Typha bio-based aggregate mixed with natural clay to form composites: the compressive strength, the hygric performance and the fire reaction of composites are studied

Abstract

This work is part of the PNEEB / TYPHA project for the use of an invasive reed, the Typha Australis, as a thermal insulation which aims to contribute to the energy efficiency of buildings in Senegal. The Typha australis is widespread in aquatic environments and in humid regions, particularly in the Senegal River valley, whose proliferation has become an ecological threat. In this study, an agromaterial based on aggregates of Typha australis and clay is prepared: the influence of the morphology and of the amount of Typha on the behaviour of the material are investigated. Different combinations are tested. The first two have almost the same amount of binder but they differ in the production mode of the Typha aggregates: one type of the aggregates uses the longitudinal section of the plant while the other uses its cross-section. The third combination is an aggregate produced by cross-section with a higher amount of binder. Compression tests are carried out and the following properties are determined: apparent modulus and compressive strength. The Moisture Buffering Value is also characterized. The reaction to fire is estimated. The results show an impact of the amount of aggregates on the compressive strength. However, the influence of the morphology of the aggregates is negligible on this test. This material is an excellent moisture regulator regardless of the part of the Typha aggregate that is used. This material can be considered as a combustible but non-flammable material due to the presence of clay.