Abstract
Green materials and structures have gained the worldwide attention over the past few years. Interest in the utilization of lignocellulosic biomass in the form of natural fibres (biofibres usually derived from plant) as organic filler into lightweight fibre reinforced composites for sustainable building constructions is steadily increasing.
Excellent physical and mechanical properties of hemp as fast growth predetermine its use in building materials (biocomposites) prepared with inorganic matrix.
With a world production of 214,000 ton, hemp is one of the 10 major primary plants grown as source of bast fibres (i.e. fibres obtained from the exterior part of the stem) and hurds (i.e. inner woody part of the stem, also called shives), used for various industrial purposes, such as: textiles, cordage, panelling, biofuel, paper, plastic composites and building materials.
In particular, the hemp hurds, which in the past was discarded (only fibres and seeds were used), is now of great interest for the unique properties that confers to building materials. Key problem for successful application of hemp hurds is heterogeneity and hydrophility resulting in high moisture sorption sensitivity of biomaterial. Chemical and/or physical treatment of the fibres surface is applied to decrease the hydrophility and modify lignocellulosic material composition.
In this paper presented results of capillary absorption of biocomposites based on hemp hurds slices (untreated and chemically treated) as a filler and two various type of binders (conventional Portland cement and alternative MgO-cement). Capillary absorption demonstrates the ability of building materials containing open pores the absorbing moisture. Effect of various types of binder and influence of modified hemp hurds on properties of composites were observed.
