Behavior of reinforced concrete ring beams strengthened with sustainable materials

Abstract

Reinforced Concrete Ring Beams (RCRBs) have been used in Reinforced Concrete (RC) buildings, tanks, and roof shell structures, such as domes and cones. The curviness feature of RCRBs may result in excessive tensile stresses that may consequently generate critical cracks in concrete, particularly when the beams are constructed with Normal Concrete (NC). This paper presents experimental and numerical investigations on the structural behavior of RCRBs strengthened with sustainable materials. The experimental results on 12 RCRBs constructed with various types of concrete and strengthened with several techniques are presented and discussed. The specimens were made of NC, Engineered Cementitious Composite (ECC), High Strength Concrete (HSC), and High Strength Fiber Reinforced Concrete (HSFRC). Three strengthening techniques were employed for strengthening, including the External Bonded Reinforcement (EBR) with stainless-steel plates (SSPs), the Near Surface Mounted (NSM) with steel bars, and the pre-stressing system. Three-dimensional Finite Element Models (FEMs) were developed by using ABAQUS software to simulate the nonlinear performance of RCRBs. The test results show that the use of sustainable materials in RCRBs can remarkably improve the strength and ductility of RCRBs. In addition, the strengthening techniques are effective in enhancing the responses of RCRBs against the applied loads. Moreover, the thickness and configuration of SSPs significantly affect the ultimate and energy absorption capacities of RCRBs. Finally, a good agreement is observed between numerical predictions and experimental results, suggesting that the finite element model can be employed for further investigations.