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In this study, we investigate the spatial distributions of the internal structures in semirigid base materials (SRBMs) and explore their effect on the service performance of the SRBMs. X-ray computed tomography (X-ray CT) was used to conduct a spatial voids structure analysis. Three variates were selected to study the factors influencing the spatial distributions of the internal structures, including freeze-thaw cycles, curing time, and cement content. The results show that, with the increase in the number of freezing and thawing cycles, the average porosity, void area, and void number of the SRBM samples increased, and the average void diameters of all samples initially increased and then decreased. These trends led to an increase in the mass loss ratio and strength loss ratio. Increasing the cement content and extending the curing time decreased the average number of voids, average void area, and average void diameter and decreased the mass loss ratio and strength loss ratio of the SRBMs. The top and bottom of the SRBM samples were more porous than the middle of the samples, whereas the maximum value of the average void diameter was observed in the middle of the samples. [ABSTRACT FROM AUTHOR]

The service performances of asphalt pavement, especially rutting, will be inevitably affected by climate change. However, existing studies have generally focused on the rutting depth and rutting life, and thus became insufficient for comprehensively evaluating the influence of climate change on rutting over the service life. A resilience assessment method for asphalt pavement rutting is developed to solve the above problem. First, the original resilience method is extended to fit the system whose performance level continues to decline. Then, the calculation formulas of rutting resilience are derived by combining the rutting prediction model and the level assessment model. Subsequently, the influence degrees of climate change in representative cities on rutting resilience are studied. The results suggest that neglecting climate change in rutting design of asphalt pavement will lead to insufficient resilience, especially in northern China. Furthermore, the predicted temperature under RCP8.5 should be employed for asphalt pavement design. [ABSTRACT FROM AUTHOR]

• Capture appropriate models in the discussion of TNn, TN5d and CR. • TNn and TN5d extreme events influence on pavement temperature with depth. • Identify the low-temperature performance based on winter temperature extremes. Winter temperature extremes are of major interest due to their potential damaging impacts related to pavement temperature and thermal cracking. In the present paper, three climate indices are adopted to describe the feature of winter temperature extremes. Statistical models for indices are analyzed based on the observed data in Harbin. The threshold values with their 99.9% cumulative frequency are proposed. Experiments were carried out in order to investigate the impacts of winter temperature extremes on pavement temperature and low-temperature performance of asphalt mixture. The results show that Weibull distribution is an appropriate model in the discussion of air temperature and its duration, and Frechet is the best-fitted model for the rate of air temperature change. Comparisons of experimental results indicate the importance of winter temperature extremes to asphalt pavement temperature. The influence of low-temperature properties by different temperature conditions is also analyzed. The low-temperature performance in Harbin can be accurately quantified by linear interpolation. [ABSTRACT FROM AUTHOR]