International Journal of Civil and Structural Engineering Research ISSN 2348-7607 (Online) Vol. 9, Issue 2, pp: (60-67), Month: October 2021 - March 2022, Available at: www.researchpublish.com
Effect of SHEAR SPAN-TO DEPTH RATIO of Concrete Beams Reinforced with GFRP bars on Shear under fire Exposure M. A. OSMAN1, Hala Mamdouh2, Ahmed H. Ali3, Hamdy. M. Mohamed4, and T.S.kamal5 1
Professor of Civil Engineering, Helwan University, Cairo, Egypt. E-mail:m_osman62@yahoo.com 2 Assoc. Professor of Civil Engineering, Helwan University, Cairo, Egypt. E-mail: dr_hala_mamdoh@yahoo.com 3 Assistant. Professor of Civil Engineering, Helwan University , Cairo, Egypt E-mail: Ahmed.Ali@usherbrooke.ca 4 Assoc. Professor of Civil Engineering, Helwan University , Cairo, Egypt. E-mail: Hamdy.Mohamed@usherbrooke.ca 5 Lecturer assistant, Civil Engineering, Helwan University, Cairo, Egypt. E-mail: taher.sayed030@gmail.com
Abstract: Glass bars for concrete reinforcement, known as glass fiber-reinforced polymers (GFRPs), are new natural inorganic materials with distinct mechanical properties that have been used recently in the construction field. Generally, the FRPs bars have no yield before the brittle failure as steel bars and their behavior, when exposed to fire, is still under investigation, this paper presents an experimental study to get more knowledge about the characteristics and the fire resistance of a concrete beam reinforced using GFRPs. Three-scale concrete beams were constructed and tested up to failure under direct fire at 500 ◦C for an hour. Shear span-to depth ratio is the main parameter of this study. Beam (B1) had distance from face of support 670 mm ,beam (B2) had distance from face of support 250 mm and beam (B3) had distance from face of support 500 mm .All beams had 30 mm concrete cover , exposed to fire for an hour and three GFRPs reinforcement bars were used. The results are discussed in terms of load capacity, cracking behaviour, and failure modes. Moreover, the experimental results are compared with theoretical calculations according to the ACI code and other codes. The results show that when distance from face of support over effective depth greater than 2.5 the beams act as slender beams while distance from face of support over effective depth less than 2.5 the beams act as arch action. Our results also showed that when distance from face of support over effective depth 2.02 the failure load incress by percent 60.3% and beam failure as shear failure while distance from face of support over effective depth 1.01 the failure load incress by percent 221.7% and beam failure as flexural failure . More studies are needed to justify our observations in details and determine their applicabilities under different conditions. Keywords: Shear span, Concrete Beams, Depth ratio, GFRP bars.
1. INTRODUCTION The development of Fiber Reinforced Polymer (FRP) materials began in the 1940s for military and aerospace applications (C. Ballinger, 1) .FRP are be-coming increasingly popular in the engineering applications as alternative to conventional engineering materials. The unique characteristics of FRP such as their light weight, their resistance to corrosion, and the lower cost of construc-tion and maintenance, are very promising in the application of FRP in civil engineering (Z. M. Lin, 2). A fiber is a material made into a long filament. According to (Zobel, 3), a single fiber usually has a diameter up to 15 um. Bigger diameters generally increase the probability of surface defects. The aspect ratio of length and di-ameter can be ranging from thousand to infinity in continuous fibers. They usually occupy 30-70% of the volume of the composite and
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