Cover
Vol. 16 No. 2 (2025)

Published: December 15, 2025

Pages: 178-190

Research Paper

Strength and Behavior of Light Weight Concrete Specimens Confined by Carbon Fibers

Karwan mohammed 1 Dilshad kakasor Jaf
1Department of Civil engineering, College of Ebgineering, University of Salahadding Erbil, Iraq
History
  • Received: August 17, 2025
  • Revised: October 14, 2025
  • Accepted: November 15, 2025
  • Available Online: December 15, 2025
DOI

https://doi.org/10.37649/AJES-25-021

Abstract

This paper investigates ultimate strength of lightweight concrete specimens: cubes, cylinders, and prisms wrapped by different layers CFRP respect to several curing periods. The specimens were prepared and tested under compressive and flexural loading at the ages of 7 days and 28 days with varying confinement levels (from unconfined; 0L to double-layer of CFRP, i.e., 2L). The results showed that all three factors: confinement level, specimen geometry and curing age had a significant effect on both compressive strength as well as flexural strength. Indigenous soft soil was wrapped with various CFRP wraps to study the change in failure mode from brittle to ductile with an increase in confinement and two-layer WR-CFRPs exhibited the maximum gains in compressive and flexure-up to 48% compressive, 380% of flexural strength when compared with unconfined specimens. Cylindrical samples prove always more pronounced strengthening effect than cubes, probably because of having a more even stress field and less influence to the corner effects. Besides, the confinement effect became more significant when specimens were left to cure for 28 days, highlighting initiation of concrete maturity requirement for best CFRP development. The findings indicated that early-age confinement (7-day, 2L) achieved strength equal or superior to shear-critical fully cured unconfined specimens, and confirmed the potential of CFRP in emergency repair and retrofitting. However, the ultimate strengths were the best when using both multi-layer CFRP confinement and full curing. These results highlight the synergistic relationship between geometry optimization, curing regimen and advanced fiber reinforcements in enhancing the structural response of lightweight concrete structure.

Keywords

References

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