THE EFFECT OF GYPSUM ON LIME-FLY ASH COMPOSITIONS: LITERATURE REVIEW AND ANNOTATED BIBLIOGRAPHY

This review, which covers over 65 articles, examined the literature until 1973 on topics pertinent to the use of waste sulfate. Since waste sulfate utilization is relatively new, the emphasis of the literature search was on use of gypsum in pozzolanic mixtures. The areas covered, therefore, were the strength and engineering properties of lime-fly ash, lime-pozzolan, lime-fly ash-aggregate, lime gypsum-pozzolan and lime-gypsum-fly ash mixtures. Compound identification studies of clays, pozzolans and fly ash with both lime and lime-gypsum mixtures were also reviewed. The literature showed that the addition of gypsum to pozzolan or fly ash mixtures does alter its engineering properties and could be used to advantage. Also the chemical reactions that occur in lime-fly ash-gypsum mixtures are similar to other natural pozzolans. Therefore, it should be feasible to use waste sulfate as the source of gypsum.