Mitigating self-desiccation of cement composites via cellulose microfibers: Evidence of the microscopic behavior

Abstract

Water-saturated cellulose microfibers (CMFs) incorporated into fresh cement composites can mitigate microcracking induced by self-desiccation during drying. To understand the mechanism underlying the water supply via CMFs to the pore systems, this study utilized a nonlinear impact resonance acoustic spectroscopy (NIRAS) technique. The hysteresis nonlinearity parameter (𝛼) from the NIRAS was used to quantify the microstructural changes in three different specimens (0, 0.3, and 1% dosage of CMFs). Computed tomography (CT) tests and mass tracking were conducted to obtain more insights into the mitigation of self-desiccation. The results show a remarkable reduction in α, confirming the mitigation of microcracking formation over time. Furthermore, the trend of α was consistent with the pore size distribution estimated by the CT test, which provides quantitative evidence to support the mitigation of self-desiccation promoted by CMFs. We envision that these findings can be used as guidelines for enhancing the durability of cement composites facilitated by CMFs.