Publications Scientifiques

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Author: search.filters.author.Safi, BrahimAuthor: search.filters.author.Saidi, Mohammed

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Now showing 1 - 10 of 13
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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.
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    Effect of nanosilica-doped superplasticizer on the properties of cement mortars
    (STEF92 Technology, 2023) Safi, Brahim; Mechakra, Hamza; Saidi, Mohammed; Lecheb, Samir
    Recently, nanotechnology has attracted a considerable scientific interest due the potential new uses of non-particles, which can improve the properties of cement mortars or concretes, such as Nanosilica. Nanoparticles, like those of nanosilica, have been shown to have unique physical and chemical properties different from those of conventional cement additions. Nanosilica was used either to replace part of the cements or as an addition to improve the performance of the cement such as accelerating the hydration of the cement phases. This work investigates the effect of nanosilica adding to superplasticizer on fresh and hardened properties of cement mortars. For this, three superplasticizer types of three different firms doped with nanosilica (NS) at 1.5% wt. of superplasticizer (SP) to estimate the effect of nanosilica-based superplasticizer on the properties of cement mortars in the fresh and hardened state. An experimental study was conducted to evaluate the three SP based on NS on fresh and hardened properties. Our results show that nanosilica is compatible with the three superplasticizer, what is remarkable on the mortars in the fresh state, with a good workability which is between (24cm and 28cm) and a total absence of segregation which acts on the mechanical properties of the self-consolidating mortar in (3,7 and 28 days).
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    Behavior of mortars hydraulic and organic matrix in aggressive environments
    (2013) Saidi, Mohammed; Safi, Brahim; Samar, Mohamed Faouzi; Benmounah, A.; Hamiane, Messaoud
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    Optimization of the process of cooking and drying of brick
    (isjaee, 2010) Saidi, Mohammed; Hamiane, Messaoud; Benmounah, A.; Safi, Brahim
    The construction materials play an enormous part in the economy of the country; this industry comprises a very varied range of products going of simple pottery passing by brick of construction until the technical porcelain and the industry of cements. As, this production takes a so important rise as the realization of manufacturing plant becomes a daily reality. This realization of quite quantitative factory that qualitative depends on the availability of a raw material of quality, means of production in good knowledge and operating condition to make allowing a perfect control of the process. Considering, the enormous part which plays the construction materials in particular the bricks of construction in the economy of the country. We were interested to make a study concerning the production unit of bricks of Boudouaou (east of Algeria) on the technological, thermal and economic level since the essential study is made on the thermal part in order to calculate the acceptable mode of cooking and to calculate the combustion of gas. The study of the heat balance enables us to know how calculations can be carried out and of knowing how and the energies brought to the furnace spent are consumed. This study enabled us to make a saving in gas in the order of 63.5 m³/h and to make a profit of energy of 266.37 kJ/kg of product and to obtain a better use of the drier and furnace with a possible maximum thermal efficiency
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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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    Performance of Self-Compacting mortars containing foam glass granulate
    (2015) Safi, Brahim; Aboutaleb, Djamila; Saidi, Mohammed; Benmounah, Abdelbaki; Benbrahim, Fahima
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    Influence of nanosilica and a polycarboxylate superplasticizer on the pheological and electrokinetical properties of cement pastes
    (Academic Journals, 2014) Samar, Madjid; Benmounah, Abdelbaki; Safi, Brahim; Kheribet, Rabia; Saidi, Mohammed
    The effect of individual and combined addition of both nanosilica (NS) and polycarboxlate ether plasticizer (PCE) admixtures on cements pastes was studied. the sole incorporation of NS increased the water demand, as proved by the mini-spread flow test…