SANDWICH PANEL MADE OF CHAFF AND HEMP FIBRES AND METHOD FOR MAKING THE SAME, APPLICABLE IN CIVIL CONSTRUCTIONS SECTOR

摘要

The invention relates to a sandwich panel made of chaff and hemp fibres and to a method for making the same, with applicability in the field of civil constructions to be used as a partition board with high acoustic and thermal properties. According to the invention, the panel comprises a 40 mm-thick core made of 23...24% hemp fibres, 38...39% mineral binder and 38...39% water, externally confined by two 5 mm-thick rigid faces which comprise each 42...43% saturated chaff, 21...22% hydrated lime, 21...22% cement and 15...16% water, the acoustic performance being improved by perforating one of the external rigid faces, at a percentage of perforated surface of 10%, 20% or 30%, depending on the desired version, at a perforation diameter of 1 cm. The method, as clamed by the invention, consists in separately making the external rigid faces by mixing in a clean vessel the chaff saturated with water, along with dry mineral binders, hydrated lime and cement, homogenized with a preset amount of water, the resulting composition being then evenly poured into a wooden mould, the core of the sandwich panel being made by atomizing the hemp fibres with a cement-based solution obtained by mixing the mineral binder with water and placing it in a shutter between the external rigid faces, the whole assembly being kept there for 24 h, at a temperature of 24°C and a humidity of 40%, after which it is removed from the shutter.