Abstract
The yield of hemp dry matter in Latvia's agro-climatic conditions depending on the variety accounted for an average of 7.4 - 12.4 t ha-1. Dependence on the version being subject to inspection, the yield of dry matter for variety 'Futura' was 11.0 to 12.4 t ha-1, 'Bialobrzeskie' - 9.5 to 10.7 t ha-1, but for 'Tygra' - 7.4 to8.7 t ha-1, and the total fiber yield - respectively 3.15, 2.65 and 2.40 t ha-1.Three industrial hemp varieties 'Bialobrzeskie', 'Futura75' and 'Tygra' were tested for natural hemp fiber (with splint) tensile strength. Samples to be measured were selected and sized in 50 mm long pieces of fibers, for each thickness was measured in three places and its average value was calculated. In order to secure the samples in the test machine, a previously elaborated method was used ensuring convenient fixing and correct disruption of the sample. Results of the experiments were indicative of the cutoff stress of tensile strength for non- blanched fiber of three varieties of hemp with bast addition. The 'Tygra' variety of fibers is having the greatest resistance. Their average tensile strength amounted to 558 MPa, which is equivalent to the tensile strength of high quality steel. It should be noted that the experiments have established a large distribution of the measurement results. The tensile strength of individual samples ranged from 715 MPa to 373 MPa. This is explained by the fact that hemp fiber is a non-homogeneous material, and its properties are varied within wide limits. It should be noted that tensile strength of fiber of all the varieties is large enough to allow it to be used for reinforcement of foam gypsum. The aim of this study was to evaluate hemp (Cannabis sativa L.) as a building material resource.
