This article deals with the influence of both morphology and amount of Typha on hygrothermal behavior of a Typha–clay composite for building application. An agromaterial containing the fiber mix of Typha Australis and clay was made in three samples: three fiber mixtures were prepared with different amounts Typha and cut type (transversal or longitudinal). The physical properties of these materials were studied in terms of porosity, apparent and absolute density, thermal conductivity, and hygric properties. Results show a real impact of the Typha fraction type and its volume content on hygrothermal properties of the studied material due to the porosity. The transversal fraction of Typha (80% in volume weight) seems to be the optimal composition for a better hygrothermal behavior.
The gradual development of government policies for ecological transition in the modern construction sector leads researchers to explore new alternative and low environmental impact materials with a particular focus on bio-sourced materials. In this perspective, the mechanical, thermal insulation, and the sound absorption performances of a spent coffee grounds/potato starch bio-based composite were analyzed for potential application in buildings. Based on thermal conductivity and diffusivity tests, the coffee grounds waste biocomposite was characterized as an insulating material comparable with conventional thermal insulation materials of plant origin. Acoustical tests revealed absorption coefficients in the same range as other conventional materials used in building acoustical comfort. This bio-sourced material presented a sufficient compressive mechanical behavior for non-load-bearing structures and a sufficient mechanical capacity to be shaped into building bricks. Mechanical, thermal, and acoustic performances depend on the moisture environment. The groundwork was laid for an initial reflection on how this composite would behave in two opposite climates: the continental climate of Reims in France and the tropical climate of Belém in Brazil.
14 March 2018 in Science and Technology for the Built Environment
Global environmental issues are arising over the developed and developing world. Improving energy efficiency and reducing Green Gases emissions become the key issues in all the economic sectors and, in particular, the building sector that is one of the most energy-consuming. It is, therefore, important to find alternative building materials with low-environmental impact contributing to global sustainability. In that context, this study reports on the performance of sustainable materials produced from natural resources as hemp-concrete or from recycled-waste nonbiodegradable materials including recycled polyethylene terephthalate. Three façades employing three different materials (hemp-concrete, hemp-concrete with brick and recycled polyethylene terephthalate) were investigated in three cities in France (Nancy and Carpentras) and Italy (Perugia) with different climate. The energy performance of each façade was assessed in terms of cooling and heating demands, electrical consumption for a constant flow rate ventilation mode, considering different orientations. The study also shows the effect of window size (10%, 25%, and 40%) on the annual energy consumption.