The Future of Concrete
By Korey Pangburn, Assistant Project Manager, DEI Incorporated
Concrete is one of the most common building materials around. Whether it’s in the foundations of a pole-barn or the columns and decks of a 100,000 person capacity stadium, if a structure is being built, they will be using concrete in one form or another. This fundamental material has been used in various forms for centuries, and most people would think not much has changed since. Let’s take a look at some of the latest advances in the concrete industry.
“Green” Concrete
Portland cement is one of the 3 major components in freshly mixed concrete, the other two being aggregate (like sand and gravel), and water. Unfortunately, cement production creates a substantial amount of air pollution and requires a lot of energy. To help reduce the impact on the environment, some new cementitious materials have been developed. Some of these cement alternatives use waste products from other industries. Fly ash from coal power plants, and slag from steel and iron plants can be used to replace some of the Portland cement (or all in certain mixes) in concrete mixes. By using the fly ash and slag that’s already been produced, concrete plants can reduce the amount of cement they use and offset it with what could almost be called recycled material.
Another form of eco-friendly concrete is carbon-absorbing concrete, or decarbonizing concrete. In combination with cleaner cement, some companies are developing concrete that can actively absorb and store carbon dioxide from the atmosphere. This process, called carbon mineralization, already happens to our concrete naturally. It is possibly detrimental to typical concrete though and may cause premature cracking and corrosion. By controlling that process, there are concrete mixes being tested now that can safely absorb CO2 from the atmosphere through out the life of the structure, further offsetting the amount of pollution created during cement production.
Self-Healing Concrete
Self-healing concrete is currently under development. One technique being studied is the use of super absorbent polymers mixed throughout the concrete. This slows the curing time, and prevents the concrete from shrinking, which is the most common cause of cracked concrete paving and sidewalks. Another method involves using crystalline admixtures that, when re-exposed to air or water at the surface of the crack, begin to release cementitious compounds.
3D Printing with Concrete
Another great advancement comes not from the concrete or cement itself, but how it’s used. Also called additive manufacturing, 3D printing is the process of creating an object by adding layers of material on top of one another. Most will be familiar with desktop 3D printers that use plastic filament, where the plastic is fed into the printer, melted and then deposited in layers. The same process, albeit mounted on a large truck and not a computer desk, can be used with cement to build houses. A 4-person crew can erect the shell of a house in half the time of traditional framing, with half the crew.
With advances in cement and concrete still on the horizon, including sustainability and affordability, there’s no end in sight to our use of this foundational building material.
