Nanocellulose for ecological nanoengineered strain-hardening cementitious composites incorporating high-volume ground-glass pozzolans

Nanomodification of concrete has a promising potential to allow engineering concrete properties for specific applications. This study shows how nanoscale cellulose filaments (CF) can be used as a novel tool for tailoring the properties of strain-hardening cementitious composites (SHCC) incorporating high-volume ground-glass pozzolans (HVGP) towards improved strength and ductility. CF was introduced (at 0 - 0.10% by weight of cement) into SHCC incorporating ground-glass pozzolans (GP)-also known as postconsumption glass powder-in replacement of fly ash (FA) at 0, 40, and 100%. Micromechanical guidelines were adopted for tailoring SHCC formulations. The performance of resulting SHCC was then validated by uniaxial tensile and flexural tests. Results indicate that CF allows nanoengineering matrix and interface properties by increasing matrix elastic modulus and imparting a significant slip-hardening effect. Consequently, higher complementary energy and lower crack tip toughness were obtained, thereby leading to enhanced ductility. Therefore, whereas at high GP content (above 40%) matrix strength increases at the detriment of its ductility, the incorporation of CF imparted a characteristic slip-hardening effect enabling restoring the ductility loss at high GP content. This made possible to produce SHCC with up to 100% GP replacement of FA exhibiting higher strength and ductility than conventional FA-SHCC (with similar water to binder ratio), while contributing to promoting ecoefficiency.