Abstract
Plaster is a widely used material in the construction industry, mainly as plaster paste for coating. The biggest producer of plaster in Brazil is the Araripe Gypsum Production Complex. There is an evident need to know the properties and characteristics of this material, focusing particularly on the finished product as coating for internal walls. Hence, this research project consisted in a characterisation study of five gypsum samples from the Araripe Complex, and an evaluation of the bond strength of the coatings made of gypsum plaster paste. The characterisation study was carried out in the anhydrous state, by means of granulometry, unit weight, specific gravity, free water and crystallisation content tests; in the fresh state, normal consistency, setting time and calorimetry tests were performed; and in the hardened state, hardness and compressive strength were tested. The bond strength tests were performed on gypsum plaster paste made on a ceramic base, with and without pre-wetting of the base. The results showed that the plaster pastes had satisfactory and similar performances, regardless of the size of the manufacturer, however, some normative requirements were not met.
Keywords:
Gypsum plaster; Characterisation; Bond strength
