Cement-MgO synergetic stabilized earth-straw mix: From material performance to building simulation

Abstract

The production of traditional building materials like cement, lime, and common fired bricks consumes considerable energy and resources and causes atmospheric pollution. Thus, it’s essential to develop more eco-friendly materials for new construction. This research focuses on an earth-straw mixture stabilized hybridly with cement and active MgO. Three aspects scaled from material mix design and mechanical performance to building energy-saving simulation were examined. Three types of earth were considered, and the effects of MgO on M−ME were studied through compression strength, thermal conductivity and TGA tests. The best compressive strength achieved was 12.5 MPa (about 167 % of the standard for non-burned bricks and 125 % of the standard for minimum fired bricks), and the best thermal conductivity was 0.371 / (m·K) (only 44.2 % of that of common fired bricks). Using Design Builder software, energy load differences between M−ME and fired clay brick walls were simulated under given conditions, and the indoor thermal environment was analyzed. Based on the amount of wall earthwork used in the project, the M−ME wall (YC3) can theoretically capture approximately 12.80 kg/m³ of carbon from the air under natural curing conditions, mean while reducing heating energy consumption by 9.49 %. Overall, the utilization of soil and the presence of plant straw give M−ME advantages in carbon footprint and thermal performance over sintered and concrete bricks. As a new energy-saving material, M−ME significantly contributes to carbon reduction in production and operation phases, possessing great potential in decarbonizing the emission of the building sector.