This report evaluates the effectiveness of rubber-asphalt and ebonite-asphalt mixes based on a review of published literature and unpublished reports. It discusses in detail various aspects of these mixes, including: diffe ent applications, physical properties, experiences of state highway agencies, and claimed advantages and problems associated with their use. The addition of ground tire rubbe...

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 ...

Abstract In order to explore the rheological properties of high content warm mix recycled asphalt binder, was added into prepare asphalt. The optimum regenerant and Sasobit REDUX determined by basic performance test temperature scanning test. chemical composition studied FITR. low crack resistance were analyzed DSR BBR tests, determined. results show that when is 10%, its recovers level base ca...

This study presents a finite element (FE) micromechanical modelling approach for the simulation of linear and damage-coupled viscoelastic behaviour of asphalt mixture. Asphalt mixture is a composite material of graded aggregates bound with mastic (asphalt and fine aggregates). The microstructural model of asphalt mixture incorporates an equivalent lattice network structure whereby intergranular...

Language: English The Challenge At the outset the asphalt paving process seems to be simple. Trucks deliver hot mix asphalt from plants to the construction site. There the asphalt is loaded on asphalt pavers that evenly spread the asphalt. Finally, compactors compact the asphalt to its required density. Despite this relatively structured process our research shows that there are significant dis...

BACKGROUND Asphalt workers are exposed to bitumen fume and vapour, and to exhaust from engines and passing traffic. AIMS To assess the occurrence of respiratory symptoms and signs of airflow limitations in a group of asphalt workers. METHODS All 64 asphalt workers and a reference group of 195 outdoor construction workers from the same company participated in a cross-sectional study. Spirome...

We report on dry asphalt roads acting as 'mayfly traps'; that is, they lure swarming, mating and egg-laying mayflies in large numbers. To explain this surprising behaviour, we performed multiple-choice experiments with Ephemeroptera in the field, and measured and compared the reflection-polarization characteristics of an asphalt road and a mountain creek from which mayflies emerge. We show here...

The National Center for Asphalt Technology (NCAT) completed a roundrobin study in March to determine the accuracy and precision of the NCAT asphalt content tester. The Center has conducted research since 1990 to develop this test method for determining asphalt content of hot mix asphalt (HMA) mixtures by ignition (See the fall, 1994, issue of Asphalt Technology News). In the ignition method, a ...

Research on waste tire pyrolysis carbon black (PCB) in bitumen mixtures indicates that it has excellent high-temperature rutting resistance; however, the degradation of low-temperature crack resistance and water stability PCB-modified asphalt limits its wide application. Therefore, hot-mix (HMA) were enhanced by addition chicken feather (WCF). Based response surface methodology (RSM), a varianc...

This paper characterizes the effects of artificial short term aging in the laboratory on the rheological properties of virgin 80/100 penetration grade asphalt binder. After several years in service, asphalt mixture started to deteriorate due to aging. Aging is a complex physico-chemical phenomenon that influences asphalt binder rheological properties causing a deterioration in asphalt mixture p...