The use of cactus mucilage in gypsum plaster: effects in water absorption and static flexion strength

Abstract

The use of gypsum plasterboards in construction projects has increased due to several factors, including the ease and speed of installation since it is a dry construction method. In Brazil, most gypsum production is destined to making these panels. Gypsum plaster has a fast setting time and thus requires inclusion of admixtures to extend it. Such admixtures allow the modification or addition of properties to the material. Most of them are synthetic and expensive, increasing the cost of the final product. This study investigated a natural admixture, the mucilage extracted from cactus Nopalea cochenillifera and from Opuntia ficus-indica, added to gypsum plaster paste in powder and gel. The mucilage of both cacti proved to have additive properties, reducing of water consumption by the paste, and changing the rate of water absorption and flexural strength in the specimens molded.