Properties of High-Strength Flowable Mortar Reinforced with Palm Fibers

This study was conducted to determine some physical and mechanical properties of high-strength flowable mortar reinforced with different percentages of palm fiber (0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6% as volumetric fractions). The density, compressive strength, flexural strength, and toughness index were tested to determine the mechanical properties of this mortar. Test results illustrate that the inclusion of this fiber reduces the density of mortar. The use of 0.6% of palm fiber increases the compressive strength and flexural strength by about 15.1%, and 16%, respectively; besides, the toughness index (I5) of the high-strength flowable mortar has been significantly enhanced by the use of 1% and more of palm fiber. 1. Introduction High-strength concrete or mortar subjected to axial compression is known to be a brittle material with almost no strain-softening behavior. Adding fibers to plain matrix has little or no effect on its precracking behavior but does substantially enhance its postcracking response, which leads to a greatly improved toughness and impact behavior. The application of fibers in concrete was regarded very difficult in the past, due to insufficient workability of fiber reinforced mixtures. The development of superplasticizer has proven to offer significant improvement in application of fibers like in slabs and floors, shell domes, rock slope stabilization, refractory linings, composite metal decks, seismic retrofitting, repair and rehabilitation of structure, fire protection coatings, concrete pipes and [1]. Over the last three decades, fiber-reinforced concrete (FRC) has been the subject of many investigations. Researches have been performed on the behavior of fiber-reinforced concrete subjected to various types of loading and incorporating different fibers ranging from steel, glass, plastic, and natural fibers in various sizes and shapes [2]. Natural fibers have the potential to be used as reinforcement to overcome the inherent deficiencies in cementitious materials. In recent years, there has been sustained interest in utilizing natural fibers in cement composites and in manufacturing products based on them with a view to have alternate building materials, which are energy efficient, economical, and ecofriendly. If the function of natural fibres in a relatively brittle cement matrix is to achieve and maintain toughness and ductility of the composite, then, the durability of such fibres in a highly alkaline cement matrix must be taken into consideration and ensured by effective modifications made either to the fibre