Abstract:

Gypsum is a hydraulic binder obtained by the calcination process of Gyps which has a chemical formation of CaSO4 at approximately 200-250ºC. It is commonly used in very fine form and when mixing with water, it turns into solid form by the hydration reactions.There are two types of gypsum. But, commonly used form of gypsum is ‘beta type’ known as ordinary gypsum . Beta type of gypsum is obtained by the calcination process in vertical or turning ovens. This type of gypsum is mostly used in construction and decoration works. From the mechanical aspect, it is less durable than cement, for this reason, it cannot be preferred to be used in load bearing systems. But, it can be used for internal plasters which are not exposed to water and humidity.Since the ancient times, gypsum is known as a binder. It was invented before the lime and used for the production of mortars and plasters commonly in the countries with terrestrial climate. Since the Middle Age, it was used in mosques, madrasas, Turkish baths and tombs as a finishing or ornamental material.The properties of hydrated gypsum change according to the amount of mixing water. The density of gypsum decreases as the ratio of water/gypsum increases. As the density decreases, the thermal conductance decreases and the sound absorption increases. The mechanical strength decreases logarithmically depending on the ratio of water/gypsum. In humid conditions, the mechanical strength decreases in a ratio of 1/3

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