This study introduces Virginia's efforts to apply high-speed texture measurement as a tool to improve the uniformity of hot-mix asphalt (HMA) pavements. Three approaches for detecting and quantifying HMA segregation through measuring pavement surface macrotexture were evaluated: (1) applying the methods proposed in NCHRP Report 441, which build on the ability to predict the expected "non-segregated" macrotexture; (2) using acceptance bands for texture similar to those used for HMA density; and (3) considering the standard deviation of the macrotexture as a measure of construction uniformity. Based on the findings from a series of field tests, the researchers concluded that macrotexture measurement holds great promise as a tool to detect and quantify segregation for quality assurance purposes. None of the available equations for predicting non-segregated macrotexture (the approach in NCHRP Report 441) was found to work for all the construction projects evaluated. Additional information is necessary to establish target macrotexture levels. The acceptance bands approach produced reasonable results in most of the field-verification experiments, but it was significantly influenced by the actual variability within the section. An approach that used target levels of standard deviations was selected for further testing and implementation on a pilot basis

This research was conducted to study more realistic explanations of how variables are created and dealt with during hot mix asphalt (HMA) paving construction.--P. ii.

Previous research indicated that density, gradation, and asphalt content change due to segregation. A rolling nuclear gage capable of measuring both density and hydrogen count was evaluated for its ability to detect and measure both density and asphalt content. Eight projects (four recently constructed pavements and four during construction) were used to evaluate this instrument. Longitudinal density profiles were obtained for each project at transverse quarter points across the lane. Additional testing included infrared thermography and traditional destructive testing of cores.

Structural Behavior of Asphalt Pavements provides engineers and researchers with a detailed guide to the structural behavioral dynamics of asphalt pavement including: pavement temperature distribution, mechanistic response of pavement structure under the application of heavy vehicles, distress mechanism of pavement, and pavement deterioration performance and dynamic equations. An authoritative guide for understanding the key mechanisms for creating longer lasting pavements, Structural Behavior of Asphalt Pavements describes the intrinsic consistency between macroscopic performance and microscopic response, structure and material, as well as global and local performances, and demonstrates the process of pavement analyses and designs, approaching science from empirical analyses. - Analyzes the external and internal factors influencing pavement temperature field, and provide a review of existing pavement temperature prediction models - Introduces a "Bridge Principle through which pavement performance and fatigue properties are consolidated - Defines the intrinsic consistency between macroscopic performance and microscopic response, structure and material, as well as global and local performance - Summaries the mechanistic response of pavement structure under the application of heavy vehicle, distress mechanism of pavement, pavement deterioration performance and dynamic equations, and life cycle analysis of pavement