The architectural precast plant of J. W. Peters in Algonquin, IL, has two small batch plants specifically designed to deliver many small mixes during the day. The plant uses mixers that can make 20 cubic yards of concrete at a time. Because maintaining a steady temperature in aggregate is important, Peters uses a system that injects radiant heat into aggregate bins. Safety devices are built into the plant. It will automatically shut off for several reasons, including too much water in the mix. Slump tests are performed on the first mix of the day, and periodically throughout the day. The mixers are cleaned on a nightly basis.