Abstract
An environmentally friendly and rational way of using wood waste is by introducing it into composite compositions. This paper investigates the use of wood chips from 10 to 60% for creating a thermal insulation composite. Prepared wood chips of various fractions were mixed with the sapropel/gypsum mixture. The composite with wood chips and a mixed sapropel/gypsum binder was hardened without thermal curing. Gypsum was added to absorb water from the sapropel and to give the composite its initial strength. Hydrated lime was used to improve the compressive stress of the binding material. The composite density varied from 400 to 1050 kg/m(3), thermal conductivity varied from 0.0912 to 0.193 W/(m·K), and compressive stress varied from 0.2 to 7.9 MPa. The density of the composite and the studied properties depended on three factors: the ratio of sapropel to gypsum, the ratio of wood chips to binder, and the level of compaction. The content of sapropel/gypsum varied from 10 to 90%, the ratio of wood chips to binder varied from 0.5 to 1.5, and the compaction level varied from 16 to 40% according to the initial height of the mould. The main characteristics of the prepared composites with different sapropel/gypsum and wood chip ratios were determined. The density, compressive stress, and thermal conductivity results were statistically analysed.