Fiber-Sizing-Based Enhancement of Materials Durability for Seismic Retrofit

E-glass/epoxy-based jackets have been demonstrated to be an effective means of providing lateral confinement for the seismic retrofit and strengthening of concrete columns. When fabricated using appropriate procedures and covered with a protective coating these materials show good environmental durability. However, E-glass fibers are susceptible to attack and degradation by moisture and alkalis, causing concern for their use in humid and very moist climates or in applications where the jacketed columns are immersed in water. This paper describes the enhancement of durability through change in the sizing used on the fibers. Results of ring burst tests on three differently sized systems after immersion in a severe environment [water at 60°C (140°F)] are detailed, and it is shown that the use of the appropriate sizing can significantly reduce moisture-related degradation.