Application of rice husk in the development of new composite boards. (10th July 2018) - António, Julieta
Highlights: Rice husk waste is an abundantly accumulated agro-industrial waste product. Composites made from rice husks, expanded cork and recycled rubber granules. Weighted reduction in impact sound pressure level ranging from 20 dB to 27 dB. Thermal conductivity varying from 0.060 to 0.074 W/(m.°C). Abstract: The main objective of the paper is to propose a new composite material incorporating rice husk. This paper reports an experimental study on the mechanical, thermal and acoustic performance of new composite boards made of rice husk waste intended for construction applications. In this study, rice husk was mixed with expanded cork granules or recycled rubber granules in 50/50 and 75/25 (weight percent) proportions. A TDI-based polyurethane pre-polymer was used as binder in 20% of the mass of the fillers. A sufficient number of small boards were produced to perform small-scale tests and assess properties such as compressive strength, thermal conductivity, dynamic stiffness, improvement in impact sound insulation, sound absorption and transmission loss. The results are very interesting, in particular: the thermal conductivity, at 10 °C, varies from λ 10 = 60.0 mW/(m.K) to λ 10 = 74.3 mW/(m.K); the weighted reduction of the impact sound pressure level, ΔL w, ranges from 20 dB to 27 dB; the noise reduction coefficient (NRC) ranges from 0.15 to 0.45, with maximum sound absorption coefficient of 0.96 for composite B1. These results suggest that optimized construction solutions based on these composite materials could improve the thermal and acoustic performance of buildings.