Thermal Performance Study of Plaster Reinforced with Alfa Fibers

One-hundred percent local plaster-based building materials were developed using local Alfa (Stipa tenacissima L.) fibers from eastern Morocco region. Indeed, the incorporation of natural fibers in building materials is one of the promising approaches to design new bio-based materials and green the building sector. The present study concerns the fabrication, the investigation of the thermophysical properties and the energy saving potential of local Alfa-plasterboard for roofing applications. Different mixtures with different percentages of Alfa (2%, 4%, 6%, and 8%) were prepared to assess the effect of fibers on the energy performance of plaster. For comparison purposes, fibers with a diameter of 3mm were used to ensure homogenized mixtures. Thermal tests, using TPS method show that the integration of Alfa fibers in plaster-based matrices improves their thermal insulation quality of about 34%, and slows the heat transfer rating of 26.9% compared to the reference case. Besides the utility of Alfa fibers in improving the compressive properties of plaster, the addition of 8% by mass of Alfa fibers reduces the density of the plaster by 10.5% while increasing its thermal storage capacity by 1.4%. The thermal diffusivity values obtained from the hot disk and the flash methods were consistent. A maximum thermal capacity of plaster was observed with the incorporation of 4%. In terms of performance analysis, numerical simulations show that the retrofit using 40 mm-thick Alfa plasterboard reduces the energy requirements of residential buildings by approximately 4%, divided into 8.6% for cooling and 2.3% for heating, which represents an annual reduction of 1.9 kWh m(-2).