Mechanical and thermal properties of cement mortar composites incorporating micronized miscanthus fibers

This study examines the impact of incorporating micronized miscanthus fibers into a cement mortar, focusing on the mechanical and thermal effects. Initially, an experimental procedure was devised to create mortar mixtures with varying amounts of miscanthus fibers, with a maximum dosage of 7 wt%. This involved saturating the fibers with water beforehand to maintain the workability of the fresh mixes. The resulting hardened bio- based mortars were then evaluated after 28 days in terms of their microstructure, me- chanical strength (assessed through flexural and compression tests), and thermophysical properties (measured using the Hot-Disk technique to determine thermal conductivity/ diffusivity and volumetric heat capacity). The experimental findings revealed significant enhancements (up to 87%) in the thermal resistance of the mortars due to the addition of fibers. However, this improvement was accompanied by a considerable reduction in me- chanical strength. As a result, while these bio-based mortars are unsuitable for structural applications, they still possess adequate mechanical properties for handling and are appropriate for insulation purposes in constructionANR-11-LABX-022-0

Numerical modelling and experimental study of heat and moisture properties of a wall based on date palm fibers concrete

In the present paper, we study with both experimental and numerical aspect the heat and moisture transfer properties of a wall based on concrete filled with the natural fibers. The wall was placed in climatic chamber and temperature and relative humidity were monitored at different depths. A developed model describing heat and moisture transfers in porous building materials was implemented in COMSOL Multiphysics and solved with the finite element method. The obtained results are compared with experimental data. A relatively good agreement was obtained for both temperature and relative humidity variation at different depths. Finally, the developed model gives almost a good prediction despite the classical difficulties encountered at the experiment, which is very promising for the prediction of the hygrothermal behavior of bio-based building materials at different conditions

Controlled Emissivity Coatings to Delay Ignition of Polyethylene

International audienceSemi-opaque to opaque films containing small amounts of various aluminium particles to decrease emissivity were easily prepared and coated onto low-density polyethylene (LDPE) sheets. The thermal-radiative properties (reflectivity, transmissivity and absorptivity) of the films were measured and related to the aluminum particles' content, size and nature. Time-to-ignition of samples was assessed using a cone calorimeter at different heat flux values (35, 50 and 75 kW/m 2). The coatings allowed significant ignition delay and, in some cases, changed the material behaviour from thermally thin to thick behaviour. These effects are related both to their emissivity and transmissivity. A lower emissivity, which decreases during the degradation, and a lower transmissivity are the key points to ensure an optimal reaction-to-fire

Recycling and Reuse of Materials and Their Products

International audienceThis important book is an overall analysis of different innovative methods and ways of recycling in connection with various types of materials. It aims to provide a basic understanding about polymer recycling and its reuse as well as presents an in-depth look at various recycling methods. It provides a thorough knowledge about the work being done in recycling in different parts of the world and throws light on areas that need to be further explored. Emphasizing eco-friendly methods and recovery of useful materials

Recent Advances in Flame Retardancy of Textile Related Products

International audienceReplacement of existing flame retardants (FR) with sustainable and environmentally friendly alternatives for textiles, polymers, and composite materials in domestic, transport (automotive, rail, aerospace, and marine), civil emergency and military, construction and other industries requires a multidisciplinary approach from textile technology to the physics and chemistry of fire. This Special Issue of Polymers is the result of the scientific work and subsequent discussions and collaborations that took place during four years (May 2012–May 2016) of the COST Action MP1105 "FLARETEX: Sustainable flame retardancy for textiles and related materials based on nanoparticles substituting conventional chemicals". The Action involved 30 countries and more than 850 participants attended the 20 organized events up to December 2015; four events including the final conference are planned for 2016. The participants included post graduate students, early career researchers, established academics, engineers, and researchers/technologists from industry. The work done by the members of this Action from 2012 until 2016 is an important source of information regarding recent developments in the area of fire safety, and environmentally friendly flame retardant solutions for textiles and related materials.This Special Issue of Polymers is devoted to the “Recent Advances in Flame Retardancy of Textile Related Products", the theme of the COST Action MP 1105. This Special Issue will include papers with the most recent advances on Thermal Stability and Fire Retardancy of Textiles, Polymer Blends and Composite Materials. The publication will respect all rules and procedures requested by the journal and by the Editorial Office of MDPI. On behalf of the Guest Editors, we would like to invite you to submit your unpublished and original results which may be part of this Special Issu

Recent Advances in Flame Retardancy of Textile Related Products

International audienceReplacement of existing flame retardants (FR) with sustainable and environmentally friendly alternatives for textiles, polymers, and composite materials in domestic, transport (automotive, rail, aerospace, and marine), civil emergency and military, construction and other industries requires a multidisciplinary approach from textile technology to the physics and chemistry of fire. This Special Issue of Polymers is the result of the scientific work and subsequent discussions and collaborations that took place during four years (May 2012–May 2016) of the COST Action MP1105 "FLARETEX: Sustainable flame retardancy for textiles and related materials based on nanoparticles substituting conventional chemicals". The Action involved 30 countries and more than 850 participants attended the 20 organized events up to December 2015; four events including the final conference are planned for 2016. The participants included post graduate students, early career researchers, established academics, engineers, and researchers/technologists from industry. The work done by the members of this Action from 2012 until 2016 is an important source of information regarding recent developments in the area of fire safety, and environmentally friendly flame retardant solutions for textiles and related materials.This Special Issue of Polymers is devoted to the “Recent Advances in Flame Retardancy of Textile Related Products", the theme of the COST Action MP 1105. This Special Issue will include papers with the most recent advances on Thermal Stability and Fire Retardancy of Textiles, Polymer Blends and Composite Materials. The publication will respect all rules and procedures requested by the journal and by the Editorial Office of MDPI. On behalf of the Guest Editors, we would like to invite you to submit your unpublished and original results which may be part of this Special Issu

Sensitivity analysis of transient heat and moisture transfer in a bio-based date palm concrete wall

International audienceHygrothermal mathematical models are commonly used to describe heat and moisture transfer in porous and bio-based building construction materials. This allows to evaluate their thermal insulation capacity, as well as their ability to regulate external climatic conditions and ensure indoor comfort for inhabitants. In this paper, a sensitivity analysis is performed on Kunzel's model, while it is applied to simulate the hygrothermal behavior of a wall structure made of a new bio-based building material (cement composite including date palm fibers). In a first part, the effects of finite variations of material properties/boundary conditions on the model's outcome are investigated. In a second step, specific transfer modes are neglected in the model, in order to study their influence on the numerical predictions. The results of this parametric study show that special attention should be paid to few parameters (heat capacity and density for heat transfer, sorption isotherm and water vapor resistance factors for moisture transfer) at the expense of others. Uncertainties on these influent parameters may result in large error accumulation, especially when modeling the moisture transfer process. Furthermore, initial boundary conditions and sensors position appear to be possible sources of discrepancies in the calculated RH profiles. Finally, the pure conduction model is found to provide good estimation of the temperature profiles compared to the full model, whereas liquid transfer must always be taken into account in the model to ensure accurate RH predictions through a bio-based date palm concrete wall

Nouveaux matériaux biosourcés à base de bois de palmier dattier pour l'isolation thermique dans l'habitat

International audienceNouveaux matériaux biosourcés à base de bois de palmier dattier pour l'isolation thermique dans l'habita

Use of hollow metallic particles for the thermal conductivity enhancement and lightening of filled polymer

International audienc

Effect of filler size on thermophysical and electrical behavior of nanocomposites based on expanded graphite nanoparticles filled in low-density polyethylene matrix

International audienc