Investigating the Accuracy and Factors Affecting the Pay Factor of Asphalt Concrete

Pay factors are an integral part of the quality assurance. Since the production and supply of asphalt cannot meet all the specifications in accordance with the criteria, determining the relationship between quality and payment is important. The results of the studies on 21 Marshall mix design and 592 sheets of quality assurance and field inspections from asphalt plants show that in preparing the mixing design some cases of inaccuracy in determining the type of traffic, sampling, determining the optimum bitumen content and using The mixing plan is seen for a period of several years. In general, quality control has been low in the 12 projects examined, and there are no recommendations for general technical specifications. Marshall's experiments in this study that affect the pay factor are performed without hammer calibration and are sometimes computable mistakes. It was also found that in some of these projects, in spite of the lower percentage of Marshall parameters inside the specification, they had a higher pay factor, which could be considered And considering the reasons for the non-conformance in this research, it can determine the ineffectiveness of the selected pay factor or indicate that the use of (QA) results for acceptance and payment to the contractor, regardless of quality control (QC) Cannot be used as a way to increase the quality of asphalt pavements and to include costs based on the life cycle.