| ASTM C270-86a "Mortar for Unit Masonry" lists different types of mortars (M,S,N,O) that can be produced from a proportion or a property specification. For M or S mortars using the proportion specification, masonry cement had to be combined with Portland cement. The new revision ASTM C270-86a now allows the use of masonry cements alone for all types of mortars. This study attempts to determine whether mortars produced by the proportion specification meet the performance specification requirements of C270. In this study laboratory mortars made with eight different brands of masonry cements have been tested for the properties of compressive strength, air content, and water retention. In addition, type S and type N mortars made with Portland cement-lime combination have also been evaluated. In addition job site mixes cured both in laboratory air and outside air have been evaluated for properties like compressive strength and air content. (Abstract shortened with permission of author.). |
