in dry dense sand in both cases of lateral and axial loadingconditions.First, the confining effect of GFRP pipes on the concrete core wasinvestigated by laboratory tests on short composite cylindrical cross sectionssubjected to axial compression. Four point bending tests on concrete, GFRPhollow pipes and GFRP composite cross sections have followed toinvestigate the flexural behavior. Laboratory model tests of the GFRPcomposite piles, installed in dry sand, have been performed to investigate thebehavior under axial compression and lateral loading.The test results showed that the internal capacity of the proposedcomposite section significantly exceeds the sum of the individual loadcapacity of the two materials in both cases of axial and flexural loadings.The ultimate strength and strain of the tested GFRP-Concrete cross sectionsare comparable to the published equations for axial ultimate strength.