Expansão de presa de gesso tipo IV (pedra) de alta resistência em diferentes técnicas de manipulação e marcas diversas Setting expansion of high resistance type IV gypsum (stone) using different handling techniques and several manufacturers

The purpose of this study was to evaluate the effect of manual (M) handling in open air and of vacuum (V) mechanical handling of different brands of high resistance stone gypsum. 48 test specimens were built in a device conceived by Garlipp, Bombonatti, in which setting expansion of test specimens was measured. Data were submitted to Kruskal-Walls and Mann-Whitney tests (0.05) and had demonstrated the following results: Durone IV (M) 0.092a, Durone IV (V) 0.090a. EliteRock (M) 0.085a; EliteRock (V) 0.087a. SilkyRock (M) 0.088a; SilkyRock (V) 0.090a. GilRock (M) 0.085a; GilRock (V) 0.083a. The results permitted to conclude that there is no difference between the types of gypsum tested, nor between the manual handling technique in open air and the vacuum mechanical handling technique.