One of the main objectives of the top asphalt layer is to provide a protective surface against water penetration and other harmful liquids such as chemicals. However, current construction equipments do not provide finished asphalt surfaces that meet this quality and therefore, allowing the intrusion of several liquids through the asphalt layers and deeper into the underlying soils. Subsequently...

PROBLEM STATEMENT When designing and evaluating asphalt pavements, engineers must have an understanding of how the pavement materials will react to the stresses and strains of vehicle loads at varying temperatures. When a load is applied to asphalt concrete at a certain temperature, to what degree will the pavement "bounce back" to its original height? Pavement designers predict this spring-lik...

Permeability of an asphalt pavement is one of the most important parameters that have a direct influence on its design life. It is an intrinsic property that relates the average fluid velocity to a constant pressure gradient; however, the external pressures on a saturated pavement pore structure are often dynamic due to the repeated tire loading in the field. A dynamic permeability constant, th...

Class C fly ash is a coal combustion product normally produced from lignite or subbituminous coal obtained as a result of the power generation process. In recent years, efforts were taken to incorporate self-cementing fly ash into full-depth reclaimed (FDR) asphalt pavements to improve the structural capacity of asphalt pavement base layers. In this study, an existing asphalt pavement in County...

The fatigue cracks are observed in asphalt surfaces much more than ruts. This paper deals with the influence of carbon nano-tube on the fatigue life of asphalt mixtures. These samples are made up of the slabs cut by the asphalt cutting saw. Fatigue beams contain 0, 0.3, 0.6, 0.9, 1.2, and 1.5 percent of Carbon Nano-tube. The fatigue experiment was conducted using a 4-point semi-sinusoidal loadi...

A pavement structure consists of several layers for the primary purpose of transmitting and distributing traffic loads to the subgrade. Rutting is one form of pavement distresses that may influence the performance of road pavements. Geosynthetics is one type of synthetic materials utilized for improving the performance of pavements against rutting. Various studies have been conducted on using d...

in this study, an artificial neural network was developed in order to analyze flexible pavement structure anddetermine its critical responses under the influence of standard axle loading. in doing so, more than 10000four-layered flexible pavement sections composed of asphalt concrete layer, base layer, subbase layer, andsubgrade soil were analyzed under the impact of standard axle loading. pave...

this paper identifies eleven types of asphalt pavement distress types, commonly occuring in tehran metropolitan area. of these, five distresses namely: corrugation; utility cut depression ;pot holes; alligator cracking; and loss of bridge deck surfacing are rather common. however, others namely: shear failure; shrinkage cracks; lane joint cracks; bleeding; and shoulder distress are less prevail...

The performance of asphalt binders at high and low temperatures has an important role on the rutting and crackingresistance of asphalt pavements. Crumb Rubber Modified (CRM) is one of the asphalt modifiers that improves asphaltphysical and mechanical properties and helps reducing environmental pollution. In this research, three unmodifiedand six CRM modified binders were teste...

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 ...