A contractor smooths out concrete on a sidewalk.For the last 200 years, the role of concrete has been set in society. The miracle chemical reaction that binds water, sand, rock, and a dry compound containing limestone can be found in our bridges, buildings, pipes, and highways. Concrete is everywhere.

And therein lies the problem. In our effort to reduce carbon emissions, a lot of attention is given to the 1.4 billion fossil-fueled vehicles and farting cows that increase our carbon footprint. But concrete generates almost 10% of all human-caused carbon emissions.

Fortunately, there are workarounds, and Washington State is becoming a proving ground for new ideas in the production and use of concrete. The only thing lacking up until now is a business case.

The occasional shake of a quake challenges builders and manufacturers alike to think outside the box when it comes to using materials that are not only cost-effective but also long-lasting and disaster-resistant. Add in the need to battle climate change, and concrete is ripe for reinvention.

So, what’s new in the concrete world in Washington?

Innovation is happening on many fronts. The main focus is on finding new materials to replace the limestone in concrete since it is a real resource hog. Possibilities include granulated slag from steel mills and even algae. One Seattle building near Green Lake was way ahead of its time, using locally sourced minerals to bind its foundation 112 years ago. It’s still standing firm.

In Eastern Washington, those crafty researchers at Washington State University have even been toying with a “carbon-negative” cement that uses black biochar made from plants. Not only is it strong, but it also traps carbon as it hardens.

Worldwide, cement production stands at 4.2 billion tons. That’s about 1,000 pounds per human. The crushed limestone and clay must be heated to 2,700 degrees to manufacture the mix. The byproduct of this process is carbon dioxide. Add in the emissions from the kiln, whether it’s fueled by oil, coal, or natural gas, and you can see why cement is such a problem for the environment.

To reinvent the material, researchers are looking back in time. The ancient Romans built the Colosseum and all those cool arched aqueducts that stand today using volcanic pumice, a pozzolan that doesn’t release carbon dioxide when mixed with water.

So you won’t have to Google it, a pozzolan is a material that doesn’t have the property of cement by itself, but when mixed with calcium hydroxide and water, it becomes very cement-like in form and function. The primary pozzolan in use today is fly ash, but its days are numbered since it is a byproduct of coal combustion.

Back to Washington State University. WSU is experimenting with biochar, which has been used as a fertilizer since ancient times. It’s widely available, as it uses heated wood and plant debris. In its initial state, it’s not a very good binder. However, the WSU team has found a way to condition the biochar to add the necessary strength. As an added bonus, it recycles alkaline wastewater in the process.

The resulting bricks can stand up to 660 pounds per square inch of lateral force and 5,000 pounds per square inch of compression. That’s the industry standard for concrete products, so it shows tremendous promise.

But that’s just the beginning, say researchers. Thanks to support from the Spokane Tribe of Indians and the Washington State Department of Commerce, workers will create their first experimental roadway using various recipes. The real-world test will help the team solidify their mix and get it ready for prime time.

Want to see more concrete examples of Washington’s legendary innovation?

Read all about it in The Seattle Times…