Use of Alternative Pozzolanic Materials Towards Reducing Cement Content in Concrete Pavements
Status: Developing RFP
Today there is a resurgence of interest in using natural and recycled materials-based pozzolans, to reduce the amount of cement and other supplementary cementitious materials in a concrete mix (such as coal combustion derived flyash). In pozzolanic substitution, replacement of cement translates to a significant reduction of carbon footprint. This substitution must be done without compromising the resiliency and durability of the concrete.
Although much research has gone into pozzolanic substitution, there is a paucity in the knowledge base regarding the sustainable limits in the use or inclusion of limestone in the blends. Additionally, there is a missing link between limestone content and actual micro and nano influence because of the intrusion porosimetry of limestone that may have influence on absorption and possible desorption within the matrix. This study will focus on identifying some natural pozzolans, as well as some new recycled materials-based pozzolans, and incorporating them into new pavement test sections. It will also determine the maximum allowable limestone content that can be included in those mixtures, while still providing sufficient durability. Trial mixing will be an integral part of the research process. Suggested alternative pozzolans may include ground glass, recently specified under ASTM C1866-20, finely ground rice husks, as well as other materials of interest.
Each cell will be subjected to the whole gamut of rheological and mechanical tests as well as durability and petrographic analysis. Calorimetric signatures will be required at the plant or during delivery whichever the chosen PI recommends. At the end of the first-year, representative cores will be taken for petrographic analysis. Joints and surfaces will be observed for early degradation and ride quality. To augment non-destructive testing with MIRA or other devices to evaluate in situ effect of the concrete on pavement performance, periodic readings from vibrating wire sensors and dynamic load tests will form part of the data set for analysis during annual performance reports.
- Fatih Bektas, MSU-Mankato
- Dan Gancarz, Illinois Tollway
- Alf Gardiner, Braun Intertec
- Rita Lederle, University of St. Thomas
- Maria Masten, MnDOT (TL)
- Somayeh Nassiri, Washington State University
- Luke Pinkerton, Helix Steel
- Xijun Shi, Texas State University
- Jake Sumeraj, Illinois Tollway
- Hao Yin, Horizon Engineering Consulting
- Initial Project proposal (doc), 4/21/2021