AK Hot Mix Asphalt Job Mix Formula Verification

Abstract and project information last updated: 18 January 2013. Project updates are dated below.

Workers in orange safety vests shovel a line of dark asphalt mixture parallel to a road that is paved on the opposite side. A green piece of machinery that is flattening the line of asphalt is in the foreground, approaching the viewer.

Credit: Peng Li

Workers collect loose hot mix asphalt mixture working in Nenana, Alaska in August 2010 as part of a project to verify the formula for the use of such mixtures in Alaska.

AUTC
Project
Number
309024
Principal
Investigator
Juanyu (Jenny) Liu (UAF)
jliu6@alaska.edu
Funding
Agency

US Department of Transportation (RITA)

Alaska Department of Transportation & Public Facilities

Project
Budget
230000
Start
Date
1 August 2009
Estimated
End Date
31 January 2012

Abstract

Some asphalt pavement does not last as long as it should, which means that every year, the state spends significant sums on repair and maintenance of Alaska’s paved roads. Since hot mix asphalt is the major paving material used in Alaska, assuring the quality of this material is a critical issue for contractors, ADOT&PF, and other agencies responsible for pavements. This project is assessing elements related to HMA quality assurance specifications and evaluating how well contractors meet the requirements of job mix formulas. During summer 2010, researchers field-tested a rehabilitation and resurface project at Mile 287–305 of the Parks Highway, just south of Nenana. Asphalt mixtures with four different scenarios were sampled from nine sublots. The mixtures included specimens mixed and compacted using JMF in the laboratory; loose mixtures collected from windrow, and either compacted in the field using a portable gyratory compactor or compacted in the laboratory; AUTC Ongoing Projects and cores retrieved from the field. Pertinent data from ADOT&PF and from contractors at each phase of lab/design, production, and new construction were obtained, including general project information, details of the materials and JMF used in the construction, and all construction test data. Over the next year, four primary tests for JMF properties will be conducted in the university lab, including aggregate gradation, asphalt content, mix volumetrics (e.g., air voids and voids in the mineral aggregate), and density. In addition, hot mix asphalt performance will be investigated to further verify the JMF and evaluate any impact of the construction process. These performance tests will include an indirect tension test for low-temperature performance and a dynamic modulus and rut test with a simple performance tester. Project results will lead to revision of current mix design protocols, benefit the asphalt-paving process, and ensure the quality of HMA. Verification will enhance the long-term performance of HMA pavements and significantly reduce the state’s pavement maintenance and repair budget.

Final Report

Verification of Job Mix Formula for Alaskan HMA
6 Nov 2014

Verification of Job Mix Formula for Alaskan HMA
Jenny Liu, Peng Li
JMF-final-report_0710.pdf

Related Project Activity

6 November 2014

Verification of Job Mix Formula for Alaskan HMA

by billy.connor

JMF final report_0710

28 March 2011

Verification of Job Mix Formula for Alaskan Hot Mix Asphalt

by billy.connor

Jenny Liu presents project update to the Peer Review Committee on March 17, 2011 for the project AK Hot Mix Asphalt Job Mix Formula Verification. The attached pdf contains the slides presented.
JMF for Alaskan HMA