• This study aims to promote the reuse of stone powder generated in large quantities annually in domestic and international regions, including the Chugoku area, focusing on its application in construction (ground improvement).
• Indoor experiments were conducted to elucidate the physical properties, such as strength development characteristics, of cement-stabilized soils mixed with granite and limestone-derived stone powders.
• The investigation revealed that cement-stabilized soils mixed with granite and limestone-derived stone powders not only reduce cement usage but also promise to mitigate socio-economic and environmental impacts, potentially leading to significant cost savings in construction projects.

  The construction industry is a major global consumer, utilizing approximately 24% of the world's raw materials and contributing about 11% of CO2 emissions. Within this, cement production alone accounts for roughly 8% of these emissions, prompting efforts to mitigate its societal, economic, and environmental impacts. Currently, materials such as steel slag and fly ash have been proposed and utilized to replace cement partially, but further reductions are necessary. This study focuses on stone powders, which are abundant in the demolition and decoration industries and are currently wasted. 

  Previous studies have shown that granite-derived stone powders, particularly abundant in the Chugoku region, including Hiroshima Prefecture, exhibit varying characteristics suitable for reuse as ground materials, depending on their particle size. This paper extends these investigations to include limestone-derived powders, evaluating the physical properties of ground materials mixed with different-origin powders and assessing their socio-economic and environmental impacts. The tests revealed that while limestone-derived powders do not enhance strength based on particle size, they contribute to early strength development.

   Consequently, using mixtures of granite and limestone-derived stone powders reduces cement requirements and water usage, potentially mitigating socio-economic and environmental impacts associated with construction activities.

Paper Info
Nakayenga, J., Inui, M., Guharay, A., Hata, T.*: Effect of limestone and granite stone powder on properties of cement-treated　clay composites and their socioeconomic and environmental impacts. 
CONSTRUCTION AND BUILDING MATERIALS, 393,132064. 
10.1016/j.conbuildmat.2023.132064 AUG 2023.