Expanded Perlite in Civil Engineering: A Review of Its Potential for Low-Carbon and Circular Construction

The growing demand for low-carbon, resource-efficient, and multifunctional construction materials has intensified interest in solutions that can support both circular economy strategies and sustainable urban development. Expanded perlite—a lightweight volcanic material with low embodied energy and multiple functional properties—is increasingly considered a potential component of circular and nature-based material systems. This paper critically examines whether expanded perlite can serve as a sustainable alternative in civil engineering applications, contributing to reduced material consumption, improved thermal performance, and lower environmental impact across the life cycle. The review provides an overview of current applications of expanded perlite in lightweight concretes, insulation systems, green roofs, water-retention substrates, and other technologies relevant to resilient and net-zero cities. It also identifies key research gaps related to long-term durability, large-scale implementation, and life-cycle assessment, while emphasizing the need for proper handling procedures due to health concerns associated with dust exposure. By situating expanded perlite within the context of circular design and low-carbon construction, the paper highlights its potential role in decarbonizing the built environment and advancing the transition toward climate-resilient and regenerative urban systems.