Enhanced Performance of Stabilized By-Product Gypsum

Abstract

Blended calcium sulfate (BCS), a by-product gypsum blended with lime or limestone, has been used as a base course material on some of Louisiana’s highways. Although BCS has high strength in dry conditions, its poor water resistance has largely limited its application in highway construction. A series of laboratory tests identified the factors that dictate the strength development of nonstabilized BCS. BCS was subsequently stabilized with various cementing agents to improve its water resistance. The mechanical properties of stabilized BCS, including its unconfined compressive strength, water resistance, volumetric expansion, and durability, were also evaluated. Finally, recommendations were made for the application of stabilized BCS as a base course material.