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 April 2023 is Niwesh Koirala, a Ph.D. student in civil engineering at Texas Tech University (Lubbock, Texas, USA).
BIO:
Niwesh Koirala is currently pursuing both his master’s and PhD degrees at Texas Tech University, Lubbock, Texas. He is also a member of the Texas Tech Center for Multidisciplinary Research in Transportation (TechMRT), where he serves as a Research Assistant under the supervision of Professor Moon Won. Niwesh’s primary area of research is Continuously Reinforced Concrete Pavements (CRCP), overlays, and concrete materials. He is highly skilled in using Finite Element Analysis (FEA) and Python programming to develop and analyze CRCP models. His expertise extends to fieldwork as well, where he is responsible for installing and preparing strain gauges and sensors to collect valuable data related to CRCP behavior.
TITLE:
Development of Design Details for CRCP Whitetopping in Texas
The slab thickness design of continuously reinforced concrete pavement (CRCP) has evolved by adjusting certain input values in conventional concrete pavement design, since the AASHTO ’93 rigid pavement design was based on the findings from the AASHO Road Test, and CRCP was not included in the Road Test. However, this has resulted in conservatism that has negatively affected CRCP performance in Texas. The TxCRCP-ME program has corrected some of these issues, but there is still a need for a design procedure for unbonded CRCP overlays and whitetopping. Said that, the current CRCP design procedures have limitations. To indeed overcome this limitation, the current research attempts to develop deflection based CRCP design for Whitetopping.
Over three years, a TXDOT funded research project, which is a joint effort between Texas Tech University and Texas A&M Transportation Institute, aims to achieve the research goal, for which numerous tasks have been performed. Majorly, this includes literature review, survey on experiences and practices related to CRCP overlay designs, development of evaluation procedure for existing pavement conditions, developing deflection based CRCP slab thickness design, and developing reinforcement details at Intersections and Unbonded Overlays.
In regards of developing deflection based CRCP slab thickness design, we are conducting the following activities:
- Firstly, we identify CRCP projects with varying slab depths within Texas where concrete is not yet placed.
- Then, we select projects and a test section which needs to be at least 1000 feet in length (Figure 1a).
- After that we conduct the FWD test on the ASB layer in the test section and perform DCP of the subgrade (Figure 1b).
- Finally, conduct the FWD test on the CRCP layer at the same location after concrete placement. This is done ideally just before traffic is open.
Figure 1: (a, left) Typical test section (1000ft) (b, right) FWD Testing in the field
The long-term vision for this research project is to come up with deflection-based CRCP design which could be in the form of a catalog design (Figure 2) or a simple Excel-based program with an efficient interface, where the user provides all deflection values, design ESAL, and a desired reliability and the program would yield the required slab thickness.
Figure 2: A potential catalog design
Significance of this research: Most of the design procedures available for CRCP are for new pavement systems. However, TxDOT has many miles of rigid pavements that need structural enhancements, and deteriorated asphalt intersections that also require rehabilitation. For both applications, CRCP presents an optimum pavement type for rehabilitation. Unfortunately, no reasonable design procedures are available for those applications. If this research becomes successful, the implementation of the to-be-developed design procedure will be a valuable tool for the designs of unbonded concrete overlay and whitetopping with CRCP. This will eventually enhance TxDOT’s ability to optimize statewide pavement rehabilitation strategies.
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/
JANUARY 2023: Dan King, Ph.D. Candidate, Department of Civil and Environmental Engineering, Iowa State University (Ames, USA): https://www.concretepavements.org/2023/01/26/student-research-spotlight-january-2023/
FEBRUARY 2023: Kathryn Kennebeck, Ph.D. Candidate, Department of Civil and Environmental Engineering, University of Pittsburgh (Pittsburgh, USA): https://www.concretepavements.org/2023/02/28/student-research-spotlight-february-2023/
MARCH 2023: Sinan Kefeli, Ph.D. Candidate, Department of Civil and Environmental Engineering, Iowa State University (Ames, USA): https://www.concretepavements.org/2023/03/13/student-research-spotlight-march-2023/