The Fremont Bridge is steel tied arch bridge over the Willamette River in Portland, Oregon. It carries traffic on Interstate 405 and US Highway 30 between downtown and north Portland. . The bridge was constructed in 1973, and the paving on the original steel deck consisted of epoxy asphalt concrete followed by an asphalt concrete overlay. The pavement performed for nearly 40 years before it nee...

The present experimental research investigates the feasibility of partial substitution of styrene-butadiene-styrene (SBS) with ground granulated blast-furnace slag (GGBS) for the modification of bitumen and porous asphalt mixtures. The control asphalt mixture and the seven modified porous asphalt mixtures have been analyzed separately and their performance was compared. Modified bitumen and asp...

BACKGROUND Controversy exists as to the potential of asphalt fumes to induce respiratory symptoms and lung functional impairments. OBJECTIVE To examine the respiratory effects, if any, of occupational inhalation exposure to asphalt fumes. METHODS In this cross-sectional study, 74 asphalt workers and 110 unexposed employees were investigated. The prevalence of respiratory symptoms among subj...

Rutting is one of the most important distresses in asphalt pavements due to its frequency. Rutting or channeling, could be classified in three types: 1) mechanical deformation (rutting in subgrade or base), 2) plastic flow (unstable asphalt layer), and 3) wheel path consolidation. The plastic flow of bituminous mixture depends on many factors; one of this is the type of asphalt used in the mixt...

Basic oxygen furnace slag (BOF) is widely used in road construction, but there is a lack of characteristics in different asphalt mixtures. This study investigates the properties of hot-mixed asphalt (HMA), containing stone mastic asphalt (SMA), porous asphalt (PA), and dense-graded BOF as a partial substitution for natural aggregates. The purpose of this study is to evaluate various BOF slag co...

Marshall Test design methods are used to design TLA modified asphalt mixture and base asphalt mixture respectively, and their pavement performance is tested. The results showed that there is a transforming coefficient of 1.15 between OAC of 40% TLA modified asphalt mixture and that of base asphalt mixture, and ultimate gradation of the TLA modified asphalt mixture is finer than previous gradati...

The basic oxygen furnace slag (BOF) was wide used in road construction, but there was a lack of characteristics in different asphalt mixtures. This study investigates the properties of hot-mixed asphalt (HMA) containing stone mastic asphalt (SMA), porous asphalt (PA) and dense-graded BOF as a partial substitution for natural aggregates. The purpose of this study is to evaluate various BOF slag ...

BACKGROUND Asphalt workers are exposed to polyaromatic hydrocarbons (PAHs) from hot mix asphalt via both inhalation and dermal absorption. The use of crumb rubber modified (CRM) asphalt may result in higher exposure to PAHs and more adverse effects. Our aim is to assess occupational exposure to PAHs from conventional and CRM asphalt paving by measuring PAH metabolites in urine, and to investiga...

To solve the problem of rutting and fatigue damage to asphalt pavement, rutting and fatigue performances of Qingchuan rock asphalt modified asphalt were studied, based on the dynamic shear rheometer test, the dynamic creep test, the rutting test, the indirect tensile fatigue test, the small-sized acceleration loading test, the compressive resilient modulus test, the BISAR3.0 Program and the rut...

The central purpose of the research is to support the California Department of Transportation (Caltrans) Quieter Pavement Research Program, which has as its goals and objectives the identification of quieter, safer asphalt pavement surfaces. The research conforms with Federal Highway Administration (FHWA) guidance provided to state departments of transportation (DOTs) that conduct tire/pavement...