Preparation and hardened properties of lightweight gypsum plaster based on pre-swelled bentonite

摘要

Lightweight gypsum plasters (LGPs) were successfully prepared by adding pre-swelled bentonite to gypsum paste. As the content of bentonite slurry increased from 0% to 40%, the excessive water in the swelled bentonite could not be consumed completely, leading to an increase in the median size of pores in the LGP as well as increased porosity. The increasing bentonite content decreased the dry density, compressive strength, flexural strength and enhanced thermal insulation property, yielding LGPs with dry density, compressive strength, flexural strength and thermal conductivity of 784-1196 kg/m(3), 3.9-11.7 MPa, 2.1-3.9 MPa, and 0.116-0.143 W/m K, respectively. More importantly, the pores that formed in the montmorillonite layers of the bentonite enhanced the humidity-controlling ability of the LGPs. (C) 2019 Elsevier Ltd. All rights reserved.