MnROAD | NRRA | Structure & Teams | Geotechnical Team
Improving Moisture Resistance/Control of Pavement Foundation Systems via Engineered Water Repellency
Status: Active
MnDOT Contract #: 1036336 WO13
Project overview
The overarching research objective of this proposal is to evaluate the use of organo-silane (OS) to control water and increase subgrade and overall pavement system performance. It will also explore the extent to which OS can mitigate frost heave-thaw settlement and freeze-thaw weakening of frost susceptible pavement foundation layers. This will be achieved through the completion of four objectives: (1) collect both subgrade soils and OS materials, (2) develop a viable treatment design for field construction; (3) construct test sites with OS (as well as control) and evaluate their geomechanical (e.g., stiffness, strength, freeze-thaw durability) and environmental (e.g., temperature, moisture, and matric suction) performances; and (4) collect data and calibrate numerical models. Advanced technologies provided as a match to the project will be used, including Light Detection and Ranging (LiDAR) and shape array sensors (SAS).
Tasks
Task 1: Material collection & analyses
Subgrade soils from MnROAD will be collected. Based on the PI`s previous laboratory results, it is decided to focus on one commercially available product. It should be noted that subgrade soils should have a high SiO2 content to be able to bind well with OS materials. Therefore, it is important to determine the chemical characteristics of subgrade soils before OS treatment. Thus, all subgrade soil samples will be air-dried for both physical and chemical laboratory analyses. Samples will be analyzed by X-ray diffraction (XRD) using a Siemens D500 X-ray diffractometer equipped with a diffracted beam monochromator and a sample spinner to determine the SiO2 and other oxide contents of the subgrade soil. In addition, particle size distribution of the subgrade soils will be determined via sieve analysis and hydrometer analyses (ASTM D422). The specific gravity (Gs) of all soils will be measured in accordance with ASTM C311. Liquid limit and plastic limit of all materials will be determined in accordance with ASTM D43187. Moreover, subgrade soil collected will be treated with different OS at different concentrations to determine the optimum design mixtures that will be implemented in the field demonstration test sections. Contact angle and water droplet penetration time tests will be conducted on OS treated subgrade samples to select the minimum treatment level resulting in the maximum reliable water repellency. The research team will develop relationships that are not a function of the chemical (per se), but rather the resulting hydrophobicity. The chemicals will be prepared at varying dosages to achieve a range of contact angles in the hydrophobic range (e.g., > 90o) when mixed with subgrade soils.
- Deliverable: A full soils report to complement the growing database of information
Task 2: Construction of field test Sections/development of field testing plan/monitoring at MnROAD
Two identical roadway sections will be built (one with selected OS and concentration and one with no treatment) at MnROAD facility in summer 2024. The research team will summarize as built details of both sections (e.g., thickness of each pavement layer, width, material types used along with the locations of temperature, moisture, shape array, and matric suction sensors). All sensors will be provided by University of North Carolina-Charlotte, as well as their installation. OS treatment will be applied on subgrade layer. It is important to install the sensors mentioned above at least every 6 inches in depth from top of base layer to 8 ft depth into subgrade to observe the full temperature and moisture profile during monitoring. It is also recommended to place these sensors at the center and edge of the pavements.
During construction stage, the research team will conduct the following tests on each test section DCP, LWD, and FWD results. FWD tests will be conducted before and after the surface layer (either rigid or asphalt) is built. Field tests proposed to be collected every 50 ft in all test cells. In addition, both base and subgrade samples will be collected to determine index properties of the materials.
Under this task, the research team will analyze the FWD, pavement surface conditions (e.g., IRI, rutting) and frost heave-thaw settlement measurements (e.g., LiDAR and SAS). In addition, using the fieldcollected temperature and moisture data, the number of freeze–thaw (F-T) cycles and the frost depth of each test section with depth will be determined. From the analyses of this data, the research team plans to determine the number of F-T cycles of base and subgrade layer for each year as well as in total. Such data will be used to evaluate the impact of the utilization of OS on the following parameters: (1) F-T cycles and frost depth; (2) moisture variation; and (3) variation of elastic modulus with the F-T cycles. After completion of previous tasks, the research team will summarize the findings from the field and conduct analyses on the results. Based on the data analyses, a detailed review will be done of pavement performance data and recommendations on the best construction practices will be provided.
- Deliverable: Construction monitoring and testing report, long-term field test results report & presentation
Task 3: Modelling
Modeling will evaluate the extent to which the efficiency of the use of OS varies under a broader range of spatial and temporal conditions, especially in terms of the rate and duration of freezing and thawing, as well as scale effects not observed in the laboratory. Modeling of the complex thermo-hydro-mechanics of the freezing and thawing soil will be conducted in response to climatic inputs. The PIs intend to calibrate field test results with the COMSOL Multiphysics platform and then use these models to predict future behavior of these designs. The field results obtained in this work will be used to inform models. These models will help predict the extent to which OS inclusion: (1) impacts the maximum frozen soil depths; and (2) delays freezing of soils, frost heave, and strength loss, across a range of climate conditions and soils with specific characteristics. In this task, the measured soil and climate data will be utilized as input into the multi-physics modeling software, COMSOL. This model will be calibrated and then used to evaluate efficacy under other conditions, including design (OS treatment, subgrade thickness), loading (weight/frequency), and weather/site conditions (temperature, access to moisture).
- Deliverable: The results will be a calibrated model that can make informed predictions
Task 4: Final report
Three months prior to the end date, the research team will submit the draft final report documenting all tasks completed, conclusions, and recommendations along with the curated data in Excel files for future use, analysis, and interpretation. The final report will be submitted to the project TAP members. Their feedback will be incorporated into the final report.
- Deliverable: Final report and presentation
Project team
Email the Project Team
Principal Investigator: Bora Cetin, Ph.D., Department of Civil and Environmental Engineering, Michigan State University, cetinbor@msu.edu
Technical Liaison: Sinan Coban, Ph.D., E.I.T., WisDOT, haluksinan.coban@dot.wi.gov
Project Technical Advisory Panel (TAP): Contact us to join this TAP
- Çeren Aydin, MnDOT
- Emil Bautista, MnDOT
- Terry Beaudry, MnDOT
- Sinan Coban, WisDOT (TL)
- Amir Golalipour, FHWA
- Deepak Maskey, Caltrans
- Eric Olson, Solmax
- Joseph Podolsky, MnDOT
- Supraja Reddy, Illinois Tollway
- Marcos Sanchez-Pliego, MnDOT
Related materials
- Initial project proposal (PDF), 5/5/2023
- TAP Kickoff Meeting (PDF), 1/25/2024