Tribo-Mechanical Behavior of Geopolymer Composites with Wasted Flax Fibers

Abstract

The paper presents the research results on the mechanical and tribological properties of geopolymers reinforced with natural fibers. As a matrix, conventional fly ash and dry construction sand in proportion 1:1 were used. Materials were activated with Na activator. Wasted flax tow in an amount of 0.25-1% by weight was introduced as a reinforcement. The test results showed that with the increase in the fiber content, the bending strength increases, while the compressive properties are comparable to the matrix material. Based on the obtained research results, the optimal content of flax tow was determined at the level of 0.5% by weight. In addition, the abrasion resistance of geopolymer composites was determined using the so-called Boehme shield. This test consists of measuring the change in sample height. The sample is placed on a disc sprinkled with abrasive powder, then pressed and put into rotation. The abrasion results showed that the addition of fibers in the form of waste pulps does not reduce the abrasion resistance, which should be considered as a positive effect. Research also revealed that wasted flax fibers could be successfully used as a reinforcing material in geopolymeric materials as an alternative to the utilization of waste fibers, and additionally may also have a positive effect on the mechanical and tribological properties of geopolymers materials.