Behaviour of Shear Deficient Reinforced Concrete Beams with Externally Bonded Aluminum Plates

Abstract

Enhancing the shear capacity of reinforced concrete (RC) beams was done using many different ways and materials. Steel and Fiber reinforced polymers are the most common materials used to strengthen RC beams in shear. However, the aim of this research is to investigate the performance of aluminum alloy in strengthening RC beams deficient in shear. In this research, the shear capacity of reinforced concrete beams strengthened with externally bonded aluminum (Al) plates are investigated and analyzed. The aluminum alloy metal has been selected due to its thermal resistance, high strength to weight ratio, corrosion resistance and may be low cost compared to other metals. Twenty six beams have beam strengthened with externally bonded aluminum alloy and tested under four point loading to failure. The beams were divided into two groups. Group "A" includes six beams that are shear deficient in both sides and strengthened with aluminum alloy plate 5083-0. Group "B" consists of 20 beams that are shear deficient in one side only and strengthened externally with aluminum alloy 5083-111. The beams were designed to fail in shear and then strengthened with aluminum alloy plates with different reinforcement ratio, strip spacing and strip orientation. The parameters that were considered to investigate the effectiveness of using aluminum plates to strengthen shear deficient reinforced concrete beams as compared to the control beam included load-carrying capacity, deflection and change in stiffness, variation of strain in plates, change in beam ductility and failure modes. The results of all tested beams showed an increase in the load carrying capacity ranged from 10% to 89% from the control beam. A finite element was developed for group "A" beams as a benchmark to compare experimental and numerical results. The results showed a great agreement between both results. In addition, an equation for shear contribution of aluminum plates to RC beams was developed and built up using three different codes which are ACI440-08, TR55 and FIB 14. The test results showed a greet agreement and some variability with the values predicted by the equations of FIB14.