Flexural Behavior of Reinforced Concrete Voided Slabs Strengthened with Different Types of FRP: State-of-the-Art Review

Abstract

Some reinforced concrete slabs may require rehabilitation or strengthening due to load increment caused by a change in the function for which they were built or unintentional errors during design or execution. There are numerous techniques for such problems. The rehabilitation or strengthening of structural members using fiber-reinforced polymer (FRP) is one of the most recent techniques. This technique is widely spread due to its high tensile strength and lightweight; also, the thickness of the strengthened structural member decreases when these materials are used. This paper provides a comprehensive review of several strengthening techniques in terms of their results, advantages, and the extent of their effect on the flexural behavior of voided concrete slabs. Research has shown that this type of strengthening contributes to improving the slabs’ performance, as it contributes to increasing the first crack load and the ultimate load, and it contributes to decreasing the value of the deflection corresponding to the ultimate load and improves the ductility and toughness of these slabs. Also, the flexural strength of these slabs increases with the number of strengthening layers used. CFRP is one of the best types of FRP. It was found that the presence of voids caused a decrease in the flexural strength and an increase in the deflection value; however, the process of strengthening with polymer fibers for this type of slab recovers and compensates for losses from the presence of voids.