Failure Analysis of Damaged Prestressed Concrete Cylinder Pipes Strengthened with Prestressed Carbon Fiber-Reinforced Polymers
Abstract
Prestressed concrete cylinder pipes (PCCPs) are widely used in large-scale water conservancy projects. Due to factors such as materials, design, construction, and operation, the prestressed steel wires in PCCP may break, resulting in damage to PCCP. Hence, an innovative approach for repairing damaged PCCPs with prestressed carbon fiber reinforced polymers (CFRPs) was proposed. A hydraulic pressure experiment was performed on a full-scale PCCP, and the damage maps in damaged section and repaired section were compared, which revealed that the prestressed CFRPs had an obvious repair effect. Then, a finite element model was established for a damaged PCCP repaired with prestressed CFRPs. Afterwards, a simplified analytical model was proposed. The results of the experiment, finite element (FE) simulation and analytical model were in good agreement. Finally, the effects of broken wires number, and the value of CFRP prestress on the PCCP performance were analysed. The results showed that these three factors substantially influenced the PCCP bearing capacity. When broken wires number was less than or equal to 30, the damaged PCCP could be repaired with 4 layers of CFRP with 20% prestressed.