This paper provides an incremental layerwise finite element formulation for the viscoelastic analysis of multilayered pavements.  The constitutive behavior of asphalt concrete is represented by the Prony series. Layerwise finite element has been shown to provide an efficient and accurate tool for the numerical simulation of laminated structures. Most of the previous research on numerical simula...

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...

This report provides a summary of the results of the various studies completed in the Partnered Pavement Research Program (PPRC) during the period 2000–2004. In addition, preliminary findings of investigations, initiated but not yet implemented during this period, are included. The results are based on the combined results of analytical developments, laboratory testing of pavement materials, an...

A significant problem associated with asphalt concrete mixtures is the lack of durability resulting from an inadequate asphalt cement content. Additional asphalt cement added to increase durability results in flushing, bleeding and a significant loss In stability. Fibers have been used in stone matrix asphalt and open-graded friction course pavements successfully throughout Europe to allow high...

air cooled blast furnace slag is a by product made of gradually air cooled molten blast furnace slag, and is often stored in stockpiles near the iron mills and usually occupy a wide area around the iron mills. from this perspective the further use of these materials can have its own merits. air cooled blast furnace slag can be used in asphalt mixtures because of their proper frictional properti...

the available methods for predicting mechanical characteristics of pavement layers are categorized into two general groups, destructive and non-destructive. in destructive method, using coring and pavement subgrade and performing necessary experiments on them, the quantities of layers properties will be identified. in non-destructive method, the attained deflection is measured by applying the l...

Chemical deicing plays a fundamental role for traffic safety on roads and runways in winter season. Traditional deicing chemicals, such as sodium chloride and urea have, however, undesirable effects on surface and ground waters. For more sustainable road and runway winter maintenance, easily biodegradable organic salts such as acetates and formates, have been proposed and taken into use. Next t...

This study explored the feasibility of lignin based biofuel co-product (BCP) for subgrade soil stabilization, and more specifically, its impact on Hot-Mix Asphalt (HMA) pavement performance using the Mechanistic-Empirical Pavement Design Guide (MEPDG). The HMA pavement systems with BCP stabilized subgrade under different traffic and climate conditions were modeled using mechanistic based damage...

External pressures applied to a saturated pavement pore structure are often dynamic due to the repeated tire loading. Therefore, a dynamic permeability constant is more realistic representation of the response of a pavement pore structure than the Darcy’s permeability. To investigate the unsteady (dynamic) fluid flow in asphalt pavements, a 3D fluid flow model was developed using the lattice Bo...

The objective of this study is to review existing literature in the area of nano-modification of asphalt and proceed to apply nano-materials to asphalt to improve the performance. This study integrates literature review, preparation, and characterization of nano-modified asphalt materials. In the experimental testing montmorillonite, nanoclay at 2% and 4% by weight of asphalt was blended in asp...