Effect of malic and citric acid on the crystallisation of gypsum investigated by coupled acoustic emission and electrical conductivity techniques

• Published in: Journal of materials science Vol. 41; no. 21; pp. 7210 - 7217
• Main Authors: ERSEN, A, SMITH, A, CHOTARD, T
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.11.2006; Springer Nature B.V
• Subjects: Acoustic coupling; Acoustic emission; Acoustics; Additives; Applied sciences; Buildings. Public works; Carboxylic acids; Citric acid; Correlation analysis; Crystallization; Electrical conductivity; Electrical resistivity; Emission analysis; Exact sciences and technology; Gypsum; Lime. Gypsum plaster. Plaster elements; Materials; Materials science; Plasters; Resistivity; Solid surfaces; Surface chemistry; Scanning electron microscopy; Electrical conductivity; Coupled method; Crystallization; Acoustic emission; Gypsum; Malic acid; Plaster; Experimental study; Citric acid
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-006-0918-6

Plaster or gypsum (CaSO4·2H2O) is obtained from a suspension of β calcium hemihydrate (CaSO4·1/2H2O). The effect of two additives, known to retard setting, namely citric and malic acids, on the electrical conductivity and on the acoustic emission (AE) has been studied. This work presents the correlation obtained between these two techniques and their ability to differentiate between the crystallisation of a plaster with or without an organic additive. In particular, the surface adsorption of these carboxylic acids on solid surfaces has been evidenced by a specific acoustic emission activity.