DEVELOPMENT OF A QUALITY ASSURANCE PROGRAM FOR PORTLAND CEMENT CONCRETE IN SOUTH CAROLINA

This report describes the development of a Quality Control/Quality Assurance (QC/QA) specification for structural concrete for the South Carolina Department of Transportation. The specification requires QC sampling and testing to be performed by the contractor which is then verified by the Department on a less-frequent sampling schedule. Acceptance of in-place structural concrete is based on 28-day concrete compressive strength and percent air content in the concrete delivered to the site. QC tests required by the specification include mixture temperature, slump, unit weight, aggregate gradation and moisture content. Payment is based on the percent within limits (PWL) and a pay factor (PF) applied to individual lots. This report also includes a summary of four workshops conducted throughout the state of South Carolina to inform contractors and department employees of the new specification and its requirements for sampling, testing, QC plans, control charts, and other changes. Appendices to this report include the specification, a proposed implementation plan, a sample QC plan to be submitted by the contractor for each project, and a draft form to be used by the contractor and Department to track PWL and PF for individual lots.