STUDENT SPOTLIGHT: Each month, or every other month, a student will provide a 1-page illustrated abstract of the research they are currently conducting. This is a wonderful opportunity for the student, for our International Society for Concrete Pavements (ISCP) Members, and for the transferring and sharing technology/research through our concrete paving industry.
The ISCP “STUDENT RESEARCH SPOTLIGHT” for January 2023 is Dan King, a Ph.D. student in civil engineering at Iowa State University (Ames, USA).
BIO:
Dan King is a PhD student in Civil Engineering at Iowa State University, where he also works as a Research Engineer for the National Concrete Pavement Technology (CP Tech) Center. Working under Dr. Peter Taylor and Dr. Halil Ceylan at Iowa State, Dan’s research focuses on concrete overlays, characterizing their behavior and performance and analyzing how concrete overlays can be used to improve the performance, sustainability, and resilience of the nation’s pavement network.
At the CP Tech Center, Dan helps direct a number of the center’s technology transfer activities, education initiatives, and research projects on topics including concrete overlays, preservation, mix design, durability, and fiber-reinforced concrete. He previously earned his Bachelor’s and Master’s degrees at the University of Illinois at Urbana-Champaign and worked for the Iowa Concrete Paving Association and Iowa Ready Mixed Concrete Association, where he provided his expertise in concrete pavements and materials to assist Iowa’s construction and engineering communities.
TITLE:
Survival Analysis of Concrete Overlays on Low-Volume Roads in Iowa
owa has one of the highest densities of rural roadways in the United States, and concrete overlays are an important part of that network. More than 2,000 centerline miles of concrete overlays have been paved in Iowa over the last few decades, including many overlays on low-volume rural roads. To obtain a probabilistic assessment of concrete overlay service life, a survival analysis was performed using automated pavement condition data collected on Iowa’s concrete overlays, paying particular attention to the performance of overlays on low-volume roads.
Concrete overlays were found to perform very well, with a 30-year survival probability of 85.3% for all projects to rehabilitation or reconstruction, and 76.6% for overlays only on low-volume roads.
Survival life was reduced when the survival condition was changed to performance thresholds based on a pavement condition index (PCI) of 60/100 and an International Roughness Index (IRI) of 170 in/mi, but was still good overall. Overlays tended to reach the failure condition for PCI before IRI, indicating that cracking and joint spalling were more common distresses than surface roughness. Another important finding was that concrete on asphalt (COA) overlays had a longer median survival life and a greater 30-year survival probability than concrete on concrete–unbonded (COC–U) overlays. Overall, concrete overlays have performed well in Iowa and are well suited to low-volume roads and rural county highways.
Concrete Overlay Strategies for Improving Pavement Resilience
Increases in flooding events and rising groundwater levels caused by climate change threaten to weaken pavement foundations, which can have a major impact on flexible pavement service life. Rigid pavements are not as sensitive to the strength of underlying layers, and analyses of the structural response of concrete pavements after major flooding events in recent years has shown them to be much more resilient to the effects of inundation. One potential method to improve the resilience of existing asphalt pavements that are vulnerable to flooding is to construct concrete overlays, which have a shorter construction schedule and are much less resource-intensive than reconstruction, and which behave similarly to a conventional rigid pavement, including in their resilience to inundation.
Typical asphalt pavement sections on collector and arterial streets under Iowa climatic and soil conditions were identified and evaluated under a variety of theoretical flooding scenarios to determine the impact of inundation on service life. Three types of concrete overlay designs were then developed for these typical asphalt pavement sections under the same conditions. A life cycle cost analysis (LCCA) was performed to compare the costs and performance of the concrete overlay strategies to a conventional flexible pavement strategy under the theoretical flooding scenarios.
The results of the LCCA indicate that a variety of concrete overlay designs can provide more cost-effective performance when pavement foundation layers become inundated, depending on the roadway functional class and frequency of flooding. These findings indicate that concrete overlays can be a useful method for improving resilience of existing flexible pavements and mitigating the costs of flood damage.
ISCP would like to feature a “STUDENT RESEARCH SPOTLIGHT” each month, or every other month. If you would like to nominate a student, or if you are a student and would like to nominate yourself or a colleague, please send ISCP an email to: newsletter@concretepavements.org
ALL SPOTLIGHTS:
DECEMBER 2021—Inaugural: Katelyn Kosar, Phd Student-Department of Civil and Environmental Engineering, University of Pittsburgh (Pitt): www.concretepavements.org/2021/12/14/new-at-iscp-student-research-spotlight/
JANUARY 2022: Aniruddha Baral, Ph.D. Candidate-Department of Civil and Environmental Engineering, University of Illinois-Urbana-Champaign: www.concretepavements.org/2022/01/15/student-research-spotlight-jan-2022/
FEBRUARY 2022: Jordan Ouellet, Tech, BEng, MASc, PhD Candidate, Teaching and Research Assistant, University of Illinois at Urbana-Champaign: www.concretepavements.org/2022/02/26/student-research-spotlight-february-2022/
MARCH 2022: Sampath Kumar Pasupunuri, Ph.D. candidate, Pavement Engineering-School of Civil Engineering, University of Nottingham, UK: https://www.concretepavements.org/2022/03/31/student-research-spotlight-march-2022/
APRIL 2022: Anupam B R, Pursuing his doctorate-Indian Institute of Technology Bhubaneswar, India: https://www.concretepavements.org/2022/04/15/student-research-spotlight-april-2022
MAY 2022: Andréia Posser Cargnin, Ph.D. Candidate, Polytechnic School, University of São Paulo (São Paulo, Brazil): https://www.concretepavements.org/2022/05/09/student-research-spotlight-may-2022/
JUNE 2022: Charles Donnelly, Ph.D. Candidate, Department of Civil and Environmental Engineering, University of Pittsburgh (Pittsburgh, USA): https://www.concretepavements.org/2022/06/24/student-research-spotlight-june-2022/
JULY 2022: Amir Malakooti, Ph.D. Candidate, Department of Civil and Environmental Engineering, Iowa State University (Ames, Iowa, USA): https://www.concretepavements.org/2022/07/30/student-research-spotlight-july-2022/
AUGUST 2022: Haoran Li, Ph.D. Candidate, Department of Civil and Environmental Engineering, University of Pittsburgh (Pittsburgh, USA): https://www.concretepavements.org/2022/08/24/student-research-spotlight-august-2022/
SEPTEMBER 2022: Sumit Nandi, Ph.D. Candidate, Department of Civil Engineering, Indian Institute of Technology Roorkee (Roorkee, India): https://www.concretepavements.org/2022/09/18/student-research-spotlight-september-2022/
OCTOBER 2022: Eric Ribeiro da Silva, Ph.D. Candidate, Department of Civil Engineering, Polytechnic School of the University of São Paulo (São Paulo, Brazil): https://www.concretepavements.org/2022/10/20/student-research-spotlight-october-2022/
NOVEMBER 2022: Zachary Brody, Ph.D. Candidate, Department of Civil and Environmental Engineering, University of Pittsburgh (Pittsburgh, USA): https://www.concretepavements.org/2022/11/18/student-research-spotlight-november-2022/
DECEMBER 2022: Jesús Castro Pérez, Ph.D. Candidate, Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign (Urbana, USA): https://www.concretepavements.org/2022/12/17/student-research-spotlight-december-2022/