Torsional Strengthening of Fire Damaged Reinforced concrete Beam Using Stainless Steel Wire Mesh

Abstract

This research explores the impact of fire exposure on reinforced concrete beams, particularly focusing on their behaviour and load-carrying capacity under torsion. The study addresses the significant challenges posed by the materials’ vulnerabilities and the extreme thermal conditions during fires. Experimental evaluations were carried out on fire-damaged concrete beams, exposing them to controlled heating at 200°C and 400°C for 2 hours (120 minutes), simulating realistic fire scenarios based on ISO 834 standards. Ten square reinforced concrete beams (1300Ö150Ö150 mm) were cast and subjected to fire exposure. Thermocouples were strategically placed at both ends and the mid-span of the beams to monitor internal effects. Additionally, two normal square reinforced concrete beams of the same dimensions were cast, with strain gauges on the reinforcement to assess torsional effects. Subsequent torsional loading tests showed a significant reduction in strength, retaining only half of the original value, after cooling and testing in a torsion frame. To evaluate structural performance and the effectiveness of Stainless-steel wire mesh (SSWM), torsional loading tests were conducted. The results demonstrate a substantial improvement in torsional strength and stiffness of fire-damaged concrete beams when strengthened with SSWM, regardless of the fire temperature. The use of SSWM emerges as a promising solution for enhancing torsional strength in fire-affected reinforced concrete beams exposed to varying fire temperatures. In conclusion, this research offers valuable insights into mitigating the adverse effects of fire on structural elements and provides a foundation for developing robust rehabilitation strategies for fire-damaged concrete structures. Through its comprehensive experimental approach and definitive findings, this study significantly advances the understanding and management of fire-induced damage in concrete structures.