Which aggregate is commonly used in lightweight insulating concrete?

Perlite is an aggregate commonly used in lightweight insulating concrete due to its unique properties. It is a volcanic glass that expands when heated, creating a lightweight, aerated material that has excellent insulation properties. This characteristic allows for reduced weight in construction applications while maintaining thermal performance, making perlite an ideal choice for applications where insulation and weight reduction are critical factors.

In contrast, sand and granite are heavier aggregates that do not provide the same level of insulation and lightweight characteristics as perlite. While cement is essential in concrete mixtures for binding aggregates, it does not serve as an aggregate itself. Therefore, perlite is specifically chosen for its ability to enhance insulation in lightweight concrete formulations.