Mechanical properties of hemp yarn impregnation in cementitious matrix
Abstract
Natural fibers are achieving progress in their application; it is diversified into engineering constructions such as building materials. Today, hemp yarn uses as reinforcements in cementitious composites to replace synthetic fibres such as glass fibers. For a sustainable economic development, natural fibers include low price, low density, high specific strength and elastic modulus, unlimited and sustainable availability, and low abrasive wear of processing machinery, as well as their availability as renewable resources. Mechanical properties of plant fibers are much lower when compared to those of the most widely used competing reinforcing glass fibers but their specific properties, especially stiffness are comparable to the glass fibers. This paper is an investigation on the effect of embedded continuous hemp yarn in the microstructure and mechanical properties of cementitious composites. The quantitative physical of yarn impregnation was done by experimental methods such as measurement of capillary rise using colored water which permits to observe movement of water in the hemp yarn celluloses. The results were discussed on the basis of the wettability of the yarn. In addition, porosity accessible to water has determined according to AFPC-AFREM procedure. And mercury intrusion porosimetry (MIP) classic test authorizes to determine pores size associated to presence the yarn in the matrix and it compared to reference samples that qualitative and quantitative yarn impregnation. In addition, Flow rate measurements leads to measure the flow rate of water along the yarn and identical pore size. Pull-out test was used to determine the
mechanical parameters at pre-peak and post peak zone. Extracted length enhances characterization un–impregnated yarn when the embedded length is extracted entirely. All physical parameters determined previous have related to pull-out parameters in order to understand the correlation between physical and mechanical parameters.
