Jaue2025-031 Environmental Impact of Unfired Bricks in the Brick Manufacturing Process

Abstract

In recent years, with the global advancement of carbon neutrality goals, the construction industry—being one of the major sources of CO₂ emissions—faces an urgent need to transition toward greener practices. To achieve decarbonization in this sector, the development of low-carbon and energy-efficient building materials has become essential. Traditional fired bricks require high-temperature kiln processes, often exceeding 1000°C, and rely on energy sources such as gas, heavy oil, or electricity. This results in significant energy consumption and CO₂ emissions.

In contrast, unfired bricks have been developed as environmentally conscious building materials. Unfired bricks are thinner than conventional fired bricks and have been designed as interior finishing materials with environmental control functions such as heat storage and humidity regulation. They do not require high-temperature firing; instead, they are manufactured using low-temperature drying with residual heat from tunnel kilns. This dramatically reduces the energy use and CO₂ emissions associated with conventional firing. Additionally, unfired bricks are made solely from excavated soil without the need for additives, further minimizing raw material-related emissions.

However, the production process of both fired and unfired bricks involves several stages—such as soil excavation, mixing, molding, compression, and drying—all of which contribute to energy use and carbon emissions. Therefore, this study conducts a detailed environmental impact assessment of the brick manufacturing process and quantitatively evaluates the CO₂ emissions associated with unfired bricks, aiming to clarify their potential as a low-carbon alternative in the construction industry.