CFRP Strengthening of Circular Geo-Polymer Concrete Slab with and without Openings
Received: 29 December 2024 | Revised: 23 January 2025 | Accepted: 27 January 2025 | Online: 3 April 2025
Corresponding author: Haider Raad Ali
Abstract
The current study investigates the eco-friendly concrete and specifically Geopolymer Concrete (GPC), and its behavior in reinforced concrete circular slabs both with and without openings. It also examines GPC strength utilizing Carbon Fiber Reinforced Polymer (CFRP) sheets under punching shear. Slag-based GPC was used to cast the slabs. The experimental part included testing six circular slabs divided into two groups with a diameter of 700 mm and a thickness of 70 mm, and a cast circular column with dimensions of 150 x 150 mm at the top face in the middle. The slab components of these samples were strengthened with a distorted 8 mm diameter dispersed across the section of 75 mm c/c. The circular column was reinforced by 5Ø6mm bars, with a 2Ø6@50mm tie to prevent local failure in the column before the slab. The investigated experimental variables included the column location and the strengthening schemes. Measurements were made for the first cracking load, mid-span vertical deflections, and ultimate load capacity. Also, the crack patterns were marked, and the failure mode was observed. Furthermore, the mechanical properties of the slag-based GPC were studied. The results showed that the modulus of rupture and modulus of elasticity were about 3.2 and 29725 Mpa, respectively, and the compressive Strength (fcu) about 45 Mpa. Each slab's initial crack appeared at a load between 23 and 50 kN of its ultimate capacity.
Keywords:
circular flat slabs, GPC, geopolymer concrete, strengthening, CFRPDownloads
References
Y. Tian, "Behavior and modeling of reinforced concrete slab-column connections," Ph.D. dissertation, University of Texas, Austin, 2007.
J. G. MacGregor and J. K. Wight, Reinforced Concrete: Mechanics and Design, Subsequent edition. Upper Saddle River, N.J: Pearson College Div, 2004.
A. A. Abdulhussein and M. H. Al-Sherrawi, "Experimental and Numerical Analysis of the Punching Shear Resistance Strengthening of Concrete Flat Plates by Steel Collars," Engineering, Technology & Applied Science Research, vol. 11, no. 6, pp. 7853–7860, Dec. 2021.
J. Moe, Shearing strength of reinforced concrete slabs and footings under concentrated loads. Skokie, Illinois: Portland Cement Association. Research and Development Laboratories, 1961.
B. O. Aalami, "Design of Post-Tensioned Floor Slabs," Concrete International, vol. 11, no. 6, pp. 59–67, Jun. 1989.
B. Binici, "Punching Shear Strengthening of Reinforced Concrete Slabs Using Fiber Reinforced Polymers," Ph.D. dissertation, University of Texas, Austin, 2003.
H. A. Ali and M. H. Al-Sherrawi, "An Experimental Investigation of Slab-Column Connection Strengthened with Steel Collar under Eccentric Load," Engineering, Technology & Applied Science Research, vol. 14, no. 6, pp. 17672–17677, Dec. 2024.
T. Mohammed, W. Alsaraj, and L. Zghair, "Structural Behavior of Self-Compacting Bendable Mortar Beams reinforced by GFRP Bars under Monotonic Loads," Engineering, Technology & Applied Science Research, vol. 14, no. 6, pp. 17848–17858, Dec. 2024.
H. Raad and A. Sabah, "The Behavior of Punching Shear Strength on Geo-Polymer Concrete Circular Slabs with Openings: A Review," Al-Rafidain Journal of Engineering Sciences, pp. 42–64, Nov. 2024.
D. Schnerch, K. Stanford, and B. Lanier, "Use of High ModulusCarbon Fiber Reinforced Polymer (CFRP) for Strengthening Steel Structures," North Carolina State University.
D. Kasim and W. AlSaraj, "Effect of Stirrups Shaped on Shear Capacity of Self-Compacting Concrete Beams Provided by External Steel Plate," Al-Rafidain Journal of Engineering Sciences, pp. 525–535, Jun. 2024.
A. Kumar, Rajkishor, N. Kumar, A. K. Chhotu, and B. Kumar, "Effect of Ground Granulated Blast Slag and Temperature Curing on the Strength of Fly Ash-based Geopolymer Concrete," Engineering, Technology & Applied Science Research, vol. 14, no. 2, pp. 13319–13323, Apr. 2024.
GB/T 18046-2017, Ground granulated blast furnace slag used for cement,mortar and concrete. Chinese GB Standards [spc], 2018.
Iraqi Specification. (1984). No. 45/1984, Aggregate from natural sources for concrete and construction. Baghdad, Iraq: Central Agency for Standardization and Quality Control, Planning Council.
ASTM E291-18, Standard Test Methods for Chemical Analysis of Caustic Soda and Caustic Potash (Sodium Hydroxide and Potassium Hydroxide). West Conshohocken: ASTM International.
ASTM C494/C494M-17, Standard Specification for Chemical Admixtures for Concrete. West Conshohocken: ASTM International.
ACI Committee 440, ACI PRC-440.1-15:Guide for the Design and Construction of Structural Concrete Reinforced with Fiber-Reinforced Polymer Bars. ACI, 2021.
ASTM A615/A615M-09b, Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement. West Conshohocken: ASTM International, 2012.
ACI Committee 440, 440.2R-08 Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures. ACI, 2008.
ACI Committee 318, ACI CODE-318-19: Building Code Requirements for Structural Concrete and Commentary. ACI, 2019.
Downloads
How to Cite
License
Copyright (c) 2025 Haider Raad Ali, Ali Sabah Al Amli
This work is licensed under a Creative Commons Attribution 4.0 International License.
Authors who publish with this journal agree to the following terms:
- Authors retain the copyright and grant the journal the right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after its publication in ETASR with an acknowledgement of its initial publication in this journal.
