What is "rastra"

n. (alternative form of arrastra English)

Rastra is a tradename for a particular insulating concrete form (ICF) used to make walls for buildings. It is one of the earliest such products, in production since 1972, and is composed of concrete and thastyron. Thastyron is a mixture of plastic foam and binder that is composed of eighty-five percent recycled post consumer polystyrene waste that are molded into blocks. The main components of rastra are cement, water and expanded polystyrene.