A New Test for Sulfate Resistance of Cements

Abstract

Sulfate attack on concrete can either be of expansion-cracking type due to ettringite formation or of surface deterioration type due to acidic nature of sulfate solutions. The present test methods for determining sulfate resistance generally evaluate the expansive attack phenomenon. Since low C3A portland cements are not susceptible to this type of attack, new methods need to be developed to test the long-time resistance of these cements to the acidic type of sulfate attack. An attempt to develop a laboratory method involving immersion of small specimens of cement paste in a sulfate solution held at constant pH is described. Preliminary results are given for five different types of cements tested in accordance with the new method.