, Professor, Civil, Environmental and Geo-Engineering
Heinz Stefan, Former Researcher, Civil, Environmental and Geo-Engineering
A major task in any transportation agency pavement management system is selecting the appropriate alternative for rehabilitation and maintenance, whether preventive or corrective. While deterioration models for classical pavement design are well-established, the models for rehabilitation are less understood due to the lack of performance data available and lack of understanding surrounding the fundamental mechanism related to various rehabilitation procedures. This work investigated the use of surface treatments to delay the aging process in the asphalt surface and to mitigate the formation of microcracks that lead to pavement deterioration. Both traditional and nontraditional pavement material characterization methods applied. The nontraditional methods consisted of X-Ray Photoelectron Spectroscopy (XPS) for quantifying aging; for microcracks detection, electron microprobe imaging test (SEM) and fluorescent dyes for inspection of cracking were investigated. The spectral analysis of asphalt pavements to determine aging was also presented. Traditional methods, such as Bending Beam Rheometer (BBR), Direct Tension (DTT), Dynamic Shear Rheometer (DSR) and Fourier Transform Infrared Spectroscopy (FTIR) for asphalt binders and BBR and Semi-Circular Bending (SCB) for mixtures were used to determine the properties of the field samples studied in this effort. In addition, a substantial analysis of measured pavement temperature data from MnROAD and simulations of pavement temperature using a one-dimensional finite difference heat transfer model were performed. The experimental work and analyses will provide scientific support in the development of optimum timing for application of surface treatments.