Strengthening of Reinforced Concrete Cantilever Beams by Using Externally Bonding and Near-Surface Mounting Strengthening Techniques
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Abstract
This research aims to study the efficiency of using different strengthening techniques to strengthen the reinforced concrete cantilever beams. Carbon fiber reinforced polymer (CFRP) strips and laminates with different patterns are used for this purpose. The practical program consisted of casting and testing of nine reinforced concrete cantilever beams (RCC). All these specimens had the same dimensions of (200×300×1250) mm, as well as the same main and secondary reinforcement. One of these beams was considered a reference beam with no strengthening, while the other eight beams were strengthened with the mentioned strengthening techniques. The strengthening variables included the type of CFRP (strips or laminate), the number (or equivalent area) of strips and the laminates, and the strengthening technique (external bonded EB and near surface mounted NSM). All specimens were tested until failure under point load at the free end of the beams. The results showed that all the used strengthening techniques increased the strength of beams for ultimate load and stiffness, with increasing ratios ranging from 37% to 67%. The strengthened tested beams noticeably increased with the CFRP layer (or area) for both types of CFRP (strips and laminates). Also, the CFRP laminate showed a higher effect in the increase in beam strength than the CFRP strips. Related to the strengthening technique, the Near Surface Mounted technique showed a higher effect in increasing beam strength than the External Bonded technique for different strengthening types and amounts.
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References
Hool GA, Johnson NC. Elements of Structural Theory - Definitions. In: Handbook of Building Construction. Volume 1. 1st ed. New York: McGraw-Hill; 1920:2.
Danraka MN, Mahmod HM, Oluwatosin OKJ. Strengthening of Reinforced Concrete Beams Using FRP Technique: A Review. International Journal of Engineering Science 2017; 7(6):13199.
Fucheng W, Shujuan Y, Zhe F. Enhancement of Cantilever Beams with Fibre-Reinforcement Plastic. Chemical Engineering Transactions 2018; 64:85-90.
Edina AS, Al Quraishya QA, Salmanb MM. Improvement of Flexural Behavior of Reinforced Concrete Cantilever Hollow Beam by Using Carbo-DUR CFRP. International Journal of Advanced Science and Technology 2019; 28(20):1210-1228.
Abdulrazak R, Tahar HD, Rabia B, Tounsi A. Mechanical Behavior of RC Cantilever Beams Strengthened with FRP Laminate Plate. Advances in Computational Design 2021; 6(3):169-190.
Mashrei MA, Makki JS, Sultan AA. Flexural Strengthening of Reinforced Concrete Beams Using Carbon Fiber Reinforced Polymer (CFRP) Sheets with Grooves. Latin American Journal of Solids and Structures 2019; 16(4):e176. DOI: https://doi.org/10.1590/1679-78255514
Abdulrahman MB, Salih SA, Abduljabbar RJ. The Assessment of Using CFRP to Enhance the Behavior of High Strength Reinforced Concrete Corbels. Tikrit Journal of Engineering Sciences 2021; 28(1):71-83. DOI: https://doi.org/10.25130/tjes.28.1.08
AlAli SS, Abdulrahman MB, Tayeh BA. Response of Reinforced Concrete Tapered Beams Strengthened Using NSM-CFRP Laminates. Tikrit Journal of Engineering Sciences 2022; 29(1):99-110. DOI: https://doi.org/10.25130/tjes.29.1.08
Salih YA, Sabeeh NN, Yass MF, Ahmed AS, Abdulla AI. Behavior of Ferrocement Slabs Strengthening with Jute Fibers Under Impact Load. International Review of Civil Engineering 2020; 11(2):66-72. DOI: https://doi.org/10.15866/irece.v11i2.17322
Qeshta IM, Shafigh P, Jumaat MZ, Abdulla AI, Ibrahim Z, Alengaram UJ. The Use of Wire Mesh–Epoxy Composite for Enhancing the Flexural Performance of Concrete Beams. Materials and Design 2014; 60:250-259. DOI: https://doi.org/10.1016/j.matdes.2014.03.075
Abdulla AI. Behavior of RC Beams Strengthened by CFRP and Steel Rope Under Frequent Impact Load. Journal of Advanced Sciences and Engineering Technologies 2018; 1(1):30-42. DOI: https://doi.org/10.32441/JASET.001.1.05
Abdulla AI, Mahasneh KN, Shaheen MW, Khazaal AS, Ali MI. Behavior of Reinforced Concrete Beams Strengthened by CFRP and Wire Rope. Journal of Advanced Sciences and Engineering Technologies 2018; 1(3):33-45. DOI: https://doi.org/10.32441/jaset.02.03.04
Iraqi Standard Specifications No. 5. Portland Cement. Central Agency for Standardization and Quality Control, Planning Council; Baghdad, Iraq: 1984.
Iraqi Standard Specifications No. 45. Aggregate from Natural Sources for Concrete. Central Agency for Standardization and Quality Control, Planning Council; Baghdad, Iraq: 1984.
ASTM A615/A615M-15a. Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement. American Society for Testing and Materials; 2018.
ACI Committee 211.1-91. Standard Practice for Selecting Proportions for Normal, Heavyweight, and Mass Concrete (ACI 211.1-91). American Concrete Institute; 1991.
Wu HC, Eamon CD. Strengthening of Concrete Structures Using Fiber Reinforced Polymers (FRP): Design, Construction and Practical Applications. 2017. DOI: https://doi.org/10.1016/B978-0-08-100636-8.00002-8
ASTM C39-14. Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens. American Society for Testing and Materials; 2014.
ASTM C496/C496M. Splitting Tensile Strength of Cylindrical Concrete Specimens. American Society for Testing and Materials; 2017.
ASTM C1018. Standard Test Method for Flexural Toughness and First-Crack Strength of Fiber-Reinforced Concrete. American Society for Testing and Materials; 2018.
ACI 544.4R-88 Report. Design Considerations for Steel Fiber Reinforced Concrete. American Concrete Institute; 1988.