Strengthening of High Performance Reinforced Cement Concrete Hollow Beams Using Fibre Reinforced Polymer Laminates

Abstract

Concrete is a versatile building material that it ranks second in the world in terms of per capita consumption next to water. Each year, Reinforced Concrete (RC) components are used to construct millions of structures, including residential units, commercial buildings, industrial buildings, and bridges. These constructions incorporate RC elements extensively. While there is a lot of knowledge on the behaviour and strength of solid RC beams and Beam Column Joints (BCJ), a suand#64259;cient amount of information on the behaviour and strength of hollow RC beams and BCJs with longitudinal holes is lacking. The inclusion of longitudinal holes in structural elements results in a reduction in its own weight. As a result, the size of other structural parts such as columns and foundations that support these beams and BCJs will be lowered, resulting in material savings. Additionally, important utility services such as water supply, sewage, air conditioning ducts, electricity, and telephone cables can be routed via the longitudinal gaps of these beams as needed. With these considerations in mind, an attempt was made to investigate the behaviour and strength of RC hollow beams and BCJs with a longitudinal hole. The primary objective of this investigation is to characterize the behaviour and strength of rectangular reinforced concrete hollow beams and BCJs when subjected to gradually increasing and symmetrically applied loads. This research also explores the behaviour of hollow RC beams and BCJs externally reinforced with Carbon Fibre Reinforced Polymer (CFRP) sheets and internally reinforced with steel rods. An experimental program was performed on hollow RC beams to investigate the behaviour of the CFRP reinforcement systems. The results of the test showed that all reinforced samples provided higher flexural strength and ductility values compared to the unreinforced control Beam. In contrast, the beams reinforced with steel fiber reinforcement and CFRP sheets achieved higher ductility compared to the CFRP sheet strengthened