The consideration of air void content effect on asphalt concrete elastic modulus in pavement design

Introduction. It has been demonstrated that air voids are inherently structural defects in asphalt concrete. The article presents information on mathematical models that take into account the influence of air void content on both the elastic modulus of asphalt concrete and the service life of the pavement, expressed as the cumulative number of design loads that the pavement can withstand before failure. Therefore, considering air void content when determining the elastic modulus of asphalt concrete used in pavement design is a relevant and practically significant task.

Materials and methods. The analysis of methods for accounting the damage accumulation effect applied to the fatigue destruction resistance calculation of asphalt concrete and other materials has been performed. Relying on this analysis, it was concluded that the damage theory can be used to determine the elastic modulus of asphalt concrete. The analogy between Yu. N. Rabotnov’s damage parameter and air void content is emphasized. Furthermore, the possibility of applying the principle of deformational equivalence between a damaged and a homogeneous medium to the calculation of asphalt concrete elastic modulus is justified. The concept proposed by L.M. Kachanov, which involves an increase in stress magnitude with an increasing number of damages, was applied to the calculation of tensile stress in bending.

Results. The results of calculating the elastic moduli of bitumen-based asphalt concrete (grades BND) with varying air void content, but within the limits permitted by GOST R 58406.2-2020, have been presented. This let the authors to supplement the data on elastic modulus values for asphalt concretes in GOST R 71404-2024. The reason to add the data in GOST R 71404-2024 is explained by the fact that the temperature of the asphalt concrete mix in different parts of the dump truck body varies, which leads to different compaction conditions for the mix based on its temperature. In this case, tests of cores taken from sampling points located close to each other show almost identical bitumen contents, but different air void contents. Therefore, when designing flexible road surfaces, it is necessary to focus on the elastic moduli of asphalt concrete that correspond to the maximum limits for the content of air voids.

Conclusion. The obtained results allow to make more detailed pavement design calculations.

1. Kosenko N.V., Goryachev M.G. Justification of the loading duration of the street and road network pavements. Advanced Science and Technology for Highways. 2025; 2: 20–22. (In Russ.)

2. Kosenko N.V., Goryachev M.G. Justification of Design Parameters of Asphalt Concrete According to GOST R 58406.22020 for Pavement Design. Advanced Science and Technology for Highways. 2022; 2: 24–27. (In Russ.)

3. Kosenko N.V., Goryachev M.G., Dmitriev S.M., Yarkin S.V. Investigational studies of asphalt concrete elastic moduli for pavement design. Russian Journal of Transport Engineering. 2024; 11(1). Available at: https://t-s.today/PDF/04SATS124.pdf (in Russ.). Https://doi.org/10.15862/04SATS124. (In Russ.)

4. Uglova E.V. Forecasting of the residual resource asphalt concrete coverings with the account real working conditions. Bulletin of Volgograd state university of architecture and civil engineering. Series Construction and Architecture. 2017; 36(17): 43–47 (in Russ.)

5. Uglova E.V., Tiraturjan A.N., Eganyan G.V. Calibration of the prediction model for fatigue damage accumulation in asphalt courses of flexible pavements for the conditions specific to the Russian Federation. IOP Conf. Series: Materials Science and Engineering. 2019; 698: Article No 077010. https://doi.org/10.1088/1757-899X/698/7/077010

6. Uglova E.V., Tiraturyan A.N., Shilo O.A. Prediction of Failure Fatigue Accumulation in Asphalt Concrete Layers of Flexible Pavements. Russian Journal of Building Construction and Architecture. 2019; 55(3): 52–61. (In Russ.) Doi 10.25987/VSTU.2019.55.3.006

7. Pegin P.A., Kapski D.V., Burtyl Yu.V. Development of Assessment Methodology for Pavement Longitudinal Evenness When Road Construction Durability Changes. Bulletin of scientific research results. 2022; 4: 37–47. (In Russ.) Https://doi.org/10.20295/2223-9987-2022-4-37-47

8. Burtyl Y. V., Kapski D. V. Modelling the relationship of smoothness and resistibility in non-rigid pavements based on theoretical and practical studies. The Russian Automobile and Highway Industry Journal. 2022; 19(4): 570-583. https://doi.org/10.26518/2071-7296-2022-19-4-570-583

9. Iskakbayev A.I., Teltayev B.B. Rossi C.O. Deformation and strength of asphalt concrete under static and step loadings. In book: Transport Infrastructure and Systems. 2017; 3-8. Https://doi.org/10.1201/9781315281896-1

10. Elnashar G., Bhat R.B., Sedaghati R. Modeling pavement damage and predicting fatigue cracking of fexible pavements based on a combination of deterministic method with stochastic approach using Miner’s hypothesis. Applied Sciences. 2019; 1: Article No 229. doi.org/10.1007/s42452-019-0238-5

11. Fahad M., Nagy R. Fatigue damage analysis of pavements under autonomous truck tire passes. Pollack Periodica. 2022; 17(3): 59–64. Https://doi.org/10.1556/606.2022.00588

12. Olexa T., Mandula J. Comparison of complex modulus and elasticity modulus of bitumen bonded materials. Pollack Periodica. 2016; Т. 11. №3. С. 131–140. Https://doi.org/10.1556/606.2016.11.3.12

13. Aleksandrova N.P., Chusov V.V., Stolbov Y.V. Criteria Of Strength And Plasticity Of Asphalt Concrete With The Account Of Effect Of Accumulation Of The Damage While Influence Of Re-Load. IOP Conference Series: Materials Science and Engineering. 2018; Article No. 022021.

14. Chusov V.V., Aleksandrova N.P., Semenova T.V. Accounting Of Damage Of Asphalt Concrete In The Criteria For Calculating The Pavement. IOP Conference Series: Materials Science and Engineering. 2021; 1079: 5: Article No. 052016.

15. Aleksandrov A.S., Aleksandrova N.P., Semenova T.V. Application of the principle of energy equivalence of continuous and damaged bodies to calculation of asphalt concrete coatings by strength and plasticity criteria. News of higher educational institutions. Construction. 2018; 711(3): 79–88.

16. Aleksandrova N.P., et al. Experimental investigation of damage accumulation in asphalt-concrete coatings. News of higher educational institutions. Construction. 2019; 724(4): 114–127.

17. Hassan N.A. et al. Effects of air voids content on the performance of porous asphalt mixtures. Journal of Engineering and Applied Sciences. 2016; 20(11): 11884–11887.

18. Igwe E.A. Effects of Air Voids Variation on Stiffness Property of HMA Concrete Modified with Rubber Latex. International Journal of Emerging Trends in Engineering Research. 2015; 9(3): 86–93.

19. Igwe E.A., Ottos C.G. Investigating the Effect of Air Voids Content in Fatigue Life of Hot Mix Asphalt Mixtures: Case Study of Rubberized Asphalt Concrete. International Journal of Innovative Science, Engineering & Technology. 2016; 3(5): 56–64.

20. Salini R., Lenngren C., High air-void volume implications for asphalt concrete service-life and price penalty. The Civil Engineering Journal. 2022; 1: article No 5: 1–8.

21. Baimukhametov G., Gayfutdinov R., Khafizov E. Calculation of the influence of various compaction on the wear resistance of asphalt concrete using material loss calculation approach. Magazine of Civil Engineering. 2024; 17(1): Article no. 12505. Https://doi.org/10.34910/MCE.125.5

22. Ekwulo, E.O., Eme, D.B. Expected traffic, pavement thickness, fatigue and rutting strain relationship for low volume asphalt pavement. The International Journal Of Engineering And Science. 2013; 2(8): 62–77.

23. Owais M. Analysing Witczak 1-37A, Witczak 1-40D and Modified Hirsch Models for asphalt dynamic modulus prediction using global sensitivity analysis. International Journal of Pavement Engineering. 2023; 24(1): Article No 2268808. Https://doi.org/10.1080/10298436.2023.2268808

24. Asadi B., Hajj R., Al-Qadi I.L. Asphalt concrete dynamic modulus prediction: Bayesian neural network approach. International Journal of Pavement Engineering. 2023; 24(2):. Article No 2270569, Https://doi.org/10.1080/10298436.2023.2270569

25. Belhaj M., et al. Evaluating Factors Influencing Dynamic Modulus Prediction: GRA-MLR Compared with Sigmoidal Modelling for Asphalt Mixtures with Reclaimed Asphalt. Infrastructures. 2025; 10: Article No 269. https://doi.org/10.3390/infrastructures10100269

26. Hanandeh S., et al. Prediction the Dynamic Modulus of Hot Asphalt Mix Using Genetic Algorithms and Neural Network Modeling. Civil Engineering Journal. 2025; 11(7): 2765–2781. Https://doi.org/10.28991/CEJ-2025-011-07-08

27. Simchuk E. N., Zhdanov K. A., Dedkovsky I. A. Improving approaches and methods for assessing physical and operational properties of road asphalt concrete in Russia. Roads and Bridges. 2021; 45(1): 181–221.