Prescriptive and performance specification—A specification is an explicit set of requirements to be satis-fied by a material, product, system, or service (ASTM 2013). In the concrete construction industry, the primary types of specifications are materials specifications and construction specifications. The former provide minimum requirements for composition and properties, and the latter form part of the contract between owner and contractor. Specifications can be of the prescriptive or performance type, or they may include components of each.
A prescriptive specification for concrete focuses on the properties and composition of raw materials; mixture proportions; batching, mixing, and trans-port of fresh concrete; and a range of construction operations from placing to curing. Prescriptive specifications rely on observed or implied relationships between the details speci-fied and the desired final, in-place, or end-product concrete performance.
Under a prescriptive specification, the desired end-product performance may or may not be described. A performance specification, however, defines required results, the criteria to judge performance, and verification methods without requirements for how the results are to be obtained.