In this study, stiffness modulus parameters of asphalt concrete were determined experimentally for different temperature and exposure times. The stiffness modules were calculated according to Nijboer stiffness module. Basic physical properties and the quantity of bitumen of asphalt core samples were designated for determining the stiffness modules. The samples were exposed to 17 C (reference te...

This study examined the long-term effectiveness of permeable pavement as an alternative to traditional impervious asphalt pavement in a parking area. Four commercially available permeable pavement systems were evaluated after 6 years of daily parking usage for structural durability, ability to infiltrate precipitation, and impacts on infiltrate water quality. All four permeable pavement systems...

The Arizona Department of Transportation (ADOT) has used crumb rubber from ground tires since the late 1960's to primarily reduce reflective cracking. In 1988, ADOT started to use crumb rubber mixed with hot asphalt, commonly referred to as asphalt rubber (AR) as a binder in hot mix asphalt (HMA). Typically, these mixes are either open-graded or gap-graded and from half inch to one inch or one ...

In this paper, the possibility of improving the global response of asphalt materials for pavement applications through the use of hydrated lime and Electric Arc-Furnace Steel Slag (EAFSS) was investigated. For this purpose, a set of asphalt mortars was prepared by mixing two different asphalt binders with fine granite aggregate together with hydrated lime or EAFSS at three different percentages...

The building code for radon prevention and the associated practical guidelines were revised in Finland in 2003-2004. Thereafter, preventive measures have become more common and effective and indoor radon concentrations have been markedly reduced. In this study, the indoor radon concentration was measured in 1500 new low-rise residential houses. The houses were randomly selected and represented ...

Heavy oil and bitumen are a potential alternative energy source to conventional light crude. However, recovery of these resources can have substantial environmental impact. Downhole upgrading offers the prospect of both improving recovery, and decreasing environmental impact. However, use of catalysts to enhance downhole upgrading is limited by the need for one that can survive the extreme coki...

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...

Steel slags are the major byproduct from the conversion of iron to steel in the basic oxygen (major type), electric arc and open hearth (minor type) steelmaking processes. Steel recovery from the slag results in a processed aggregate with both positive (wear resistant, skid resistant, rough textured, angular, well graded, stripping resistant) and negative (heavy, expansive) features. Considerab...

Historically, research has shown that it is neither physically possible nor economically feasible to construct an asphalt concrete pavement surface that provides skid resistance at an adequate level throughout the pavement's service life. Consequently, engineers utilize a seal coat maintenance technique as one way of improving friction performance on roadways. This maintenance technique consist...