Development of Structural Type Mortars Reinforced with Coconut (Cocos Nucifera) Fiber: Chemical, Thermal, and Mechanical Behavior

In this research, the effect of the addition of coconut fibers coated with hydrophobic substances as reinforcement material in mortars was evaluated. Fibers of different sizes (1, 2, and 5 cm) were pretreated with linseed oil and paraffin wax, in order to obtain a mortar/fiber ratio of 0.5% and 1% by weight. The chemical resistance of the fibers were evaluated before and after being exposed to a concentrated solution of Ca(OH)2 in order to simulate the alkaline environment of the cement. The physicochemical characterization of the fibers was conducted by DTG (derivative thermogravimetry), TGA (thermogravimetric analysis), and FTIR (Fourier transform infrared spectrometry). The mechanical strength of the fiber-reinforced mortars was evaluated by compression and flexural tests. The effect of fiber degradation on mechanical behavior was evaluated between 28 days of processing. The results showed that the highest compressive and flexural strength were obtained with the composites reinforced with coconut fiber of 0.5% by weight, length of 1 cm, and paraffin wax as the impregnation substance.