CEAT-OMP Projects 2005
The CEAT Center research partnership with the O'Hare Modernization Program began in 2005. The objective of the OMP is to create a modern and efficient air traffic system based on parallel East-West runways. The $6.6 billion program includes construction of 35 miles of runways and taxiways, placement of 2.2 million cubic yards of Portland cement concrete, 29 million cubic yards of earthwork, 220 miles of storm sewers and underdrains, and 650 miles of ductbanks and cabling. This enormous investment in infrastructure creates a compelling opportunity for gains to be realized from active research that is responsive to the specific needs of the project. The research program will illuminate many of the technical issues faced by OMP engineers, providing for improved and more cost-effective decisions.
Three technical work areas have been identified for the Center to pursue in the first year of the partnership.
Faculty Investigator(s): Erol Tutumluer and Marshall Thompson
Subgrade performance is a key factor in the overall performance of a pavement system. This project provides testing and analysis to establish stabilization requirements in support of the design of pavements at O'Hare.
The preliminary concrete pavement design for the O'Hare Modernization Program is:
- 15-17 inches of PCCP Surface
- 6-inch Hot Mix Asphalt Base
- 6-inch Asphalt Treated Permeable Base
- "Stabilized" Subgrade Zone (SSZ) (Thickness to be determined)
- Prepared Subgrade
North Runway (9-27) paving is programmed for the Spring 2006. The 9-27 subgrades will be primarily "fill," but there will be some cut areas. A considerable quantity of excavated soil from the "Deep Pond" was previously stockpiled and will be used as fill.
There are remaining issues concerning subgrade support and the "Stabilized" Subgrade Zone. This project will consider these issues and provide input to OMP for their evaluation and potential adoption.
- Establish pavement design input(s) for subgrade support.
- Establish stabilization requirements with respect to:
- Need for subgrade stabilization
- Stabilization admixture(s) selection
- Stabilization depth
- Estimate "Subgrade Support" for various combinations of subgrade stabilization treatments and prepared subgrade conditions.
Faculty Investigator(s): Leslie Struble
Overview and Objectives:
The objective of this project is to survey and test the suitability of local materials (coarse aggregate, sand, cement, and admixtures) for use in portland cement concrete. This project will interact closely with the project on portland cement concrete mix design. Particularly important is the potential for concrete deterioration due to reactions involving the aggregate (alkali-silica reaction, alkali-carbonate reaction, and freeze-thaw cycles). The project will provide a database of aggregate and sand properties and recommendations concerning aggregates, cements, and admixtures.
The Illinois Department of Transportion (IDOT) is an important resource of information for this project. Immediately available data will be a useful starting point for identifying preferred aggregate sources from the 250 quarries currently serving the State of Illinois. For example, IDOT maintains a testing program for coarse aggregates produced in the Illinois marketplace, and publishes results listing results by quarry here. The list currently includes about 20 quarries serving IDOT District 1 with crushed coarse aggregate meeting their highest quality “40 Design Life” rating. These are generally crushed dolomitic limestone aggregate sources that IDOT believes to have not only excellent freeze-thaw durability but also high ASR resistance. Further evaluation of the most attractive aggregate sources is a core component of this project. The proposed work includes a physical testing program that will provide substantial and detailed knowledge of the performance and variability of fine and coarse aggregates from different sources, as well as consideration of cements and admixtures available to OMP.
In previous work at UIUC for IDOT, we have identified siliceous fine aggregates in Illinois that caused damaging expansion in concrete pavements due to alkali-silica reaction in concrete. The primary reactive component is chert. Therefore sands will be examined for the presence of chert and for reactivity using standard tests.
Through testing at IDOT, experience has been gained in the identification of limestone coarse aggregate that causes damaging expansion and cracking in concrete pavements due to freeze-thaw cycles (the so-called D-cracking). Based on IDOT testing results, aggregate sources will be recommended that show only very good freeze-thaw resistance.
With limestone aggregate, hardness is always a concern. Aggregate that is too soft produces concrete with poor abrasion resistance. Aggregate hardenss will be measured using standard tests.
Other aggregate properties required for concrete mix proportioning will be measured, such as gradation and moisture content.
Aggregate sampling will be done in consultation with quarry management and IDOT personnel to assure that test results are representative of the range of aggregate materials likely to be encountered during concrete production.
The soil and groundwater associated with the OMP will be tested for sulfate content to determine the potential for expansion and cracking of the concrete due to sulfate reaction.
If testing indicates that any of these deterioration processes is likely, recommendations will be made for mitigating damage through the cementitious materials (portland cement and mineral admixtures).
Wherever possible, standard ASTM tests will be utilized.
In previous ACBM research, UIUC has gained experience in testing rheology of cement paste to detect combinations of cement and high-range water-reducing admixture that produce slump loss in concrete. If the project on PCC mix proportioning indicates that such chemical admixtures will be used, then specific cement-admixture combinations will be tested for rheological behavior.Return to top
Faculty Investigator(s): Jeffery Roesler and David Lange
The concrete materials selected for airfield concrete pavements have a large impact on its structural and functional performance. The concrete materials must be optimized to produce a mix that can be easily mixed, placed, cured, and resist the environmental and mechanical loading that will be applied over its service life. The concrete mix design must accommodate volumetric changes at early-ages without premature cracking, limit the amount of thermal and moisture curling, and minimize the long-term contraction-expansion movements which lead to poor joint performance.
Over the past five years, the UIUC concrete pavement and materials research group has been actively involved in experimental research of airfield concrete pavement that specifically addresses concrete shrinkage, creep, and stress development; concrete fatigue, characterizing and design of concrete pavements; curling of concrete slabs; joint design; and fiber-reinforced concrete materials (1-13).
The objective of this research proposal is to investigate concrete material properties required to achieve long-term performance at the Chicago O’Hare International Airport (ORD) and then to develop material constituents and proportions to assure the desired material properties will be met. The project will include analysis of the existing concrete mix designs used for airfield applications, available materials suitable for the proposed mix designs, laboratory tests to determine the shrinkage, creep, and strength of proposed mixes, consideration of mix designs to produce optimal joint types and spacing, and review of fiber-reinforced concrete materials for airfield applications. Appropriate modeling of the results will be completed to extend the understanding of materials not included in the laboratory-testing program. It is expected that the following work plan will take approximately two years to complete with the time critical tasks to be completed first.Return to top