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, our International Society for Concrete Pavements (ISCP) Members, and technology/research transfer throughout our concrete paving industry.
The ISCP “STUDENT RESEARCH SPOTLIGHT” April 2022 is Anupam B R, Currently pursuing his doctorate at the Indian Institute of Technology Bhubaneswar, India.
Bio:
Anupam B R earned his master’s degree in transportation engineering from the National Institute of Technology Hamirpur, India and is presently pursuing his doctorate at the Indian Institute of Technology Bhubaneswar, India. Mr. Anupam is currently working with Professor Umesh Chandra Sahoo and Professor Prasenjit Rath on ‘Performance Assessment of Cool Pavements Embedded with Phase Change Materials’.
Title: “Reduction in Pavement Surface Temperature using Sold-Liquid Phase Change Material”
Abstract:
Higher pavement surface temperature contributes to the urban heat island (UHI) effect. Also, a higher temperature differential between the surface and bottom of the slab in concrete pavements leads to higher warping stresses. One of the prospective ways to reduce surface temperature is the incorporation of phase change materials (PCM) in pavements. During a rise in the temperature in the daytime, the PCM undergoes a phase change from solid to liquid by absorbing heat at its fusion temperature, thus controlling the rise. Similarly, as the pavement temperature drops during the night, the PCM releases the heat energy stored by changing its phase again from liquid to solid at its fusion temperature.
However, the direct incorporation of PCM in concrete interferes with the cement hydration and adversely affects the mechanical strength. Therefore, it is necessary to encapsulate the PCM using an encapsulating medium, such as Expanded Clay Aggregates (ECA) with high porosity as used in this study. The preparation process of PCM impregnated ECA is shown in Figure 1.
The PCM impregnated ECAs were introduced into the cement concrete as a partial replacement for the coarse aggregates. The developed composite was found to be satisfactory in terms of its mechanical strength at a replacement level up to 10 %. Trail concrete slab sections were cast using this latent heat storable concrete provided at the top one-third depth of the slab, and the thermal performance was assessed under solar radiation. The variation in surface temperatures of these slabs was monitored using T-type thermocouples and a data logger installed in the field, continuously for one year. The reduction in the pavement surface temperatures measured for a year can be seen in Figure 2. A maximum reduction of 4.12 °C and a mean reduction of 2.24 °C may be considered significant taking into account the UHI and warping stresses.
Further, an enthalpy-porosity-based heat transfer model for simulating the melting of PCM in the concrete pavement under solar radiation was developed under this study. The temperature contours after 1-hour exposure to incoming solar radiation of 700 W/m2 and the corresponding liquid fraction contours of a single encapsulated PCM at 360s time interval are shown in Figure 3.
From the numerical analysis, an increase in the cooling potential was observed with an increase in the porosity of encapsulating material. Also, it was observed that the cooling
potential increased with an increase in the thermal conductivity of concrete, which may be attributed to the effective melting of PCM and increased heat transfer to lower layers.
From this ongoing study, it is observed that cooler concrete pavements can be successfully constructed by using PCMs encapsulated in suitable mediums.
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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: BIO: Sampath Kumar Pasupunuri, Ph.D. candidate studying pavement engineering in the school of civil engineering at the University of Nottingham, UK:
www.concretepavements.org/2022/03/31/student-research-spotlight-march-2022/