The importance of water in traditional gypsum works

Abstract

Until the second half of the 20th century, the traditional architecture of the Iberian Peninsula was directly linked to the resources available in its immediate surroundings, naturally diversification the built heritage throughout the territory. In its gypsiferous areas, we find a great versatility of construction systems in which the main binder used is traditional gypsum, although this material has been forgotten in the 20th and the 21st century architecture, meanwhile industrial gypsum currently plays a secondary role in the construction sector. Gypsum, like any traditional binder, is a material that is particularly sensitive to the amount of water with which it is mixed, which will be strongly linked to the technique of application, among other technological parameters. Thus, the final performance of the product is, among other things, a consequence of this water/gypsum ratio, as Francisco Arredondo states in some of his works. In them, the behaviour of an industrial gypsum is analysed as a function of the mixing water, relating it in turn to other parameters such as compressive strength, water absorption and bulk density. The aim of this work is to study the influence of the mixing water on the physical and mechanical properties of different traditional plasters, taking into account previous studies, the diversity of traditional uses of gypsum and current application techniques.