This paper describes the effects of reinforcement by randomly distributed nylon fibers and addition of nanoclay on some engineering properties of a typical asphalt concrete. The properties of asphalt concrete reinforced by different percentages of 25 mm nylon fibers have been compared with those of the mixtures containing different percentages of nanoclay and those in which both the fibers and ...

The National Institute for Occupational Safety and Health (NIOSH) has a partnership relationship with the asphalt paving and roofing industries and their associated unions. Our partners saw in the EHP Focus article “Paving Paradise: The Peril of Impervious Surfaces” (Frazer 2005) the statement on page A459: “Asphalt is one concern, as it contains coal tar pitch, a recognized human carcinogen .....

In this paper, annoyance ratings from traffic noise recorded on cobblestones, dense asphalt, and open asphalt rubber pavements are assessed with regard to car speeds and traffic densities. It was found that cobblestones pavements are the most annoying; also while open asphalt rubber pavement imposes less annoyance than dense asphalt it is not significantly different. Higher car speeds always le...

In addition to lower emissions warm mix asphalt has several advantages over hot mix asphalt such as fuel energy savings, decreased binder aging and an extended paving season (Photo courtesy: Matthew Corrigan, FHWA) The National Center for Asphalt Technology (NCAT) is evaluating warm mix asphalt (WMA) technologies. WMA technology allows the mixing, lay down, and compaction of asphalt mixes at si...

Asphalt pavement itself is a mixture made up of mainly aggregates, binders, and fillers that acts as a composition used for pavement construction. An experimental program was setup to determine the fatigue performance test of Asphalt with three different grades of conventional binders. Asphalt specimen has achieved the maximum optimum bulk density and air voids with a consistent bulk density of...

Conventional asphalt binder derived from the petroleum refining process is widely used in pavement engineering. However, asphalt binder is a non-renewable material. Therefore, the use of a co-production of renewable bio-oil as a modifier for petroleum asphalt has recently been getting more attention in the pavement field due to its renewability and its optimization for conventional petroleum-ba...

Adhesion between asphalt and aggregate plays an important role in the performance of asphalt mixtures. A low-frequency adhesion fatigue test was proposed in this paper to study the effect of environment on the asphalt-aggregate adhesion system. The stress-based fatigue model had been utilized to describe the fatigue behavior of thin-film asphalt and aggregate system. The factors influencing the...

Asphalt pavements undergo long-term aging due to oxidation of the asphalt binder. As a pavement oxidizes, it stiffens and eventually cracks. The use of an antioxidant in an asphalt binder could retard aging, thus increasing the pavement’s service life. Lignin is a known antioxidant and is highly available from timber and many agricultural products. A wet-mill ethanol process produces several co...

Recycling of asphalt concrete is increasingly used as a major rehabilitation method in Japan because it can conserve natural resources, reduce costs and save energy. In this study, reclaimed asphalt concrete from Tokyo International Airport was evaluated for use in four types of base materials: recycled granular material, recycled cement stabilized material, recycled cement-emulsified asphalt s...

The substantial increase in oil prices over the past few years has been reflected in asphalt prices. Moreover, the maximization of fuel production in refineries has reduced asphalt supply. These conditions have prompted the development of alternative sources of asphalt binders, including bio-oils derived from the fractionated fast pyrolysis of biomass that comes from agricultural and forestry r...