Quality of materials and workmanship directly influences the life of pavements, maintenance costs, levels of service and user costs. Background concepts of quality, quality control (supplier/contractor QC), quality assurance (owner QA), performance and specifications (general and product - method, end result (ERS) and performance) are introduced. Sampling and testing requirements for pavement materials - characteristics, sampling, statistics, testing and retesting - are examined. Practical examples are drawn from aggregates, hot-mix asphalt and hot in-place recycling to illustrate the concepts and their application from both contractor and agency viewpoints. Emphasis is placed on QC/QA guidance and understanding ERS basics, rather than statistics. While undoubtedly controversial in the current tendering process milieu, bonus, value engineering and life-cycle cost selection concepts as incentives to innovation and quality improvement for desired performance are discussed. The importance of agency-contractor partnering for quality, and mechanisms to achieve this are described as a component in total quality management (TQM). Even the most sophisticated ERS can yield deficient payments if all involved do not carry out their responsibilities effectively. The evolution of ERS and performance-based requirements does not require a revolution in thinking, but rather a clear understanding of the concepts involved and the eventual advantages to both agencies and contractors through quality mangement. (A)
Samenvatting