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

Document Type : Original Article

Authors

1 Kermanshah Management and Planning Office Chairman of the Committee on Construction Equipment and Materials

2 Professor, Department of Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran.

Abstract

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.

Keywords


   -جمشیدی، م. ر. و ولی نژاد، ح.، (1396)، "مخلوط‌های آسفالت، طراحی با روش‌های آسفالت ممتاز"، تهران، طراح.
-حمیدی­جو، ر. (1396)، "کارگاه آسفالت"، تهران، سنجش و دانش.                  
 
-خرازی، ا. م. و ولی نژاد، ح.، (1393)، "آسفالت ترجمه کامل کتاب MS-4 از مؤسسه آسفالت آمریکا"، تهران، طراح.
 
- معاونت امور فنی، دفتر امور فنی و تدوین معیارها و کاهش خطرپذیری ناشی از زلزله، (1382)، "مشخصات فنی عمومی راه"، نشریه 101، تجدید نظر اول، سازمان مدیریت و برنامه‌ریزی کشور، تهران، ایران.
 
-Brown, D.C., (2006),­”The Asphalt QC Challenge –States Wrestle with Tests-for-Pay Issue”, Public Works Magazine.
-Denneman, E­., (2007), ­”HMA Permanent Deformation Study Preliminary Results”, Prepared for the for the Gautrans Technology Development Symposium 24 May.
 
-Mang, T., (2005),­”Fundamentals and Practice of Asphalt  Mixture Design Procedures  to Assure Adequate Performance”, Conference on Pavement Engineering, Taiwan.
 
-NCHRP, R., (2001),­”Testing and Inspection Levels for Hot-Mix Asphaltic Concrete Overlays”, Transportation Research Board, Washington ,DC.
 
-Radha, A., Nii, A.O., (2006),­”Quality Control and Quality Assurance of  Hot Mix Asphalt Construction in Delware”, University of  Delware.
    
-Strezs, A., Alksnis, M. (2004),­”Comparative Testing Compaction of  Laboratory Equipment and Abilities Organized by The Latvian Road Administration”, Netherlands.