Natural Fiber–Reinforced Cement Mortar Composite Physicomechanical Properties: From Cellulose Microfibers to Nanocellulose

Abstract

Using asbestos in building materials is a risk to human health, which has driven the interest in utilizing other natural fibers, such as cellulosic fibers, in cement-based building materials. There have been studies on cement-based composites reinforced with cellulose microfibers or nanocellulose. However, to the best of our knowledge, the effect of cellulose fiber reinforcement, at different scales (micro and nano), on cement-based composite properties has not yet been studied, from raw natural fiber to nanocellulose. Moreover, comparing data from the literature on cellulose-reinforced cement composites is difficult because there are many variables (e.g., matrix, cement, sand, dosification, water:cement ratio, superplasticizer, and fabrication method) that affect the final composite performance. In the current work, different cement-based composite properties reinforced with cellulose fiber were compared using the same variables and fabrication method. After the addition of microfibers, the strength of mortar decreased compared with plain mortar, the reduction being higher as the fiber content was increased. On the other hand, after the addition of nanocellulose fiber, the density hardly changed compared with unreinforced mortar. Contrary to microfiber addition, the presence of 0.25% by weight nanocellulose in mortar slightly increased the flexural strength. The mechanical properties obtained in the current study were compared with literature data for similar systems.