M. CHIKOUCHE Mohamed aziz

The aim of this work is to quantify cement hydration as a function of the mechanical and chemical characteristics of mortar cement. To control the quantity of hydrated cement, we adopted the thermogravimetric thermogravimetric (TGA) method, which enabled us to determine the degree of hydration α(t),This technique is coupled with carbonation and ordinary mortar strength. The experimental data obtained were correlated and interpreted the evolution of strength and carbonation as a function of the degree of hydration, unavoidable. Cements containing different percentages of slag.The evolution of kinetics was studied for 3, 7 and 28 days. According to the results obtained, the hydration rate is inversely proportional to the addition content in the cement. The degree of hydration is directly related to the formation of hydrates and portlandite. The greater the quantity, the greater the hydration.The Bhatty Bhatty method is verified for calculating the degree of hydration and can be successfully applied to composite cements.

This article aims to propose a solution to two environmental problems. One
is the silting up of dams, despite the dredging operations. The other
represents the rate of cement used in the mortar or concrete. The solution is
to introduce the calcined dredged sludge as a cement substitute. Treatment
at 600 °C with different heating rates (5, 10 and 20 °C/mn) was applied to
make the mortar and measure setting time and hydration temperature. This
substitution increased the values of both tests due to the dilution and filler
effect. Choosing the last speed, different percentages have been selected (5,
10 and 20%) to produce ordinary concrete and the follow up of the
compressive strength and water absorption tests. The results of the two
tests are lower than the control. In concrete, the pozzolanic reaction is very
weak to develop a compact structure due to a lack of reactive silica. The
results obtained for 5% and 10% of substitution are very encouraging.

This article aims to propose a solution to two environmental problems. One is the silting up of dams, despite
the dredging operations. The other represents the rate of cement used in the mortar or concrete. The solution
is to introduce the calcined dredged sludge as a cement substitute. Treatment at 600 °C with different
heating rates (5, 10 and 20 °C/mn) was applied to make the mortar and measure setting time and hydration
temperature. This substitution increased the values of both tests due to the dilution and filler effect.
Choosing the last speed, different percentages have been selected (5, 10 and 20%) to produce ordinary
concrete and the follow up of the compressive strength and water absorption tests. The results of the two
tests are lower than the control. In concrete, the pozzolanic reaction is very weak to develop a compact
structure due to a lack of reactive silica. The results obtained for 5% and 10% of substitution are very
encouraging.

This work aims to propose a solution to two environmental problems. One is the siltation of
dams. The other represents the rate of cement used in mortar and concrete. The solution is to introduce
calcined dredging sludge as a substitute for cement. A heat treatment at 600°C was applied to the sludge.
Different treatment rates were applied for the preparation of mortars (5, 10 and 20°C/min) to measure the
rate of non-evaporable water and the porosity accessible to water. In the first test, the interval is very tight
(3.20-3.40%), in the second test, the best porosity is attributed to 600/20 mortar with 18.50% of the total
volume, against 19% in CEMI mortar. This substitution improves the compactness of mortars by tightening
the capillary pores. For concrete, the last processing rate was adopted and different percentages were
selected (5, 10 and 20%). The sound propagation in the UPV test is greater than 4 Km/s with a slight
advantage to CEMI concrete followed by concrete with 5%, 10% then 20% of substitution. In concrete, the
pozzolanic reaction is very weak to develop a compact structure due to a lack of reactive silica and a low
percentage of kaolin (13%). The results obtained for 5% and 10% substitution are very encouraging for the
use of these types of cement in second-order works.

In seeking comfort and security, humanity polluting its environment. Cement plants generate greenhouse gases constantly. At the same moment, dams are submerged by a disease named "siltation". Face to this, we tried to elaborate a new compound cement with a dredged sludge as a raw material. Treated at 600°C and introduced at 10% alongside clinker and gypsum, the new cement was subjected to compressive strength and chloride ion migration tests. The results were reasonable, but cement develops a weak pozzolanic activity because of a low kaolin percentage.

La diminution de l’exploitation des ressources naturelles, est la préoccupation majeure des pays. Le dépôt des sédiments au fond des barrages empêchant la bonne exploitation de ceux-ci et l’engloutissement des minerais naturels par l’industrie cimentaire sans deux problèmes que tous les pays cherchent à réduire. Dans ce travail, nous proposons une solution à ces deux problèmes environnementaux. Elle consiste à introduire les sédiments déposés, comme remplaçant du ciment dans un béton ordinaire. Après un traitement thermique, les sédiments ont été substituées au ciment à différents pourcentages (5-10-20%) pour la confection d’un béton ordinaire. Ces bétons ont été comparés à un béton témoin, avec le même rapport E/C et sans excès de vibrations. Les mesures physiques comme l’affaissement, le retrait et l’absorption capillaire ont révélées une dépendance à la substitution sous l’effet de la dilution. Quant à la résistance à la compression, elle diminue suite à l’absorption d’une partie de l’eau d’hydratation du ciment par les sédiments dragés. L’analyse thermogravimétrique, indique un manque de silice réactive pour alimenter la réaction pouzzolanique. Les courbes de la quantité de portlandite produites et l’eau non évaporable par les bétons modifiés, sont inférieures à celles du béton de référence. Les constatations de cette étude annoncent qu’une substitution de 5% de ciment par les sédiments, produit un béton acceptable. Ce pourcentage peut contribuer à la réduction du niveau de ciment dans le béton ordinaire et minimiser l’effet de sédimentation des barrages.

The silting-up of dams and the cement level used in concrete represent a very significant environmental problem. In this work, we propose the solution to these environmental damages. This solution consists in the introduction of dredged sludge after heating treatment, as a cement substitute in ordinary concrete. Different percentages of cement (5-10-20%) have been replaced by dredged sludge, with the same W/C ratio and without excess vibration.
Physical measures like subsidence (which goes from 75mm for a reference, to 60mm for a concrete with 20% dredged sludge) and shrinkage have revealed dependence on substitution under the effect of dilution. The compressive strength decreased with the incorporation of the treated sludge. It decreases from 41Mpa for the reference concrete, to 39Mpa for a concrete with 5% substitution, to reach 30Mpa for a concrete with 20% substitution in 28 days as an example. Thermogravimetric analysis indicates a lack of reactive silica to supply the pozzolanic reaction. The portlandite rate curves produced by modified cement concrete are lower than the reference concrete.
The results reveal that the substitution of 5% of cement by dredged sludge leads to an appropriate concrete. This percentage can increase to 10% with the use of admixtures, which leads to decrease the level of cement and minimize the siltation effect.

The aim of this article is to propose a two environmental problems solution. One is the silting up of dams, despite the expensive dredging operations and the absence of a policy for the reuse of dredged sludge stored on non-agricultural land. The other represents the rate of cement used in the concrete. The dredged sludge is introduced after heating treatment at 600°C into the cement matrix of an ordinary concrete represents the proposed solution for both problems. In these eco-concretes, the cement has been replaced by treated dredged sludge at different percentages (5-10-20%) with a similar amount of water. Physical measurements and mechanical tests like shrinkage, absorption, and ultrasonic pulse velocity indicated dependence on substitution under dilution effect. Thermogravimetric analysis like the produced portlandite rate indicates a lack of reactive silica to supply the pozzolanic reaction. The results reveal that the substitution of 5% of cement by treated sludge leads to an appropriate concrete and minimizes the siltation effect.

Les usines de ciments engloutissent des milliards de tonnes de terres non renouvelables d’argile et de calcaire. En parallèle les barrages voient leur capacité de stockage se réduire à cause de la sédimentation.
Ces deux problèmes environnementaux, nous ont incité à introduire la boue de dragage du barrage K’sob de M’sila dans la matrice cimentaire d’un béton ordinaire.
L’étude minéralogique de cette boue, a révélée une fraction phylliteuse comportant les trois groupes d’argiles avec 11% de kaolin, 20% d’illite et 12% de chlorite. Chimiquement, les éléments majeurs sont la silice à hauteur de 48% et l’oxyde de calcium avec un pourcentage de 19%.
Après l’étape de séchage, le broyage a été mené afin d’aboutir à une finesse voisinant les 7000 [g/cm²]. La boue de dragage à subit un traitement thermique à 600 °C avec un temps de maintien de cinq heures et une vitesse de chauffage 20 °C/min.
Cette boue traitée thermiquement a été substituée au ciment à différents pourcentages (5-10-20%) dans la matrice cimentaire d’un béton ordinaire nommé (Bt5, Bt10, Bt20) respectivement. Ces bétons ont été comparés à un béton témoin (Bt0) élaboré par un ciment de type CEMI.
Trois types d’essais ont été menés pour apprécier les caractéristiques des differents bétons : essais physiques (Affaissement, retrait), essai mécanique (résistance à la compression) et essai thermogravimétrique ( taux de portlandite produite).
Les essais physiques ont démontré que le béton témoin (Bt0), ainsi que le béton (Bt5) enregistrés le même taux d’affaissement avec 7,5 [cm], cette mesure décroit avec l’introduction de la boue de dragage traitée pour atteindre 6[cm] pour le béton Bt20. Ce décroissement est dû à la diminution du taux de ciment et au pouvoir de la boue traitée à absorber l’eau destinée à l’hydratation du ciment. Le retrait sous l’effet de la substitution à augmenter de 105% pour le béton Bt5, 110% pour le béton Bt10 et 119% pour Bt20 après 90 jours. Cette augmentation est due au manque des produits d’hydratation qui ont pour effet de réduire les pores dans le béton.
La résistance à la compression à 28jours de durcissement comme exemple a révélée une résistance à la compression de 41Mpa pour le béton témoin. Cette valeur diminue pour le Bt5 enregistrant 39Mpa, le Bt5 donne 38Mpa le Bt10 développe la résistance la plus faible 30Mpa. Sachant qu'à 600°C, il y a que le kaolin qui se transforme en métakaolin, cette boue traitée thermiquement ne développe pas un caractère pouzzolanique élevé à cause d’un manque de silice et d’alumine réactive dans les ciments modifiés.
Les mêmes cubes utilisés dans l’essai précédent ont été broyés afin de calculer le taux de portlandite produite par les différents ciments. Le CEMI a enregistré à tout âge les valeurs les plus supérieures. Cette diminution des valeurs pour les ciments modifiés, ne reflète pas un caractère pouzzolanique, sinon on aurait des résistances à la compression supérieures.
Sur la base des de ces résultats expérimentaux obtenus, on peut dire que le béton Bt5 est le plus proche par ces caractéristiques au béton Bt0. Mais, avec l’adjonction d’adjuvant, on peut éliminer plus de boue est ainsi utilisé 10% de boue de dragage.

The aim of this paper is to investigate the effect of hot climate on the performance of roller-compacted concrete which is used for pavement. Mixes were placed in different environments in order to simulate the local climate conditions. Large-scale test has been carried out to assess the mechanical strength development in function of curing mode, temperature treatment and silica fume addition. Compressive strength, splitting tensile strength, shrinkage and capillary absorption of water were evaluated according to the program tests. The main results showed that an increase in temperature (over 40°) affects negatively the physical and mechanical properties due to malformation of hydration products, while cure methods showed a higher efficiency of the improvement in such properties. However, it should be noted that the wet cure method gave the best results as it provides appropriate and effective conditions to the hydration process. Regarding the effect of silica fume addition, even an improvement in the compressive strength was confirmed; however, it has a negative impact on the shrinkage.

The aim of this work is to better understand the physical and chemical phenomena involved in hydrated mix (clinker + addition) during the natural carbonation process, to characterize cement with supplementary cementitious materials (SCMs) under various curing environment. The prepared cement pastes were characterized by thermogravimetric analysis. The results showed a considerable influence of the environment on the properties of mortars and cement and a perfect correlation between compressive strength, natural carbonation, nonevaporable water, and portlandite content. It was observed that the reduction of the curing period makes the mortars more sensitive. The kinetics of process was evaluated from Ca(OH)2 content and nonevaporable water contained in mortars. These two parameters reflect the hydration progress of the water/cement ratio studied. The weight loss due to Ca(OH)2 decomposition, calculated by DTA/TG analysis, shows the effect of the pozzolanic reaction and the natural carbonation. The supplementary cementitious materials (SCMs) play a considerable role in the slowing down of the aggression environment.

This study aims to produce an eco-cement by using heat treated dam’s sludge as an additive to clinker. Different heat treatment cycles were applied to the dam’s sludge: three temperatures selected in the range between the dehydroxylation and decarbonation temperatures (600, 700 and 800 °C) reached by adopting different heating rates (5, 10 and 20 °C/min). The analysis of DRX, DSC–TG, FTIR results show that the heat treatment cycles let to the change of the sludge structure allowing its use as a pozzolanic additive to produce cements. The optimal heat treatment cycle is 600 °C with a holding time of 5 h and a heating rate 20 °C/min. Normalized mortars have been designed using modified cements constituted by 5% of gypsum, different percentage of heat treated sludge (5–10% and 15%) and clinker. The compressive strengths at 28 days lead to the choice of blending 85% clinker, 10% heat treated sludge and 5% gypsum to produce modified cements. The influence of the thermal activation of the dam’s sludge on the technical properties such as normal consistency, fineness, setting time, heat of hydration, compressive strength have been investigated and tests were conducted according European standards. Results reveal that heat treatment at 600 °C with a rate of 20 °C/min conducts to an activated sludge with no emission of carbon dioxide and the higher strength resistance when added to clinker at 10%. However, whatever the fineness or the rate of heat treatment, the percentage of kaolinite (11%) existing in the natural sludge is not sufficient to develop by heat treatment at 600 °C hydration products allowing significant improve of mechanical resistance of modified cements by comparison to CEMI.

In Algeria, arid and semi-arid climate regions are predominated by steep slopes and soft rocks, this lithology is daily attacked by erosion of water, wind, desertification and overgrazing. These effects encourage the deposition of sludge in the reservoirs and dams.
In this study, we are proposing to incorporate the mud from K'sob dam to product cements in partial substitution of clinker. However, this incorporation is not immediately because the hydraulic ability of mud. The heat treatment was selected from DSC-TG analysis and our selections of temperatures are for every test respectively, 600 °C, 700 °C and 800 °C, with different increase of heating such as 5(°C /min), 10(°C /min) and 20(°C /min). After these steps the treated sludge has been mixed with the clinker from the M'sila (Lafarge Group) cement factory and gypsum (10% mud, 85% clinker and 5% gypsum) to make cements.
Treated sludge have a good pozzolanic activity index and modified cement a good workability, also with the application of a treatment rate of (20 °C/min) allowed us to appreciate the brutal change in structure of kaolinite and transformation to metakaolinite to create an active pozzolan. Resistance of cement with sludge heated of 800 °C in an increasing of heating 20 °C/min in 28 day is 44 (Mpa) although, in the same condition the resistence of CEMI is 45 (Mpa).

Les régions à climat aride ou semi-aride en Algérie sont prédominées par des fortes pentes et sont en majorité constituées d’un substrat de roches tendres. Cette nature lithologique est chaque jour agressée par l’érosion hydrique et éolienne, la désertification,...etc. Ces conditions favorisent le dépôt des boues dans les retenues et les barrages.
Dans cette étude on propose d’incorporer la boue de dragage du barrage ksob dans les ciments en substitution partielle du clinker. Cette incorporation n’est pas immédiate, des cycles thermiques ont été appliqués à la boue de dragage afin d’optimiser son effet pouzzolanique. Il en ressort que le cycle optimal est de 600°C avec un temps de maintien de 5h est une vitesse de montée en température de 20°C/mn.

Ce travail s’inscrit dans le cadre de recherche des ajouts capables d’être mélangés au clinker afin de donner naissance à un ciment performant. L’ajout est une
marne argileuse très répondue dans la région de M’sila utilisée dans la poterie locale.
Après calcination à différentes températures de 600°C et 800°C, les nouveaux ciments, ont des résistances caractéristiques appréciables grâce à une activité pouzzolanique majeure. La surface spécifique ainsi que les composants chimiques jouent un rôle déterminant dans l’augmentation du mouillage des grains de ciments, ce qui engendre un temps de prise réduit

This work is an experimental approach based on the method of experimental plans to determine a specific formulation of a resin concrete. In this study, an unsaturated polyester resin (thermosetting resin) was used with two types of mineral fillers (dune sand and crushed sand), and with the addition of a marble powder to ensure the continuity of the particle size mixing granular. The lack of the methods for developing this kind of composite materials, had led us to perform an initial experimental approach to define the experimental field, that is to say determine the mass proportions of the various compounds of mixture of our study. In the second approach, we have established and implemented fully experimental plans with three factors namely: Factor 1: sand, factor 2: resin, factor 3: marble powder. Test results being the density of polymer concrete and the mechanical resistances. Finally, multi-parameters regression allowed us to determine predictive mathematical models for the different responses of the study. Tests results showed that at three days we got a tensile strength of about 16 MPa with a resin concrete density of 1.9 g/cm3. This shows the advantages of this material.

This work lies within the general scope of the valorization of local materials, having for interest the improvement of the physicochemical and mechanical characteristics of the products resulting from recovery entering the clothes industry of the elements of structures and construction. The principal goal relates to the valorization of mud of dredging of the stopping 'Ksob – Algeria'. The mud and the abundant red argillaceous marl in the area, contain kaolin and iolite. These clays are respectively calcited with 750 and 780 °C and are mixed with the clinker in order to study their influences on the properties of cementing materials. Compared with a Portland cement, it is noted, that with each increase in the rate of addition, a reduction in the calcium oxide rate and a growth of the silica rate. The various results of the tests of compression show that standard cement R10 has a good resistance in compression, at 28 days, it is about 42 to 43 MPa, that of Portland cement is 44 MPa whereas, for the concretes, resistances in compression observed exceed the 50 MPa. These results put forward the influence of the sandy and muddy clay additions, on the properties of cementing materials, thus showing the economic and environmental interest of the substitution of the clinker by the burnt clays.