text: For foundation used in residential building cement Portland concrete concrete having f'c 3000ksi @ 28 days is commonly used. Since concrete is delivered from the concrete plant you do not need to specify how to make it. It is mixed in accordance with ASTM (American Society of Testing Materials) standards which are incorporated in virtually all building codes.\nMore important is define that it should be placed on in-excavated soil, that there should not be standing water in the excavation. If you need to get smooth edges, forming is required either in wood or metal forms. Forms shall be lubricated for easy removal. I would suggest that minimum reinforcing steel to be installed. Although it is more expensive steel assures that concrete will not crack during the settlement of the soil. Once at the site, the concrete must be placed and compacted. These two operations are performed almost simultaneously. Placing must be done so that segregation of the various ingredients is avoided and full compaction—with all air bubbles eliminated—can be achieved. Whether chutes or buggies are used, position is important in achieving these goals. The rates of placing and of compaction should be equal; the latter is usually accomplished using internal or external vibrators. To properly cure concrete must be kept damp during the several days it requires to set and harden.