This report is essentially a synthesis of pertinent information concerning the use of fly ash as an ingredient in concrete for highway construction. It has been prepared to provide a basis for an adequate response by the Department of Highways and Transportation to requirements of the Resource Conservation and Recovery Act and the Environmental Protection Agency pertaining to the use of this by-product in concrete purchased with federal funds. Special attention is given to the quality control and acceptance problems associated with highway usage of fly ash concrete, with emphasis on problems relating to air entrainment. References to the background literature that established the suitability of fly ash as a pozzolan and its use in concrete are The requirements for fly ash as set forth in ASTM Specification C618 are reviewed and the- characteristics to be expected from concrete containing fly ash are discussed. It is recommended that the Virginia Department of Highways and Transportation permit the use of fly ash in concrete at the option of the contractor with prior approval by the state. It is also recommended that suitable specifications for this use be prepared following the guidelines previously recommended by the Concrete Research Advisory Committee.