Evaluation of Axle Equivalency Load Factors Based on the Fatigue Criterion of Asphalt Layer Using Dissipated Energy Method and Compared with Proposed Factors in Asphalt Pavement Regulations of Iran Roads

Document Type : Scientific - Research

Abstract

Equivalency load factor is one of the most important factors in design of pavement, that shows the influence of traffic on pavement distress. This factor can be defined experimentally according to Asphalt Pavement Regulationd of Iran Roads (Publication 234) and the only concern in choice of the factor is the type of the axle (single, tandem and tridem) no matter whether wheels are single or dual. In this study equivalency load factor of heavy axle load mentioned in Asphalt Pavement Regulation of Iran Roads was determined based on two approaches: Strain and dissipated energy and according to the fatigue criterion and then compared to the equivalency load factors in AASHTO and Asphalt Institute regulation. 3D-Move program was used to analyze pavement sections (thin, medium, and thick) and in three vehicle speeds 10, 50 and 100 km/h at the bottom of the asphalt layer. The results showed that equivalency load factor of single axles with single wheels is independent of pavement thickness number, vehicle speed and applied method in calculation of this factor. Also, it was observed that equivalency load factor of single axle in the maximum distress method has the same quantities for both strain and dissipated energy method. In this research, equivalency load factor of single axle with dual wheels obtains less than one for single axle with single wheel with similar weight that it needs to pay attention to this matter in Asphalt Pavement Regulation of Iran Roads. Also, equivalency load factor of AASHTO and Asphalt Institute are less than the calculation values obtained in this study.

Keywords


-Abdel-Motaleb,M. E. (2007) “Impact of high-pressure truck tires on pavement design in Egypt”, Emirates Journal for Engineering Research, pp. 65-73.
 
- Chatti, K., Manik. A., Salama, Ch, El Mohtar, H. and Lee, H. (2009) “Effect of Michigan multi-axle trucks on pavement distress”, Final report, Michigan Department of Transportation February 
 
Chatti, K., Lee . H. and El Mohtar. H. (2004) “Fatigue life predictions for asphalt concrete subjected to multiple   axle loadings”, Proceedings 8th International Symposium on Heavy Vehicle Weights and Dimensions, Johannesburg, South Africa, March
 
- Chatti, K., Lee. D. and  Kim, T. (2000) “Truck damage factors using dissipated energy versus peak strains”, 6th international Symposium on Heavy Vehicle Weights and Dimensions.
 
- Chaudry, R. and Memon, A. B (2013) “Effects of variation in truck factor on pavement performance in Pakistan”, Journal of Engineering and Technology, pp.19-30.
 
- Guide for mechanistic-empirical design of new and rehabilitated pavement structures (2004) “Appendix II 1:Calibrationof Fatigue Cracking Models for Flexible Pavements”(NCHRP).
 
- Huang, Y. H. (2004) “Pavement analysis and design”, Prentice Hall,  New Jersey.
 
- Garber, N. J. and  Hoel, L. A. (1988) “Traffic and highway engineering”, West Publishing Company, St. Paul, Minnesota, 959 pages.
 
- Jordhal, P. R. and Rauhut, J. B. (1983) “Flexible pavement model VESYS  IV-B”, Report prepared for Federal Highway Administration under Contract DTFH61-C·00175.
 
- Judycki, J. (2011) “Determination of  equivalent axle load factors on the basis of fatigue criteria for flexible and semi-rigid pavements”, Journal of  Road Materials and Pavement Design, pp.187-202.
 
- SHRP-A-404. (1994)  “Fatigue response of   asphalt-aggregate mixes”, Strategic Highway Research Program, National Research Council, Washington, DC.
 
- Siddharthan, R.V., Sebaaly, P. E., El-Desouky, M., Strand,T  and Huft, D.( 2005) “Heavy off-road vehicle tire-Pavement Interactions and Response,” Journal of Transportation Engineering, ASCE, Vol. 131(3), pp. 239-247.
 
- Siddharthan, R.V., El-Mously, M., Krishnamenon., N. M. and Sebaaly, P.E. (2002) “Validation of a pavement response model using full-scale field tests”,  International Journal in Pavement Engineering, Vol. 3, No. 2, pp. 85-93.
 
- Siddharthan, R.V., Krishnamenon, N and Sebaaly, P. E (2000) “Pavement response evaluation using finite-layer approach”,  Transportation Research Record, No. 1709, TRB, pp. 43-49.
 
- Zhang, Z., Kawa., I.and Hudson, W. R. (2005) “Impact of changing traffic characteristics and environmental conditions on performance of pavements”, Report No. FHWA/TX-05/0-1713-2, Center for Transportation Research of University of Texas at Austin.
 
- آیین‌نامه روسازی آسفالتی راه‌های ایران - نشریه شماره 234   (1390)    تجدید نظر اول، معاونت برنامه‌ریزی و نظارت راهبردی رییس جمهوری.
 
- بهزادی، غلامعلی(1383) " ﺗﺄﺛﻴﺮ ﺧﻮاص ﭘﻼﺳﺘﻴﻚ ﻻﻳﻪﻫﺎی روﺳﺎزی راه در ﺿﺮﻳﺐ ﺑﺎر ﻫﻢ ارز"، اولین کنگره ملی مهندسی عمران، دانشگاه صنعتی شریف، 22-24 اردیبهشت ماه 1383
 
- خاکی، علی منصور و سرکار، علیرضا " ﺍﺛﺮﺍﺕ ﻣﺪﺕ ﺯﻣﺎﻥ ﺑﺎﺭﮔﺬﺍﺭﻱ ﺑﺮ ﺭﻭﻱ ﺿﺮﺍﻳﺐ ﺑﺎﺭ ﻫﻢ ﺍﺭﺯ ﺩﺭ ﺭﻭﺳﺎﺯﻱﻫﺎﻱ ﺍﻧﻌﻄﺎﻑﭘﺬﻳﺮ"، ﻧﺸﺮﻳﻪ ﺑﻴﻦﺍﻟﻤﻠﻠﯽ ﻋﻠﻮﻡ ﻣﻬﻨﺪﺳﻲ ﺩﺍﻧﺸﮕﺎﻩ ﻋﻠﻢ ﻭ ﺻﻨﻌﺖ ﺍﻳﺮﺍن، ﺟﻠﺪ 18،  ﺷﻤﺎﺭﻩ ٢، ﺗﺎﺑﺴﺘﺎن 1386، ص. ٧٧-٨٥