The overall goal of this project is to develop a fundamental understanding of the behavior of Cellulose Nanocrystal (CNC) and Nanofibrilated Cellulose (NFC) with the goal of using this information to develop a new generation of CNC/NFC-based cementitious materials that show high strength and toughness. CNCs/NFCs are an alternative to other types of nanoreinforcements that have high aspect ratio, elastic modulus and strength, low density, reactive surfaces that enable easy functionalization and are readily water dispersible without the use of surfactant or modification. In addition, the sources that CNCs/NFCs are extracted from are themselves sustainable, biodegradable, carbon neutral, and have low environmental, health and safety risks. This research offers a different perspective to material design and characterization by studying the structure-function relationship through an integrated approach that combines processing, structural and chemical characterization, state-of-the-art microscopy and bottom-up multiscale modeling to unravel the physical mechanisms that underpin CNCs/NFCs nanomechanics, and relate this to the macroscopic properties of CNC/NFC-reinforced cementitious materials through extensive experimental tests at different length scales. There is a quest to develop a new generation of high-performance multifunctional, renewable and sustainable infrastructure materials that radically break traditional engineering paradigms. The development of innovative, green CNC/CNF reinforced cement composites can drive the performance and use of these materials offering an alternative for other environmentally harmful nanoparticles. The use of higher performance materials is one way to ?do more with less?. Furthermore, these materials can help lowering the carbon footprint by reducing the amount of materials needed in the built infrastructure. The graduate students involved in this project will be trained in a truly interdisciplinary setting. Information learned in this research program will be directly brought into the classroom at graduate and undergraduate levels, and disseminated at international conferences and in journal publications.