Hardening process of polymeric adhesive mortars: Approach by phase angle analysis from oscillatory rheometry

Abstract

The main goal of this work was to study the viscoelastic behaviour of cement-polymer fresh mortar using an oscillatory rheometer to compare the influence of polymers percentage (%P), aggregate/cement (A/C) and water/solid (W/S) ratios on hardening process mechanisms of polymeric mixes evaluating the phase angle. A Brazilian Portland cement type CPII-F-32, limestone sand and two usual polymers, namely herein as latex (ethylene vinyl acetate – EVA) and cellulose ester (Methyl Hydroxyethyl Cellulose- MHEC) were used. For the experimental analyses, eleven mortars mixtures were tested using different values of aggregate/cement volumetric ratio (A/C), polymer percentage (%P) in relation to the cement mass and water/solid materials ratio (W/S). It was used three values of %P (4%; 5.5% and 7%), five values of A/C (2.5; 3.5; 4.5; 5.5 and 6.5) and tree initial moisture ratio (0.56; 0.68 and 0.79). From the experimental tests it was possible to conclude that the moisture rate stands out as the most influential parameter for changing the phase angle of the mixture during the time testing, the use of oscillatory rheometer method could be applied for evaluation of physical properties changing like the initial hardening process of adhesive mortar in suspension.