A COMPARATIVE RESEARCH OF THE MECHANICAL BEHAVIOUR OF LIGHTWEIGHT CELLULAR CONCRETE ELEMENT WITH REGULAR AND IRREGULAR POROSITY DISTRIBUTION

Abstract

Due to the accelerated changes in the ecological environment and climate, the sustainable design of buildings has become one of the necessary solutions to discuss environmental problems and cope with the global crisis. In 2019, the building and construction industry accounted for 36% of global final energy use and 39% of energy-related carbon dioxide emissions, according to the United Nations Environment Programme's (UNEP) Global Status Report for Buildings and Construction. Therefore, the adoption of sustainable building materials will bring considerable economic, environmental, and social benefits at all levels. Over the years, Lightweight Concrete (LWC) has made an outstanding contribution to energy efficiency and sustainability in the construction industry. Although it has some advantages over conventional concrete including reducing buildings’ dead loads and low thermal conductivity, it must also be known that too low density compromises its mechanical strength. In the existing literature review, a variety of different densities of LWC and corresponding strengths have been developed and tested. This paper proposes a new conceptual LWC design inspired by nature. These bioinspired LWC structures were fabricated by Fused Deposition Modelling (FDM) techniques using 5% Polylactic Acid (PLA) infill in Additive Manufacturing (AM). The finished product is subjected to Digital Image Correlation (DIC) and compression testing to understand the mechanical properties and porosity effects of this new concept LWC. The data obtained are also compared with both control cubes and foam concretes (FCs) of the same density. The findings show that bioinspired macrostructures with low porosity (42%) may have the potential to replace LWCs due to their high mechanical strength and low density. Further research could scale up the samples to larger sizes with the same porosity and perform a mechanical test to better understand their mechanical properties.