Influence of Nanofibrillated Bacterial Cellulose on the Properties of Ordinary and Expansive Mortars

This study uses two types of nanofibrillated bacterial cellulose (NFBC), a culture solution containing NFBC (B(f)) and a purified solution (P(f)), to investigate the influence of NFBC on the basic properties of mortar. The flow test, air content test, setting time test, restraint expansion test, dry shrinkage test, strength test and freeze–thaw test were performed. The results show that the flow of fresh mortar increases for B(f) and decreases for P(f), while the setting time of mortar is delayed for B(f). The dry shrinkage is slightly decreased as a result of using NFBC in expansive mortar. In addition, for both types of NFBC, the strength is not significantly affected in ordinary mortar, while the compressive strength tends to increase slightly after 28 days of underwater curing in expansive mortar. Moreover, the frost resistance improves as the air content increases in ordinary mortar. In expansive mortar, the frost resistance is improved for B(f), but the frost resistance is not improved for P(f). This investigation has revealed that NFBC can be used as an admixture to improve the properties of mortar, such as frost resistance.