Concrete is one of the oldest materials on the planet, but it has taken thousands of years for it to mature. Scientists have only begun to decode how concrete behaves at the atomic level. Those molecular structures are yielding new clues that could change the way industry builds.
Groundbreaking research at the Massachusetts Institute of Technology promises to yield super cements that would reduce their environmental impact and push performance to new extremes. Cement groups funding the project also are using MIT's research to bolster their multibillion-dollar marketplace, which isn't setting well with makers of competing materials, such as asphalt.
Concrete is the world's most consumed man-made material. Production of portland cement, the binder that holds together concrete, accounts for about 5% of the world's annual carbon dioxide emissions. The material also has economic impacts. Recent findings from MIT's Concrete Sustainability Hub, whose work is being funded under a $10-million, five-year grant from the Portland Cement Association and Ready Mixed Concrete Research and Education Foundation, claim that concrete is less susceptible to commodity price fluctuations, especially oil prices, than asphalt. The finding has lawmakers in Washington, D.C., considering a revision to federal procurement protocols, such as how contracting agencies calculate life-cycle costs of investments in roads, buildings and other infrastructure. The changes could impact the price competitiveness of asphalt.
Cement lobbyists argue that infrastructure in the U.S. is underfunded, so any move to shave construction costs is good. Others disagree. "It would be really unprecedented for the Congress and the executive office of the White House to take control over the pavement design for roads in our country," says Jay Hansen, executive vice president at the National Asphalt Pavement Association.
MIT's August report, "The Effects of Inflation and Its Volatility on the Choice of Construction Alternatives," suggests that highway authorities, when conducting a life-cycle cost analysis (LCCA), should use escalation rates indexed to a material's historical inflation rate rather than to a fixed, general inflation rate. The paper forecasts real asphalt prices rising by 95%—largely due to oil prices—and real concrete prices dropping by 20% over the next 50 years. It sees steel and lumber prices falling a respective 28% and 44% in the same period.
"Asphalt inflation is likely to outstrip overall inflation, meaning that an LCCA assuming constant real costs will exaggerate asphalt's price competitiveness," according to MIT's August report.
Since the report's release, several measures in Congress have included language that would require the government to review its LCCA calculations. December's omnibus spending package included a review of material-specific inflation in Circular A-94, the Office of Management and Budget's protocol for calculating costs. Furthermore, the Senate's proposed two-year transportation bill also calls for a similar review.
NAPA recently hired an economics firm, Jack Faucett Associates, to scrutinize the MIT study (whose lead author is Lawrence Lindsey, former director of the National Economic Council and economic adviser to former President George W. Bush). In a white paper released this month, the NAPA study concludes that "the use of historical data in a forward-looking LCCA is not considered valid." It also accuses the concrete industry of pushing the MIT findings "in an effort to become the pavement of choice."
PCA says it is using the MIT data to benefit taxpayers and its own members. "Government funding is always going to be challenging," says Brian McCarthy, PCA's president and CEO, adding, "We see that by bringing this research to the table, by bringing it to local state DOTs, our members will have a better chance at gaining market share." Concrete represents less than 10% of all U.S. pavements.
An official with the American Road and Transportation Builders Association, a trade group that claims to be agnostic on materials, declined to comment on the MIT paper but agrees material prices are more important today than in the past.