Development of a Quality Assurance Program for Portland Cement Concrete in South Carolina

摘要

This report describes the development of a Quality Control/Quality Assurance (QC/QA) specification for structural concrete for the South Carolina Department of Transportation (SCDOT). The specification requires quality control 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. Quality control (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, quality control plans, control charts, and other changes.