Evolution of Cementitious Binders: Overview of History, Environmental Impacts, and Emerging Low-Carbon Alternatives

Cementitious binders have long been a keystone of construction, evolving from ancient lime mortars in Neolithic structures to the widespread use of Portland cement in the 19th century, which remains critical in modern construction. This review traces the historical development of cementitious binders and highlights how their widespread adoption has also brought significant environmental challenges, particularly carbon dioxide emissions and intensive energy consumption. To mitigate these impacts, supplementary cementitious materials (SCMs), such as fly ash, slag, and silica fume, have been adopted to reduce clinker consumption and improve sustainability. Despite these advancements, cement continues to be one of the largest industrial contributors to global emissions. In response, alternative binders have been explored. Alkali-activated binders (AABs) demonstrate considerable potential to reduce emissions while offering enhanced durability and performance. These emerging technologies provide a pathway toward more sustainable construction practices. This review is based on a structured survey of the peer-reviewed literature, conference proceedings, and technical reports up to 2025, synthesizing key themes related to historical evolution, environmental impacts, and emerging low-carbon alternatives. The findings aim to inform the development of sustainable building materials for the future.