Effect of textile density and number of layers on the flexural behaviour of RC beams strengthened with steel reinforced grout systems

Alotaibi, Sultan; Thermou, Georgia; Hajirasouliha, Iman; Guadagnini, Maurizio

Abstract

This paper presents the results of an experimental investigation on the flexural behaviour of reinforced concrete (RC) beams strengthened with multi-layer Steel Reinforced Grout (SRG) systems. The effect of textile density (4 and 8 cords/in) and number of layers (1 and 2 layers) was examined through a series of four-point bending tests on six RC beams. All beams were instrumented with a set of LVDTs to measure deflection and slip of the SRG composite and a set of strain gauges to obtain the strain in the internal reinforcement. A Digital Image Correlation (DIC) system was also used to obtain crack patterns and strain maps. All strengthened beams developed a comparable load-deflection response, and the strengthened beams exhibited an overall stiffer response. The use of the low-density steel textiles (4 cords/in) enabled a better distribution of the grout around the cords and resulted in a better composite behaviour of the SRG system and a full exploitation of the textiles, which eventually failed by tensile rupture regardless of the number of textile layers. The use of high-density steel textiles (8 cords/in) compromised the bond between the textile and the matrix and interlaminar shear failure developed at the textile-matrix interface of the beams strengthened with a single layer of textile, while the beams strengthened with two layers ultimately failed by end debonding of the SRG composite. The SRG composite provided an enhancement in load carrying capacity ranging from 10% to 28%, while still ensuring a similar deflection performance.

• Journal Article Type: Article
• Acceptance Date: Apr 25, 2024
• Online Publication Date: May 8, 2024
• Publication Date: Jun 7, 2024
• Deposit Date: Apr 30, 2024
• Publicly Available Date: May 9, 2025
• Journal: Construction and Building Materials
• Print ISSN: 0950-0618
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 430
• Article Number: 136424
• DOI: https://doi.org/10.1016/j.conbuildmat.2024.136424
• Keywords: Strengthening; Retrofitting; flexure; beams; Steel Reinforced Grout; Digital Image Correlation
• Public URL: https://nottingham-repository.worktribe.com/output/34332671