Class F Fly Ash Assessment for Use in Concrete Pavement

Project Details









Konstantin Sobolev, Mohamadreza Moini, Rani Pradoto, Marina Kozhukhova, Ismael Flores-Vivian, Scott Muzenski, Habib Tabatabai, Hani H Titi


Wisconsin Department of Transportation


Concrete pavements, Durability, Evaluation, Fly ash, Mix design, Pavement performance, Paving, Specifications, Strength of materials

Project description

The Wisconsin Department of Transportation (WisDOT) currently specifies Class C fly ash for use as a partial replacement for Portland cement in concrete pavements. Class F fly ash sources were eliminated from WisDOT specifications in the 1990s due to high values of loss on ignition (LOI) which led to difficulties in establishing and maintaining a proper entrained air void system in the concrete used in paving applications. A recent study that looked at the use of Class F fly ash demonstrated its potential usage in WisDOT specifications. However, research is needed to evaluate the feasibility of expanding current specifications to allow for use of Class F fly ash in concrete paving applications with southern Wisconsin aggregates. In order for Class F fly ash to be a viable alternative as a supplemental cementitious material, its use must produce mixes that meet current performance standards in respect to strength (including early strength) and durability, when compared with a commonly used Class C fly ash. The main objective of this study is to evaluate whether the locally available Class F fly ash from Elm Road Generating Station, operated by WE Energies and located in Oak Creek, Wisconsin, will provide satisfactory performance in concrete pavement, in comparison with a Class C fly ash from Columbia Energy Center currently in use. The study will also provide mix design guidance related to acceptable proportions of Class F fly ash that can be used in paving applications without negatively impacting performance.