Investigating the properties of local minerals as a supplementary cementitious material for foamed concrete

Abstract

Portland cement production is currently one of the major sources of global carbon dioxide emissions. This makes Portland cement production a significant contributor to global climate change. To mitigate these environmental impacts, Supplementary Cementitious Materials (SCMs) are expected to provide an appropriate and effective solu - tion. This study focuses on examining the potential of quartz sand and kaolin from Aceh, Indonesia, as materials utilized as SCMs in the production of foam concrete. These two materials were selected due to their pozzolanic activity, which allows them to react with the calcium hydroxide formed during cement hydration and act as additional binding agents. The primary objective of this study is to reduce the carbon footprint of foam concrete and to sustainably enhance its mechanical properties. The percentage variations of quartz sand and kaolin used as SCMs were investigated at 0% (as a control), 5%, 10%, 15%, and 20%. The physical, chemical, and microstructural properties of the specimens were tested at curing ages of 7, 28, and 56 days. The results of the study indicate that quartz sand and kaolin can function as SCMs. This is because quartz sand and kaolin contain calcium silicate hydrate (C-S-H) as a binding agent. The use of SCMs at 10% of the cement weight has a very significant impact on mechanical properties as the curing age of the concrete increases. Based on these conditions, it can be proven that quartz sand and kaolin derived from local mineral rocks in Aceh have very effective potential for use as SCMs in foam concrete, as demonstrated by the microstructural patterns, and can serve as sustainable alternative materials.