• Are concrete makers moving fast enough to switch to lower-carbon products?
  • Newsletter
  • Donate
Clean energy journalism for a cooler tomorrow

Are concrete makers moving fast enough to switch to lower-carbon products?

A new report says major manufacturers of concrete and cement are dragging their feet on decarbonization — and government inertia isn’t helping either.
By Ingrid Lobet

  • Link copied to clipboard
(VCG via Getty Images)

In the spring of 2017, one California state legislator was trying to advance a significant climate bill. The Buy Clean California Act would direct the state to use its enormous purchasing power to require manufacturers to reveal how much carbon dioxide was released in the manufacture of building materials. This would help create a market for cleaner products.

But one day in May of that year, as interested parties weighed in and the language of the bill evolved, all references to concrete and cement disappeared. The bill, AB 262, sponsored by former Assemblymember Rob Bonta (D), now California’s attorney general, ultimately did become law. That meant public project managers had to start taking into account the climate impact of construction materials including glass, rebar and steel beams — but not concrete or cement, the glue that holds concrete together.

That’s a significant omission because cement is responsible for an estimated 7 to 8 percent of carbon dioxide emissions worldwide. In the United States, California is the second-largest producer of cement after Texas.

Now a paper published by the American Economic Liberties Project argues that it’s no surprise that cement was removed from California’s Buy Clean legislation. The authors say that industry players exert too much influence over government standards, thwarting innovation in the emerging clean concrete” sector.

Concrete is the fundamental building material in things like highways and high-rise buildings, and the industry has rigorous performance standards to ensure safe construction. But the global firms that dominate the industry have little incentive to innovate, even though cleaner concrete options have been proven to be safe, according to the report.

Incumbents are closely intertwined with the bodies that establish the standards and codes that largely determine which cements and concretes are used in construction projects,” the report says. It points out that state highway departments, some of the largest purchasers of concrete, at best are failing to change their procurement practices at the pace required by climate change, and at worst are actively lobbying against progress.

The concrete industry is heavily consolidated

The American Economic Liberties Project is an advocacy organization founded on antitrust principles that opposes industry concentration in many sectors. The funding for its report on concrete came from the ClimateWorks Foundation, according to Krista Brown, one of the authors.

Five global building materials companies — Cemex, LafargeHolcim, Martin Marietta Materials, Buzzi Unicem and HeidelbergCement — control 43 percent of cement manufacturing in the United States, according to industry research firm IBISWorld. Typically, there are only a few factories in a given region that make cement, which is by far the highest-carbon component of concrete. That cement is then distributed to dozens of plants that mix it with aggregate and sand to make concrete, which is then dispatched to construction sites, often in those familiar rotating concrete trucks.

Global building materials companies are often vertically integrated, owning both cement kilns and concrete plants, plus the rock quarries and mines further upstream.

The report argues that these companies are heavily invested in the status quo and thus often work against change. Manufacturers do invest in and tinker with clean concrete technologies, but these efforts rarely progress past demonstration projects, the authors state. To the extent incumbents are exploring low-carbon cements, they have not commercialized them at scale.”

Carbon-cutting tech has been slow to come to market

The report warns that regulators should make sure dominant firms do not buy up clean cement and concrete startups and collect intellectual property but then fail to deploy it.

One example the report cited is that of Solidia Technologies, an alternative cement company whose process allows for lower temperatures, which means lower carbon emissions. Solidia also cures its cement in rooms enriched with carbon dioxide, which leads the concrete to absorb more CO2. This also makes it a good match for precast concrete, often used to construct buildings.

Cement giant Lafarge, a unit of Swiss company Holcim, invested in Solidia back in 2014. The next year Lafarge announced it had reached an agreement to commercialize Solidia’s low-carbon process. But six years later, there has been little progress made toward commercialization, the report says.

Responding to a request for comment, Holcim representative Anne Schlatter said the company has just announced a pledge to reach net-zero carbon by 2050. Last year it launched a new product, ECOPact green concrete, that is now being sold in 25 markets, she added.

Using less material is one of the most important ways to reduce carbon emissions from this industry, many experts say. To that end, Schlatter said Holcim is working on 3D concrete printing, a process whereby robots lay down wet concrete in layers, which reduces the amount of concrete needed. Some companies are using 3D concrete printing to make a range of structures, from backyard dwelling units to wind turbine bases.

Last month, Lafarge signed a contract with the China National Building Material subsidiary Sinoma International Engineering to build a factory to make calcined clay, a tried-and-true component that yields cement with lower embedded carbon.

The report also questions whether Mexico-based Cemex will make a serious effort to market its net-zero concrete product, Vertua. Cemex has a net-zero target for all of its concrete by 2050, as well as a 2030 goal of 40 percent lower emissions compared to 1990 levels.

Jorge Luis Perez Aguirre of Cemex said in an email that Vertua, initially launched in 2018, is being introduced globally and the company continues the rollout of Vertua during 2021.” Press releases indicate projects in the U.K., France, Germany, Poland, Mexico and Colombia are using the product.

Industry and government inertia holds back lower-carbon alternatives

Some of the points made in the paper have been echoed at cement industry conferences. For example, the authors take issue with the grindingly slow pace of change within government agencies that set performance codes and standards for cement. This is a major barrier for startups that are seeking to offer new lower-carbon cements.

You have to get your cement approved as an acceptable material, and that is extremely difficult,” said Ian Riley, CEO of the World Cement Association.

Some industry insiders cite the innate conservatism of structural engineers, whose job it is to make sure bridges and other structures do not fall down, as the reason for the inertia. But there are known lower-carbon methods that don’t compromise safety. The problem, many say, is that project specifications are written in a way that doesn’t allow these innovations.

The written specifications take precedence over what architects and construction firms might wish to do to reduce carbon emissions, limiting their options, said Lionel Lemay, executive vice president of the National Ready Mix Concrete Association. For example, he said, many project specifications require the exclusive use of Portland cement, the most common cement variety, even though there is a widely known material that can serve as a partial substitute, Portland limestone cement, which reduces carbon emissions.

Major buyers of cement could push for these lower-carbon alternatives, according to industry experts. State departments of transportation (DOTs), which are some of the nation’s largest consumers of cement, could play an outsize role in moving markets.

Michael Ireland, president and CEO of the Portland Cement Association, which represents nearly all the major cement producers including LafargeHolcim and Cemex, recently wrote that if state DOTs encouraged the increased adoption of Portland limestone cement by just 10 percent by 2030, we could reduce nearly 10 million metric tons of CO2” by then.

The American Economic Liberties Project report cites only one DOT committed to using lower-carbon concrete (specifically carbon-injected concrete) in future construction projects: the Hawaii Department of Transportation. California’s department of transportation, Caltrans, demonstrated significant opposition” to the inclusion of cement in the Buy Clean California Act in 2017, because that would significantly increase [Caltrans’] costs,” the report states.

To date, a handful of states have taken action to promote low-carbon alternatives,” report author Brown said. The report argues that states and local governments should commit to purchasing lower-carbon cements and concretes and should set carbon-intensity targets for major projects.

When asked for comment on the report, a Caltrans spokesperson said that new specifications issued on October 15 allow for more lower-carbon cement, but they still do not require any. The department did not respond to a question about its role in shaping the 2017 bill. The Texas Department of Transportation also failed to respond to queries.

Brown doesn’t buy the proposition that big cement companies are genuinely pushing for low-carbon cement or concrete requirements. In fact, the report asserts that industry pushback is a key reason cement was removed from the 2017 Buy Clean California legislation.

Kathryn Phillips, who worked on that 2017 legislation while she was director of Sierra Club California, agreed. She said cement was taken out of the law because cement-related companies reached out to many of the 300 concrete plants across California and asked them to oppose its inclusion.

It didn’t take much to stir up concrete plants in every district that could call up their legislator” and say the jobs at that plant would be lost if the bill included cement, she said. The opposition just became too hard” to overcome.

Ingrid Lobet currently divides her time between reporting on climate solutions and investigative work on climate, energy and environmental health.