Pedro A Serigos

Incorporating Surface Microtexture in the Prediction of Skid Resistance of Flexible Pavements

Monitoring and managing the skid resistance of the highway network is necessary for controlling and reducing the number of road accidents. High-speed measurements of surface texture can be used as a surrogate parameter for controlling a pavements surface friction on the highway network. The two components of surface texture that affect skid resistance are the macrotexture and the microtexture. However, the technologies commonly used for measuring pavement texture at highway speeds account only for the macrotexture. This study explored ways to characterize the microtexture of pavement surfaces with the main objective of quantifying the effect of accounting for both components of the texture on the prediction of skid resistance, as measured by a British pendulum tester. Various methods for characterizing the microtexture were compared to determine which one better predicted surface friction. The study used field measurements of surface texture and friction performed on various in-service flexible pavements. The surface microtexture was characterized by a series of texture parameters calculated in both the spectral and the spatial domains. The impact of incorporating the microtexture on the prediction of the British pendulum number was evaluated through analysis of a series of models specified by each of the proposed parameters. The results of the analysis showed a drastic improvement in predicting the British pendulum value when the authors accounted for both components of the surface texture, as opposed to only the macrotexture. In a comparison of the analyzed methods for characterizing the microtexture, the use of spectral parameters led to the best prediction of the pavement surface friction. A series of recommendations is provided for the calculation of microtexture parameters.

Evaluation of rut-depth accuracy and precision using different automated measurement systems

Collecting accurate rutting data is important in order to assess network-level pavement conditions and to determine maintenance and rehabilitation needs and funding levels in order to optimize the use of available economic resources. The technical objective of this study was the assessment of the rut-depth (RD) accuracy and precision of different continuous automated systems (CAS), which represent the state-of-the-art for the automated data collection of rutting, and discrete automated systems (DAS), which are still used by several Department of Transportations (DOTs) in the United States. The RD values analyzed in this study were obtained by 1) field measurements at highway speeds using five different optical CAS, and 2) calculation simulating the use of DAS with different configurations. The analysis of the first type of values assessed the closeness of the RD produced by the different CAS to the RD manually measured for this study. The analysis of the second type of values assessed the effects of the number of sensors and the width of measurement on the DAS’s accuracy and precision. In addition, the impact of the RD accuracy and precision on the assessed pavement condition at network-level was analyzed for both the CAS that participated in the experiment and the simulated DAS.

RETRACTED: Accuracy and Precision Assessment of High-Speed Measurements of Pavement Surface Cracking

This paper presents an independent evaluation of the accuracy and precision of high-speed field measurements of pavement surface distresses taken by three different 3D systems that represent the state-of-the-practice of automated distress collection equipment. The analyzed distress data were collected from a field experiment that comprised twenty 550-ft test sections that included both flexible and rigid pavements. The high-speed measurements produced were compared to manual measurements taken statically by experienced raters. The paper also presents a qualitative comparison between the crack maps produced at highway speeds and digital crack maps collected statically by manual measurement of the cracks. In addition, before-and-after analyses were conducted to assess for the change in accuracy achieved after conducting a visual inspection, and manual corrections, of the automated measurements.

Performance Related Specifications Development of Hot Mix and Concrete Pavement Projects Using Field Data

Fundamental purpose any of construction specification is to ensure the expected longterm performance of the final product. Performance Related Specification (PRS) incorporates the economic implications associated with superior or inferior pavement construction practices since it translates to extended or reduced pavement service life. Generally, earlier PRS development studies were based on performance data collected from either pilot pavement construction projects or the models built based on experimental pavement sections such as MEPDG. This study primarily focuses on constructing PRS framework utilizing field performance data and actual quality control measurements obtained during road construction projects. Laboratory density of plantmix and placement density of compacted hot mix pavement and as-constructed ride quality of both hot mix and concrete pavements are identified as performance-sensitive parameters. A performance related pay adjustment scheme that is governed by these performance-sensitive quality control parameters is developed.