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Weigh-in-Motion (WIM) systems are used in order to reduce the number of overloaded vehicles. Data collected from WIM provide characteristics of vehicle axle loads that are crucial for pavement design as well as for the development of pavement distress prediction models. The inaccuracy of WIM data lead to erroneous estimation of traffic loads and in consequence inaccurate prediction of pavement distress process. The objective of the paper is to present a new methodology of heavy traffic axle load spectra (ALS) correction due to weighing errors (systematic and random) that occur in WIM systems. The theoretical solution which is proposed in the paper was validated successfully. The method enables correction of erroneous data to make traffic load statistics used for pavement design more reliable and precise, with no necessity to remove high number of records, as it is used in other methods. The practical meaning of the newly developed method was emphasised by analysis of the effect of relative and random error of WIM data on pavement fatigue life estimation, as well as on the estimated percentage of overloaded vehicles. Mechanistic-empirical approach (M-EPDG) was used for this purpose. [ABSTRACT FROM AUTHOR]

• The new approach to fatigue life determination, based on pseudo strain energy density was developed. • The energy consumed to counteract the healing effect is considered in this approach. • The new test procedure for Dynamic Shear Rheometer was proposed and named: Discontinuous Linear Amplitude Sweep test (named D-LAS) • Various asphalt mastics were evaluated according to the newly developed method. • Fatigue life of tested mastics exhibits logarithmic growth with an increase in the duration of rest periods. Rest periods between cyclic loads can lead to recovery of damage and extension of fatigue life. This phenomenon is referred to as healing. Healing is clearly observed in bituminous materials, such as asphalt mastics, which belong to the components of asphalt mixtures. Due to the nature of road pavement traffic loading, which is characterized by series of intermittent pulses with rest periods, consideration of healing is necessary for accurate fatigue life estimation. Nevertheless, the vast majority of existing methods relies on relationships established using continuous load conditions. The paper presents a new approach to fatigue life determination, based on pseudo strain energy density. Two components of energy released in fatigue test are considered: the energy responsible for damage growth and the energy consumed to counteract the healing effect. Theoretical derivations were verified in experimental tests, which were performed on asphalt mastics using the Dynamic Shear Rheometer (DSR). It was shown that fatigue life increases with the duration of rest periods on a linear-log scale. Moreover, fatigue life and healing abilities of the analysed asphalt mastics were affected by the type of bitumen and filler, as well as the ageing process. [ABSTRACT FROM AUTHOR]

Overloaded vehicles have a significant impact on pavement fatigue life and distress. As the studies show, the phenomena intensify when the control of traffic is poor. The paper presents the results of the research including analysis of weigh in motion data from eight stations and analysis of asphalt pavement fatigue caused by mixed traffic. Distributions of vehicles axles load including the multiple axles effects are presented. Mixed axle loads were transformed into equivalent number of standard 100 kN axle loads. The regression model of load equivalency factor depending on the axle load distribution and the percentage of overloaded vehicles is presented. The analysis of the effect of overloaded vehicles on decrease of fatigue life of a pavement structure is presented. The analysis has shown that the increase of percentage of overloaded vehicles from 0% to 20% can reduce the fatigue life of asphalt pavement upto 50%. [ABSTRACT FROM PUBLISHER]

High-modulus asphalt concrete has numerous advantages in comparison to conventional asphalt concrete, including increased resistance to permanent deformations and increased pavement fatigue life. However, previous studies have shown that the construction of road pavements with High Modulus Asphalt Concrete (HMAC) may significantly increase the risk of low-temperature cracking. Those observations were the motivation for the research presented in this paper. Four test sections with HMAC used in base and binder courses were evaluated in the study. Field investigations of the number of low-temperature cracks were performed over several years. It was established that the number of new low-temperature cracks is susceptible to many random factors, and the statistical term "reversion to the mean" should be considered. A new factor named Increase in Cracking Index was developed to analyze the resistance of pavement to low-temperature cracking. For all the considered field sections, samples were cut from each asphalt layer, and Thermal Stress Restrained Specimen Tests were performed in the laboratory. Correlations of temperature at failure and cryogenic stresses with the cracking intensity observed in the field were analyzed. The paper provides practical suggestions for pavement designers. When the use of high modulus asphalt concrete is planned for binder course and asphalt base, which may result in lower resistance to low-temperature cracking of pavement than in the case of conventional asphalt concrete, it is advisable to apply a wearing course with improved resistance to low-temperature cracking. Such an approach may compensate for the adverse effects of usage of high modulus asphalt concrete. [ABSTRACT FROM AUTHOR]

The reinforcement of asphalt layers with geosynthetics has been used for several decades, but proper evaluation of the influence of these materials on pavement fatigue life is still a challenging task. The presented study investigates a novel approach to the reinforcement of asphalt layers using a new type of geogrid composite, in which square or hexagonal polypropylene stiff monolithic paving grid with integral junctions is bonded to polypropylene non-woven paving fabric. The laboratory fatigue tests were performed on large asphalt concrete beams reinforced with the new type of geocomposite. Unreinforced samples were used as reference. Test results were analysed in several aspects, including the standardised approach based on stiffness reduction, but also using energy dissipation. The effect of reinforcement on pavement fatigue life was also estimated. Based on the obtained final results of fatigue life calculations, it can be concluded that the evaluated geogrid composites have an evident positive effect on pavement performance and have a significant potential to extend the overall pavement life, especially in the case of hexagonal grid. [ABSTRACT FROM AUTHOR]