Strength and thermal conductivity properties of thermowood-cement composition

The paper studies the ways that technological characteristics of thermal wood concrete production have on its strength and thermal conductivity properties. Thermal wood concrete (TWC) is a new, effective wood-cement composition of authors’ development. To produce it the authors used crushed thermally modified wood (TMW) with a certain shape and size as a filler. The research is rationalized by the fact that currently we are facing a lack of both fundamental and applied experimentally confirmed data on thermal wood concrete. The paper discusses the studies of the compressive strength and thermal conductivity of four groups of TWC samples that were obtained with three types of filler, differing in size and shape, molding method and strength class of cement-sand mortar. The authors determined general impact patterns of the above-mentioned factors on strength and thermal conductivity properties as well as specific indicators. Moreover, the paper describes the strength classes and grades of thermal wood concrete that ranged from B1.5 to B3.5 and from M25 to M50, respectively. Thermal conductivity for standard samples ranged from 0.21 to 0.4 W/(mK). It has been concluded that thermal wood concrete with a finer TMW filler has the most balanced combination of strength, thermal conductivity and deformation properties. Following the results, the authors proposed practical recommendations for thermal wood concrete production, and further courses for its improvement and research.