ABSTRACT

The addition of microparticles in cementitious materials is a method that has been investigated in recent decades, presenting the possibility of improving the mechanical performance of these materials. The goal of this study is to evaluate the influence of the addition of a microparticle, microcrystalline cellulose (MCC), on the mechanical properties of cementitious mortars. This evaluation was carried out using different dosages of MCC in relation to the cement mass, and a point to be considered is the search for the maintenance of the workability of the cement mortar, through the adjustment of its water/cement ratio (w/c). Tests were performed to determine consistency index, compressive strength, flexural tensile strength, absorption tests and the image capture of the mortars by Scanning Electron Microscopy (SEM). According to the results of the tests, it was found that, among the analyzed MCC dosages, mortar with 0,2% of MCC, in relation to the cement mass, presented the best mechanical performance, when compared to performance reference mortars. The increments of compressive strength reached were: 4% at 3 days of age, 9% at 7 days and 2% at 28 and 56 days. There was a 6% increase in the flexural tensile strength of the mortars at 28 days of age. The results of the absorption tests showed that mortars with 0,2% of MCC in relation to the cement mass were those with a lower water absorption index and lower voids index. Through SEM, it was possible to identify the MCC within the cementitious material and to verify the way it is disposed inside the material.

Keywords
MCC; compressive strength; flexural tensile strength; absorption; SEM