The Jack of All Building Materials

By Mason Nichols

Few would question concrete as a key component of the world’s infrastructure. Twice as much concrete is used globally than plastic, aluminum, steel and wood combined. This statistic alone proves the major role concrete plays in meeting our everyday needs (1).

However, what many fail to realize is that technology and concrete go hand in hand. Research on methods to make concrete even more versatile than it already is has allowed it to be used in a nearly endless array of projects and designs. The question thus becomes: Just how versatile of a building material is concrete, exactly? The following examples showcase ongoing concrete advancements, ranging from rapid repairs on roadways to research into “living” buildings.

Precast concrete pavement systems

DOTs, contractors and engineers are increasingly turning to precast concrete pavement systems (PCPSs) as the go-to solution for road repairs that must be made quickly, efficiently and with minimal traffic disruption. Designed for an expansive variety of roadway applications, including intersections, horizontal curves and more, PCPSs are cast and cured off site before any roadwork begins, dramatically reducing the need for traffic mitigation by shortening construction time and allowing the repaired road to reopen immediately upon installation (2). While the slabs can be installed at anytime throughout the day, they are typically installed at night during non-peak hours, reducing risk to workers and lessening delays for drivers.

In Syracuse, N.Y., precast pavement slabs were used for just this purpose in August. Two bridge decks required quick repairs to be made in time for the New York State Fair, scheduled to open just under a month after construction began. A PCPS solution was chosen for the job precisely because of its ability to significantly reduce project duration, according to NYSDOT (3).

Tough talk

While concrete possesses a well-established legacy of strength, researchers are always attempting to make one of the world’s strongest materials even stronger (4).

Jason Weiss, Ph.D., civil engineering professor at Purdue University, has been hard at work for nearly a decade enhancing concrete’s durability through the process of internal curing. Traditionally, concrete is cured by adding water at the surface level. Weiss’ method mixes things up by providing water pockets inside the concrete to enhance the material’s durability (5).

The internally cured concrete has already proven its mettle in Utah, where two bridges were built: one with traditionally cured concrete and one with Weiss’ internally cured alternate. Engineers found the internally cured bridge to be 20 times less likely to crack than its counterpart.

Living, breathing concrete

With the construction industry continuing to focus on sustainability, researchers at the Universitat Politècnica de Catalunya (UPC) in Barcelona, Spain, are putting a whole new spin on the term “green building.”

The Structural Technology Group at UPC has developed a biological concrete that functions as a “living facade,” supporting the growth of lichens, mosses and other microorganisms. Currently, vertical garden systems – designed to achieve the same effect – require complex supporting structures. However, UPC’s biological concrete allows for organisms to grow directly on the surface, achieving a striking aesthetic effect while also allowing for several environmental advantages (6).

Researchers hope to succeed in accelerating the growth of organisms on the biological concrete so that surfaces acquire an attractive facade in less than a year.

Versatility in perspective

Concrete is the most used building material on earth, but has revealed itself to be a quick-change artist as well, capable of meeting the needs of seemingly any project. Innovations in the design and use of concrete will continue to allow for the overall enhancement of the precast concrete industry, opening up possibilities for producers now and into the future.

 Mason Nichols is NPCA’s communication coordinator.

Notes:

1. www.sustainableconcrete.org/?q=node/42
2. For more information on PCPSs and to watch a video of PCPS installation, visit precast.org/pavement.
3. www.syracuse.com/news/index.ssf/2013/07/i-81_to_close_temporarily_in_syracuse_starting_next_friday.html
4. Earlier this year, the Bureau of Reclamation’s Materials Engineering and Research Lab employed a 5-million-lb press to break a concrete cylinder 6 ft high and 3 ft in diameter. The concrete cylinder withstood pressure up to 4.4 million lbs before finally giving way. View the video at www.youtube.com/watch?v=bu3Oq910PPc
5. www.purdue.edu/newsroom/releases/2013/Q1/indiana-using-new-concrete-to-increase-bridge-life-span.html
6. www.upc.edu/saladepremsa/al-dia/mes-noticies/researchers-at-the-upc-develop-a-biological-concrete-for-constructing-201cliving201d-facades-with-lichens-mosses-and-other-microorganisms/?searchterm=concrete