ALTERNATIVE APPROACHES TO SEISMIC RESILIENCE IN RC STRUCTURES

This experimental study investigates strain mitigation strategies to enhance repairability and energy dissipation in reinforced concrete beams. Three specimens were tested: (۱) conventional steel-reinforced, (۲) debonded-steel with collar tubes at hinges, and (۳) GFRP-reinforced. At ۳.۵% drift, conventional design developed localized ۳۵ mm cracks, while debonded-steel (۱ mm) and GFRP (۳ mm) specimens showed distributed cracking, significantly reducing repair needs. Considering the damage states of ATC ۵۸, at drift of ۳.۵%, the specimen with conventional design and that with debonded rebars could be categorized in DS۲ and DS۱, respectively. This means that the specimen with debonded rebar could satisfy damage state required for immediate occupancy (IO) even at drift of ۳.۵%. Failure modes differed: steel rebars buckled at ۳.۵% drift, whereas GFRP rebars ruptured at ۵.۵% drift. Debonded-steel specimens improved energy dissipation capacity versus conventional design, while GFRP specimens exhibited minimal dissipation. The study demonstrates that collar tube implementation—a simple modification to current practice—effectively enhances resilience by preventing strain localization. These findings offer practical alternatives to traditional base shear or drift-based design approaches for improving structural repairability.

کلیدواژه ها:

Resilience ، Damage localization ، Damage state ، Interstory drift ، Debonding