References of "Kenaï, Saïd"
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See detailDurability of mortar and concretes containing slag with low hydraulic activity
Hadj Sadok, Ahmed; Kenaï, Saïd; Courard, Luc ULg et al

in Cement & Concrete Composites (2012), 34(5), 671677

Granulated blast furnace slag has been widely used as a partial substitute for Portland cement in many applications because of advantages which include cost reduction, reduction in heat evolution and ... [more ▼]

Granulated blast furnace slag has been widely used as a partial substitute for Portland cement in many applications because of advantages which include cost reduction, reduction in heat evolution and improvement of durability properties. However, the effectiveness of slag depends on its hydraulic reactivity. In this paper, the results of an experimental study on the effect of slag with low hydraulicity on the mechanical and durability properties of concrete and the performance of mortar under sulfate attack are discussed. Special attention is given to gas permeability and water absorption of slag concrete. The durability of slag concrete is improved at long term at low Water/Binder ratio. Sulfate resistance of mortar is improved by slag replacement up to 30%. [less ▲]

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See detailMicrostructure and durability of mortars modified with medium active blast furnace slag
Hadj Sadok, Ahmed; Kenaï, Saïd; Courard, Luc ULg et al

in Construction & Building Materials (2011), 25(2), 1018-1025

Mechanical characteristics and durability properties of blast furnace slag cement composites largely depend on the hydraulic activity of the slag. In this paper, a Granulated Blast Furnace Slag with a low ... [more ▼]

Mechanical characteristics and durability properties of blast furnace slag cement composites largely depend on the hydraulic activity of the slag. In this paper, a Granulated Blast Furnace Slag with a low reactivity index is used in modifying mortar composition. Microstructure and durability of mixes containing 0%, 30% and 50% of slag as substitution to OPC are respectively compared and analyzed. Water porosity, Mercury Intrusion Porosity and pore size distribution are studied after 28, 90 and 360 days of wet curing. A qualitative microstructure analysis of mortars is proposed with Scanning Electron Microscope (SEM). The durability of mortar is evaluated through capillary water absorption and chloride diffusion tests. The results indicate a finer porosity and lower water absorption for slag mortars at old ages (90 and 360 days). Moreover, lower chloride diffusion for 50% blast furnace slag substitution is observed. [less ▲]

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See detailPerméabilité au gaz et aux ions chlore des mortiers à base de laitier de faible hydraulicité
Hadj Sadok, Ahmed; Kenaï, Saïd; Courard, Luc ULg

in Innovation et Valorisation dans le génie civil et les matériaux de construction (2011)

La durabilité des bétons au laitier de haut fourneau dépend fortement de l’activité hydraulique du laitier. Dans cette étude, un laitier algérien, caractérisé par une faible hydraulicité, est utilisé dans ... [more ▼]

La durabilité des bétons au laitier de haut fourneau dépend fortement de l’activité hydraulique du laitier. Dans cette étude, un laitier algérien, caractérisé par une faible hydraulicité, est utilisé dans la fabrication de mortiers comme substituant du ciment à des taux de 0, 30 et 50%. En plus d’une caractérisation mécanique, l’effet du laitier sur la durabilité des mortiers est évalué par des essais de perméabilité à l’oxygène, de diffusion de chlorures en régime permanent ainsi que de conduction des ions chlore (essai accéléré ASTM). Les résultats montrent, malgré une faible réactivité du laitier, une amélioration de la perméabilité à l’oxygène à long terme (360 jours) pour les mortiers au laitier, particulièrement pour un taux de 50%. La présence du laitier réduit la perméabilité aux ions chlore, d’une part, en augmentant le temps de passage des chlorures à travers le mortier et, d’autre part, en diminuant le taux de diffusion. Par ailleurs, une faible conduction des chlorures est observée pour les mortiers au laitier, montrant une similitude avec les résultats d’essai de diffusion en régime permanent. [less ▲]

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See detailTransport properties of mortars and concretes modified with medium hydraulic activity ground granulated blast furnace slags.
Hadj Sadok, Ahmed; Kenaï, Saïd; Courard, Luc ULg et al

in Sustainable Construction Materials and Technologies (2010, June)

Mechanical characteristics and durability of ground granulated blast furnace slag cement composites depends on the hydraulic activity of the slag. Algerian Blast furnace slag is characterized by a quite ... [more ▼]

Mechanical characteristics and durability of ground granulated blast furnace slag cement composites depends on the hydraulic activity of the slag. Algerian Blast furnace slag is characterized by a quite slow reactivity. Porosity and transport properties of mixes containing up to 50% OPC replacement are compared and analyzed. Mechanical strength, pore size distribution and capillary water absorption are studied after 28 and 90 days of wet curing. The durability of blast furnace slag cement concrete is evaluated through nitrogen permeability and water penetration depth under pressure. First observations seem to indicate finer porosity and lower water absorption than with 100% CEM I 52.5 mortars. Moreover, lower permeabilities to nitrogen and water are also observed for 50% blast furnace slag substitution. [less ▲]

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See detailMechanical and durability properties of concrete using contaminated recycled aggregates
Debieb, Farid; Kenaï, Saïd; Courard, Luc ULg et al

in Cement & Concrete Composites (2010), 32(6), 421-426

The degradation of concrete structures due to chlorides and sulphates penetration is of obvious importance in civil engineering as having major impact on structural durability. In this paper, the results ... [more ▼]

The degradation of concrete structures due to chlorides and sulphates penetration is of obvious importance in civil engineering as having major impact on structural durability. In this paper, the results of an investigation on the effect of contaminated crushed concrete aggregates on mechanical properties and durability of recycled concrete are presented. Natural aggregates concrete (NC) slabs were cured in water, sea water, chloride solutions or sulphate solutions and then crushed to obtain virgin and contaminated (polluted) recycled aggregates. The properties of natural (NA) and recycled aggregates (RA) and the mechanical properties and durability performances of a new concrete made from 100% of RA are analysed. The results show that contaminated RA are much sensitive to chlorides than sulphates and are rapidly leached when soaked into water. Significant differences were observed between the properties of original and new concrete and the results clearly show the necessity of taking these contaminations into account. [less ▲]

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See detailRoller Compacted Concrete with contaminated recycled aggregates
Courard, Luc ULg; Debieb, Farid; Kenai, Saïd et al

in Construction & Building Materials (2009), 23

Recycling waste building materials from construction and demolition (C&D) sites is increasingly investigated for economical and environmental reasons. Roller compacted concrete (RCC) is a special dry ... [more ▼]

Recycling waste building materials from construction and demolition (C&D) sites is increasingly investigated for economical and environmental reasons. Roller compacted concrete (RCC) is a special dry concrete mix; laid down and compacted like a soil, it is especially used for the construction of massive structures like dams or large horizontal surfaces like road foundation. In this paper, natural concrete slabs were cured in water, sea water, chloride solutions or sulphate solutions and then crushed to obtain virgin and contaminated (polluted) recycled aggregates. The aim of this research is the total replacement (100% coarse and fine) of natural aggregates (NA) by recycled concrete aggregates (RA) in the composition of a roller compacted concrete. The natural and recycled aggregates are characterised and compared. The mechanical properties and durability performances of concrete with contaminated RA are analysed. The experimental results showed that the polluted RA are much richer in chlorides than in sulphates and are leached if they are soaked in water. Significant differences were observed between the properties of original and new concrete and the results demonstrated the need of taking these contaminations into account. [less ▲]

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