Thermal mass reduction is one means of making buildings more energy efficient. By using materials that absorb, store, and release heat, the indoor temperature of a building can be stabilized in hot and cold climates for improved comfort. Researchers focused on hollow masonry units by incorporating expanded polystyrene waste into block mortar with the goal of improving the thermal insulation performance. Not only does EPS concrete exhibit good thermal and acoustic insulation properties, but its use is economical and environmentally friendly, write Youmna A. Y. Ali, Ezzat H. A. Fahmy, Mohamed N. AbouZeid, Yoursy B. I. Shaheen, Mohamed N. Abdel Mooty, and Yosra El Maghraby in their paper “Thermal Characteristics of Hollow Block Masonry Units Incorporating Expanded Polystyrene Wastes.”
The authors used a dual-track approach pairing experimental testing of mortar and block thermal conductivity with 3D finite element–based computational modeling of hollow blocks under multiple heat-transfer scenarios including conduction, convection, and radiation. The research determined how EPS influences the blocks’ thermal insulation properties to identify the optimal mix for enhanced energy efficiency. The results offer more insight into EPS-modified masonry and the prospect of using it as a system. Read their full findings in the Journal of Materials in Civil Engineering at https://ascelibrary.org/doi/10.1061/JMCEE7.MTENG-21106. The abstract is below.
Abstract
The increasing demand for energy-efficient and sustainable building materials has driven research into lightweight and thermally insulating construction units. This study aims to enhance the thermal performance of hollow masonry blocks by partially replacing sand in cement mortar with varying percentages of expanded polystyrene (EPS). The primary objective is to evaluate the effect of EPS incorporation on the thermal conductivity of both mortar mixtures and hollow blocks. The thermal conductivity (𝑘 value) of the mortar was measured experimentally, while the thermal behavior of three-dimensionally modeled EPS hollow blocks was analyzed using ANSYS Fluent software under four heat transfer scenarios: conduction only, conduction and radiation, conduction and convection, and combined conduction–convection–radiation. Experimental results showed that increasing the EPS content significantly reduced the thermal conductivity of mortar, with values ranging from 1.8 W/m·K for the control mix to as low as 0.16 W/m·K. Numerical simulations yielded similar trends for hollow blocks, with 𝑘 values ranging from 1.43 W/m·K (control) to between 1.27 and 0.25 W/m·K for EPS blocks across the different heat transfer modes. These findings confirm the potential of EPS as an effective additive for improving the thermal insulation of masonry units.
Explore more about filling masonry blocks with expanded polystyrene waste to improve insulation in the ASCE Library: https://ascelibrary.org/doi/10.1061/JMCEE7.MTENG-21106.