Performance of fire damaged cement and geopolymer concrete slabs retrofitted with BFRP laminates under static loading

Abstract

Many of the existing reinforced concrete structures throughout the world are in urgent need of rehabilitation, repair, or reconstruction. Because of deterioration due to various factors like corrosion, lack of detailing the failure of bonding between beam, column joints, accidental fire, loss of strength, deflection, etc. Use of externally bonded FRP for strengthening the structures has received considerable attention in recent years. This study exclusively focuses on assessing the load-carrying capacity of fire-damaged Cement and Geopolymer Concrete structural elements wrapped with BFRP laminates. And the scope of this study is expected to provide cost-effective and retrofit solutions that can be implemented in the concrete industry. The slab specimens were subjected to temperatures of 200, 400, 600 and 800°C for a period of 1, 2, and 3 hours followed by retrofitting with BFRP laminate. The results showed that the ultimate load-carrying capacity of both cement and geopolymer concrete slabs increased when exposed to 200ºC for 1 hour. However, beyond this point, the capacity started to decrease. Nevertheless, a decline in ultimate load capacity was noted for higher temperature ranges and prolonged fire exposure durations.The application of Basalt FRP wrapping to the soffit of slabs led to an 80% increase in the ultimate load capacity of both cement and geopolymer concrete slabs that had been damaged by fire. The analysis of test data led to the conclusion that retrofitting with Basalt FRP Laminates achieved a strengthening effect on the firedamaged cement and geopolymer concrete slabs.