Browsing by Author "Bouaissi, Aissa"

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    An experimental study on damaged cementitious mortars repaired by glass/epoxy composite materials
    (Sciendo, 2020) Aribi, Chouaib; Bouaissi, Aissa; Safi, Brahim; Saidi, Mohammed
    This paper presents an experimental investigation on the post-repair flexural response of mortars with and without damage. In order to improve the mechanical properties of the damaged mortars, which were subjected to different loads ranging between 40 % and 90 %, the mortars specimens were reinforced and repaired using two different composite materials, the first with only epoxy resin, while the second consisted of a mixture of epoxy resin and glass fiber. The results show a significant improvement in the stiffness damaged. Therefore, the reinforced specimens by a layer of resin on the lower side surface increased the bending strength by 58 %, when compared to those control samples. The reinforcement using composite resin-fiber of glass exhibited considerable increases in the safety of constructions. The SEM images of damaged samples with and without repair, revealed the impact of reinforced glass fibers-mortar on the matrix-mortar by improving theirs mechanical performances
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    Synthesis of resin from Alfa stem to applied as an adhesive corrosion-resistant coating
    (Springer Nature link, 2025) Toubal, Sara; Aribi, Chouaib; Chentir, Imen; Safi, Brahim; Bouaissi, Aissa; Saidi, Mohammed
    The demand for eco-friendly alternatives to petrochemical-based phenolic resins has risen due to increasing concerns about climate change, environmental impact, and manufacturing costs. This study introduces a sustainable approach by partially replacing phenol with lignin, a natural polymer rich in phenolic groups, extracted from Alfa stems. Using the alkaline method, 50% of phenol was substituted with lignin to synthesize phenol–formaldehyde (PF) resins. The synthesized lignin–phenol– formaldehyde (LPF) resin was characterized to verify its chemical structure and physical properties. The resin demonstrated significant antioxidant and antibacterial activity, particularly against E. coli and P. aeruginosa gram-negative bacteria at a concentration of 20 mg/ml. Additionally, the lignin substitution provided notable advantages over conventional industrial resin formulations. The lignin’s properties closely influenced the formulation of the LPF resin, making it similar to the reference CPF resin. However, the lower intensity observed in the LPF resin suggests potential limitations in the methylol group formation compared to the CPF resin. The antioxidant activity of LPF resin has been effectiveness in preventing cor- rosion on steel surfaces. When applied as an anti-corrosion coating and compared to industrially used CPF resins, LPF resin demonstrates its efficacy in such applications. Also, it should be noted that the impedance modulus of the elaborated resin coating remained consistently low throughout the entire immersion period, indicating its stable performance.