The measurement of conductance provides a non-destructive and continuous method for studying the hydration of plaster of Paris and improved dental stone. The kinetics can be described by two parameters: an induction period, to and a first order reaction constant, k, for the decrease of conductance. The influence of additives on both parameters has been studied.
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References
1.
Weiser, H.B. and Moreland, F.: The Setting of Plaster of Paris, J Phys Chem36:1-30, 1932.
2.
Le Chatelier, H.: Sur la Cuisson du Platre, C R Acad Sci96:1668-1671,1883.
3.
Ketelaar, J.A.A. and Heymann, D.: Radioactive Exchange Studies on the Transformations of the Hydrates of CaSO4, Rec Trav Chim73:279-286, 1954.
4.
Birss, F.W. and Thorvaldson, T.: The Hydration of Plaster of Paris, Can J Chem33:870-880, 1955.
5.
Budnikoff, P.P. : Zur Theorie der Erhartung des Stuckgipses und zur Frage der Existenz von Löslichem Anhydrit, Kolloid-Z42:151-154,1927.
6.
Budnikoff, P.P. : Die Beschleuniger und Verzogerer der Abbindegeschwindigkeit des Stuckgipses, Kolloid-Z44 :242-249, 1928.
7.
Hansen, W.C. : Hydration of Calcined Gypsum, Ind Eng Chem22:611-613, 1930.
8.
Weiser, H.B. ; Milligan, W.O.; and Ekholm, W.C.: The Mechanism of the Dehydration of Calcium Sulfate Hemihydrate, J Am Chem Soc58:1261-1265, 1936.
9.
Ridge, M.J. and Surkevicius, H.: Hydration of Calcium Sulphate HemihydrateI. Kinetics of the Reaction, J Appl Chem12:246-252, 1962.
10.
Ridge, M.J. and Beretka, J.: Calcium Sulphate Hemihydrate and Its Hydration , Rev Pure Appl Chem19:17-44, 1969.
11.
Schiller, K. : Mechanism of Re-crystallization in Calcium Sulphate Hemihydrate Plaster, J Appl Chem12:135-144, 1962.
12.
Schiller, K. : The Ionic Concentration in the Suspending Liquid during the Hydration of a Slurry, J Appl Chem15: 581-584, 1965.
13.
Picherit, E. : Die Beeinflussung beim Abbinden von Gipsen durch Verschiedene Faktoren, Die Ziegelindustrie18 :454-458,1966.
14.
Wiegman-Ho, L.: The Kinetics of the Hydration of Calcium Sulfate Hemihydrate and Cement, Investigated by an Electrical Resistance Method, Dissertation, University of Amsterdam, June, 1979.
15.
Rehbinder, P. and Segalova, E.: Proceedings, Second Int. Congr. of Surface Activity, London : Butterworths, 1959, Part, pp. 492-505.
16.
Gremion, A. : Controle des Temps de Prise du Platre par Mesure de la Conductibilite Electrique, Tonind-Ztg101 :33-37,1977.
17.
Preisler, E. : Methode zur Untersuchung des Abbindens von Calciumsulfat - Halbhydrate durch Messung der Electrischen Leitfahigkeit, Zement - Kalk - Gips30:219-223, 1977.
18.
Karmazsin, E. and Murat, M.: Study of a "SOLID + LIQUID → SOLID" Reaction (Hydration of Calcium Sulfate Hemihydrate) by Simultaneous Isothermal Calorimetry and Electrical Resistivity Measurement, Cem Concr Res8 :553-557,1978.
19.
New American Dental Association Specification No. 25 for Dental Gypsum Products, JADA84:640-644, 1972.
20.
Gmelins Handbuch der Anorg. Chemie, 8te Aufl, Weinheim: VerlagChemie, Calcium Teil B, 1952, pp. 714, 763, 764.
21.
Jorgensen, K.D.: Studies on the Setting of Plaster of Paris , Odontol Tidskr61:305-346, 1953.
22.
Schiller, K.K. : Types of Plaster Hydration; Their Causes and Practical Significance, Proc. Int. Rilem Symposium, May, 1977.