Experimental Study on Mechanical Properties of Concrete Confined with Plastic Pipe

Plastic pipe-confined concrete (PPC) is a composite system obtained by filling a plastic pipe with concrete. PPC focuses on piers exposed to the tidal zone or the air-earth zone in marine and saline environments and protects them from salt damages by isolating and eliminating the exposed zones of the concrete structure from the aggressive substances. High-density polyethylene (HDPE) pipes were chosen to make PPC. Ultimate strength, the stress-strain curve, ductility of PPC and the effects of plastic-pipe thickness, and the compressive strength of core concrete f^sub cu^ on them were investigated in this paper. Results indicate: 1) the ductility ratio of PPC is 1.17 to 4.27 times that of common concrete (CC), and the energy absorption E of PPC is 10.7 to 26 times that of CC; 2) the pipe thickness and f^sub cu^ have significant effects on onset behavior and post-peak behavior of the stress-strain curves and the ultimate strength of PPC; and 3) the ductility ratio of PPC greatly increases with the increase of pipe thickness and decreases with the increase of f^sub cu^. [PUBLICATION ABSTRACT]