Designing, Producing, and Constructing Fine-Graded Hot Mix Asphalt on Illinois Roadways

Buttlar, William; Na Chiangmai, Chaiwat; Al-Qadi, Imad L.; Murphy, T.R.; Pine, W.J.

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https://hdl.handle.net/2142/74921 Copy

Description

Title

Designing, Producing, and Constructing Fine-Graded Hot Mix Asphalt on Illinois Roadways

Author(s)

• Buttlar, William
• Na Chiangmai, Chaiwat
• Al-Qadi, Imad L.
• Murphy, T.R.
• Pine, W.J.

Issue Date

2015-04

Keyword(s)

• aggregate
• asphalt concrete
• Bailey Method
• coarse-graded asphalt mixtures
• fine-graded asphalt mixtures
• hot mix asphalt

Geographic Coverage

Illinois

Abstract

Fine-graded (F-G) asphalt concrete mixtures are composed of an aggregate structure in which the fine fraction controls the load-carrying capacity of the mix. Other states have reported benefits in using F-G mixtures, including improved compaction, lower segregation, and lower permeability—resulting in longer life. Rutting concerns have been mitigated through the use of manufactured sand. This study investigates the feasibility of using F-G mixtures for IL 19.0 mm (3/4 in) asphalt binder courses in Illinois. A careful laboratory investigation, including mix designs guided by the Bailey Method, was conducted, then followed by extensive laboratory performance testing. Performance tests indicated that the F-G mixtures had equivalent or superior rut and crack resistance to a reference coarse-graded (C-G) control mixture. Limited field trials demonstrated the F-G mixtures were easier to compact, led to higher pay factors, and had significantly lower permeability than traditional C G mixtures, while being similar in cost. Whether designing a coarse- or fine-graded mixture, optimum asphalt content will be the same when using the same materials and targeting the same VMA and voids level, provided asphalt absorption remains constant. Limited full-scale accelerated pavement tests also demonstrated similarity in rutting resistance between the C-G and F-G mixtures investigated. Recommendations for implementation of F-G mixtures are provided, along with a revised draft specification for 19.0 mm mixtures. The revised specification provides upward adjustments to the lower side of the gradation band at the primary control sieve to lessen the likelihood of designing segregation-prone binder mixtures and raises the upper band to permit F-G mixtures to be designed. These principles apply to surface course mixtures as well.

Publisher

Illinois Center for Transportation/Illinois Department of Transportation

Series/Report Name or Number

Illinois Center for Transportation Series No. 15-009

ISSN

0197-9191

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/74921

Sponsor(s)/Grant Number(s)

Illinois Department of Transportation, R27-079

Copyright and License Information

No restrictions. This document is available to the public through the National Technical Information Service, Springfield, Virginia 22161

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