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Project Details
STATUS

In-Progress

START DATE

07/06/17

END DATE

06/30/19

FOCUS AREAS

Safety

RESEARCH CENTERS InTrans, CTRE
SPONSORS

Federal Highway Administration State Planning and Research Funding
Illinois Department of Transportation

PARTNERS

Federal Subaward from Univ of Illinois at Urbana-Champaign

Researchers
Principal Investigator
Neal Hawkins

Associate Director, InTrans

Co-Principal Investigator
Omar Smadi

Director, CTRE

About the research

Pavement markings provide critical guidance to motorists, especially under dark (un-lit) conditions. However, the ability to see pavement markings on a wet, rainy night is problematic given that the presence of water considerably decreases pavement marking retroreflectivity.

This project evaluated the performance of several all-weather pavement marking products in an effort to provide guidance on their use on Illinois Department of Transportation (IDOT) roadways. In addition, a laboratory evaluation was completed in an effort to simulate degradation mechanisms of these pavement markings so that future all-weather materials can be evaluated in a timely manner within the laboratory rather than on public roadways.

The study found that only 15 percent of the all-weather products provided a retroreflectivity of 50 millicandelas per meter squared per lux (mcd/m²/lux), which is noted as (mcd) within the report, under continuous wetting conditions.

The laboratory evaluation showed some promise for the dry retroreflectivity performance given that data variability was low and there the correlation was good initially with the field data. The correlation was not as good, however, as the markings aged, and correlation in wet conditions was not good either.

Project Details
STATUS

Completed

START DATE

10/01/09

END DATE

07/31/13

RESEARCH CENTERS InTrans, CTRE
SPONSORS

California Department of Transportation
Colorado Department of Transportation
Federal Highway Administration Transportation Pooled Fund
Illinois Department of Transportation
Indiana Department of Transportation
Iowa Department of Transportation
Minnesota Department of Transportation
Missouri Department of Transportation
Wisconsin Department of Transportation

Researchers
Principal Investigator
Chris Williams

Director, AMPP

Student Researcher(s)
Andrew Cascione
Jianhua Yu

About the research

State highway agencies are increasingly intersted in using recycled asphalt shingles (RAS) in hot mix asphalt (HMA) applications, yet many agencies share common questions about the effect of RAS on the performance of HMA. Previous research has allowed for only limited laboratory testing and field surveys. The complexity of RAS materials and lack of past experiences led to the creation of Transportation Pooled Fund (TPF) Program TPF-5(213). The primary goal of this study is to address research needs of state DOT and environmental officials to determine the best practices for the use of recycled asphalt shingles in hot-mix asphalt applications.Agencies participating in the study include Missouri (lead state), California, Colorado, Illinois, Indiana, Iowa, Minnesota, Wisconsin, and the Federal Highway Administration. The agencies conducted demonstration projects that focused on evaluating different aspects (factors) of RAS that include RAS grind size, RAS percentage, RAS source (post-consumer versus post-manufactured), RAS in combination with warm mix asphalt technology, RAS as a fiber replacement for stone matrix asphalt, and RAS in combination with ground tire rubber. Field mixes from each demonstration project were sampled for conducting the following tests: dynamic modulus, flow number, four-point beam fatigue, semi-circular bending, and binder extraction and recovery with subsequent binder characterization. Pavement condition surveys were then conducted for each project after completion.

The demonstration projects showed that pavements using RAS alone or in combination with other cost saving technologies (e.g., WMA, RAP, GTR, SMA) can be successfully produced and meet state agency quality assurance requirements. The RAS mixes have very promising prospects since laboratory test results indicate good rutting and fatigue cracking resistance with low temperature cracking resistance similar to the mixes without RAS. The pavement condition of the mixes in the field after two years corroborated the laboratory test results. No signs of rutting, wheel path fatigue cracking, or thermal cracking were exhibited in the pavements. However, transverse reflective cracking from the underlying jointed concrete pavement was measured in the Missouri, Colorado, Iowa, Indiana, and Minnesota projects.

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