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 October 2023 is Omar K. Omar, a Ph.D. student at Louisiana State University (Baton Rouge, USA).
BIO:
Omar K. Omar is currently pursuing his Ph.D. degree in Engineering Science at Louisiana State University under Dr. Marwa Hassan’s supervision. He holds a master’s degree in Engineering Science from Louisiana State University and a bachelor’s degree in Civil Engineering. Omar’s primary research area focuses on the utilization of vacuum impregnation to incorporate bacteria into lightweight aggregate for self-healing concrete applications. He possesses extensive expertise in utilizing analytical techniques such as Scanning Electron Microscopy (SEM), Energy-dispersive spectroscopy (EDS), X-ray diffraction analysis (XRD), and Raman spectroscopy analysis. Furthermore, Omar has gained practical experience through his involvement in fieldwork, having worked for five years on demanding mega projects involving steel structures and concrete structures.
TITLE:
Assessing the Impact of Bacteria with Sodium Lactate and Calcium Lactate on the Self-healing Efficiency, Mechanical Properties, and Water Permeability of Bacterial Concrete
The significance of sustainable concrete development cannot be overstated, considering its widespread use as a construction material and the need to reduce greenhouse gas emissions associated with its production. Self-healing concrete technologies offer a promising approach to improving the durability and sustainability of transportation infrastructure. One such technology is bacterial concrete, which has the potential to seal microcracks through the process of microbial-induced calcite precipitation (MICP). MICP relies on the metabolic activity of bacteria, which produces carbon dioxide as a by-product of respiration. The carbon dioxide dissolves in water to form carbonate ions, which react with calcium ions in the cementitious matrix to produce calcium carbonate.
However, protecting the bacteria within the concrete is crucial due to the challenging conditions they face. Vacuum impregnation of bacteria into lightweight aggregate; is one of the promising protection techniques, especially that aggregate occupies 60% to 75% of the total volume of concrete. Moreover, the success of this technology relies on the availability of suitable mineral precursor compounds and viability of bacteria species. Calcium lactate and sodium lactate are lactic acid derivatives, which effectively improve the mechanical properties of concrete materials. Accordingly, the present study included two mineral precursors, calcium lactate and sodium lactate. The viability of bacteria species is a critical factor in the MICP process. Previous studies have evaluated different alkaliphilic bacteria species for their potential application of bacteria in self-healing concrete. Bacillus pseudofirmus exhibited the highest survival rate among the alkaliphilic bacteria species. Consequently, the primary objective of this study was to enhance the healing efficiency of bacterial concrete in subtropical climates by using vacuum impregnation to introduce Bacillus pseudofirmus bacteria with two different mineral precursors namely calcium lactate and sodium lactate into a lightweight aggregate (LWA).
To accomplish this objective, specimens of concrete were prepared, including both those with impregnated coarse lightweight aggregate (LWA) and control specimens. Various properties and characteristics of the samples were assessed, including compressive strength, crack healing efficiency, flexural strength, and strength recovery. To confirm the presence of calcite in the bacteria-containing samples, X-Ray Diffraction (XRD) analysis and Raman spectroscopy analysis were conducted. Additionally, the chemical composition of the healing products was examined using scanning electron microscopy (SEM) in combination with energy x-ray dispersive spectroscopy (EDS). The SEM/EDS technique allowed for the observation of the chemical composition of the healing products. Furthermore, the water permeability of both the control sample and the sample that exhibited the highest self-healing efficiency was compared.
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/
APRIL 2023: Niwesh Koirala, Ph.D. Candidate, Department of Civil and Environmental Engineering, Texas Tech University (Lubbock, USA): https://www.concretepavements.org/2023/04/07/student-research-spotlight-april-2023/
MAY 2023: Christian A. Sabillon, Ph.D. Candidate, The University of Texas at Austin (Austin, Texas, USA): https://www.concretepavements.org/2023/05/05/student-research-spotlight-may-2023/
JUNE 2023: Saima Yaqoob, Ph.D. Candidate, KTH (the Royal Institutes of Technology) (Stockholm, Sweden): https://www.concretepavements.org/2023/06/15/student-research-spotlight-june-2023/
JULY 2023: Ricardo Hungria, Ph.D. Candidate, Louisiana State University (Baton Rouge, USA): https://www.concretepavements.org/2023/07/11/student-research-spotlight-july-2023/
AUGUST 2023: Megan Darnell, Ph.D. Candidate, University of Pittsburgh (Pittsburgh, USA): https://www.concretepavements.org/2023/08/07/student-research-spotlight-august-2023/
SEPTEMBER 2023: Jitendra Patel, Ph.D. Candidate, Alma Mater Studiorum – Università di Bologna (Italy): https://www.concretepavements.org/2023/09/05/student-research-spotlight-september-2023/