Aggregates for Concrete
concrete with a density (unit weight) of 2200 to 2400 kg/m. 3 (140 to 150 lb/ft. 3). Aggregates of expanded shale, clay, slate, and slag (Fig. 53) are used to produce struc tural lightweight concrete with a freshly mixed density ranging from about 1350 to 1850 kg/m. 3 (90 to 120 lb/ft. 3). Other lightweight materials such as pumice, scoria, perlite, vermiculite, and diatomite are .