16th International Conference on Composite Structures ICCS 16 A. J. M. Ferreira (Editor) © FEUP, Porto, 2011 PORTLAND CEMENT MORTAR MODIFIED WITH WATER SOLUBLE POLYMER AND MONTMORILLONITES Teresa M. Piqué and Analía Vázquez • Polymer and Composite Material Group, INTECIN, Engineering Faculty, University of Buenos Aires (FIUBA), Avenida las Heras 2214, C1127AAR, Buenos Aires, Argentina • e-mail: [email protected], [email protected] web page: http://www.fi.uba.ar , http://www.uba.ar/secyt/institutos/insuc-intecin.php Key words: Portland cement mortar, Water soluble polymers, Montorillonites ABSTRACT The cement hydration reaction, the morphology and the flowability of a Portland cement paste with water–cement ratio, w/c = 0.45 modified with water soluble polymer and chemical modified montmorillonites have been investigated in previous research, being the ratio of polymer to cement, p/c = 1.80 wt% and the ratio of montmorillonite to polymer m/p = 4 wt%. The polymer and modified polymer admixtures produced an increase in flexural, tensile strength and the elastic modulus. After these studies, sand was added in order to analyze the mortar behavior. The w/c was varied from 0.30 to 0.45. The ratio of polymer to cement and t clay to polymer stayed fixed. When sand was added properties changed because of the increase of air in the mortar matrix due to the surfactant effect of the polymer. Varying the w/c ratio and applying different casting process the amount of air in the mortar was controlled. Flexural strength was increased when compared to a cement mortar with the same air content.