Fiber and clay composites: Influence of miscanthus fibers on mechanical and rheological properties

Abstract

In this paper, the influence of miscanthus fibers as a reinforcement of a clay material is observed. The aim is to explore sustainable materials using organic fibers, in order to achieve a low CO2 balance for construction. Miscanthus fibers were first characterized by it’s water absorption, by the volume change when absorbing water and by it’s aspect ratio to get ideas how well miscanthus is suited as a fiber. Then, the composite material, a mixture of miscanthus and kaolinite clay was observed, testing rheological and mechanical properties as well as the density and shrinkage changes occurring due to the influence of fiber content. Fibers had undergone different treatments where they were dried, soaked and coated, showing effect of the homogeneity and of the water absorption of the fibers on the composite material. Results show, that as fiber content increases, workability decreases, with the fibers properties dominating with a content higher than 20%. It was also found, that mechanical strength, namely flexural and compression strength, both decrease due to fibers of the mix. Finally fiber treatment showed differences as soaked fibers are preferred for flexural strength, whereas dried fibers are the preferred treatment for compression strength. Conclusively, a miscanthus reinforcement in clay only worsens mechanical and rheological properties and is therefore not advised for use in those areas.