Effects of Modified Expanded Perlite Aggregate and Air Entraining Agent on Properties of Polymer Modified Lightweight Thermal Insulation Mortars

Expanded vitrified perlite (EVP) and hydrophobic expanded perlite (HEP) as lightweight aggregate and air entraining agent (AE) were added into mortar to decrease its thermal conductivity. Mixture of powder polymer additive (MPPA) includes redispersible polyethylene vinyl acetate (VAc/E), methyl cellulose (MC) and starch ether (ST) were used as organic binding agent as well as water retention and consistency controlling agent. The results show that the bulk density, thermal conductivity, mechanical properties, dry shrinkage ratio of mortars all decrease with the increase of the mass ratio of aggregate to cement (m(A)/m(C)); and the higher consistency, lower bulk density and thermal conductivity, and reduced dry shrinkage ratio can also be observed by adding AE in mortar at the constant water/cement-ratio, however, worsened mechanical properties of mortar are also observed at the same time