Mechanical properties of CFRP-strengthened prestressed concrete cylinder pipe based on multi-field coupling

Abstract

Broken prestressing wires in prestressed concrete cylinder pipe (PCCP) can cause incident of pipe burst. A method was proposed to repair damaged PCCP with broken wires by externally bonding carbon fiber reinforced polymer (CFRP). A finite element model was established and calibrated against the data from a prototype-scale laboratory test. Upon calibration, a three-dimensional numerical model was built to simulate the response of PCCP pipeline with five segments. Multi-field coupling was accomplished by Mesh-based parallel Code Coupling Interface (MpCCI) to incorporate the soil–pipe interaction and the effect of hydrodynamic pressure for PCCP. The effect of externally bonded CFRP to repair PCCP with broken wires was systematically analyzed. Results show that at a certain number of broken wires, the use of CFRP for pipe repair can significantly reduce the strains for each pipe component and increase the resilience of PCCP. The improved PCCP performance was assessed on the basis of crack visibility in the concrete core, and the deformation of the steel cylinder. The CFRP strain was much less than its ultimate strain, when cracks in the concrete core became visible and the steel cylinder yielded, suggesting that failure of PCCP could be ahead of CFRP.