Rubblization is considered one of the sustainable surface preparation techniques before placing a hot mix asphalt (HMA) overlay that involves breaking the concrete pavement into pieces. The design of the structural overlay thickness for rubblized projects is difficult as the resulting structure is neither a true rigid pavement nor a true flexible pavement. The most important aspect of the desig...

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...

It is well known that the performance of hot mix asphalt (HMA) in service life is closely related to a proper aggregate gradation. A laboratory study was conducted to investigate the effects of nominal maximum aggregate size (NMAS) on the performance of stone matrix asphalt (SMA). The volumetric characteristics and performance properties obtained from wheel tracking tests, permeability test, be...

Historically, research has shown that it is neither physically possible nor economically feasible to construct an asphalt concrete pavement surface that provides skid resistance at an adequate level throughout the pavement's service life. Consequently, engineers utilize a seal coat maintenance technique as one way of improving friction performance on roadways. This maintenance technique consist...

this paper aims to assess the application of support vector machine (svm) regression in order to analysis flexible pavements. to this end, 10000 four-layer flexible pavement sections consisted of asphalt concrete layer, granular base layer, granular subbase layer, and subgrade soil were analyzed under the effect of standard axle loading using multi-layered elastic theory and pavement critical r...

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 .....

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...

Environment conservation and diminishing natural resources caused an increase in popularity of the application of renewable bio-origin resources for the construction of road pavement. Currently, there are known additions of bio-origin materials for bitumen modification. Such material is also used as a flux additive for bitumen or as a rejuvenator once working with reclaimed asphalt pavement (RA...

—Continued on Pg. 2 The new Preservation Group (PG) experiment will provide answers for cash-strapped state and local agencies that need cost-effective ways to maintain existing asphalt roadways. Budgets are tight, but agencies still have the same task: keeping aging pavements in good condition for the driving public. When applied at the right time, pavement preservation treatments, such as chi...