Experimental investigation on the use of alpha fibres as reinforcement of cementitious materials
Fibers commonly used in cementitious composites have been derived from non-renewable resources. Economic issues related to the rising costs of fossil resources, their increasing scarcity, and environmental impacts inherent to their production therefore lead to explore other material resources. In this regard, plant fibers could be used instead of non-renewable fibers which can present an important pathway in the future of the construction industry. In North Africa, Alfa is a widespread plant in the dry regions of the Mediterranean highland. In Morocco, the Alfa plant covers a large area estimated at more than three million hectares.
Research has already been conducted on the incorporation of plant fibers in cementitious materials. It was highlighted that in fresh state, the hydrophilic character and the nature of these fibers significantly affect the rheology of the material. In hardened state, these fibers allow to decrease the rheology of the material, and thus enhancing their hydrothermal properties. From a mechanical point of view, plant fibers could increase the compressive and/or the flexural strengths.
This study investigates the potential of using Alfa fibers as reinforcement of cementitious composites. Firstly, chemical and physical characterizations of Alfa fibers were performed as well as morphological observations were realized. Secondly, the fibers were added to cement mortar by two ratios 1 and 1.5% by volume to optimize the mix design formulation. Physical and mechanical properties of the composites were tested after 28 days of curing. Results exhibit that Alfa fibers provide a high crystallinity index of about 74.62 wt% and a good thermal resistant which can reach until 360 °C. Furthermore, adding 1% by volume of Alfa fibers allow to produce a lighter composite and improve the compressive strength of the reinforced mortar of about 14.87%. The enhancement of mechanical properties was confirmed by SEM observations (scanning electron microscope) showing the good fiber/matrix adhesion.