Properties of lightweight plaster materials made with expanded polystyrene foam (EPS)

Abstract

Gypsum is a natural material commonly used in building construction and its most often use is still in the form of interior plasters and plasterboards. However, during the last years several studies dealing with the reduction of density have arisen and new gypsum composites have being developed in response to enable quicker and easier installation.Former research results have shown that the most favourable material to produce lightweight plaster composites is expanded polystyrene beads (EPS). But, apart from density reduction, it involves an important mechanical strength decrease.The reinforcement of plaster composites can be accomplished by incorporating additives, such as fibres, plasticizers and bonding agents. In the EPS plaster composite the best results are achieved by adding bonding agents. Moreover in a water to binder ratio of 0.8 and 2% EPS with bonding agent, the decline in density achieved is at least 44% while mechanical strength of the composite improves in comparison to and EPS plaster composite without the addition of any other additive.