Mixtures of 12 commercial portland cement clinkers and water were filtered at 7 minutes and at 2 hours after m ixing, and the chemical composition, pH, conductivity, surface tension, and density of the extracts were determined. The effects on the composition and physical properties of the extracts, produced by the addition of small amounts of various materials to the pastes, were studied in parallel experiments. The added materials included gypsum, which was used in preparing the cements from the clinkers, calcium chloride, calcium ace tate, fluosilic ic acid, sucrose, T D A, tannic acid, and triethanolamine.In the majority of the extracts, soda and potash were present in greater amounts than an y of the other dissolved oxides. Relatively high concentrations of sulfate occurred in the extracts of the clinkers that contained the larger amounts of potash. The lime concentration and basicity of the extracts were largely determined by the amounts of alkali oxides present. The concentration of silica corresponded approximately to the reported solubility of silica in lime solutions. Low concentrations of oxides of the R 20 a group were found except in extracts from pastes con taining the added organic materials.

A. Makes any warranty or representation, express or implied, with respect to the accuracy, completeness, or usefulness of the information contained in this report, or that the use of any information, apparatus, method, or process disclosed in this report may not infringe privately owned rights; or B. Assumes any liabilities with respect to the use of, or for damages resulting from the use of any infonnation, apparatus, method, or process disclosed in this report.As used in the above, "penon acting on behalf of the Commission" includes any employee or contractor of the Commission to the extent that such employee or contractor prepares, hondles or distributes, or provides access to, any infonnation pursuant to his employment or contract with the Commission. Ml UNCLASSIFIED io^!i5^l DISCLAIMER

No abstract