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Derya Genc, Doctor of Philosophy (Expected Graduation in 2020)

Derya Genc is a graduate research assistant pursuing a MS and PhD in Geotechnical Engineering at Iowa State University. Her research focuses on freeze-thaw monitoring and modeling of frost depth under granular roadways in Iowa. She earned her BSc degree in Civil Engineering at Middle East Technical University, Turkey in 2016. Her areas of research interest include computational thermal-hydraulic modeling and sensor systems.

Jaime Schussler (Christopher Gannon/Iowa State University)

Jamie Schussler, Doctor of Philosophy (Expected Graduation in 2022)

Jaime Schussler is a graduate research assistant pursuing a Ph.D. in Civil Engineering, starting in June of 2018. Jaime’s research focus in construction stormwater management evaluates in-field temporary erosion and sediment control measures. Her project titled “Field Monitoring of Erosion and Sediment Control Practices,” funded by the Iowa DOT, combines water quality and geotechnical analysis to determine the treatment efficiency of current best management practices. In addition, the project aims to develop implementable improvements for the Iowa DOT through enhanced design guidance. This project is ongoing though April of 2020.

Prior to her arrival at Iowa State University, Jaime graduated with a B.S. in Civil Engineering from West Virginia University in May of 2018. During her undergraduate studies, she participated in the Water and Environmental Management Program at UniLaSalle in Beauvais, France. This interdisciplinary program involved an intensive study of the EU Water Framework Directive and its implementation across Northern France. This program exposed Jaime to the collaborative research process, and inspired her to pursue her graduate studies. Aside from her research, Jaime is passionate about mobilizing young women toward STEM fields. Beginning with her membership in Alpha Omega Epsilon, a sorority for women in STEM, Jaime was heavily involved with philanthropy and outreach activities at WVU. This continued with her involvement in “The Road Less Traveled” at Iowa State. As she progresses in her degree, Jaime looks forward to providing useful research results to connect stormwater management within the Iowa Water Nexus and mobilizing you women, like herself, to opportunities in STEM.

2018 Commencement Program Photos

Patrick Bollinger, Doctor of Philosophy (Expected Graduation in 2022)

Patrick is a graduate research assistant pursuing a Ph.D. in Civil Engineering focused on soil stabilization and recycled materials. Pat and his wife are originally from the Mid-Atlantic but just moved from North Central Florida, where Pat obtained his B.S. in Civil Engineering from the University of Florida in 2018. Prior to returning to school, Pat had a successful 20 year career as a contractor and project manager in the fields of roofing and photovoltaic installations. He is energized by cross-discipline research that combines his interests in geotechnical engineering, sustainable materials, and applications for use in construction. His ultimate goal is to teach civil engineering and construction coursework. In his spare time, Pat is fond of ISU athletics, World Cup soccer, and enjoying the outdoors.

Sinan Coban, Doctor of Philosophy (Expected Graduation in 2020)

Haluk Sinan Coban earned his BSc degree in Civil Engineering from Istanbul Technical University (ITU), Turkey in 2015. His BSc graduation project was on the design of traditional and mechanically stabilized earth (MSE) retaining walls under static and seismic loadings. In 2017, he completed his MSc degree in Geotechnical Engineering at Iowa State University. His master’s thesis focused on subgrade soil stabilization with lime sludge and traditional calcium-based stabilizers. His research interests include soil stabilization, freeze-thaw and wet-dry durability, use of recycled materials in pavement construction, and pavement sustainability. He is currently a PhD student in Geotechnical Engineering and his research topic is about determining pavement design criteria for recycled aggregate base and large stone subbase.

Articles Published:

  1. Coban, H.S., Cetin, B., Likos, W.J., Edil, T.B., Ceylan, H., and White, D.J. (2019) ‘Construction and Preliminary Performance Evaluation of Recycled Aggregate Base and Large Stone Subbase Layers”, International Journal of Pavement Engineering, in review
  2. Yilmaz, O., Coban, H.S., Cetin B., and Edil, T.B. (2018) “Use of Standard and Off-Spec Fly Ashes for Soil Stabilization ”, Journal of Materials in Civil Engineering ASCE, vol. 31 (2), article no. 04018390
  3. Coban, H.S., Cetin, B., Likos, W.J., and Edil, T.B (2019) “Construction Evaluation of Recycled Aggregate Bases and Large Stone Subbases,” Proceedings of the 99th Annual Meeting of the Transportation Research Board, Washington, D.C., 6 p. (CD-Rom).
  4. Coban, H.S. and Cetin, B. (2018) “The Use of Lime Sludge Alone and With Class C Fly Ash for Subgrade Soil Stabilization,” Proceedings of the 98th Annual Meeting of the Transportation Research Board, Washington, D.C., 13 p. (CD-Rom)

 

Masrur Mahedi, Doctor of Philosophy (Expected Graduation in 2019)

Mr. Mahedi joined the Sustainable Geotechnical Infrastructure Group (SGIG) at Iowa State University for his PhD in 2016. He has received his M.S. in Civil Engineering from the University of Texas at Arlington (UTA), in 2015 and B.Sc. from Bangladesh University of Engineering and Technology (BUET), Dhaka, Bangladesh in 2013. His research interest includes soil stabilization, in-situ testing and environmental sustainability of transportaiton infrastructure built with recycled materials.

Articles Published:

  1. Mahedi, M., Cetin, B., and Cetin, K.S., (2019) “Freeze-Thaw Performance of Phase Change Materials (PCM) Incorporated Pavement Subgrade Soil,” Construction and Building Materials, vol. 202, 449-464
  2. Mahedi, M, Cetin, B., and White, D.J., (2018) “Performance Evaluation of Cement and Slag Stabilized Expansive Soils”, Journal of Transportation Research Record, 1-10.
  3. Mahedi, M., Cetin, B., and White, D.J. (2018) “Cement, Lime, and Fly Ashes in Stabilizing Expansive Soils: Performance Evaluation and Comparison,” Journal of Materials in Civil Engineering-ASCE, in review.
  4. Mahedi, M. and Cetin, B.* (2018) “Geoenvironmental Aspects of Cement/Fly Ash and Cement/Slag Amended Soils: Leaching Behavior of Elements,” Chemosphere, in review
  5. Mahedi, M., Cetin, B., and Dayioglu, A.Y. (2018) “Leaching Behavior of Aluminum, Copper, Iron and Zinc from Fly Ash and Slag Stabilized Soils,” Waste Management, in review
  6. Luo, C., Wang, Z., Zhang, Y., Yang, B., Sunghwan , K., Cetin, B., Ceylan, H., Mahedi, M., and Horton, R. (2019) “The influence of Concrete Grinding Residue on Soil Physical Properties and Plant Growth,” Journal of Environmental Quality, in review
  7. Luo, C., Wang, Z., Zhang, Y., Yang, B., Sunghwan , K., Cetin, B., Ceylan, H., Mahedi, M., and Horton, R. (2019) “Concrete Grinding Residue Effects on Soil Properties and Plant Growth along Selected Minnesota Highway Roadsides,” Journal of Environmental Quality, in review
  8. Mahedi, M. and Cetin, B. (2019) “Leaching of Elements from Fly Ash and Slag Stabilized Pavement Subgrade Soil”, Proceedings of the 99th Annual Meeting of the Transportation Research Board, Washington, D.C., Extended Abstract

 

Praveen L.S. Gopisetti, Doctor of Philosophy (Expected Graduation in 2020)

Mr. Gopisetti received his M.S. from Bradley University in 2017. His M.S. thesis focused on application of artificial neural networks to predict the International Roughness Index (IRI) of flexible and rigid pavements. Currently, he is a PhD student in Geotechnical and Materials Engineering and his research topic is evaluating climate data and investigation of reflective cracking, faulting and IRI models in pavement ME Design. his research interests overall includes application of neural networks, improvement of climate data for pavement design and pavement preservation.

Articles Published:

  1. Gopisetti, L.S.P., Cetin. B., Forman, B.A., Schwartz, C.W., Ceylan, H., Durham, S., (2019) “Evaluation of four different climate sources on pavement mechanistic-empirical design and impact of surface shortwave radiation”. Submitted to Journal of Pavement Engineering (in review).

 

Shafkat Alam Khan, Doctor of Philosophy (Expected Graduation in 2020)Mr. Khan joined ISU in Spring 18 as a PhD Student specializing in Geotechnical Engineering. He received his BSc in Civil Engineering from Bangladesh University of Engineering and Technology. He conducted extensive work to analyze bored pile capacity via use of PLAXIS software. He has been developing numerical models and running simulations pertinent to geotechnical engineering and construction management field. He is currently developing a decision making asset management tool for the Iowa local agencies to efficiently maintain their granular roadway network. His hobbies are either travelling or learning photography, law or contemporary history.
Sajjad Satvati, Doctor of Philosophy (Expected Graduation in 2020)Mr. Satvati`s research has focused mainly on the non-destructive geotechnical/geophysical field testing, design of unpaved roads, analysis of surface wave propagation and dynamic deflection, and cost analyses of granular roadways built with different material mixtures. He has also been working on stabilization of granular roadways with quarry fines by-products. For this project, he has been investigating the implementation of quarry fines by-products into the granular road surface. His research tries to correlate the plasticity and cementitious characteristics of these particles to determine whether they can bind coarse aggregate materials. In addition, during his M.S. studies he worked on slope stabilization by using planar and tubular geogrids and geotextiles.
Yijun Wu, Master of Science (Expected Graduation in 2019)Mr. Wu is an M.S. student/graduate research assistant specialized in geotechnical engineering at Iowa State University. He has worked on sustainability assessment of granular roads built with recycled materials. He is currently investigating the performance of granular roadways stabilized with 12 different mechanical chemical stabzilization methods.
Bo Yang, Doctor of Philosophy (Graduated in 2018)Dr. Yang received his M.S. and PhD from the Civil, Construction and Environmental Engineering at Iowa State University. His doctoral research investigated the effects of concrete grinding residue on soil properties and its reuse and recycling potential for soil stabilization purposes. He also investigated the use of bio-based materials in asphalt pavement preservation and pavement subgrade soil stabilization.

Articles Published:

  1. Yang, B., Zhang, Y., Cetin, B., Ceylan, H. (2018) “Concrete Grinding Residue – Management Practices and Reuse for Soil Stabilization,” Journal of Transportation Research Record, accepted
  2. Yang, B., Cetin, B., Zhang, Y., Ceylan, H., Kim, S., and Mahedi, M. (2018) “Evaluation of the Effects of Concrete Grinding Residue (CGR) on Soil Properties,” Journal of Environmental Management, in review
  3. Luo, C., Wang, Z., Zhang, Y., Yang, B., Sunghwan , K., Cetin, B., Ceylan, H., Mahedi, M., and Horton, R. (2018) “The influence of Concrete Grinding Residue on Soil Physical Properties and Plant Growth,” Journal of Environmental Quality, in review
  4. Luo, C., Wang, Z., Zhang, Y., Yang, B., Sunghwan , K., Cetin, B., Ceylan, H., Mahedi, M., and Horton, R. (2018) “Concrete Grinding Residue Effects on Soil Properties and Plant Growth along Selected Minnesota Highway Roadsides,” Journal of Environmental Quality, in review.

 

Tung P. Hoang, Doctor of Philosophy (Graduated in 2018)

Dr. Hoang received his PhD from the Department of Civil, Construction, and Environmental Engineering, Iowa State University. He is currently an assistant professor  in the Department of Civil Engineering at the University of Danang – University of Science and Technology, Danang, Vietnam. His research focuses on use of bacteria and enzymes to improve soil strength.

Articles Published:

  1. Hoang, T., Alleman, J., Cetin, B., Ikuma, K., and Choi, S. (2018) “Sand and Silty-Sand Soil Bio-Stabilization Using Bacterial Enzyme Induced Calcite Precipitation (BEICP),” Canadian Geotechnical Journal, accepted.
  2. Hoang, T., Alleman, J., Cetin, B., and Choi, S. (2018) “Engineering Properties of Bio-Cementation of Coarse- and Fine-Sand Catalyzed By Bacterial Cells and Bacterial Enzyme,” Journal of Materials in Civil Engineering-ASCE, in review.

 

Yang Zhang, Doctor of Philosophy (Graduated in 2016)

Dr. Yang Zhang is a Postdoctoral Research Associate at the Program for Sustainable Pavement Engineering and Research (PROSER) at Iowa State University. His research interest is but not limited to seasonal variations in pavement foundation support conditions and various in situ tests. Dr. Zhang also has research experience on low-volume road rehabilitation and preservation, soil stabilization, forensic evaluation and assessment, concrete material, and road frost action analysis.

Articles Published:

  1. Yang, B., Zhang, Y., Cetin, B., Ceylan, H. (2018) “Concrete Grinding Residue – Management Practices and Reuse for Soil Stabilization,” Journal of Transportation Research Record, accepted.
  2. Zhang, Y, Daniels, J.L., Cetin, B., and Baucom, I.K. “Effect of Temperature on pH, Conductivity, and Strength of Lime-Stabilized Soil”, Journal of Materials in Civil Engineering ASCE, in review.
  3. Yang, B., Cetin, B., Zhang, Y., Ceylan, H., Kim, S., and Mahedi, M. (2018) “Evaluation of the Effects of Concrete Grinding Residue (CGR) on Soil Properties,” Journal of Environmental Management, in review.

 

H. Sinan Coban, Master of Science (Graduated in 2017)

Haluk Sinan Coban earned his BSc degree in Civil Engineering from Istanbul Technical University (ITU), Turkey in 2015. His BSc graduation project was on the design of traditional and mechanically stabilized earth (MSE) retaining walls under static and seismic loadings. In 2017, he completed his MSc degree in Geotechnical Engineering at Iowa State University. His master’s thesis focused on subgrade soil stabilization with lime sludge and traditional calcium-based stabilizers. His research interests include soil stabilization, freeze-thaw and wet-dry durability, use of recycled materials in pavement construction, and pavement sustainability. He is currently a PhD student in Geotechnical Engineering and his research topic is about determining pavement design criteria for recycled aggregate base and large stone subbase.

Articles Published:

  1. Coban, H.S., Cetin, B., Likos, W.J., and Edil, T.B (2019) “Construction Evaluation of Recycled Aggregate Bases and Large Stone Subbases,” Proceedings of the 99th Annual Meeting of the Transportation Research Board, Washington, D.C., 6 p. (CD-Rom).
  2. Coban, H.S. and Cetin, B. (2018) “The Use of Lime Sludge Alone and With Class C Fly Ash for Subgrade Soil Stabilization,” Proceedings of the 98th Annual Meeting of the Transportation Research Board, Washington, D.C., 13 p. (CD-Rom)

 

 

Mustafa Dayioglu, Master of Science (Graduated in 2015)

Research Title:Improving the Engineering Properties of Expansive Belle Fourche Clay by Using Chemical Additives

Expansive soil problems are frequently observed in the northern plains (North Dakota and South Dakota, Montana, Wyoming and Colorado) and southwest states (Texas and Arizona) of the United States and billions of dollars are spent each year for repairing structures (Wyoming Office of Homeland Security 2014). Repair costs of the structural damages due to the expansive soil problems are usually much more expensive than the cost to stabilize the soil prior to construction. Different techniques have been used to mitigate the volumetric instability of soils such as changing the applied compaction energy and moisture content, pre-wetting expansive soils before the construction, building moisture barriers and waterproof membrane. In addition to those methods, another widely used technique is mixing the soil with chemical additives such as cement, fly ash and lime. The main objective of this study is to improve the engineering properties (strength and swelling pressure) of Belle Fourche clay, which is obtained from Belle Fourche Shale that is one of the most common expansive shales in South Dakota (Brandner 2009), to provide adequate foundation for pavements. To achieve this goal, the locally available Belle Fourche Shale was mixed with 3 different chemical additives: class C fly ash, class F fly ash and lime. A number of tests were conducted on Belle Fourche clay as well as mixtures of Belle Fourche clay with class C and class F fly ashes and lime. Swelling pressure and unconfined compression strength of the soil and mixtures were measured. In addition, the impacts of curing period, chemical additive type and content on the engineering properties of Belle Fourche clay were investigated. Lastly, the effect of freeze and thaw (F-T) cycles on the swelling pressure and strength of specimens was studied.

MERRA Brian Ruppelt, Master of Science (Graduated in 2014)

Research Title: Performance of Different Climate Data Sources in Mechanistic-Empirical Pavement Distress Analyses

Accuracy and reliability of the input data are critical in the MEPDG approach for predicting pavement performance. Climatic factors affect the behavior of all layers in the pavement system and have a direct influence on several deterioration processes including thermal cracking, frost heave and thaw weakening, rutting, (Mills et al. 2007; Johanneck and Khazanovic, 2010; Meagher et al. 2012). It is known that climate is a crucial parameter that must be taken into account during the design of pavements. However, there have been concerns about the reliability and accuracy of the climate data provided with the MEPDG software.

To address this need, our research team used a new and spatially comprehensive weather data source for MEPDG software in addition to data available from ground-based weather stations. NASA’s Modern-Era Retrospective Analysis for Research and Applications (MERRA) product can be used to provide hourly climatic data for MEPDG analysis. MERRA is a global climate reanalysis product that combines computed model fields with ground-, ocean-, atmospheric-, and satellite-based observations. The purpose of this research project was to identify the best climate sources to use in MEPDG pavement performance predictions. The results of this study showed that MERRA is as reliable as ground-based weather stations for critical weather data. In addition, MERRA has several advantages over currently available ground-based weather sources: denser, more uniform, and broader spatial coverage; better temporal frequency and continuity; excellent data consistency and quality.

Stephanie Jones Stephanie Jones, Master of Science, (Graduated in 2014)

Research Title: Evaluation of Potential Applications of Recycled Concrete Aggregate and Fly Ash for Acid Mine Drainage Remediation

When feasible it is of best practice to prevent the formation of acid mine drainage (AMD) using source control measures such as sealing or flooding of underground mines, solidification of mine tailings, and disposal of mine wastes in sealed waste heaps.  Unfortunately, these treatment methods can be extremely costly, requiring continuous chemical input and large volumes of virgin material, such as lime (CaO) and limestone (CaCO3).  In an effort to reduce the high costs of AMD treatment, interest has developed in various applications of low-cost waste products, such as fly ash and recycled concrete aggregate (RCA), for AMD remediation.  Both RCA and fly ash are highly alkaline, exhibiting unique binding properties that could make them effective alternatives to costly, lime and limestone treatment.

The objective of this study, through laboratory testing and analysis, was to evaluate the low-cost construction waste products, recycled concrete aggregate and fly ash, as remediation materials for AMD treatment.  Column Leach Tests (CLTs) were conducted to assess the impact of fly ash and RCA on pH, electrical conductivity, alkalinity, oxidation reduction potential (Eh); and concentrations of Ca, Cu, Cr, Fe, Mg, Mn, and Zn in AMD. Following the CLTs, additional analytical methods were conducted to better understand the treatment process on a molecular basis.  X-ray fluorescence spectroscopy (XRF) was used to evaluate the impact of oxide, alkalinity, and unburned carbon content of the remediation materials on their capacity to sorb metals from AMD.  In addition, Geochemist’s Workbench was employed to create a geochemical model to better understand changes in aqueous speciation of AMD caused by treatment.

LewisAA Janile O. Bestgen, Master of Science (Graduated in 2014)

Research Title: Environmental Suitability Recycled Concrete Aggregates Used in Highway Base Layers

The use of recycle materials in pavement systems in lieu of natural aggregates has been an interest for some time. Crushed waste concrete, termed recycled concrete aggregate (RCA), is  considered as an alternative material to be used in roadway construction.  Using recycled materials increases the sustainability of the project because the environmental and economic impacts associated from mining and processing of natural aggregates are minimized and/or eliminated.  This also diverts concrete waste streams from landfills, saving valuable space. Recycled concrete aggregate use is widespread in many countries but it is shown that RCA materials have potential to leach metals. The objective of this study was to understand the impact of atmospheric exposure time, reaction time, L:S ratio, particle size and pH on the leaching behavior of the selected metals (Ca, Cr, Cu, Fe and Zn) and to identify the leaching controlling mechanisms of metals, and also to compare the concentration levels obtained from the Batch Water Leach tests (WLT) against the concentration levels obtained from Synthetic Precipitation Leaching Procedure tests (SPLPs), and Toxicity Leaching Procedure tests (TCLP), which were selected to simulate the exposure of RCA to potentially more acidic water environment.