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...

Hydrogen sulfide poisoning from inhalation of roofing asphalt fumes is a rare but devastating injury. Two cases of toxic inhalation involving exposure to several gases, including hydrogen sulfide, evolved from cooling asphalt, are presented. Both victims were treated with supportive measures, including 100% normobaric oxygen, and one also received sodium nitrite. In one patient rapid, complete ...

Environmental and health aspects of road materials have been discussed for a long time, mostly regarding bitumen and bitumen fumes. However, just a few studies on other types of road materials have been reported. In this doctoral study, two types of materials, asphalt release agents and bituminous sealants, were investigated with regard to chemical characterization and emission profiles. Beside...

This work addresses the development and assessment of a fiber optical viscometer using a simple and low-cost long-period fiber grating (LPFG) level sensor and a capillary tube mechanism. Previous studies of optical viscosity sensors were conducted by using different optical sensing methods. The proposed optical viscometer consists of an LPFG sensor, a temperature-controlled chamber, and a cone-...

Preliminary notes In the course of court trials and for the purpose of legal proceedings, forensic engineers often produce estimations of the explosive mass based on the explosion effect using empirical formulas. This paper describes experimental surface explosions of variable mass of known explosive charge on the asphalt with the objective to make correlations between causes and consequences o...

Work in the asphalt industry has been associated with nonmalignant respiratory morbidity and mortality, but the evidence is not consistent. A historical cohort of asphalt workers included 58,862 men (911,209 person-years) first employed between 1913 and 1999 in companies applying and mixing asphalt in Denmark, Finland, France, Germany, Israel, the Netherlands, and Norway. The relations between ...

For many years, the asphalt industry has been aware of the energy savings and environmental benefits inherent in cold mix or warm mix asphalt technologies. Environmental awareness and the need for improved energy efficiency has increased rapidly over the past few years and extensive measures such as the air pollution reduction targets set by the European Union under the Kyoto Protocol have enco...