Enhancing thermal insulation in cement mortar with silica aerogel and recycled PET plastic
Year: 2025
Type: article
Abstract: Rising energy costs create a significant challenge in balancing thermal comfort for building occupants with reduced energy consumption. This study addresses this challenge by developing two cement-based mortars with favourable physical and mechanical properties for enhanced thermal insulation. The mortars incorporate silica aerogel modified with 10% silane coupling agent KH-570 at three different dosages (3%, 5%, and 7%) as a volume replacement to natural sand. One mortar utilises conventional ingredients, while the other incorporates 3% recycled polyethene terephthalate (PET) as a volume replacement for natural sand to explore the potential for sustainable construction practices. To evaluate the performance of these mortars, we investigated setting time, flow of fresh mortar, and dry bulk density. The mechanical properties assessed were compressive and flexural strength. Finally, the thermal conductivity and microstructure of the mortar samples were also analysed. The thermal conductivity of mortar has been reduced by up to ⁓ 55% compared to standard mortar samples due to partial substitution of sand in mortar with hydrophobic silica aerogel powders and PET plastic. In addition, the same mortar mix satisfies the N-type masonry mortar according to (BS-EN 413-1:2011, ASTM c270-10, AS 1012/As 3700) standards for building compressive strength as well as workability and setting (initial and final) times so that it can be used as ordinary mortar. Therefore, one can significantly lower heat losses and energy consumption in buildings and simultaneously contribute towards disposing of PET plastic waste.
Authors: Kaniaw Marof, Lidija Šiller
Institution: Newcastle University
Language: English
Subfield: Building and Construction
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,540
Funder: Newcastle University
OpenAlex ID: W4407597751