The performance models used in the Mechanistic-Empirical Pavement Design Guide (MEPDG) are nationally calibrated with design inputs and performance data obtained primarily from the national Long-Term Pavement Performance database. It is necessary to verify and calibrate MEPDG performance models for local highway agencies' implementation by taking into account local materials, traffic informatio...

This brief provides findings on the observed effect of initial pavement smoothness (also known as initial roughness, or as-constructed roughness) on the long-term pavement roughness progression of asphalt overlays. The relationship can be used as a measure for estimating the long-term effect of pavement smoothness and for consideration when developing smoothness specifications and/or payment ad...

Long-term oxidative ageing occurs in asphalt pavements when they are exposed to the ambient environment for extended periods. This phenomenon is dependent on multiple physical fields, including heat transfer, oxygen diffusion from air into interconnected voids of pavement, void channels mastic inside, and growth oxidation products bitumen. Most existing models were established via coupling limi...

Many agencies use the AASHTO Guide for Design of Pavement Structures to design their pavement systems. The limitation inherent in this method is the empirical nature of the decision process, which was derived from a road test conducted almost 45 years ago in Ottawa, Illinois. The newly released Mechanistic-Empirical Pavement Design Guide (MEPDG), based on NCHRP Study 1-37A, has adopted a mechan...

Government agencies and transportation engineers use pavement management systems (PMS) to evaluate performance keep above the minimum acceptable standards. The Pavement Condition Index (PCI) international roughness index (IRI) are among most commonly used indices conditions. Due IRI data collection being more accessible less expensive than collecting distress data, this study aims develop PCI m...

For analysis, design, and rehabilitation purposes of flexible pavements, the temperature profile asphalt layers should be determined. The predictive models as an alternative to in-situ measurements, are rapid easy methods determine layer at various depths. These developed based on limited field data. Hence, there is a need for developing new prediction in climatic regions. In this study, data w...

Rubblization is one of the surface preparation techniques before placing a Hot Mix Asphalt (HMA) overlay that involves breaking the Portland Cement Concrete (PCC) pavement into pieces. This paper describes the structural assessment related to the long term performance of rubblized concrete pavements in Iowa. The structural performance of seven representative in-service rubblized concrete paveme...

The study presented in this paper analyzed four long-term pavement performance (LTPP) test sections located the states of New York (NY) and California (CA). Two them are flexible sections, whereas other two composite sections. levels analysis—in-state analysis cross-state analysis—were performed for these to determine impacts traffic climate conditions. was evaluated respect thermal cracking ru...

BACKGROUND In 2008, Leichsenring and Rabung performed a meta-analysis of 8 studies of longer-term psychodynamic psychotherapy (LTPP). The work was published in the Journal of the American Medical Association (vol. 300, pp 1551-1565), and they concluded that LTPP was more effective than shorter-term therapies. METHOD Given that such claims have the potential to influence treatment decisions an...

Abstract Climate attributes such as precipitation, extreme temperature, and freeze-thaw cycles along with traffic loads cause pavement distresses. The maintenance need for pavements is decided based on the condition rating International Roughness Index (IRI). Generally, an IRI less than 2.68 m/km acceptable, a greater considered unacceptable classified “very poor” of pavement. It imperative to ...