Example 2 - Concrete
An exposed aggregate concrete is considered to be a special order. An exposed aggregate concrete is the name given to the process of washing the surface of concrete with water before it is completely cured in order to leave the rocks/stones visible. Because the aggregate will be visible, it is essential that it is uniform (ie same colour and size). To produce this, it may be necessary to close down a concrete batching plant for a period of time to ensure the exact same products are being mixed without error. The batching plant may need up to three weeks notice to ensure the plant can be closed during the required time.