Resistance to Compaction of Asphalt Paving Mixtures and Its Relationship to Stiffness

2008 ◽  
pp. 131-131-15 ◽  
Author(s):  
AF Bissada
Keyword(s):  
Asphalt Paving

Asphalt paving produced to carry 20th-century truck traffic

2020 ◽  
pp. 137-149
Author(s):  
Maxwell Lay ◽  
Metcalf John ◽  
Sharp Kieran
Keyword(s):  
20Th Century ◽  
Truck Traffic ◽  
Asphalt Paving

Data Mining Statewide Department of Transportation Volumetrically Designed Asphalt Mixture Records

2021 ◽  
pp. 036119812110613
Author(s):  
Ben C. Cox ◽  
Jonathan Easterling ◽  
W. Griffin Sullivan ◽  
Alex Middleton ◽  
Isaac L. Howard
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Mechanical Tests ◽  
Unintended Consequences ◽  
Mix Design ◽  
Department Of Transportation ◽  
Database Analysis ◽  
Societal Pressure ◽  
Asphalt Content ◽  
Asphalt Paving

In recent years, the asphalt paving industry has been strained by numerous factors including increased asphalt binder costs, funding that has not kept up with material costs, increased societal pressure to recycle, and deteriorating pavement networks. Mix design should account for the market in which it is used, which is very different now than when today’s volumetric mix design practices were developed (many of the aforementioned factors were less present). Given this reality, a statewide database of all 1,452 approved mix designs in Mississippi from 2005 to 2018 was compiled and analyzed, and the objective of this paper is to present findings, trends, and unintended consequences of exclusive reliance on volumetrics. With volumetrics-only mix design, asphalt content is primarily controlled by voids in mineral aggregate (VMA), which is influenced by aggregate bulk specific gravity (Gsb). Minor Gsb deviations (i.e., within AASHTO d2 s limits), can significantly affect VMA, so much so that 99% of Mississippi’s mixes could be failing VMA while reported VMA passes. This allows mix manipulation and economization, with 0.8% asphalt content reductions possible while still meeting volumetric requirements. Recycled materials can exacerbate this issue, and common approaches to increase asphalt content (decreasing design gyration level or using finer gradations) are ineffective with fixed VMA requirements. Overall, the mix design database analysis agrees with numerous smaller studies but does so with an entire state’s actual practice. This presents a compelling case that volumetrics-only mix design has limitations, and supports ongoing efforts to reintegrate mechanical tests.

scholarly journals Preparation and characterisation of modified reclaimed asphalt using nanoemulsion acrylate terpolymer

2019 ◽  
Vol 48 (5) ◽  
pp. 363-374 ◽  
Author(s):  
Abdelrahman Moukhtar Naser ◽  
Hamada Abd El - Wahab ◽  
Mohamed Abd El Fattah Moustafa El Nady ◽  
Abdelzaher E.A. Mostafa ◽  
Long Lin ◽  
...  
Keyword(s):  
Hot Mix Asphalt ◽  
Fourier Transforms ◽  
Thermo Gravimetric Analysis ◽  
Thermoplastic Elastomer ◽  
Warm Mix Asphalt ◽  
Gravimetric Analysis ◽  
Content Type ◽  
Reclaimed Asphalt ◽  
Asphalt Paving ◽  
Modified Binder

Purpose This paper aims to investigate the best methods of utilisation of reclaimed asphalt pavements (RAP) in Egypt, to determine the effect of using 100% RAP instead of using virgin aggregates and asphalt; investigate the effect of thermoplastic elastomer polymer as asphalt modifier; and also improve the mechanical and physical characteristics and consequently improving the quality of asphalt paving, increasing service life of asphalt-paving and reducing costs. Design/methodology/approach Nano acrylate terpolymers were prepared with different % (Wt.) of and were characterised by Fourier transforms infrared (FTIR), for molecular weight (Mw), by thermo gravimetric analysis (TGA) and by transmission electron microscopy (TEM). A 4% (Wt.) of the prepared nanoemulsion terpolymer was mixed with virgin asphalt as a polymer modifier, to improve and reuse of the RAP. The modified binder was tested. The tests conducted include penetration, kinematic viscosity, softening point and specific gravity. Application of Marshall mix design types; hot mix asphalt (HMA), warm mix asphalt (WMA) and cold in place recycled (CIR). Four different mix designs used; control mix contained virgin asphalt by HMA, and the other three mix designs were polymermodified asphalt sample by HMA, WMA and CIR. Findings The research results showed that using 4 Wt.% of the prepared nanoemulsion terpolymer to produce hot mix asphalt (HMA) and warm mix asphalt (WMA) achieved higher stability compared to the control mix and cold in place recycled (CIR). Research limitations/implications This paper discusses the preparation and the characterisation of nanoemulsion and its application in RAPs to enhance and improve the RAP quality. Practical implications Nano-acrylate terpolymer can be used as a new polymer to modify asphalt to achieve the required specifications for RAP. Originality/value According to the most recent surveys, Europe produced 265 tonnes of asphalt for road applications in 2014, while the amount of available RAP was more than 50 tonnes. The use of RAP in new blended mixes reduces the need of neat asphalt, making RAP recycling economically attractive.

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