1.1 This guide describes the determination of approximate optimum SO 3 for maximum performance as a result of substi-tuting calcium sulfate for a portion of the cement.
1.2 This guide refers to the sulfur trioxide (SO 3 ) content of the cement only. Slag cements and occasionally other hydraulic cements can contain sulfide or other forms of sulfur. The determination of SO 3 content by rapid methods may include these other forms, and may therefore produce a significant error. If a significant error occurs, analyze the cement for SO 3 content using the reference test method of Test Methods C114 for sulfur trioxide.
