Asphalt pavement recycling has grown dramatically over the last few years as the preferred way to rehabilitate existing asphalt pavements. Rehabilitation of existing asphalt pavements has employed different techniques; one of them, cold in-place recycling with foamed asphalt (CIR-foam), has been effectively applied in Iowa. However, Iowa’s current cold in-place recycling (CIR) practice utilizes...

Nanoclays are new generation of processed clays of interest in a wide range of high performance composites. In other words, nanoclay is defined as a clay that can be modified to make the clay complexes compatible with organic monomers and polymers. Here, it can be said that the polymeric nanocomposites are among the most exciting and promising classes of materials discovered recently. A number ...

MATERIALS Pavement Core Samples COAL TAR AND ASPHALT CEMENT SAMPLES METHODS OF ANALYSIS Binder Content PAH Analysis Analysis of Phenols Modified Ames Assay RESULTS Coal Tar and Asphalt Cement Core Sample Analyses COMPARISON OF CORE SAMPLES WITH U.S. AND EUROPEAN ASPHALT AND COAL TARS COMPARISON OF DIN METHOD FOR PHENOLS WITH THE CORE SAMPLES COMPARISON OF MODIFIED AMES TEST RESULTS DISCUSSION C...

rutting of hot mix asphalt pavements due to increased number of heavy vehicles, especially in tropical regions, causes several performance problems. large stone asphalt mixtures have more stiffness and shear resistance and so more rutting resistance compared to conventional mixtures. hence, using these mixtures in thick layers of hot mix asphalt pavements at tropical regions could be an appropr...

Recycled aggregate pavement in bituminous can be repercussion to mitigation the exhaustion of rudimentary and asphalt, orientation alleviation quantities tailings organized into garbage dumps. This research aimed investigate performance Hot Mix Asphalt (HMA) surface with recycled concrete (RCA) as a replacement natural aggregates (NA) four substitution rates (0, 20, 40, 60) % from coarse aggreg...

Asphalt paving is a specific type of construction work: the machines and materials constantly move while the asphalt mixture constantly cools down. The machine operators do have a clear goal – to provide an equally distributed and uniformly compacted asphalt layer in time-restricted conditions. But what does it mean in particular? In reality, the asphalt should be compacted to a certain degree ...

US transportation agencies have been increasingly using recycled asphalt shingles (RAS) in hot mix asphalt (HMA) applications over the last 25 years. Initial use of RAS started with recycled postmanufacturers shingles, but now agencies are showing a growing interest in using post-consumer (tear-off) RAS in asphalt applications. Post-consumer asphalt shingles typically have 20 to 30 percent asph...

US transportation agencies have been increasingly using recycled asphalt shingles (RAS) in hot mix asphalt (HMA) applications over the last 25 years. Initial use of RAS started with recycled postmanufacturers shingles, but now agencies are showing a growing interest in using post-consumer (tear-off) RAS in asphalt applications. Post-consumer asphalt shingles typically have 20 to 30 percent asph...

Recent research shows that macro-scale cracking in asphalt binder may originate from its intrinsic defects at the nano-scale. In this paper, a molecular dynamics (MD) simulation was conducted to evaluate the nucleation of natural defects in asphalt. The asphalt microstructure was modeled using an ensemble of three different types of molecules to represent a constituent species: asphaltenes, nap...

To evaluate the condition of asphalt pavement road, two GPR systems with different frequency band were mounted in the trailer type vehicle. The GPR system with higher frequency band was used to measure the thickness of the asphalt layers and the other system with lower frequency band was used to detect the air cavity located beneath the asphalt pavement.