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Reinforced concrete structure is an effective system for resisting lateral loads. Seismic retrofitting of constructions vulnerable to earthquakes is a current problem of great political and social relevance. During the last sixty years, moderate to severe earthquakes have occurred in Morocco (specifically in Agadir 1960 and Hoceima 2004).Such events have clearly shown the vulnerability of the building stock in particular and of the built environment in general. Hence, it is very much essential to retrofit the vulnerable building to deal with the next damaging earthquake. To evaluate the performance of framed buildings under future expected earthquakes, a nonlinear static PUSHOVER analysis has been conducted. In this paper, we propose to assess the seismic vulnerability of a reinforced concrete building using carbon fiber reinforced polymer (CFRP) for different zone.

In this article, we studied the process of cold and hot mixing of sedimentary phosphates of Bouchane in order to optimize the energy requirements by reducing the organic matter and carbonates. The cold mixture is done at the ambient temperature whereas the hot mixture is made at the calcination temperature. The experimental process of the mixtures is performed under the atmospheric air using the same phosphate source and mixing in the same manner, in order to make possible the comparison between cold and hot. It appeared that the hot mixture using 33% of the same phosphate source can have an important impact on the energy saving while preserving the environment and responding to the quality requirements of the users.

Un protocole de traitement thermique d'un minerai phosphate visant l'optimisation des depenses de l'energie destinee a la calcination est ici presente. Nous avons mene une etude comparative de la calcination effectuee de deux manieres differentes sur du phosphate brut. Cette methode a ete appliquee pour enrichir le phosphate sedimentaire issu d'un nouveau site du Bassin des Gantour (Maroc). Dans un premier temps, nous avons optimise la temperature de calcination et le temps de sejour. En effet, les resultats montrent que le traitement a 800 °C pendant 30 min donne un minerai de meilleure concentration en phosphate. Il permet de diminuer le carbone organique et le dioxyde de carbone respectivement de 1,4 % a 0,15 % et 6,6 % a 1,8 %. Ainsi que l'augmentation de la teneur en P2 O5 de 30,39 % a 34,23 %. De plus, il a ete constate un impact du refroidissement sur la distribution granulometrique. Dans un deuxieme temps, il apparait que la procedure de calcination suivie d'un refroidissement par 33 % de phosphate de meme source (melange a chaud) peut avoir d'importantes retombees sur l'economie de l'energie et un gain de productivite tout en preservant l'environnement.

A model taking into account the simultaneous influence of mechanical and hygrometric actions (Mrani and al., 1995a, 1995b) was applied to study of the dehydration of a cylinder of highly deformable biphase gel (agar gel) (Mrani and al., 1995b). Numerical solution of the water transport equation and the mechanical equilibrium equation provided access to the water content and stresses and strains in the cylinder. The numerical results were validated for water content and overall deformation of gel cylinders. The model clearly shows the inversion of the curve of the faces of the cylinder observed experimentally. Three deformation phases were observed. In the first phase, when the concaveness of the faces of the cylinder was turned inwards, tractive stress appeared at the surface of the sample. More uniform distribution of the water content became established in a second phase and the cylinder recovered its initial shape corresponding to the relaxation of the stress state. In the third phase, the con...

A phenomenological equation is established for water transport in a biconstituent, isotropic, isothermal elastic medium. The equation includes a term related to the water content gradient and a term related to the deformation gradient. It is shown that in the case of an infinite plate, the transport law can be similar to Fick’s law in which water flux is proportional to the water content gradient alone. The apparent transport coefficient then depends on the hygroscopic and rheological coefficients of the medium. Experimental analysis of the evolution of water content profiles of agar gel plates validates this transport law and makes it possible to deduce the variation in apparent transport coefficient according to water content. Transport coefficients associated with water content and deformation gradients and applicable to any geometrical features are deduced.

Cette etude aborde la mesure des proprietes d'un biopolymere, le gel d'agar, au cours d'un processus de deshydratation. La morphologie du gel est mise en evidence par des observations au microscope electronique en utilisant une technique de cryofracture ; il est montre que la morphologie initiale diphasique du gel d'agar est preservee lors de l'evolution de la teneur en eau. L'etude des proprietes hygroscopiques du gel, par la determination de l'isotherme de desorption, permet, en particulier, de situer le domaine hygroscopique du materiau. On etudie ensuite le retrait du gel d'agar, par la determination des variations du coefficient de contraction et du coefficient d'expansion hygrometrique, en fonction de l'humidite du milieu. On aborde enfin l'etude rheologique du gel qui presente un comportement macroscopique elastique. La variation du module de Young en fonction de la teneur en eau est determinee par des essais de compression simple. Ce resultat est ensuite combine a des mesures de la vitesse de propagation d'ondes ultrasonores pour determiner la variation du coefficient de Poisson avec la teneur en eau.

ABSTRACT A numerical model of isothermal drying of deformable substances is proposed. The model is applied in a uni-directional case to analysis of water transport in a sphere of agar ge. The simulation program makes it possible to calculate the water content fields and def rmations and stresses in the sphere during drying. Validation of the water content profile results is proposed by the experimental study of the dehydration of gel spheres in a sugar solution. The sensitivity of internal stresses to drying conditions is then analysed.

A partir d'un modele de transport d'eau en milieu biphasique et elastique [I. Mrani, J.-C. Benet, G. Fras, Transport of water in a biconstituant elastic medium, Appl. Mech. Rev., special issue on Mechanics of swelling 48 (1995) 717–721], on examine dans cette etude les risques de fissurations induites par la redistribution d'eau dans un echantillon de forme cylindrique apres sechage. La resolution numerique de l'equation de transport de l'eau et de l'equation d'equilibre mecanique donnent acces a l'evolution de la teneur en eau, de la deformation et des contraintes dans le milieu. On s'interessera a l'etat du materiau pendant les phases de sechage, de refroidissement et de stockage. A l'issue de cette etude, les risques de fissuration sont analyses pour differents scenarios de sechage, qui determinent l'evolution de l'etat hydrique pendant le stockage.

International audience; We propose to analyse the phenomenological equation of water transport in a biconstituent medium with stresses. The work is limited to the case of elastic, isotropic behaviour and an isothermal transfer process.