Papers by Abdelkader BOUGARA
Canadian Journal of Civil Engineering, 2001
La prévision de la résistance des bétons d'aujourd'hui est devenue une préoccupation majeure pous... more La prévision de la résistance des bétons d'aujourd'hui est devenue une préoccupation majeure poussant les promoteurs de la construction à s'y intéresser de plus en plus pour prévoir le décoffrage ou la mise en précontrainte à un âge approprié. Les bétons actuels possèdent une composition différente des bétons d'hier caractérisée par la présence de certains ajouts minéraux pour améliorer ses performances et un mode de cure variant selon les moyens disponibles. Ceci nous a conduit à établir un organigramme de prévision de la résistance en compression des bétons au laitier d'El-Hadjar subissant un historique de température variable, à partir d'un béton de référence confectionné uniquement avec du clinker et conservé sous une température constante de 20°C.
DOAJ (DOAJ: Directory of Open Access Journals), Aug 1, 2022
RÉSUMÉ : La réduction des émissions de particules fines constitue le plus grand défi écologique q... more RÉSUMÉ : La réduction des émissions de particules fines constitue le plus grand défi écologique que l’industrie cimentière algérienne doit relever. L’Entreprise du Ciment et Dérivés d’Ech-Cheliff certifiée en 2003 aux normes de qualité ISO 9001, se prépare à être certifiée aux normes environnementales ISO 14001. La présente étude mène une campagne de surveillance des poussières au sein de la cimenterie. Elle a pour objectif l'échantillonnage et l'analyse des aéro-particules déposées par gravité autour de l’entreprise ECDE. Le mode de prélèvement est celui décrit dans la norme française et qui fait appel à l’utilisation de plaquettes. Sept stations de prélèvements ont été positionnées tout autour de la cimenterie et quatre séries de prélèvements ont été effectuées pour mesurer de façon continue l’évolution de la quantité des aéro-particules redéposées. Les résultats obtenus avec la méthode utilisée dans cette étude sont comparés avec ceux obtenues au moyen des opacimètres. La...
Proceedings of the International Symposium on Life-Cycle Civil Engineering, IALCCE '08, held in Varenna, Lake Como, Italy on June 11 - 14, 2008, 2008
La réduction des émissions de particules fines constitue le plus grand défi écologique que l’indu... more La réduction des émissions de particules fines constitue le plus grand défi écologique que l’industrie cimentière algérienne doit relever. L’Entreprise du Ciment et Dérivés d’Ech-Cheliff (Algérie) certifiée en 2003 aux normes de qualité ISO 9001, se prépare à être certifiée aux normes environnementales ISO 14001. Des études préalables in situ ont été effectuées au niveau de la cimenterie pour quantifier le taux de particules de poussière. La présente étude mène une campagne de surveillance des poussières au sein de la cimenterie. Elle a pour objectif l'échantillonnage et l'analyse des aéro-particules déposées par gravité autour de l’entreprise ECDE. Le mode de prélèvement est celui décrit dans la norme française et qui fait appel à l’utilisation de plaquettes métalliques minces recouvertes d’un fixateur hydrophobe. Sept stations de prélèvements ont été positionnées tout autour de la cimenterie et quatre séries de prélèvements ont été effectuées pour mesurer de façon continue...
Composite structures made from the combination of steel profile and concrete have significant loa... more Composite structures made from the combination of steel profile and concrete have significant load bearing capacity which depend on the behaviour of the two materials and their interaction, particularly in fire conditions. It is not possible to assess the fire resistance of composite members only by considering the temperature of the steel, because the presence of concrete may contribute greatly to increase the mass and thermal inertia of the member, which improve the fire behaviour of the element. The aim of this work is to develop an efficient Non-linear 3-D finite element model to examine the behaviour of Pin-ended axially loaded composite columns made from High Strength Concrete (HSC) and Normal Strength Concrete (NSC) for different fire ratings of 30, 60, 90 and 120 minutes. Two types of column were selected to investigate the effect of fire, notably HEB profile ranging from 160 to 200 encased with concrete partially or totally (PEC, TEC). These columns were tested under ISO834...
Advances in Cement Research, 2006
ABSTRACT Currently the prediction of the strength of blended cement constitutes a major preoccupa... more ABSTRACT Currently the prediction of the strength of blended cement constitutes a major preoccupation leading the promoters of such constructions to be more and more interested in predicting the timing of removal of the framework or the prestressing at suitable ages. The prediction of the strength of the slag concrete, using simple models of prediction such as Feret's model, with the introduction of the concept of the equivalent binder was studied and this led to the definition of an efficiency coefficient of the slag which defines the latter according to the cement. This efficiency coefficient, once deduced, characterised the slag from the El-Hadjar steel factory (Algeria) well and made it possible to predict the strength of a slag concrete of a given age and replacement level from the data of a reference concrete made without slag. This coefficient is defined on the basis of the age, the replacement level, the specific surface area of the slag and the curing temperature.
Pitched roof Steel frame structures are widely used in industrial buildings for practical reasons... more Pitched roof Steel frame structures are widely used in industrial buildings for practical reasons of exploitation, durability and cost efficiency. However, steel being a ductile material, it remains vulnerable to excessive temperatures. The recent accidents, which occurred in the industrial buildings of Sonatrach (petroleum industry in Algeria), in an urban area in Algiers or in an industrial zone in Skikda, remind us of the real danger and the potential risk of fire.info:eu-repo/semantics/publishedVersio
In this paper, the advanced and simplified calculation methods are used to evaluate the fire resi... more In this paper, the advanced and simplified calculation methods are used to evaluate the fire resistance of eccentrically loaded partially encased composite columns (PEC). The work consists in developing an efficient Non-linear 3-D finite element model (ANSYS) to investigate the behaviour of Pin-ended PEC eccentrically loaded at elevated temperature. The columns were tested under standard ISO834 fire. The buckling load is determined for several column heights 3; 4.5 and 6 m, by considering an eccentricity around the minor axis equal to 0,5.B ; 1,0.B and 1,5.B (B base). The numerical method presented here is compared with the simple calculation method Annex G of EN 1994-1-2. The results show that after 50 min of fire exposure, the axial load capacity of PEC is reduced to more than half, which is a fair conclusion to take into consideration in structural fire design. The comparison results show a good agreement between the two methods at high fire ratings (R90 and R120), however at low...
To protected human lives and prevent against failure of structures, the collapse oo industrial bu... more To protected human lives and prevent against failure of structures, the collapse oo industrial buidings under fire shoulds always accur inward with a minimum failure time.info:eu-repo/semantics/publishedVersio
Computers and Concrete, 2020
Construction and Building Materials, 2009
Blastfurnace slag has been widely used as a successful replacement material for Portland cement, ... more Blastfurnace slag has been widely used as a successful replacement material for Portland cement, and concrete of enhanced qualities can be achieved as a result. Due to the slag’s slow reactivity, however, the early-age mechanical properties may suffer. This paper reports the results of an investigation, carried out at Chlef University (Algeria), using Algerian slag, known to exhibit low reactivity
This paper reports results on the properties of concrete containing waste foundry sand (WFS). Fin... more This paper reports results on the properties of concrete containing waste foundry sand (WFS). Fine aggregate was replaced with 0-100% WFS. The water to cement for all mixes was kept constant. Fresh and hardened properties of concrete were investigated. Hardened properties included water absorption, strength, ultrasonic pulse velocity (UPV) and length change. Testing on hardened properties was mainly conducted at 14, 28 and 56 days. The results show that the workability of concrete reduces with the increase as the WFS increases which was attributed to the larger surface area of WFS compared with the fine aggregate used. Although the compressive strength and UPV decreased with the increase in WFS, an adequate strength was achievable even when all the fine aggregate was fully replaced with WFS. As may be expected, an increase in compressive strength is associated with a decrease in water absorption. Furthermore, there is an increase in shrinkage as the content of WFS is increased. Attempts were made to correlate the various properties investigated.
In this paper, the advanced and simplified calculation methods are used to evaluate the fire resi... more In this paper, the advanced and simplified calculation methods are used to evaluate the fire resistance of eccentrically loaded partially encased composite columns (PEC). The work consists in developing of an efficient Non-linear 3-D finite element model (ANSYS) to investigate the behaviour of Pin-ended PEC eccentrically loaded at elevated temperature. The columns were under standard ISO834 fire.info:eu-repo/semantics/publishedVersio
Cement and Concrete Composites, 2010
The performance of an Algerian blastfurnace slag has been assessed by examining the parameters in... more The performance of an Algerian blastfurnace slag has been assessed by examining the parameters influencing reactivity in a comparative study of two slags from different origins. These parameters include chemical composition, glass content, particle size distribution, heat of hydration and microstructural development. Three cement paste systems were investigated; OPC as a control, and two blended cements; 50% OPC-50% Algerian slag and 50% OPC-50% UK slag. All samples were made with a water/binder ratio of 0.4 and cured at 20°C for up to 90 days. The specimens were tested using calorimetry, thermogravimetry, X-ray diffraction, selective dissolution, back-scattered electron microscopy and compressive strength. The chemical composition of the slag has a profound influence on strength development. The heat evolved appears to be proportional to the strength development and may be used as an important indicator of the reactivity of slag. A relationship was established between the amount of calcium silicate hydrate formed and compressive strength.
RESUME : Le processus de fabrication du clinker fait de l’industrie du ciment une forte consommat... more RESUME : Le processus de fabrication du clinker fait de l’industrie du ciment une forte consommatrice en energie calorifique, mais c’est aussi une grande generatrice de rejets polluants dans l’atmosphere tels que les emissions des particules fines dont la forte et longue concentration dans l’air provoque des maladies respiratoires. L’objectif du travail presente est de determiner le niveau d’empoussierement engendree par la fabrication du ciment. Une campagne de mesure des poussieres sedimentables realisee par la methode des plaquettes, a ete effectuee sur 7 points de prelevements situes autour de la cimenterie de l’E.C.D.E de Chlef (Algerie). Les resultats trouves affichent des niveaux tres forts d’empoussierement au cours des 4 series de prelevements depassant largement le seuil acceptable (1 g/m2 jour) pour la station 5 de valeur variant de 20 a 5 g/m2 jour et un niveau tres faible d’empoussierement pour la station 3 de valeur variant de 0.07 a 0.036 g/m2 jour.
Construction and Building Materials, 2016
Abstract This investigation aims to determine the influence of pre-saturation and dried recycled ... more Abstract This investigation aims to determine the influence of pre-saturation and dried recycled concrete aggregates (RCA) on mechanical and rheological properties of concrete. Coarse ordinary aggregates (COA) were partially substituted with RCA and an amount of superplasticizer was added to keep the same workability. The results found show that concrete with dried RCA aggregates requires a great dosage of superplasticizer and achieves high compressive strength and rheological parameters. However, for concrete with pre-saturated RCA aggregates, the needed dosage of superplasticizer is reduced and the compressive strengths and the rheological parameters are decreased. The use of pre-saturated RCA aggregates is better to keep adequate superplasticizer dosage and relevant rheological parameters. Mathematical relationships are proposed to express the variation of the compressive strengths and the rheological parameters according to the concrete composition with fair correlation coefficients.
Engineering Structures, 2010
This work deals with the maximum ratio of longitudinal tensile reinforcement compatible with a gi... more This work deals with the maximum ratio of longitudinal tensile reinforcement compatible with a given level of local ductility in reinforced concrete beams, when considering the effect of high strength concrete. First, the evaluation method of the ductility factor is revealed, where an assessment procedure is presented. Then, the influence of the tension reinforcement ratio on the local ductility is discussed for high strength concrete. Furthermore, the Eurocode 8 provision concerning the criterion of the local ductility in dissipative beams is illustrated. In this respect, this criterion is examined in sections having the maximum tension reinforcement ratio adopted by Eurocode 8, by varying the strength of concrete by up to 90 MPa. The obtained tensile reinforcement ratios for a given value of curvature ductility factor by means of the setting procedure of the equations of equilibrium and compatibility show that the amount of reinforcement should be less than that proposed by the Eurocode 8 equation. Finally, a modified formula for the maximum tension reinforcement ratio ρmax is suggested instead of that recommended by Eurocode 8, which takes into consideration the effect of high strength concrete, where the validity of this formula is checked by a comparative study with other formulas for ρmax.
Uploads
Papers by Abdelkader BOUGARA