摘要: |
This synthesis describes the current quality assurance (QA) practices of state and federal departments of transportation with regard to highway materials and construction. The back- ground information for the report was developed from a review of the literature of QA practices. The results of a survey questionnaire that detail the current state of the practice of state, federal, and Canadian QA programs supplement the literature review. Departments of transportation have come to realize the importance of QA from the experience that failure to conform to either material or construction specifications can result in the failure of highway components. Construction QA programs are intended to ensure that the quality of the materials and construction incorporated in highway products is satisfactory; thus, such programs are many faceted. The use of QA programs has evolved since the 1960s into what are now, sometimes, second or third generation QA programs. QA programs contain three main ingredients, quality control (QC), acceptance, and independent assurance (IA). The manner in which these ingredients are administered and blended makes for many different versions of such programs. |