FRP bar and concrete bond durability in seawater: A meta-analysis review on degradation process, effective parameters, and predictive models

This review provides an overview of over 600 experimental data conducted on the short-term and long-term bond-slip behaviour between different types of FRP bars and concretes when exposed to seawater. Investigating bond durability is essential to ensure the long-term structural integrity and performance of reinforced concrete elements in various applications. On one hand, the degradation of the interface between FRP bar and concrete due to environmental exposure can lead to delamination and premature failure. On the other hand, certain factors, such as bar swelling and the progressive increase in concrete strength over time, can prevent significant bond reduction and, in some cases, even result in an improvement in bond strength. Other variables such as concrete and bar type, bar surface treatment, conditioning temperature and duration were found to be effective factors in the bond durability performance. The review discusses and compares the quantitative bond strength retention values before and after exposure to seawater. Understanding and quantifying the interaction between the positive effect of bar swelling and the negative effect of bar surface degradation on bond strength retention remains a significant gap in the field.