Full-scale experiment and numerical simulation of prestressed concrete cylinder pipe with broken wires strengthened by prestressed CFRP: Fid-Bau Portal

Full-scale experiment and numerical simulation of prestressed concrete cylinder pipe with broken wires strengthened by prestressed CFRP

Zhai, Kejie / Fang, Hongyuan / Guo, Chengchao / Ni, Pengpeng / Wu, Hanying / Wang, Fuming

Abstract

Highlights • The technology of wrapping prestressed CFRP to strengthen PCCP is proposed. • A full-scale test on a damaged PCCP with broken wires is conducted. • A numerical model for PCCP is established and calibrated. • The prestressed CFRP repair is more effective than the non-prestressed repair.

Abstract Prestressed concrete cylinder pipe (PCCP) is widely used in large-scale water supply projects. The most common damage mode of PCCP is caused by rupture of prestressed wires. To strengthen a damaged PCCP, the technology of wrapping prestressed carbon fiber reinforced polymer (CFRP) externally is proposed. A full-scale test on a PCCP with an inside diameter of 1400 mm and a length of 6000 mm is conducted. In the test, three pipe sections are selected with broken wires, unbroken wires, and broken wires but repaired by prestressed CFRP. The strain response of the material in each section is analyzed by applying stepwise increased internal water pressure. Then, a finite element model is established and calibrated. Compared with the section containing broken wires, the material strain of the section repaired by prestressed CFRP decreases with almost no damage, indicating that prestressed CFRP is an effective repair method for damaged PCCP. Additionally, the influence area of broken wires is rather limited, showing negligible effect beyond a distance of 1300 mm from the broken wire area. When a PCCP reaches the serviceability limit state, prestressed CFRP repair and non-prestressed CFRP repair can increase the bearing capacity of the pipe by 87.3% and 34.9%, respectively.