1.1 This specification covers the minimum material requirements and describes the procedures for installing concrete pavements and linings in corrugated steel pipes and structural plate structures in the field. Specific designs with additional or greater requirements shall be detailed in the contract documents. This specificaiton is applicable to paving or lining new pipes and for rehabilitating existing structures. The pipe to be paved or lined is described in Specifications A 760/A 760M, A 761/A 761M, and A 762/A 762M. 1.2 This specification covers pipes 48 in. (1 200 mm) and larger for pavements and 24 in. (600 mm) and larger for full linings. 1.3 New pipes are to be designed in accordance with Practice A 796 and installed in accordance with Practice A 798 for factory-made pipes and Practice A 807 for structural plate structures. Structures to be rehabilitated shall be structurally stable. 1.4 Pipes with plant installed concrete pavements and linings are covered under Specification A 849. 1.5 This specification is applicable to product in either inch/pound units as A 979 or in SI units as A 979M. Inch/pound units and SI units are not necessarily equivalent. SI units are shown in brackets in the text for clarity, but they are the applicable values when materials are orderd to A 979M. 1.6 This standard may involve hazardous materials, operations and equipment. The standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.