New anchorage technique for NSM-CFRP flexural strengthened RC beam using steel clamped end plate Yasmeen Taleb Obaidat ⇑ , Wasim S. Barham, Abdelmalek H. Aljarah Civil Engineering Department, Jordan University of Science and Technology, P.O. 3030, 22110 Irbid Jordan highlights  A new mechanical anchor system to clamp the NSM-CFRP strip is used.  The new anchorage system provides a greater resistance capacity to reach yield load than the conventional system.  The beams strengthened with the new anchorage system technique showed more toughness than beams strengthened with NSM-CFRP only. article info Article history: Received 1 May 2020 Received in revised form 5 July 2020 Accepted 8 July 2020 Available online xxxx Keywords: Reinforced concrete Repair Flexural strength Near-Surface Mounted (NSM) Carbon Fiber Reinforced Polymer (CFRP) Anchorage device, steel clamped abstract Using appropriate techniques, or systems, is mandatory to strengthen those elements, such as the Near Surface Mounted (NSM)-Carbon Fiber Reinforced Polymer (CFRP). The goal of this paper is to find a new mechanical anchor system to clamp the NSM-CFRP strip at the end of the beam and prevent the end cover separation of the CFRP strip to increase the ultimate beam capacity load. This technique is based on using a steel plate at the end of the beam. A total of eleven reinforced concrete beams were constructed with concrete compressive strength of 35 MPa and dimensions of 250 mm  200 mm  1600 mm (height  width  length) and divided into three groups (control samples, beams with CFRP, and beams with CFRP strips and plate steel clamped). The beams were strengthened with one, two, and three CFRP strips. The main parameters studied were the type of NSM-CFRP strip fixation technique and the number of NSM-CFRP strips used. The test results show that the use of a steel plate at the end with horizontal CFRP strips in the beam is more efficient in increasing the ultimate load capacity, deflection behavior, stiffness, and toughness compared to NSM-CFRP strengthened beams. Ó 2020 Elsevier Ltd. All rights reserved. 1. Introduction Rehabilitating a structure is a significant field in civil engineer- ing. Many methods have been developed for use in repairing beams over the last decades [1]. Among those is the Fiber Rein- forced Polymer (FRP) technique, which is used for beam strength- ening. The conventional method, used to strengthen reinforced concrete (RC) beams, involves fixing the FRP on the tension face of the beam when the capacity of the existing structure is inade- quate in flexure. There are different types of FRP, such as: strips, cord, sheet, or rod. Fiber-reinforced polymer (FRP) is a composite material that consists of a polymer matrix reinforced with fibers. The most pre- ferred kinds of FRP, by specialists, are: the carbon fiber reinforced polymer (CFRP), glass fiber reinforced polymer (GFRP), and aramid fiber-reinforced polymer (AFRP) [2–5]. The carbon CFRP has shown the best performance of all because of its strong performance in the long-term loading. Also, the CFRP has been widely used to rehabilitate and strengthen the RC element structure. CFRP has several advantages, including: resistance to corrosion, easy instal- lation, high tensile strength, enhanced ductility, ultimate load capacity, and ultimate deformation of RC element compared to the conventional element [6–10]. As for CFRP, two fixation techniques are used. First, the Exter- nally Bonded (EB), where the CFRP is bonded by high strength adhesive to the concrete face [11,12]. The second fixation tech- nique is Near-Surface Mounted (NSM), where the CFRP is bonded into a groove at the concrete surface [13,14]. The use of the NSM technique to strengthen RC elements may result in the increase of the flexural capacity, shear capacity, bond carrying capacity, and the ultimate deflection, unlike the case when using the EB technique [15–18]. Researchers identified several failure modes of beams that use strengthening with the NSM-CFRP technique. It must be noted that https://doi.org/10.1016/j.conbuildmat.2020.120246 0950-0618/Ó 2020 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Construction and Building Materials 263 (2020) 120246 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat