A laboratory study to establish the concrete requirements for the Linn Cove Viaduct in North Carolina was undertaken for the contractor. This multispan precast prestressed segmental bridge is being built by the progressive placing method. The investigations conformed to the project specifications and to special requirements desired by the contractor. The laboratory work included petrographic studies and physical tests on different aggregates, concrete mix proportioning studies using conventional and high-range water reducers, accelerated heat-curing studies, creep and drying shrinkage tests, the development of field mix proportions, and preparation of a quality control procedural manual. A unique aspect of the project was the use of a volumetric mixing mobile at the site instead of a conventional batching and mixing facility.
