The term gypsum is used to refer to three main compounds of calcium sulphate: anhydrite, hemihydrate and dihydrate; but it is most often used for the dihydrate. The two main industrial uses of these compounds are in cement and in plaster products. Cement producers use a blend of gypsum and anhydrite as a set controller. Plaster is made with hemihydrate. This material is used both for bagged plaster and also to feed the plasterboard production lines. The materials are available from both primary and secondary sources.Waste plasterboard is an increasingly important secondary source but there are a number of problems which limit the proportion of thismaterial that can be used in plasterboard production. Research is therefore in progress to find other uses for it, such as lowstrength concrete mixes.
Bibliographical notePDF allowed open access by kind permission of Thomas Telford Journals. Construction Materials is a journal of the Institution of Civil Engineers. The journal homepage can be found at http://www.icevirtuallibrary.com/content/serial/coma.
- materials technology
- recycling of materials
- waste management & disposal