Experimental and numerical investigation of novel light weight concrete panels made with aerogel and phase change materials

Abstract

Silica Aerogel (SAG) mortar is an ultra-lightweight cementitious composite. It has high heat-insulating properties, which helps to reduce building heating energy consumption. However, it may also increase overheating and peak cooling demand in buildings during summer due to low thermal mass to store thermal energy. Therefore, this study aimed to increase the thermal energy storage capacity of silica aerogel lightweight concrete panels (SAGP) by integrating Capric Acid (CA) Phase Change Materials (PCM). The CA was absorbed in Hydrophobic Expanded Perlite (HEP) porous materials to develop form stable capric acid hydrophobic expanded perlite (CAHEP) composite to prevent PCM leakage when melted. Various lightweight Heat Resistive and Storage Panels (HRSP) panels were developed by replacing sand with SAG and CAHEP composite at different volume fractions. Then, the thermophysical properties and thermal performance of those HRSPs were evaluated using appropriate standards and established methods. The results showed that the integration of 60% CAHEP in SAGP resulted in 43% and 56% higher thermal storage and inertia, respectively, compared to the reference SAGP without CAHEP. The developed HRSPs also have acceptable compressive strength and drying shrinkage for thermal insulating and plastering applications. Numerical simulation showed that the application of HRSPs on the interior surface of a typical Victorian house reduced annual energy use and greenhouse gas emissions by 9.14% and 24%, respectively, in air-conditioned buildings; and reduced summertime thermal discomfort hours by 42 h in a free running house during a heatwave period. Finally, the life cycle assessment revealed that HRSPs have lower environmental impacts than SAGPs. Thus, HRSPs can be a sustainable alternative to lightweight concrete panels.