Industrial bio-based plant aggregates as hygric and insulating construction materials for energy efficient building

摘要

In this paper, the bulk density, microstructure, porosity and pore size distribution of the selected aggregates, including hemp shiv, flax shiv, rape shiv and wheat straw, are fully studied due to these properties are highly related to their excellent characteristics and more or less linked to the properties of the final product. The scanning electron microscope results showed all the selected aggregates have a highly porous and complex hierarchical structure, whereas the arrangement of pores and the thickness of cell wall are significantly different among these aggregates. All the selected aggregates had a low bulk density ranging from 30 to 130 kg . m(-3)and a high porosity between 75.81 and 88.74. The thermal conductivity of the selected bio-aggregates ranged from 0.04 to 0.06 W.m(-1).K-1. The thermal conductivity of the selected aggregates was not only depending on the bulk density of the sample but also depending on the raw material. Hemp shiv, rape shiv and flax shiv were excellent hygric regulators with moisture buffer value (MBV) ranging from 2.07 to 2.36 g.m(-2).RH-1, whereas, wheat straw had a lower MBV value ranging from 1.76 to 1.97 g.m(-2).RH-1. The results showed that particle size does not affect theMBVvalue. TheMBVvalue increases linearly with bulk density.