AASHTO HB-8

The compilation of these specifications began with the organization, in 1921, of the Committee on Bridges and Structures. The constant research and development in both steel and concrete structures practically dictates the necessity of revising the specifications every three or four years, and the 1961 edition continues this trend. Among the important revisions in the 1961 edition are the sections on Prestressed Concrete which are based largely on the report of the Joint ASCE-ACI Commmittee on Prestressed Concrete of 1958 and have been used for two years as Tentative Specifications. Changes have also been made in the sections on Reinforced Concrete and further changes are suggested by current research findings. The numerous changes concerning plate girders have followed the course of recent important research whcih may lead to some further changes in design concepts and practice. The specifications on high-strength bolts for structural connections have been revised to keep pace with the rapid expansion of the use of these fasteners and the findings of extensive research organization by the Research Council on Riveted and Bolted Structural Joints. These specifications are intended to serve as a standard or guide for the preparation of state specifications and for reference for bridge engineers.