Experimental and numerical studies of a bioclimatic and sustainable habitat : case of the valorization of Typha Australis in bio-based construction material for the thermal insulation of a building.

L’objectif de cette thèse est de contribuer à la conception d’un habitat bioclimatique et durable en valorisant le Typha Australis comme matériau de construction. Ce matériau jouera le rôle d’un isolant thermique dans le bâtiment. Ce travail est divisé en deux principales parties : Une première partie expérimentale qui consiste à concevoir et caractériser de nouveaux matériaux à base du Typha Australis en utilisant l’argile et /ou le ciment comme liant et d’étudier différents aspects qui influent sur leurs caractéristiques thermiques et mécaniques ;- Une seconde partie de simulation numérique qui consiste à évaluer la performance énergétique de ce type de matériaux sur un bâtiment en utilisant TRNSYS qui est un logiciel de simulation thermique dynamique. En effet, l’une des objectifs spécifiques est d’allier le confort thermique de ce type de bâtiment et la réduction de la facture énergétique tout en préservant l’environnement.D’une part, nous avons étudié les propriétés des matériaux (l’argile, le ciment et le Typha Australis) utilisés dans ce travail. Les deux premiers matériaux sont utilisés comme des liants et le dernier comme un granulat. Après cette étude, nous avons mis en place plusieurs formulations en utilisant dans un premier temps l’argile comme liant ensuite l’argile stabilisée avec 25% du ciment et le Typha Australis a été rajouté par substitution au liant pour des pourcentages allant de 0 à 55% avec un pas de 15%. Une étude de l’influence de la longueur et la teneur des fibres sur les propriétés thermiques et mécaniques du matériau composite argileux renforcé par le Typha Australis a été effectuée et les résultats montrent que l’augmentation de la teneur et de la longueur des fibres impactent significativement les propriétés thermiques et mécaniques. Cette étude a été précédée par une analyse hydrique qui comprends la détermination du coefficient d’absorption d’eau du Typha Australis qui a permis de montrer le caractère hydrophile du Typha Australis et la perte de masse en fonction du temps a également été déterminée. La stabilisation de l’argile avec 25% du ciment a donné des résultats prometteurs sur l’amélioration des caractéristiques thermiques et mécaniques des composites. Et d’autre part, Une simulation thermique dynamique par le logiciel TRNSYS a été effectuée. Les résultats montrent que l’utilisation de ce type de matériau comme paroi ou panneau isolant dans le bâtiment permet de réduire la consommation énergétique. Afin de trouver un meilleur compromis entre les propriétés thermiques et mécaniques, l’influence du rapport eau sur liant a été consciencieuse évaluée. Enfin, une modélisation analytique a été réalisée dans un premier temps la modélisation auto cohérente a été adoptée puis un modèle mathématique a été proposé et validé.The aim of this thesis is to contribute to the implementation of a bioclimatic and sustainable habitat through the valorization of Typha Australis as a biosourced building material. This material will play the role of a thermal insulator in the building. To do this, the study is divided into two major parts: The experimental part which consists in designing and characterizing new materials based on Typha Australis using clay and / or cement as a binder and to study different aspects that influence the thermal and mechanical characteristics; The numerical part which consists in evaluating the energetic performance of this type of materials on a building through TRNSYS which is a dynamic thermal simulation software. Indeed, the objective is to combine the thermal comfort and the reduction of the energy bill while preserving the environment.First, we studied the characteristics of the raw materials which are clay, cement and Typha Australis. The first two are binders and the last is an aggregate. After this characterization, formulations using initially the clay as a binder, then the clay stabilized with 25% of cement as a binder and Typha Australis was added by substitution to the binder for different percentages ranging from 0 to 55% with a step of 15%. Then, a study of the influence of the length and the content of the fibers on the thermal and mechanical properties of the material of the clay composites reinforced by Typha Australis was carried out and the results showed that the increase of the content and the length of the fibers impact significantly the thermal and mechanical properties. This study was preceded by a hydric analysis which included the determination of the water absorption coefficient of Typha Australis which showed the hydrophilic character of Typha Australis and the mass loss as a function of time was also evaluated. The stabilization of the clay with 25% of the cement gave promising results on the improvement of the thermal and mechanical characteristics of the composites. Then, a dynamic thermal simulation by TRNSYS was carried out which made it possible to show the interest of using this type of material as wall or insulating panel in the building, by quantifying the energy saving carried out. Finally, in order to find a better compromise between the thermal and mechanical properties, the influence of the E/L ratio was conscientiously evaluated and an analytical modeling was carried out. At first, the self-consistent modeling was adopted and then a mathematical model was proposed and validated

The influence of

Typha Australis is a plant that grows abundantly in fresh water. The proliferation of this plant causes health problems, so several measures have been taken to eradicate this problem such as: cutting the plant, coal production. So this article is about the valorisation of this plant as a bio-based material in order to solve the energy problem in the building. In this study, clay was used as a binder with a given percentage. The mixture of clay and Typha was used as an insulation panel and a comparison was made with a conventional habitat without an insulation panel. A dynamic thermal simulation was performed on TRNSYS to evaluate the influence of the use of this insulation panel on the energy consumption in the building. The results of the comparison showed that the use of this insulation panel, which is a mixture of clay and Typha Australis, reduced the energy requirement by 23%, which is a satisfactory result

Thermal performance of biosourced materials on Buildings: The case of Typha Australis

Developing countries are facing population growth, which leads, on the one hand, to increased requirements for buildings and, on the other hand, to the depletion of fossil fuels along with exposure, of people living in those areas, to some detrimental consequences of climate change. Because of these factors, we propose approaches to control energy consumption in buildings. In some countries, the architectures adopted are not adequate to the environment and climate, resulting in discomfort in those buildings, in such circumstances, residents resort to the use of energy systems, such as heating, ventilation, and air conditioning, which leads to exorbitant electricity bills. Housing consumes 40% of the world's energy and is responsible for a third of greenhouse gas emissions. Optimizing energy needs in buildings is a solution to overcome these problems. For this purpose, there are solutions such as: the design of the building characterized by its shape and envelope, while using less energy-consuming equipment. For several years, the building materials sector has been developing with a particular focus on bio-source materials, which are generally materials with good thermal performance. In order to highlight the thermal performance of bio-source materials, we will study the case of Typha Australis which is a plant of the Typhaceae family that grows abundantly in an aquatic environment mainly in the Senegal River valley.Recent studies showed that Typha Australis has good thermal insulation properties. In order to determine the impact of Typha Australis on a building, a dynamic thermal simulation was carried out using the Trnsys software according to specific scenarios, the Typha was mixed with other local materials and used as a wall insulation panel, the result of the study shows that this fiber has allowed us to optimize energy consumption in a building. Mixing Typha with other materials (e. g. clay) is a promising solution for energy efficiency in buildings

Investigation of the length and percentage fiber influence of Typha Australis on biosourced composites

This paper discusses the influence and content of Typha Australis fibers on the thermal and mechanical properties of clay composites. The objective is to find a better combination of length and percentage of fibers. This combination will allow to have a good compromise between thermal and mechanical properties. The results found at the end of this study are conclusive. Indeed, the increase of the length and the percentages of fibres improve the thermal properties but the values of the compressive resistances decrease