The conventional French fatigue test has yielded significantly different results for two asphalt materials with the same grade of pure asphalt. A research program was begun to study the influence of the asphalt nature on the fatigue behavior of asphalt materials. The program included full-scale experimentation on the circular test track of the Laboratoire Central des Ponts et Chaussees, laborat...

BACKGROUND Asphalt workers are exposed to bitumen fume and vapour, and to exhaust from engines and passing traffic. AIMS To assess the occurrence of respiratory symptoms and signs of airflow limitations in a group of asphalt workers. METHODS All 64 asphalt workers and a reference group of 195 outdoor construction workers from the same company participated in a cross-sectional study. Spirome...

Over the past decade, the Texas Department of Transportation (TxDOT) focused research efforts on improving hot mix asphalt concrete (HMAC) mix design to preclude rutting in the early life of pavements. However, these rut-resistant stiff mixtures may be susceptible to long-term fatigue cracking due to oxidative aging. This project completed initial development of an HMAC mixture fatigue design a...

This study integrates ground spectrometry, imaging spectrometry, and in-situ pavement condition surveys for asphalt road assessment. There is strong spectral evidence for asphalt aging and deterioration processes, hence field spectra showed that asphalt aging and deterioration produce measurable changes in spectra as these surfaces undergo a transition from hydrocarbon dominated new roads to mi...

In this paper, it has been attempted to evaluate the performance of asphalt overlays which were reinforced with geogrid, modified by sasobit and combination of them on rehabilitation of reflective cracking. The laboratory tests under dynamic loading in bending mode were conducted to investigate reflective cracking retardation compared to reference samples. The results illustrated that in a cert...

Rutting is one of the major distresses in the flexible pavements, which is heavily influenced by the asphalt mixtures properties at high temperatures. There are several methods for the characterization of the rutting resistance of asphalt mixtures. Flow number is one of the most important parameters that can be used for the evaluation of rutting. The flow number is measured by the dynamic creep...

This project has two main objectives; the first is to documents the effect of a porous friction course overlay on the quality of highway stormwater runoff, and the second is to assess pollutant removal of a vegetated area along the side of a road from both conventional and porous pavements. The quantity and quality of stormwater runoff from a four-lane divided highway in the Austin, Texas, area...

The objective of this study is to evaluate the rheological properties and chemical bonding of nano-modified asphalt binders blended with nanosilica. In this study, the nanosilica was added to the control asphalt at contents of 4% and 6% based on the weight of asphalt binders. Superpave binder and mixture tests were utilized in this study to estimate the characteristics of the nano-modifed aspha...

Properties of cement-stabilized gravel modified by emulsified asphalt under freezing and thawing cycle conditions were investigated by adjusting the dosage of cement. Mercury intrusion porosimetry (MIP) and Scanning electron microscopy (SEM) were introduced to analyze the influential mechanism. The results indicate that cement emulsified asphalt stabilized gravel with 5 wt % of cement performed...