THE HYDROCHLORIC ACID EFFECTS ON MODIFIED CEMENT WITH NEW COMBINATIONS BASED ON CALCINED DAM’S MUD AND NATURAL POUZZOLANA

Reducing the amount of clinker in cement industry using Supplementary Cementitious Materials (SCMs) is one of the solutions developed by researchers in our field trying to respect environmental requirements, in the same context the present work aim to test the feasibility of new combinations using two sorts of Algerian SCMs and to evaluate their behavior while exposed to hydrochloric acid. To concretize this objective we fabricated a control mortar (based on cement CEMI) and nine other mortars containing modified cements, by a binary and ternary mixtures of Portland Cement CEMI, Calcined Mud (Wastes) of Chofa Dam (CW) and Natural Pouzzolana (NP), all these mixtures were tested at fresh state for consistency and setting time of pastes, and at hardened state for apparent density measure, water absorption and compressive strength of mortars. After that the ten of them were immersed in hydrochloric acid (HCL) 5% during fifteen weeks (105 days), Then they were examined for mass loss, volume loss, density decrease (apparent density) and the visual appearance. The results obtained in the majority of tests showed that the mixtures containing SCMs especially the ternary mixtures are realizable and more advantageous than others and characterized by a higher water demand and a better behavior after both compressive and HCL attack

Elaboration of geopolymer cement based on dredged sediment

This work aims to study the feasibility of making a geopolymer cement based on dredged sediments, from the Fergoug dam (Algeria). Sedimentary clays were characterized before and after calcination by X-ray diffraction, ATG / ATD, spectroscopy (FTIR) and XRF analysis. The reactivity of the calcined products was measured using isothermal calorimetric analysis (DSC) on pastes prepared by mixing an alkaline solution of sodium hydroxide (NaOH) 8 M in an amount allowing to have a Na / Al ratio close to 1. Also, cubic mortar samples were prepared with a ratio L / S: 0.8, sealed and cured for 24 hours at 60 ° C and then at room temperature. The results obtained allowed to optimize the calcination time of 5 hours for a better reactivity of these sediments, and a concentration of 8M of sodium hydroxide and more suitable to have the best mechanical performances

La Vase Calcinée des Barrages autant qu’addition substituable partiellement au ciment : comportement vis-à-vis de l’Attaque de l’Acide Chloridrique

The dam’s calcined mud in Algeria were proposed by several researchers for its use as an addition partially substitutable for cement, that is beneficial in various fields (technical, economical and environmental), the objective of this work is to evaluate the behavior of this mud towards hydrochloric acid attack, to concretize this objective one control mortar and three mortars mixtures containing modified cement by replacing cement CEMI by the calcined mud with different mass proportion of 10%, 20% and 30%, compressive strength test until the age of 180 days have been elaborated at first time, after that the four mortars were immersed in solutions of hydrochloric acid with two types of concentrations 2% and 5% during 15 weeks (105 days), the results show that the mortars based on mud resist better than the control mortar with tan advantage for 10% replacement with the calcined mud than the other mortars.La vase calcinée des barrages en Algérie a été proposée par plusieurs chercheurs pour son utilisation autant qu’addition substituable partiellement au ciment, ce qui est bénéfique dans de multiples domaines (techniques, économique et environnemental), l’objectif de ce travail vise à évaluer le comportement des mortiers à base de cette vase vis-à-vis l’attaque de l’acide chlorhydrique, pour concrétiser cet objectif une formulation de mortier témoin et trois autres à base de ciment modifié avec des taux de substitution massique de ciment CEMI par la vase calcinée issue des sédiments de dragage du barrage Chorfa de 10%, 20% et 30%, des essais de résistance à la compression jusqu'à l’âge de 180 jours ont été élaborés en premier lieu, ensuite les quatre mortiers ont été immergés dans des solutions d’acide chlorhydrique avec deux concentrations différentes 2% et 5% durant 15 semaines (105 jours), les résultats ont montré que les mortiers à base de vase résistent mieux à l’acide chlorhydrique par rapport au mortier témoin avec un avantage pour la formulation contenant 10% de vase calcinée par rapport aux autres mortiers

La Vase Calcinée des Barrages autant qu’addition substituable partiellement au ciment : comportement vis-à-vis de l’Attaque de l’Acide Chloridrique

The dam’s calcined mud in Algeria were proposed by several researchers for its use as an addition partially substitutable for cement, that is beneficial in various fields (technical, economical and environmental), the objective of this work is to evaluate the behavior of this mud towards hydrochloric acid attack, to concretize this objective one control mortar and three mortars mixtures containing modified cement by replacing cement CEMI by the calcined mud with different mass proportion of 10%, 20% and 30%, compressive strength test until the age of 180 days have been elaborated at first time, after that the four mortars were immersed in solutions of hydrochloric acid with two types of concentrations 2% and 5% during 15 weeks (105 days), the results show that the mortars based on mud resist better than the control mortar with tan advantage for 10% replacement with the calcined mud than the other mortars.La vase calcinée des barrages en Algérie a été proposée par plusieurs chercheurs pour son utilisation autant qu’addition substituable partiellement au ciment, ce qui est bénéfique dans de multiples domaines (techniques, économique et environnemental), l’objectif de ce travail vise à évaluer le comportement des mortiers à base de cette vase vis-à-vis l’attaque de l’acide chlorhydrique, pour concrétiser cet objectif une formulation de mortier témoin et trois autres à base de ciment modifié avec des taux de substitution massique de ciment CEMI par la vase calcinée issue des sédiments de dragage du barrage Chorfa de 10%, 20% et 30%, des essais de résistance à la compression jusqu'à l’âge de 180 jours ont été élaborés en premier lieu, ensuite les quatre mortiers ont été immergés dans des solutions d’acide chlorhydrique avec deux concentrations différentes 2% et 5% durant 15 semaines (105 jours), les résultats ont montré que les mortiers à base de vase résistent mieux à l’acide chlorhydrique par rapport au mortier témoin avec un avantage pour la formulation contenant 10% de vase calcinée par rapport aux autres mortiers

Etude du comportement d'un béton autoplaçant à base de vase de dragage vis-à-vis du retrait

National audienceRESUME : La valorisation des sédiments de dragage ouvre une voie très intéressante en vue de leur utilisation en tant que matière première dans le domaine du génie civil, et plus particulièrement comme nouveaux liants pouvant être exploiter industriellement et ayant pour intérêt l'amélioration des caractéristiques physico-chimiques et mécaniques des bétons. Ce travail consiste à élaborer des ciments pouzzolaniques en substituant partielle du ciment(CEMI)) par la vase draguée du barrage de Fergoug. L'objectif est l'étude de l'influence de cette dernière calcinée à 750 C, sur le comportement d'un béton autoplçant à l'état frais et durci à savoir les performances mécaniques d'une part et les déformations différées (retrait) d'autre part. Les résultats obtenus offrent de belles perspectives pour optimiser des BAP à base de vase calcinée

Valorization of Dredged Sediments as a Component of Vibrated Concrete: Durability of These Concretes Against Sulfuric Acid Attack

Abstract Hydraulic facilities are subjected to significant siltation which, in a very short period of time, can render them unusable. In Algeria, the silting-up of a great number of dams, built for drinking water needs and for irrigation, implies the necessity and urgency to take action. Therefore, the maintenance work, which leads to dredging the deposited silt, constitutes an unbearable obligation for the preservation of the environment. Chorfa dam (western Algeria) may be mentioned as a concrete example. This study is part of a long research whose objective is to contribute to the valorization and the optimization of the formulations economically that are easy to implement and which enable to use the dredged materials in the formulation of ordinary concretes by partial substitution to cement (10, 20 and 30%) of dredged sediments, after calcination at 750 °C to make them active. Tests were carried out on concrete that was vibrated in the fresh state (setting time) and hardened state (compressive strengths and durability of concrete exposed to sulfuric acid attack) in order to determine their characteristics. The results obtained confirmed the possibility to develop concretes containing calcined silt, with proportions up to 30%, and which can meet the economic, ecological and technological objectives

Study of properties of freshly mixed self-compacting concrete containing local materials

International audienceSelf-compacting concrete (SCC), a very fluid concrete that requires no vibration during laying, presents an increasing interest for the industry because of its numerous advantages from the environmental, technological, and economical points of view. The current study is part of a research carried out at the department of civil engineering of Université Abdelhamid Ibn Badis de Mostaganem, Algeria, on the influence of the compositional parameters on the behaviour of freshly mixed SCCs. It was designed (i) to understand the role of various potential local components, such as sea sand and quarry sand (considered a natural waste), and (ii) to highlight the possible interactions between constituents. Results offer promising avenues for optimizing the SCCs in Algeria. A range of SCC formulae satisfying rheological criteria (good deformability, less bleeding, no segregation) was developped

Sedimentary Clays as Geopolymer Precursor

International audienceThis work aims to study the feasibility of making a geopolymer cement based on dredged sediments, from the Fergoug dam (Algeria) and to evaluate their construction potential particularly interesting in the field of special cementitious materials. These sediments due to their mineralogical composition as aluminosilicates; are materials that can be used after heat treatment. The objective of this study which is part of a long research whose is to contribute to the valorization of these sediments of dredging in the formulation of new concretes by complete substitution of cement. Sedimentary clays were characterized before and after calcination by X-ray diffraction, ATG/ATD, spectroscopy (FTIR) and XRF analysis. The calcination was carried out on the raw material sieved at 80 mu m for a temperature of 750 degrees C, for 3, 4 and 5 hours (calcinations times). The reactivity of the calcined products was measured using isothermal calorimetric analysis (DSC) on pastes prepared by mixing an alkaline solution of sodium hydroxide (NaOH) 8 M in an amount allowing to have a Na / Al ratio close to 1 (11). Also, cubic mortar samples were prepared with a ratio L / S 0.8, sealed and cured for 24 hours at 60 degrees C and then at room temperature until the day they were submited to mechanical testing. to check the extent of geopolymerization. The results obtained allowed to optimize the calcination time of 5 hours for a better reactivity of these sediments, and a concentration of 8M of sodium hydroxide and more suitable to have the best mechanical performances