Numerical Investigation of Porosity and Aggregate Volume Ratio Effects on the Mechanical Behavior of Lightweight Aggregate Concrete

In modern construction, Lightweight Aggregate Concrete (LWAC) has been recognized as a vital material of concern because of its unique properties, such as reduced density and improved thermal insulation. Despite the extensive knowledge regarding its macroscopic properties, there is a wide knowledge gap in understanding the influence of microscale parameters like aggregate porosity and volume ratio on the mechanical response of LWAC. This study aims to bridge this knowledge gap, spurred by the need to enhance the predictability and applicability of LWAC in various construction environments. With the help of advanced numerical methods, including the finite element method and a random circular aggregate model, this study critically evaluates the role played by these microscale factors. We found that an increase in the aggregate porosity from 23.5% to 48.5% leads to a drastic change of weakness from the bonding interface to the aggregate, reducing compressive strength by up to 24.2% and tensile strength by 27.8%. Similarly, the increase in the volume ratio of lightweight aggregate from 25% to 40% leads to a reduction in compressive strength by 13.0% and tensile strength by 9.23%. These results highlight the imperative role of microscale properties on the mechanical properties of LWAC. By supplying precise quantitative details on the effect of porosity and aggregate volume ratio, this research makes significant contributions to construction materials science by providing useful recommendations for the creation and optimization of LWAC with improved performance and sustainability in construction.