Featured in Technology Today (Volume 38, Issue 3), a quarterly publication of the Louisiana Transportation Research Center.
Louisiana’s DOTD works to design and build durable, long-lasting roads that make the most efficient use of the state’s funds while serving its drivers well. LTRC’s materials research facilities are a vital partner in that pursuit, and the initial returns on a recent innovation in asphalt design demonstrate this value. The research project, led by LTRC’s Corey Mayeux, P.E., and Moses Akentuna, Ph.D., P.E., entitled “Evaluation of Performance and Life Cycle Cost of Asphalt [8/18 Specifications],” aimed to evaluate and compare the performance of pavements constructed before and after the implementation of the 2016 DOTD specification, which introduced the balanced mix design framework to the state’s construction processes.
Akentuna, LTRC’s Asphalt Research Manager, emphasizes the value of this research: “This study was conducted to ascertain the effectiveness of the changes and improvements made in the Louisiana standard specifications in an effort to enhance roadway performance and value. Additionally, the study included a comprehensive analysis of life cycle costs to assist DOTD in determining whether the modified specifications have increased the overall value of the state’s roadways.”
To these ends, researchers assessed the available density, volumetric, and performance data on 14 pavement sections across the state, performing a life-cycle analysis to determine if the specification changes increased the service life of the pavements in question compared with those constructed under the pre-2016 specifications. Utilizing a combination of data gleaned from DOTD laboratory engineers and the state’s online mix design and records system, LaPave, they discovered the new balanced mix design performed very well by all measures.
"This study was conducted to ascertain the effectiveness of the changes and improvements made in the Louisiana standard specifications in an effort to enhance roadway performance...and increase the overall value of the state's roadways."- Moses Akentuna, Ph.D., P.E.
Highlights included overall enhanced performance in field rutting and cracking, improved service life values ranging from 0.1 to 3 years, and an average life-cycle improvement of 9.2%, all of which can substantially influence the maintenance and operation of the state’s asphalt pavements, ultimately creating significant savings for taxpayers. While the pavements constructed under the new specifications must be monitored to ensure ongoing quality and performance, these encouraging early outcomes are a substantial validation of the research and innovation happening at LTRC on a day-to-day basis.
For more information on this project and its findings, please visit LTRC Final Report 670. You can also contact Moses Akentuna, Ph.D., P.E., at (225) 767-9151 or moses.akentuna@la.gov.