| Abstract [eng] |
It was determined that hemp fiber diameter varies in very wide range – from 30 μm to 560 μm, meanwhile the polypropylene fiber diameter is very similar, ranging from 25 to 50 μm range. The hemp fibre does not string in the aqueous environment. However it dissolves and turns into cellulose which does not have the structure of fibre. It was determined that hemp fiber is alkali-resistant and it has a very limited influence on the properties of the cement paste. On the other hand, it is unsuitable to be used as a reinforcement additive in cement systems. It is because of the diversity of the fibres, uneven distribution in the structure of the binding matrix and the lack of cohesion in it. Strongly hydraulic lime with hydraulic module HM=1.7–4.5 is obtained when burning a mixture composed of 80/90 wt % marl from of Juodžiai quarry and 20/10 wt % clay of Kertupis quarry at 950–1050 oC temperature. The amount of free CaO decreases when temperature increases from 950 to 1050 oC as CaO is bonded into minerals such as belite, grossular, tricalcium aluminate and tetracalcium aluminoferrite. It was observed that synthesized hydraulic lime hydration process was selected as the classical hydraulic lime hydration process, during which the samples formed portlandite, calcium silicate hydrates, hydrogarnets and the hydrates of tricalcium aluminate hydrate. During the research was found that the shives of the hemp and synthesized hydraulic lime are proper materials to produce the blocks of a lightweight concrete, because the density of biocomposite samples vary from 260 to 385 kg/m3, the coefficient of thermal conductivity – from 0.075 to 0.11 W/ m ∙ K and the compressive strength reaches 0.5 MPa. |
