Exploratory Advanced Research . . . Next Generation Transportation Solutions

tial incompatibilities between the fly ash, admixtures, and cement. To overcome this, the project 

team is developing screening procedures to identify the influence and properties of residual carbon 

on the rate of admixture absorption. Once all challenges are overcome, innovative strategies such 

as fly ash treatment, timing and rate of admixture 

addition, and prescreening of components for optimal performance can be implemented to improve 

the response of the overall system. 

Moving Forward 

The conventional approach to using fly ash has relied on the establishment of strict limits on the 

maximum amount of fly ash and the times of year 

that fly ash can be used in construction. 

Conventional applications also have set limits on 

the composition of the fly ash to enable the fly-ashcement system to be treated the same way conventional portland cement has been treated in 

concrete. This project moves in a new direction by 

proposing innovative solutions to the use of fly ash 

in mixture proportioning. Fly ash is not used on a 

prescription basis, but on a performance basis—so 

that more fly ash can be used in concrete, and less 

will go to a landfill. New design methodologies are 

needed to predict strength, and new strategies to 

overcome issues associated with HVFA use. One 

example of innovation is the team’s work with new 

internal curing technologies, with the intention of 

efficiently supplying water for hydration directly inside the concrete after placement. Another area of 

innovation is the use of low temperature calorimetry to determine the length of curing needed to 

ensure that concrete can ultimately be exposed to 

stresses brought on by freezing and thawing.

Concrete Solutions

The project kicked off with a literature review and 

consideration of the commercial, specification, and 

quality assurance impacts associated with the use 

of HVFA. The research and innovation phase of 

The Exploratory Advanced Research Program Fact Sheet

Obstacles to HVFA Use

Many producers and transportation agencies aim to 

increase the use of fly ash in the transportation infrastructure—however, several barriers exist to implementing new mixtures. A particular concern of 

many practitioners is the difficulty of predicting 

strength gain in full-scale structures. The project addresses this problem through the use of temperature management software and the development of 

a database with analytical prediction tools. In addition, agencies and contractors worry about potenHigh volume fly ash (HVFA) concrete 

mixtures offer many benefits, including reduced cost, reduced energy content, 

enhanced environmental sustainability, 

and improved long-term performance. The 

aim of “Greatly Increased Use of Fly Ash in 

Hydraulic Cement Concrete (HCC) for 

Pavement Layers and Transportation 

Structures,” an Exploratory Advanced Research (EAR) Program project, is to identify innovative methods to overcome existing barriers to use, and work towards the 

increased use of HVFA in pavements and 

transportation structures. The 24-month 

project, part of a Federal Highway Administration (FHWA) initiative, is being conducted by Purdue University in partnership with Auburn University, the National 

Institute of Standards and Technology, 

and the National Ready Mixed Concrete 

Association.

Benefits of High Volume Fly Ash 

New Concrete Mixtures Provide Financial, Environmental, and Performance Gains
the project was designed to resolve identified issues by probing in new directions. Areas examined 

include investigating material compatibility, predicting property development, managing temperature 

and strength development, controlling internal and 

external curing, reducing early-age cracking, and 

improving freezing and scaling durability. In addition, carefully controlled large-scale test sections 

were prepared to evaluate the proposed solutions 

identified in each project phase. This form of largescale testing is unique due to the ability to carefully 

establish and monitor the environment in which the 

HVFA concrete is placed while monitoring test 

structures. 

Concrete of the Future

“The impact of this project on the materials used in 

the Nation’s transportation systems and highway 

programs is expected to be significant,” says 

Richard Meininger at FHWA. “Entirely new concepts 

are being put forward here that really get to the 

heart of the critical issues currently limiting the 

amounts and sources of fly ash used in construction,” continues Meininger. “The implementation of 

the technologies being developed is expected to 

guide the concrete mixture designs and proportions of the future, ultimately offering pavements 

and other concrete structures with a smaller carbon 

footprint and lower embodied energy while also 

showing the improved long-time performance possible with fly ash.”

Learn More

For more information on this EAR Program project, 

contact Richard Meininger at FHWA, 202-493-3191. 

(email: richard.meininger@dot.gov).

What Is the Exploratory 

Advanced Research Program?

FHWA’s Exploratory Advanced Research (EAR) 

Program focuses on long-term, high-risk research with a high payoff potential. The program addresses underlying gaps faced by applied highway research programs, anticipates 

emerging issues with national implications, 

and reflects broad transportation industry 

goals and objectives. 

To learn more about the EAR Program, visit 

the Exploratory Advanced Research Web site 

at www.fhwa.dot.gov/advancedresearch. The 

site features information on research solicitations, updates on ongoing research, links to 

published materials, summaries of past EAR 

Program events, and details on upcoming 

events. For additional information, contact 

David Kuehn at FHWA, 202-493-3414 (email: 

david.kuehn@fhwa.dot.gov), or Terry Halkyard 

at FHWA, 202-493-3467 (email: terry.halkyard@

fhwa.dot.gov).

Publication No. 

FHWA-HRT-10-022

HRTM-04/11-09(1M)E

Benefits of High Volume Fly Ash 

New Concrete Mixtures Provide Financial, Environmental, and Performance Gains

Publication No. 

FHWA-HRT-10-051

HRTM-04/05-10(1M)E

Image other side: 

Durability and Volume Change 

Specimens at Purdue University 

Photo credit: FHWA Photo 2010