Dissertations / Theses on the topic 'Fines de béton recyclé'
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Nguyen, Vu Nam. "Valorisation de fines et granulats issus de bétons recyclés comme matériaux cimentaires : Enhancement of fine and aggregate issued from recycled concrete as cementitious materials." Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30058/document.
Full textThe concrete consumption has been becoming more and more important due to the increase of urbanization requiring the rehabilitation and the construction of buildings and infrastructure. Nevertheless, the concrete production that accompanies the urban development leads to many environmental problems related to the preservation of natural resources which are not inexhaustible. Despite of recycling efforts, most of recycled materials are typically used for road works or embankment. By participating in the French National Project Recybéton, this thesis aims to assess the enhancement of recycling materials issued from deconstructed concretes by incorporating them in new concrete design. Two types of recycled materials will be studied, the powder produced in large quantities during the crushing phase of demolished concrete, and the aggregates (sand and gravel) whose the most part issued from the initial natural aggregates. Therefore, research study aims to quantify the properties of cementitious materials in various states by the use of: • recycled aggregates in the granular skeleton, grinded recycled concrete sand and powder of dust removal as supplementary cementing materials. The first part is dedicated to the study of the influence of moisture states of recycled aggregates (sand and gravel) on the concrete's rheology evolution in time and the study of their impact on 28 days compressive strength. The results obtained within the limit of experimental context will allow suggesting recommendations on the initial moisture state of recycled aggregates and their incorporation's rate in the concrete mix. The second part presents the evaluation of the feasibility of using grinded recycled concrete sand and crushed concrete powder (industrially recovered) as supplementary cementing materials. From the results, it will be possible to assess the extent that these fines are compatible with cement matrix in the fresh state, hardening state and hardened state. The third part proposes a way to limit the problem of Alkali-Aggregate Reaction (AAR) in recycled concrete. The strategy is based on two methods. The first insists to verify the applicability of the FD P18-464 documentation when using recycled aggregates. The second examines the interest in the use of mineral additives to limit or even prevent the AAR
Bouarroudj, Mohamed ElKarim. "Utilisation de matériaux naturels modèles pour la formulation de mortier contenant des sables et des fines de granulats recyclés." Thesis, Ecole nationale supérieure Mines-Télécom Lille Douai, 2019. http://www.theses.fr/2019MTLD0016.
Full textRecycled concrete aggregates (RCA) are not enough used in the construction sector, mainly because of their high water absorption capacity. These fine particles are composed of crushed natural aggregate and adherent hardened cement paste. The first part of this work consists in valuing particles smaller than 4 mm of an RCA in a mortar composition. Thus, the fresh and hardened behavior of mortar performed with recycled fine aggregate and model natural aggregate have been compared. The natural model fine aggregate has been performed to have an equivalent physical characteristics with the recycled one. This approach helped to understand the hardened behavior of the mortar made with recycled fine aggregate. The second part of this work consists in finding a recovery track for particles smaller than 125 μm of RCA, the goal is to use them as mineral addition. A characterization work show that the recycled powder is porous, thus a theoretical model and an experimental methodology allowing to estimate this porosity are developed. Finally, a comparison between mortar made with a limestone powder, and a recycled powder are compared. The results show that the recycled powder can be used as mineral additive in mortar composition
Abidar, Abdellatif. "Etude des mécanismes de régénération de l'hydraulicité de bétons recyclés dans le cadre d'une approche économie circulaire." Electronic Thesis or Diss., Université Gustave Eiffel, 2024. http://www.theses.fr/2024UEFL2039.
Full textConcrete, widely used in construction, is essential to modern society. However, as buildings reach the end of their life cycle, demolition becomes inevitable, contributing to the annual accumulation of concrete debris. This situation presents a major challenge in construction waste management. Faced with this reality, concrete recycling emerges as a necessity. This approach not only reduces the amount of waste sent to landfills but also preserves natural resources, promoting sustainable construction.This thesis is part of a research project focused on concrete recycling from a circular economy perspective. It offers an in-depth study of the regeneration of hydraulic properties of cementitious materials, aiming to understand the underlying mechanisms of this regeneration. This analysis is performed in three distinct stages. Initially, we examined a pure phase of C3S, followed by an intermediate phase using Portland cement, concluding with a study on recycled concretes from returns and demolitions.We propose a process based on the thermal treatment of powders derived from crushing cementitious materials, conducted at low temperatures ranging from 400°C to 800°C. To understand the mechanisms of hydraulicity regeneration, characterization techniques such as TGA, FTIR, 29Si-NMR, and XRD with the Rietveld method (TOPAS V6) were employed.Thermal treatments applied to various phases from 600°C revealed the formation of belite. Specifically, the β-C2S polymorph formed in the case of the pure phase, while the α'-C2S and β-C2S polymorphs formed in the case of Portland cement paste. Thermal treatments applied to returns and demolition concretes revealed similar mechanisms, with belite formation observed from 700°C onwards. These findings were confirmed by X-ray diffraction (XRD) and 29Si-NMR spectroscopy, the latter also showing complete decomposition of C-S-H at 600°C, leading to belite formation. The regenerated phases exhibit high reactivity, likely due to the strong reactivity of lime produced during thermal treatments. Consequently, almost all formed belite was consumed after 28 days of hydration. Binders obtained at temperatures between 600 and 800°C led to the reformation of hydrates such as C-S-H, Portlandite, and Ettringite.Mortars made with 100% binders from thermal treatments applied to cement pastes exceeded 16 MPa in compression after 90 days and could reach over 30 MPa when replaced by 40% CEM I, despite their high water demand. Conversely, mortars composed of 100% binders from concrete do not exceed 4 MPa in compression after 90 days but can reach over 20 MPa in compression and 5 MPa in flexion when replaced by 40% CEM I
Faubert, Jean-Philippe. "Valorisation de particules fines dans les bétons compactés au rouleau et les bétons moulés à sec." Mémoire, Université de Sherbrooke, 2013. http://hdl.handle.net/11143/10147.
Full textMartinez, Hernandez Heriberto. "Amélioration de granulats de béton recyclé par bioprécipitation." Thesis, Ecole centrale de Nantes, 2022. http://www.theses.fr/2022ECDN0009.
Full textRecycled concrete aggregates (RCA) contain, due to their origin, residual cement paste which gives them high porosity and moderate performance. The porosity leads to a strong water absorption. This is a major difficulty on the industrial level because it complicates the adjustment of water in concrete batches, which allows to control their workability in production. The RCA manufacturing process results in having more paste in the finer particles and therefore more absorption. As a result, while the industry today recycles coarse RCA into concrete relatively well, it uses small amounts of RCA sand because of their greater porosity. Yet, during the manufacture of RCA, about 50% sand and 50% coarse aggregates are obtained. Consequently, the porosity of RCA sand hinders the circular economy of concrete. A number of techniques have been proposed for removing or improving the residual cement paste, but they are expensive. The natural carbonation of RCA by atmospheric CO2 helps with decreasing their water absorption by obstructing their porosity, but this is a several month reaction. Research is ongoing to make accelerated carbonation (by concentrating CO2, for example) on an industrial scale. The present work explores an alternative idea, which consists in forming in a few days, using biocalcifying bacteria, a matrix of CaCO3 around the RCA and especially the sand part, in order to limit the access of water to their porosity. First, candidate non-pathogenic bacteria were identified, selected, adapted to the alkaline medium of RCA, then we checked their ability to produce CaCO3. In a second step, we detemined the conditions, which favor uniform bacterial colonization and production of CaCO3 on the surface of model agar media. Homogeneity is indeed mandatory to obtain good water tightness. We thus confirmed the value of selecting bacteria capable of producing biofilm. Finally, the methods developed were applied to model mortar disks facilitating visual observations. Preliminary results confirm that it is possible to significantly lower the absorption of these mortars within one month. Further work is needed to confirm these encouraging results on sand part of RCA
S, Bastien Mari-Jo. "Valorisation des granulats de béton recyclé et des granulats de verre recyclé dans les pavages industriels en béton compacté au rouleau." Mémoire, Université de Sherbrooke, 2016. http://hdl.handle.net/11143/8799.
Full textDeodonne, Kunwufine. "Etudes des caractéristiques physico-chimiques de bétons de granulats recyclés et de leur impact environnemental." Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAD013/document.
Full textPromoting the use of demolition waste as recycled aggregates presents a double objective: first to preserve natural resources and secondly to relieve storage site. In regards to natural aggregates, recycled aggregates contain mortar that influences theirs properties and those of concrete in which they are used. The objective of this thesis is to develop the use of 100 % recycled aggregates in concrete. This study was realised in patnership with the company CHYRSO. Properties of recycled concrete aggregates collected from several sources were studied to identify and analyse their specificities ; results were compared to natural ones. Normalised methods were modified in order to be applied on recycled aggregates and new methods were also proposed. Recycled aggregates present higher water absorption, lower mechanical strength, spreader granular distribution and a less circular shape compared to natural aggregates. The granulometry of recycled sand, fines content and the water absorption are properties that depend on the sampling and the robustness of protocols used. A reactivity of fines obtained from materials made at the laboratory have been established, meanwhile their influence on concrete properties is considered as minor. Finally, the absorption and morphology of recycled aggregate depend on the granular fraction. Correlation between morphological and mechanical properties with water absorption have been demonstrated. After analysing these properties, correction were proposed on mechanical performance forecasting models. It was also shown that the use of fines in recycled aggregate concretes provides better mechanical properties. For such materials, keeping aggregates less than 63μm is advisable because it provides correct granular skeletton. In order to balance the loss of workability and mechanical strength observed with the use of recycled aggregates, studies were carried with several superplasticisers. Polycarboxylates were identified as appropriate superplasticisers. Interpretations facilitate understanding of concrete formulation and concrete equivalent mortar formulation made with recycled aggregates. Thus, the complexity of absorption and desorption kinectics lead to a discusion around effective water definition. The difference between the morphology of recycled aggregates and natural ones involved a correction of the granular skeletton; finally, their weakness during mechanical test modifies the granular skeletton and need to be taken into consideration.Finally, studies on environmental impacts of recycled aggregates concrete were done and compared with those of natural aggregates concrete. This study starts interesting perspectives
Zhao, Zengfeng. "Valorisation des sables de béton recyclé pour la fabrication de mortiers." Thesis, Lille 1, 2014. http://www.theses.fr/2014LIL10004/document.
Full textVery large quantities of construction and demolition wastes and especially concrete wastes are produced yearly. At the same time, high amounts of natural aggregates are needed for construction industry. Up to now, only a small fraction of these concrete wastes is re-used as recycled concrete aggregates (RCA) for the manufacture of concrete. RCA are composed of an intimate mix between aggregates and hardened cement paste (HCP). Hardened cement paste is much more porous than the natural aggregates and the properties and proportions of HCP largely influence the properties of RCA. As a consequence, the fine fraction of RCA (FRCA), essentially composed of mortar and cement paste, possesses a large water demand which makes it harder to recycle into concrete.The objective of this research is to better understand the role played by HCP on the properties of RCA in relation with the improvement of the characterization methods of these materials and their reuse in the manufacture of mortar or concrete. Firstly, an experimental method based on salicylic acid dissolution allowing to determine HCP content of FRCA is developed. FRCA properties are then studied as a function of hardened cement paste content, particle sizes and properties/composition of the original concrete. From the obtained relationship between water absorption and cement paste content, the water absorption coefficient of the smaller fraction (0/0.63mm) can be estimated whereas it is difficult to measure. Secondly, different industrial RCA are characterized which allows us to expand the preceding conclusions to “real RCA”, meanwhile, the influence of carbonation on the properties of FRCA is also carried out. Finally, the influence of the saturation state of FRCA on the properties of fresh and hardened mortars and on their microstructure is explored. The recycled mortars with dry FRCA have better compressive strength than that with saturated FRCA, which is confirmed by the study of ITZ properties. The mechanical properties of mortars with different RCA content and replacement fraction are determined. The finer fraction of RCA has a worse influence on the mechanical properties of RAC than the coarser fraction
Chiriatti, Léon. "Etude de l'adhérence armature-béton, influence des granulats de béton recyclé et apport des mesures acoustiques." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAD040/document.
Full textThe use of recycled concrete aggregate (i.e. aggregate produced from concrete demolition rubble) has a significant impact on the mechanical behavior of reinforced concrete members. This work focuses on the influence of recycled concrete aggregate on rebar-concrete bond. First, an analytical madel of the rebar-concrete bond is developed. The original feature of this modellies in the limited number of non-free physically-based parameters on which it is based. These parameters are then experimentally determined through a pull out test campaign. Three types of concrete, including two recycled aggregate concretes, are studied. Pull-out test monitoring is completed by acoustic measurements in order to obtain data from inside the concrete bulk, where the reinforcing bar is located
Hussain, Hallshow. "Etude de la composition, du comportement mécanique et de l'endommagement d'un béton recyclé." Caen, 2002. http://www.theses.fr/2002CAEN2006.
Full textAdessina, Ayodele. "Caractérisation expérimentale et modélisation multi-échelle des propriétés mécaniques et de durabilité des bétons à base de granulats recyclés." Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1100/document.
Full textThis thesis combines experimental and theoretical approaches to characterize the mechanical and durability properties of recycled aggregate concretes (RAC). The first part of the work is devoted to the quantification of the impact of recycled concrete aggregates on the mechanical and durability properties of RAC. The results show that mechanical and durability properties of recycled aggregate concretes depend not only on the physical properties of recycled concrete aggregates but also on their quantity in the microstructure. Furthermore, statistical indentation technique is used to capture the local mechanical properties of phases in the microstructure of RAC such as the interfacial transition zones and the attached mortar. The second part of this study deals with the multi-scale modeling of the mechanical and the durability properties of RAC. The main purpose of this theoretical work is to establish models capable to predict the macroscopic behaviour based on the available information on the microstructure (obtained by optical microscopy or through indentation technique). The established models take into account the complex structure of the recycled concrete aggregates. Finally, the results of the models are compared with experimental data for discussion
Yacoub, Aiman. "Effet du traitement du sable recyclé sur les propriétés du mortier." Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1036.
Full textThe sustainability of primary resources is subjected to continuous threat via the construction industry. In fact, the amount of construction and demolition waste (CDW) produced and dumped into landfills is increasing each year. This situation forced the concrete industry to generate effective solutions such as implementing CDW as recycled concrete aggregates (RCA) to produce new types of concrete. Furthermore, a recent life cycle assessment study proved that the concrete made of RCA presents the best environmental behavior. CDW is currently used in the road and sidewalks construction and maintenance, however it needs more time and further investigations before using it completely as RCA in new concrete for building construction field because of their poor porosity properties. The recycling of the totality of the RCA in order to be used as new materials to produce new recycled concrete opens nowadays new environmental, economic and technological perspectives. Many scientific obstacles need to be studied in order to solve these perspectives. The re-use of the CDW as RCA will allow the limitation of the extraction of the raw materials and preserving the natural aggregates fields. In this thesis, we will be studying the fraction 1-4 mm of the RCA called recycled sand (RS). The water absorption of the RS influences the fresh and the hardened properties of mortar. Therefore, it is hard to maintain a constant W/C ratio since there is two phenomena during the fabrication of mortar: the absorption kinetic of the RS and the hydration reaction of the cement. In addition, the use of the RS leads to a decrease in the compressive strength and the durability properties of mortar. This decrease is controlled by three parameters: the porosity of the RS, the properties of the new cement paste and the properties of the interfacial transition zone (ITZ).The thesis proposed by the laboratory FM2D / MaST (IFSTTAR) is entitled ‘Effect of the treatment of the recycled sand on the properties of mortar’. This research subject is a comparison study between the behavior of treated recycled sand mortar and non-treated recycled sand mortar. In order to solve the problem of the use of recycled sand new mortar, we suggest two approaches:-Determining an optimal saturation state of the recycled sand in order to obtain a constant effectif W/C ratio.-Enhancing the microstructure of the RS using chemical products before using it in formulating new mortar. The treatment process proposed in this research consists of testing different chemical products with different concentrations using different application methods and different application times. The aim behind the chemical treatments proposed is, firstly, to decrease the value of the water absorption coefficient of the RS. The fresh and the hardened properties (compressive strength, durability properties, shrinkage) of mortar made with the treated RS (100% volume substitution) will be studied and compared to the properties of mortar made of non-treated RS and finally with the normalized mortar.The results obtained during this research indicate a success of the chemical treatment. The WAC of the RS decreased and the fresh and hardened properties of the mortar as well as it durability properties were enhanced compared to the mortar made of non-treated RS
Médevielle, Marion. "Utilisation de la bioprécipitation de carbonates de calcium pour améliorer la qualité de granulats de béton recyclé." Thesis, Ecole centrale de Nantes, 2017. http://www.theses.fr/2017ECDN0031/document.
Full textSands produced from demolition wastes (RCA) have a significant porosity due to the residual mortar resulting from the primary concrete. This is a brake on their recycling in concrete, as would be desirable to develop the circular economy of the sector. The natural carbonation byair of RCA is known to improve their performance. On the other hand, it is very slow and the associated storage constraints are not industrially acceptable. In addition,calcifying bacteria have been used for years to improve soils or monumental stones. In this context, the object of this thesis is to develop a method of accelerated calcification by deposition of bacteria on the surface of RCA This thesis is divided in 2 phases:- Selection and adaptation to pH12 of alkalophilic bacteria with the study of their growth and theirCaCO3 production yield, in vitro, in different environments (pH, urea or not, calcium concentration…) - RCA and mortar disk treatment with different processes whose efficiency is evaluated by a diminution of the material porosity. At the end of this work, a bacterial strain with a satisfying calcific production in contact with RCA was identified. However, the porosity reduction of the treated RCA porosity remains limited. The observations made show that this is linked to a heterogeneous deposit of calciumproduct on the surface of RCA. To conclude this work,several areas to be explored are proposed to improve the process
Le, Thang. "Influence de l’humidité des granulats de béton recyclé sur le comportement à l’état frais et durcissant des mortiers." Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10160/document.
Full textImproved techniques of characterization of recycled concrete aggregate (RCA) and a better understanding of the properties of concrete based on RCA would promote their use. The aim of this work is to study the influence of the state of saturation of RCA, especially of recycled sand, on the fresh and hardened behavior of mortars. The first part of this work is dedicated to the study of water absorption of recycled sand (RS) by different methods. The results show that the water absorption of RS is greater than that of natural sand (NS). However, the water absorption value of the RS is closely related to the used method and the pre-saturation mode. The second part is dedicated to the influence of the saturation state of aggregates on the workability of mortars. The results show that the initial saturation state, the pre-saturation mode and the pre-saturation time significantly influence the workability of the mortars. The influence of the saturation state of recycled aggregates on the hardened behavior of mortar is then studied with two mortars based on recycled dry or over-saturated sand. The microstructure is explored by scanning electron microscopy (SEM) followed by image analysis and by indentation test under the SEM. The compressive strength of mortars containing RS is lower than that of mortars made with NS. Moreover, the initial saturation state of RS does not influence significantly the compressive strength of mortars, the mean porosity of the new interfacial transition zone (ITZ) and the micro-hardness of the cement matrix. However, the saturation state influences significantly the distribution of meso-porosity in the new ITZ
Boulay, Vincent. "Valorisation des matériaux granulaires recyclés dans le béton de ciment pour usage résidentiel." Mémoire, Université de Sherbrooke, 2014. http://hdl.handle.net/11143/5917.
Full textMadjoudj, Nadira. "Valorisation de fines argileuses d'exploitation par moussage protéiniques : évaluation et optimisation des performances du matériaux élaboré." Amiens, 2004. http://www.theses.fr/2004AMIE0405.
Full textNguyen, Minh Duc. "Performances mécaniques des bétons incorporant des granulats recyclés et applicabilité des normes de dimensionnement." Thesis, Cergy-Pontoise, 2017. http://www.theses.fr/2017CERG0912.
Full textThis work is part of the ANR VBD ECOREB which aims with the project PN RECYBETON to remove the technological locks for the use of recycled aggregates for the formulation of structural concretes.For this study, six concretes of recycled aggregates corresponding to two classes of compressive strength C25 / 30 and C35 / 40 and S4 class of workability are developed. These mixtures, defined in the framework of the PN RECYBETON, are derived from two reference formulations by substituting partially or completely the natural aggregates with materials resulting from the recycling of concretes. An experimental program was carried out to determine the properties of concrete in fresh state and hardened state. The results of mechanical tests show that for the same class of compressive strength, the incorporation of recycled aggregates into the concrete induces a decrease in the tensile strength and the elastic modulus as well as an increase in the peak and ultimate strains. Under loading-unloading compression, the damage at the peak stress increases when the substitution rate is high while the damage rate becomes lower The creep tests carried out on beams loaded under three-point bending indicate that creep kinetics are influenced by the presence of recycled aggregates and is accelerated as the replacement rate is important.The experimental results of the present study together with an extensive number of results reported in the literature have allowed evaluating the current relationships used for predicting mechanical properties of recycled concrete aggregates (RAC). The validity of many analytical expressions of the stress-strain relationship has been also studied and the effect of replacement ratio was taken into account. It was pointed out that design codes relationships dedicated to assess the mechanical properties and the stress-strain compressive curve of natural aggregates concretes (NAC) are not adequate to predict the behavior of recycled aggregates concrete (RAC). It is established that these properties are related to fcm and to a parameter, which takes into account the effect of the recycled aggregates. The comparison between the stress-strain curves obtained in this thesis and some models shows that, with the proposed modifications, these models satisfactorily describe the behavior up to failure
Moisson, Marc. "Contribution à la maîtrise de la Réaction Alcali Silice par ajout de fines de granulats réactifs dans le béton." Toulouse, INSA, 2005. http://eprint.insa-toulouse.fr/archive/00000072/.
Full textThe objective of this thesis was to show that reactive aggregate fines can be used to counteract the effects of alkali silica reaction (ASR). Several mortars and concretes were made with five reactive aggregates : a quartzite, a siliceous limestone, an opal, an alluvial aggregate and a glass. The test-bar were conserved at 60°C and 100% RH or alternatively in an autoclave at 127°C. The test-bar on mortars allowed us to confirm that reactive aggregate fines reduce expansion ; the mortars in the autoclave permit to study the influence of the quantity and the fineness of fines. Finally the results were confirmed on concrete stored at 60°C, at least on a qualitative level. Mechanical tests and physicochemical studies were made with the objective to correlate the swelling caused by the ASR with microstructure. Finally, a numerical simulation, based on the software CEMHYD 3d, was made with the objective of explaining the phenomenon of reduction of the swelling by the use of reactive fines. The main conclusions are :On four out of five, reactive aggregate fines reduced or canceled the expansion due to ASR ;these fines addition raised systematically the strength of concrete ;microscopic observations made on test-bar with reactive fines did not reveal gel of ASR. On the contrary the test-bar without fines revealed a generalized contamination by inflating gel of the interfaces between paste and aggregates. The reduction in swelling is due to the lowering of alkaline concentration in the pore
Maimouni, Houda. "Suivi des échanges d’eau dans un mortier de sable recyclé modèle à l’état frais par une approche rhéologique." Thesis, Ecole centrale de Nantes, 2018. http://www.theses.fr/2018ECDN0045.
Full textThe increased interest in concrete recycling results from a willingness to reconcile the construction industry with sustainability. Recycled concrete aggregates (RCA) consist of a mix of natural aggregates and attached cement. The high porosity of RCA modifies the effective water content of a recycled concrete at the expense of its fresh and hardened performances. A testing method based on spread measurements is suggested to follow quantitatively water transfers between RCA sand and a fresh cement paste. This protocol is tested on cement paste sands (CPS) having 0.3, 0.5 and 0.7 water/cement ratios (W/C). Results show that the saturation degree of CPS embedded in a filler paste reaches a maximum no later than 6 minutes then remains quasiconstant. The saturation degree increases with the W/C of CPS ratios but remains less than 1. Moreover, similar water transfer kinetics are found whether initially dry CPS are immersed in a filler or a cement paste. The established protocol assumes a correlation between spread and effective water content of a mortar. In order to study this correlation, on the one hand, under the lubrication approximation, the yield stress of mortars is calculated from their spread radius. On the other hand, yield stress of mortars is calculated using a biphasic modelling of mortars viewed as non-colloidal suspensions in a yield stress fluid. Consistency between the two approaches is examined
El, Hilali Abdellah. "Etude expérimentale de la rhéologie et du comportement des bétons autoplaçants (BAP) : influence des fines calcaires et des fibres végétales." Cergy-Pontoise, 2009. http://biblioweb.u-cergy.fr/theses/2009CERG0458.pdf.
Full textThe research presented in this thesis develops a simple method for the formulation of self-compacting reference concrete containing limestone fillers and no added viscosity agent. The approach is dual: both experimental and theoretical (granular optimization) were conducted. The water and superplasticizer were determined through mini cone and Marsh cone tests conducted on the SCC paste. Effects of limestone filler fineness on rheological and mechanical properties of the SCC have been noteworthy. Three calcareous fillers have been introduced into the SCC paste, respectively noted "MFS", "LFE" and "MFO". The fillers had different Blaine Specific areas ‘SB’. The results demonstrated that increasing the calcareous fillers’ fineness amplified the demand for superplasticizer as well as increased its compactness and fluidity. Furthermore, it has been shown that the fillers with high ‘SB’ improved SCC durability relative to gas (CO2) and liquid diffusion; the concrete compressive strength was improved mainly at early curing ages. Also, the relationship between the elastic modulus and the SCC compressive strengths was independent of the fineness of the fillers and was very close to that recommended by ACI318-89. Is vegetable-fiber reinforced SCC mechanical strength as resistant as unreinforced SCC ? The main objective of this research was to answer this question. An experimental program was designed to study the influence of the introduction of short vegetable fibers issued from paper pulp recycling on the SCC’s properties. Four types of vegetable fibers have been studied, noted FBA, FBB, FBC and FBD. They differ in their geometric characteristics and their cellulose concentrations. The introduction of the short vegetal fibers in the formulated reference SCC with constant binder dosages led to a significant increase in the paste’s demand for water and superplasticizer, a decrease in concrete density, and an augmentation in permeability which reduced its mechanical strength and durability
Kimbonguila, Manounou Adolphe. "Modélisation discrète de la microstructure des agglomérats de particules fines en suspension." Thesis, Lille 1, 2013. http://www.theses.fr/2013LIL10112/document.
Full textThe agglomeration of fines leads to a significant increase in water demand of cement mixtures and hinders the valorization of by-products containing high fines proportions. A discrete modeling of the microstructure of fine particles agglomerates is developed. The model takes into account contact forces, physico-chemical, and hydrodynamic forces computed with the free draining approximation. The agglomeration, fragmentation and restructuring process of fractal agglomerates of fine mineral particles under shear is studied to quantify the entrapped water in the flocs. A loose initial agglomerate isolated is submitted to a constant shear rate. When the hydrodynamic forces predominate over the adhesive forces, the parent agglomerate is broken up into secondary agglomerates until reaching a steady state, where the number, size and structure of flocs can be considered constant. The influence of the velocity gradient, the physico-chemical context, particles size and their polydispersity on the microstructural characteristics of flocs at steady state is studied. It is shown that the behavior of a monodisperse dilute suspensions can be described by a dimensionless single number involving maximum cohesion force, particle size and velocity gradient
Cyr, Martin. "Contribution à la caractérisation des fines minérales et à la compréhension de leur rôle joué dans le comportement rhéologique des matrices cimentaires." Phd thesis, INSA de Toulouse, 1999. http://tel.archives-ouvertes.fr/tel-00489599.
Full textAL-RIM, KAMAL. "Etude de l'influence de différents facteurs d'allègement des matériaux argileux : Le béton argileux léger, généralisation à d'autres fines roches et applications à la cenception d'éléments de construction préfabriqués." Rennes 1, 1995. http://www.theses.fr/1994REN10213.
Full textKhoury, Eliane. "Maîtrise de l’eau efficace dans les bétons de granulats recyclés." Thesis, Ecole nationale supérieure Mines-Télécom Lille Douai, 2018. http://www.theses.fr/2018MTLD0011/document.
Full textComposed of several components (natural aggregates and adherent cement paste), RCA are not widely recommended in new concrete formulations. Their poor properties considerably complicate the determination of the effective water in fresh concrete. In a first part, a bibliographic study will highlight the wide dispersion of the results of characterization tests of RCA and the properties of fresh and hardened recycled concrete. In a second part, the heterogeneity of RCA and crushed concrete aggregates (CCA) is studied according to different parameters: granular impurities, density, cement paste content, mixing of parent concrete, and water absorption capacity according to their pre-humidification. The third part consists of three experimental studies that intend to improve effective water control in the manufacture of recycled concrete. The absorption kinetics of CCA in a cement paste is first studied. Then, the evolution of effective water in fresh concrete during mixing is studied using an original method based on the power evolution of the mixer. Finally, the effect of vacuum mixing on the properties of ordinary and recycled concretes is investigated