Analysis of Calcite, Dolomite and Texture, and Their Roles in PrematureDeterioration of Portland Cement Concrete Pavement in Kansas

摘要

Premature deterioration of concrete pavement produced with Class I limestoneindicated a need to better predict limestone that would be deleterious in the future while passing Class I test criteria. Using the information contained in the database prepared fo FHWA KS-97/4, a classification of Kansas limestone has been obtained using texture and iron content of the carbonate minerals. Iron content of both the calcite and dolomite is indicated by the colors obtained with staining. The iron content and texture information in this investigation indicate that the greater the iron content, the greater the chances that the tested limestone does not pass Class I criteria. Since the limestone in the prematurely deteriorated pavement was Class I, the high iron content may be playing an important role in the premature deterioration. Some textures seem to have less iron content as evidenced in the database. Finely textured limestones have less iron content as indicated by stained peels. Coarsely textured limestones have more iron content. A higher proportion of finely textured limestone passes criteria for Class I aggregate.