International Journal of Scientific & Engineering Research Volume 12, Issue 1, January-2021 657 ISSN 2229-5518 IJSER © 2021 http://www.ijser.org Experimental Study on Steel-FRP Reinforced Concrete Beams with Large Rectangular Openings Sameh Yehia 1 , Arafa M. A. Ibrahim 2 and Badr Faihan 3 1 Associate Professor, Faculty of Engineering, Suez University, Egypt dsyehia@hotmail.com / s.yehia@suezuni.edu.eg 2 Assistant Professor, Faculty of Engineering, South Valley University, Egypt 3 MSc. Student, Faculty of Engineering, South Valley University, Egypt Abstract— This paper investigates the structural performance of concrete beams reinforced with steel and fiber-reinforced polymer (FRP) bars that having large rectangular openings. An experimental study was conducted on three FRP steel reinforced concrete (FSRC) beams using basalt FRP (BFRP) bars. The FSRC beams were consisted of one beam without openings served as a reference beam; one beam with non-reinforced openings and one beam with reinforced openings. All beams were tested under the effect of two line loads bending test up to failure. Based on the test results, it was found that the presence of opening produces earlier cracks at opening locations. These cracks increased and propagate continuously with the increasing in applied load and lead to earlier failure. Compared to similar beams without openings, the presence of non-reinforced and reinforced openings was found to produce reductions in strength of up to 75% and 63%, respectively. Index Terms— Beams with openings, Basalt fiber-reinforced polymer, FRP, Stiffness, Ductility, Flexural strength, strengthening. . ——————————  —————————— 1 INTRODUCTION The elastoplastic characteristics of steel reinforcements have become important issues in steel reinforced concrete (SRC) structures located in harsh environments and/or active seismic zones. Fiber Reinforced Polymer (FRP) has become a practical alternative construction material replacing conven- tional steel reinforcements in reinforced concrete (RC) struc- tures due to its advantages, such as, corrosion resistance, non-conductivity, high strength-to-weight ratio and light weight. Although FRP has many advantages to be adopted as a construction material, it intrinsically lacks some important structural characteristics (e.g. ductility and initial stiffness). Therefore, composite syst ems of steel and FRP rebar’s to pro- duce FRP steel reinforced concrete (FSRC) structures have been proposed in many experimental and analytical research programs found in the literature (e.g. Ibrahim et al. 2015; Mustafa and Hassan 2018; Aiello and Ombres 2002). Through these programs, it was reported that by adding FRP bars to the SRC structures the damage of structures due to steel corrosion can be mitigated. Moreover, the seismic re- sistance can be improved through controlling both the post yield stiffness and post-earthquake recoverability; that is the life safety objectives of RC structures can be achieved. In continuation of the causes of failure of RC structures, the presence of openings in the web of RC beams leads to many problems in the beam behavior such as reduction in the beam strength and stiffness, excessive cracking, and exces- sive deflection. Despite its great influence on the structural performance of RC beams, there is ever increasing need for providing holes and openings at to the beams to allow the continuity of ducts and pipes for sanitation, heating, ventila- tion, air-conditioning, electricity, telephone and computer networks and other mechanical equipment. In fact, passing these ducts through transverse openings in the floor beam may be considered the most practical alternative arrange- ment instead of placing them underneath the soffit of the beam which needs covering them by a suspended ceiling, thus creating a “dead space” in each floor. In cases of small buildings, the saving thus achieved may not be significant compared to the overall cost but in cases of multistory build- ings, any saving in story height multiplied by the number of stories can represent a substantial saving in total height, length of air-conditioning and electrical ducts, plumbing ris- ers, and overall load on the foundation. During the last few decades, several experimental and analytical studies have been conducted to investigate the me- chanical properties of SRC beams with openings. Two main categories of studies have been carried out in this area: the first one has been conducted with the aim of finding the main parameters affecting the structural performance of such beams (e.g. Mansur et al. 2001; Al-Shaarbaf et al. 2007; Ashour and Rishi 2000; Aykac et al. 2013; Herrera et al. 2017), while the aim of the second category was directed to finding different ways for enhancing the performance of the beams and mitigating the influence of providing the open- IJSER