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In past ten years area of green technologies and materials was the most growing industry sector in the world. It is related with global warming, air pollution and energy saving. Building sector intensively increased air pollution and is related with high energy consumptions. The use of renewable or recyclable materials can reduce these problems. In current work, thermal insulating materials from hemp shives and corn starch were investigated. Structures of various shives fractions were analyzed. Different sized shives by two indicators bulk density and thermal conductivity were compared. Composite materials with various shives fractions and corn starch were prepared. Different thermal treatment for composite hardening was used. Thermal conductivity and compressive strength of composites were determined. Thermal insulating composites with a high compressive strength and low thermal conductivity were developed.

Natural fibres from flax and hemp are used as raw materials for efficient thermal insulation. In current work, tests were carried out using chopped and combed long flax fibres as well as chopped and combed long hemp fibres. Investigations have shown that thermal conductivity of natural fibres depends on their preparation method (combing, chopping) and materials density.

Impact of some nanoadditives, such as amorphous SiO₂ (AS) of pozzolanic properties and carbon fibers (CF) reduced to nanosize particles on autoclaved aerated concrete (AAC) forming mixtures, the following parameters were investigated: changes in consistence of binding material during hydration, spreadability, expansion and temperature of mixture, plasticity strength. The investigations were carried out with AAC forming mixture where 10 % lime was replaced by equivalent content of Portland cement. Upon completion of investigations, it was established that the optimal replacement of sand by AS was 1.0 % resulting in increase of temperature of AAC forming mixture by up to 2.1 %, expansion by up to 11.0 %, ultrasonic impulse velocity (UIV) by up to 3.0 % and plasticity strength by up to 271.4 %. Meanwhile the optimal replacement of sand by CF was 0.1 % resulting in decrease in temperature of AAC forming mixture by up to 1.5 %, expansion by up to 16.0 % and increase in  UIV by up to 2.0% and plasticity strength by up to 152.9 %.

DOI: http://dx.doi.org/10.5755/j01.ms.18.3.2441

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