Evaluation of external sulfate attack (Na2SO4 and MgSO4): Portland cement mortars containing fillers

Diego Jesus De Souza; Marcelo Henrique Farias De Medeiros; Juarez Hoppe Filho

Diego Jesus De Souza University of Ottawa http://orcid.org/0000-0002-7531-0084
Marcelo Henrique Farias De Medeiros Federal University of Parana http://orcid.org/0000-0003-3112-9715
Juarez Hoppe Filho Universidade Federal do Oeste da Bahia http://orcid.org/0000-0002-9645-6808

Abstract

Sulfate attack is a term used to describe a series of chemical reactions between sulfate ions and hydrated compounds of the hardened cement paste. The present study aims to evaluate the physical (linear expansion, flexural and compressive strength) and mineralogical properties (X-ray diffraction) of three different mortar compositions (Portland Cement CPV-ARI with limestone filler and, with a quartz filler, in both cases with 10% replacement of the cement by weight) against sodium and magnesium sulfate attack (concentration of SO42- equal to 0.7 molar). The data collected indicate that the replacing the cement by the two fillers generate different results, the quartz filler presented a mitigating behaviour towards the sulfate, and the limestone filler was harmful to Portland cement mortars, in both physical and chemical characteristics.