Performance and durability of hybrid cement-based composites reinforced with vegetable fibers at micro and nanometric scales

Abstract

Nanofibrillated cellulose obtained from natural, available and renewable resources, possess great potential as reinforcement in cementitious materials as a result of its high specific surface area, which greatly improves adhesion with cement particles. When incorporated with pulp microfibers in hybrid reinforcements, the mechanical anchoring of the nanofibrillated cellulose with the matrix and the higher length pulp fibers has the potential to produce cementitious materials reinforced at the nano and micrometric scales resulting in improved mechanical strength and toughness. However, the use of nanoreinforcement in cementitious materials is not established, and a literature review shows deviations from the ideal nanoreinforcement level so that the performance and durability of cementitious composites are improved. This research proposes to study the hydration kinetics of cement pastes containing varying levels of nanofibrillated cellulose; study the effect of hybrid reinforcement on the microstructure and mechanical performance of composites with different levels of reinforcement at micro and nano scales; and study the degradation of the pulp and nanofibrillated cellulose after immersion of these fibers in an alkaline environment. The composites will be produced by the slurry dewatering process followed by pressing and it will be subjected to accelerated aging tests. Physical, mechanical and microstructural tests will be carried out for evaluation the effect of hybrid reinforcement in the performance and durability of composites. The outcome of this study is expected to demonstrate the viability of the application of hybrid reinforcements at micro and nanometric scales for the development of cementitious composites with improved mechanical properties for applications in the building construction industry. (AU)