Current issue
Archive
About the Journal
About
Editorial Board
Abstract & Indexing
Contact
Editorial Policies
Authorship & COI
Ethical principles
Principles of Transparent Checklist
Open access
For Authors
Instructions to Authors
Detailing Guidelines for Authors
Review process
Review sheet
How to submit
Open Access license
ORIGINAL PAPER
Strengthening of Reinforced Normal and Self-Compacted Concrete Beams: Comparative Experimental Investigation
1
Civil Engineering Department, University of Sulaimani, Iraq
2
Civil Engineering Department, University of Halabja, Halabja, Iraq
3
Materials Engineering, Mustansiriyah University, Iraq
4
Civil Engineering Department, University of Wasit, Iraq
These authors had equal contribution to this work
Submission date: 2025-03-27
Final revision date: 2025-06-11
Acceptance date: 2025-11-12
Online publication date: 2026-03-16
Publication date: 2026-03-16
International Journal of Applied Mechanics and Engineering 2026;31(1):108-122
KEYWORDS
TOPICS
ABSTRACT
Carbon fiber reinforced polymer (CFRP) is a sustainable and long-lasting material that can improve concrete strength in many different structural contexts. This work shows how well near-surface mounted (NSM) CFRP improves the flexural behavior of both self-compacted and normal-strength reinforced concrete beams. Six sets of reinforced concrete beams were cast in three groups with normal-strength concrete and three groups with self-compacted concrete. Four groups were externally strengthened using NSM-CFRP bars, and the remaining two groups acted as control beams without CFRP reinforcement. Two NSM groups had CFRP bars placed at the sides of the beams, whereas in the other NSM two groups, the bars were buried at the bottom. For normal-strength concrete and self-compacted concrete, the experimental findings showed that side-mounted NSM-CFRP bars increased the flexural strength by 32% and 44%, respectively. The flexural strength increases were 25% and 38% when mounted at the bottom. The novelty of this work lies in its comparative evaluation of two CFRP installation procedures across two concrete types under consistent structural and testing conditions, a feature not thoroughly investigated in previous work. This dual-variable approach provides a useful understanding of how to maximize CFRP retrofitting strategies depending on the concrete type and application situation.
REFERENCES (37)
1.
Ahmad S.A., Rafiq S.K., Ahmed H.U., Abdulrahman A.S. and Ramezanianpour A.M. (2023): Innovative soft computing techniques including artificial neural network and nonlinear regression models to predict the compressive strength of environmentally friendly concrete incorporating waste glass powder.– Innovative Infrastructure Solutions, vol.8, No.4, p.119, DOI: 10.1007/s41062-023-01089-7.
2.
Talbot A.N. and Richart F.E. (1923): The strength of concrete, its relation to the cement aggregates and water.– University of Illinois Engineering Experiment Station Bulletin, No.137.
4.
Fattal S.G. (1974): Structural Performance of Low-Cost Housing and Community Buildings Under Earthquake Conditions.– Building Science Series 48, p.13.
5.
Ahmed D.A., Jumaa G.B. and Khalighi M. (2022): Mechanical properties and shear strength of rubberized fibrous reinforced concrete beams without stirrups.– Construction and Building Materials, vol.350, p.128796, DOI: 10.1016/j.conbuildmat.2022.128796.
6.
Ahmad S.A., Rafiq S.K. and Faraj R.H. (2023): Evaluating the effect of waste glass granules on the fresh, mechanical properties and shear bond strength of sustainable cement mortar.– Clean Technologies and Environmental Policy, pp.1-20, DOI: 10.1007/s10098-023-02485-4.
7.
Ahmad S.A., Ahmed H.U., Ahmed D.A., Hamah-ali B.H.S., Faraj R.H. and Rafiq S.K. (2023): Predicting concrete strength with waste glass using statistical evaluations, neural networks, and linear/nonlinear models.– Asian Journal of Civil Engineering, pp.1-13, DOI: 10.1007/s42107-023-00692-4.
8.
Ahmad S.A., Rafiq S.K. and Faraj R.H. (2023): Modeling the compressive strength of green mortar modified with waste glass granules and fly ash using soft computing techniques.– Innovative Infrastructure Solutions, vol.8, No.1, p.67, DOI: 10.1007/s41062-023-01041-9.
9.
Khan M.I. and Siddique R. (2011): Utilization of silica fume in concrete: Review of durability properties.– Resources, Conservation and Recycling, vol.57, pp.30-35, DOI: 10.1016/j.resconrec.2011.09.016.
10.
Raj A., Sathyan D. and Mini K.M. (2019): Physical and functional characteristics of foam concrete: a review.– Construction and Building Materials, vol.221, pp.787-799, DOI: 10.1016/j.conbuildmat.2019.06.052.
11.
Ahmad S.A., Rafiq S.K., Hilmi H.D.M. and Ahmed H.U. (2023): Mathematical modeling techniques to predict the compressive strength of pervious concrete modified with waste glass powders.– Asian Journal of Civil Engineering, pp.1-13, DOI: 10.1007/s42107-023-00811-1.
12.
Faraj R.H., Ali H.F.H., Sherwani A.F.H., Hassan B.R. and Karim H. (2020): Use of recycled plastic in self-compacting concrete: A comprehensive review on fresh and mechanical properties.– Journal of Building Engineering, vol.30, p.101283, DOI: 10.1016/j.jobe.2020.101283.
13.
Jafr F.S., Mohammed A.A. and Ahmed H.M. (2023): Surface area model to assess the plastic aggregate concrete properties.– Tikrit Journal of Engineering Sciences, vol.30, No.1, pp.130-142, DOI: 10.25130/tjes.30.1.13.
14.
McNeil K. and Kang T.H.K. (2013): Recycled concrete aggregates: a review.– International Journal of Concrete Structures and Materials, vol.7, pp.61-69, DOI: 10.1007/s40069-013-0032-5.
15.
Faraj R.H., Sherwani A.F.H., Jafer L.H. and Ibrahim D.F. (2021): Rheological behaviour and fresh properties of self-compacting high strength concrete containing recycled PP particles with fly ash and silica fume blended.– Journal of Building Engineering, vol.34, p.101667, DOI: 10.1016/j.jobe.2020.101667.
16.
Chan S.Y., Peng G.F. and Chan J.K. (1996): Comparison between high strength concrete and normal strength concrete subjected to high temperature.– Materials and Structures, vol.29, pp.616-619, DOI: 10.1007/BF02485969.
17.
Karataş M.A. and Gökkaya H. (2018): A review on machinability of carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) composite materials.– Defence Technology, vol.14, No.4, pp.318-326, DOI: 10.1016/j.dt.2018.02.001.
18.
Zhu J.H., Wei L., Wang Z., Liang C.K., Fang Y. and Xing F. (2016): Application of carbon-fiber-reinforced polymer anode in electrochemical chloride extraction of steel-reinforced concrete.– Construction and Building Materials, vol.120, pp.275-283, DOI: 10.1016/j.conbuildmat.2016.05.103.
19.
Hassan T. and Rizkalla S. (2003): Investigation of bond in concrete structures strengthened with near surface mounted carbon fiber reinforced polymer strips.– Journal of Composites for Construction, vol.7, No.3, pp.248.
20.
El-Wakkad N.Y. (2008): Strengthening of Reinforced Concrete Deep Beams Using Near-Surface Mounted Technique (NSM).– Ph.D. thesis, Menoufiya University, Egypt.
21.
De Lorenzis L., Miller B. and Nanni A. (2001): Bond of FRP laminates to concrete.– ACI Materials Journal, vol.98, No.3, pp.256-264.
22.
Nordin H. and Täljsten B. (2006): Concrete beams strengthened with pre-stressed near surface mounted CFRP.– Journal of Composites for Construction, vol.10, No.1, pp.60-68, DOI: 10.1061/(ASCE)1090-0268(2006)10:1(60).
23.
Cruz J.S. and Barros J. (2004): Modeling of bond between near-surface mounted CFRP laminate strips and concrete.– Computers & Structures, vol.82, No.17-19, pp.1513-1521, DOI: 10.1016/j.compstruc.2004.03.047.
24.
Li M., Soo S.L., Aspinwall D.K., Pearson D. and Leahy W. (2018): Study on tool wear and workpiece surface integrity following drilling of CFRP laminates with variable feed rate strategy.– Procedia CIRP, vol.71, pp.407-412, DOI: 10.1016/j.procir.2018.05.055.
25.
Li B., Chi Y., Xu L., Shi Y. and Li C. (2018): Experimental investigation on the flexural behaviour of steel-polypropylene hybrid fiber reinforced concrete.– Construction and Building Materials, vol.191, pp.80-94, DOI: 10.1016/j.conbuildmat.2018.09.202.
26.
Zhang Y., Chen L. and Xu Q. (2022): Bond behavior of NSM CFRP bars in normal and self-compacting concrete: Experimental and numerical insights.– Construction and Building Materials, vol.314, p.125669.
27.
Al-Salami T.H. and Hussein W.K. (2023): Anchorage mechanisms in NSM-CFRP strengthening of RC beams cast with SCC and NCC.– Engineering Structures, vol.278, p.115456.
28.
Mohammed A.M., Razaq A. and Jasim M. (2024): Optimization of near-surface mounted CFRP for retrofitting concrete members: recent advancements.– Composite Structures, vol.320, p117842.
29.
ASTM C33 / C33M-13 (2013): Standard Specification for Concrete Aggregates.– ASTM International, West Conshohocken, PA. Available at: www.astm.org.
30.
ASTM C128-15 (2015): Standard Test Method for Relative Density (Specific Gravity) and Absorption of Fine Aggregate.– ASTM International, West Conshohocken, PA. Available at: www.astm.org.
31.
ASTM C29 / C29M-17a (2017): Standard Test Method for Bulk Density (“Unit Weight”) and Voids in Aggregate.– ASTM International, West Conshohocken, PA. Available at: www.astm.org.
32.
ASTM C127-15 (2015): Standard Test Method for Relative Density (Specific Gravity) and Absorption of Coarse Aggregate.– ASTM International, West Conshohocken, PA. Available at: www.astm.org.
33.
El-Mihilmy M.T. and Tedesco J.W. (2000): Analysis of reinforced concrete beams strengthened with FRP laminates.– J. of Structural Eng., vol.126, No.6, pp.684-691, https://doi.org/10.1061/(ASCE)...).
34.
ASTM A615-16 (2015): Standard Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement.– ASTM International, West Conshohocken, PA. Available at: www.astm.org.
35.
FNARC (2005): Specification and guidelines for self-compacting concrete.– European Federation of National Associations Representing for Concrete. https://www.efnarc.org.
36.
Ali Z.S., Hosseinpoor M. and Yahia A. (2020): New aggregate grading models for low-binder self-consolidating and semi-self-consolidating concrete (Eco-SCC and Eco-semi-SCC).– Construction and Building Materials, vol.265, p.120314..
37.
Park R. (1989): Evaluation of ductility of structures and structural assemblages from laboratory testing.– Bulletin of the New Zealand Society for Earthquake Engineering, vol.22, No.3, pp.155-166.
| eISSN: | 2353-9003 |
| ISSN: | 1734-4492 |
Task: edition of a scientific journal, its internationalization and ensuring open access to the journal via the Internet
© 2006-2026 Journal hosting platform by Bentus
We process personal data collected when visiting the website. The function of obtaining information about users and their behavior is carried out by voluntarily entered information in forms and saving cookies in end devices. Data, including cookies, are used to provide services, improve the user experience and to analyze the traffic in accordance with the Privacy policy. Data are also collected and processed by Google Analytics tool (more).
You can change cookies settings in your browser. Restricted use of cookies in the browser configuration may affect some functionalities of the website.
You can change cookies settings in your browser. Restricted use of cookies in the browser configuration may affect some functionalities of the website.
