Impact of Internal CFRP strips on the flexural behavior of heat-damaged reinforced concrete beams
Rajai Z. Al‐Rousan
Abstract
and an overall length of 1100 mm concrete beams were cast, and the studied parameters were the CFRP length, position, and exposure temperature. The internal strengthening technique has been found to ensure the full utilization of the strengthening material where the externally-strengthened beams fail preceding the CFRP strain reached, and this was confirmed using the linear weighted sum method where the internal strengthening has the highest ranking based on the mechanical characteristics comparisons. Moreover, the internal CFRP reinforcement improves RC beam performance, strength, stiffness, toughness, and serviceability more than exterior CFRP sheets. However, the enhancement percentages are twice as much for internal strengthening as the external one. It has also been found that the reinforcement's location substantially impacted the number and length of flexural cracks and its failure mode. In addition, for every 1% reduction in concrete compressive strength in heat damage, the average ultimate load was reduced by 0.8%. The CFRP profitability indexes decrease as sheet number and temperature increase; the average toughness decrease at 150 °C, 250 °C, and 500 °C is 12%, 21%, and 47%, respectively.