Chloride diffusion and oxygen permeability of mortars with low active blast furnace slag

Depending on its hydraulic activity, the use of Granulated Blast Furnace Slag (GBFS) in cementitious materials contributes to improve their durability performances. In this paper, a low reactive Granulated Blast Furnace Slag with is used in modifying mortar composition. Some durability properties of mixes containing 0, 30 and 50% of slag as substitution to OPC are studied. Diffusion and conduction of chlorides at long term are analyzed with different initial wet curing periods. Microstructure of mortars after 360 days of diffusion is observed by means of Mercury Intrusion Porosimetry. The oxygen permeability is analysed at 90 and 360 days of wet curing. The results indicate good performances to chloride diffusion of the mortars with GBFS, especially for a prolonged wet curing. Moreover, the GBFS are inefficient for oxygen permeability at 90 days but they however allow a decreasing over long term

Effect of the microstructure of mortars with low hydraulicity slag on their behavior in aggressive environments

Slag is one of the most used cement additives. Due to its latent hydraulic nature, attached to its hydraulicity, it can contribute to a microstructural modification and an improvement of the durability of the concrete face of aggressive environments. In this study, a low active slag is used in the manufacture of mortars as a substitute for cement, at a maximum rate of 50%. Firstly, a study of the microstructure with mercury porosimetry was used for determination of microstructural parameters (porosity, diameters and volume distribution). The behavior of mortars in aggressive environments (sodium and magnesium sulphate and seawater) was studied later. Despite the low reactivity of studied slag, its presence especially at 50% rate, in the long term, has led to a refinement of the microstructure. This effect, among others, led to better resistivity of the mortars in the sulphate environnements

Permeability to gas and chlorides of low hydraulic properties blastfurnace slags mortars

peer reviewedLa 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

Microstructure and durability of mortars modified with medium active blast furnace slag

peer reviewedMechanical 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

Méthode simplifiée de formulation d’un béton à haute performance avec et sans fibre métallique

Le présent travail, propose une méthodologie simplifiée, s’appuyant sur des méthodes de formulation de béton connues dans la littérature et sur des essais d’optimisations au laboratoire, permettant la détermination d’une composition d’un béton à haute performance « BHP » et de béton de fibre à haute performance « BFHP ». Pour ce faire, une large caractérisation (physique et mécanique) des matériaux utilisés a été conduite. Suivie d’une étude préliminaire, ayant pour objectif d’optimiser le dosage en Superplastifiant (0,65-1%) et du ciment (500-700) kg/m3 en se basant sur des essais de résistance à la compression (3, 7, 28 jours) et des mesures d’ouvrabilité. Les caractéristiques mécaniques ainsi que la porosité du BHP optimale ont été mesurées. Ainsi, l’effet d’une nouvelle génération de superplastifiant, qui a permis la réduction du rapport E/C à 0,29, a pu être examiné. Ce dernier a permis l’obtention d’un BHP de bonne performance mécanique et de faible porosité. La méthodologie proposée a permis, à ce stade de l’étude, de formuler des bons BHP et reste à ajuster et à compléter pour la formulation des BFHP

Transport properties of mortars and concretes modified with medium hydraulic activity ground granulated blast furnace slags.

peer reviewedMechanical 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

Transport Properties of Mortars and Concretes Modified with Ground Granulated Blast Furnace Slag

ABSTRACT 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

An uncommon liver abscess secondary to an ingested foreign body: A case report

Introduction: This article discusses a case study involving a unique occurrence of a hepatic abscess caused by the presence of an ingested foreign body. Hepatic abscesses, characterized by pus accumulation within liver tissue, often result from various infections, with some cases having unidentified origins. Case presentation: This study focuses on a 75-year-old man who presented at an emergency department with persistent pain in the right upper abdomen and fever for ten days. Diagnostic tests revealed a low-density, multiloculated mass in the liver and a hyperdense linear structure near the duodenum, indicating a hepatic abscess originating from duodenal perforation due to a foreign body that had migrated from ingestion. The patient underwent antibiotic treatment and a surgical procedure involving laparotomy to extract the foreign object and drain the abscess. Conclusion: this case study underscores the rare occurrence of hepatic abscesses caused by ingested foreign bodies. Swift and accurate diagnosis, along with appropriate treatment involving foreign body removal and abscess drainage, are pivotal for favorable patient outcomes. The choice of treatment strategy impacts hospital stay duration, and understanding potential complications from foreign body ingestion enhances patient management and care

Durability of mortar and concretes containing slag with low hydraulic activity

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%