The next time you are walking on a concrete street, take a look under your feet. You may see patches of chalky white, crumbling edges, or a smattering of tiny craters on the surface. The damage is often a result of freezing and thawing of the concrete, where the expansion of frozen water builds pressure inside the material.
“If that pressure has no place to go, it will pop off the surface of concrete,” says Wil Srubar, an assistant professor and materials engineer at the University of Colorado in Boulder, a city where freeze-thaw damage is commonly seen on buildings and streets.
“We really scratched our heads and thought, ‘I wonder how nature deals with freezing temperatures?’” Srubar tells Science Friday in an on-air interview. That kind of question is the basis for many of the studies in his lab. Srubar and his team look to nature’s solutions to infuse life into static buildings and architecture.
In a recent study, Srubar and his team harnessed nature’s methods for handling freezing temperatures to tackle freeze-thaw damage in concrete. Currently, the concrete industry injects tiny air bubbles into the mixture to help alleviate pressure. But there are drawbacks, Srubar explains. The pockets of air lowers the strength and durability. They also act like “super highways” that carry water and ions, such as chlorides, through the concrete, which causes corrosion.
Instead, Srubar looked to antifreeze proteins. These small molecules are found in certain fish, bacteria, insects, and plants and help them live in extremely cold environments. They bind to ice crystals inside the organism, preventing them from freezing solid. However, the intricately folded proteins don’t mix well with the high pH conditions of concrete, explains Srubar. “They like to unfold and even disintegrate at really high pH.”
The team looked to other more stable molecules that can mimic the properties of antifreeze, and used a synthetic biomimetic polymer—one that works similar to the gelatin that makes ice cream smooth. They applied it to a solid ceramic, like concrete, and found that the polymer helped stop the freeze-thaw damage.
Growing up on a farm outside of Houston, Texas, Srubar had always been fascinated by the architectural feats of concrete on visits to the city. When he began to live in cities as an adult, he started to think more about blending aspects of the natural world with fixed materials as a way to create sustainable options.
“Take Central Park in New York City, where there’s a definitive line as to what is natural and what is human. I really started to question that paradigm,” he says. “I want to be a testbed for different materials that I’d like to see in the building industry.”
Explore more photos of living building materials—from transparent wood to bacteria-infused, regenerating scaffolds.
Necessary cookies are absolutely essential for the website to function properly. These cookies ensure basic functionalities and security features of the website, anonymously.
This cookie is used to detect and defend when a client attempt to replay a cookie.This cookie manages the interaction with online bots and takes the appropriate actions.
Issued by Microsoft's ASP.NET Application, this cookie stores session data during a user's website visit.
This cookie is managed by Amazon Web Services and is used for load balancing.
This cookie is set by the provider Akamai Bot Manager. This cookie is used to manage the interaction with the online bots. It also helps in fraud preventions
Set by the GDPR Cookie Consent plugin, this cookie is used to record the user consent for the cookies in the "Advertisement" category .
This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
This cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
This cookie is associated with Django web development platform for python. Used to help protect the website against Cross-Site Request Forgery attacks
The JSESSIONID cookie is used by New Relic to store a session identifier so that New Relic can monitor session counts for an application.
A load balancing cookie set to ensure requests by a client are sent to the same origin server.
This cookie is native to PHP applications. The cookie is used to store and identify a users' unique session ID for the purpose of managing user session on the website. The cookie is a session cookies and is deleted when all the browser windows are closed.
The TiPMix cookie is set by Azure to determine which web server the users must be directed to.
SiteLock sets this cookie to provide cloud-based website security services.
This cookie is used for load balancing purposes. The cookie does not store any personally identifiable data.
Azure sets this cookie for routing production traffic by specifying the production slot.
Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better experience for the visitors. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.
Cookie used to remember the user's Disqus login credentials across websites that use Disqus.
This cookie is installed by Google Universal Analytics to restrain request rate and thus limit the collection of data on high traffic sites.
A variation of the _gat cookie set by Google Analytics and Google Tag Manager to allow website owners to track visitor behaviour and measure site performance. The pattern element in the name contains the unique identity number of the account or website it relates to.
AWSALB is an application load balancer cookie set by Amazon Web Services to map the session to the target.
This cookie is used for storing country code selected from country selector.
Analytical cookies are used to understand how visitors interact with the website. These cookies help provide anonymized information on metrics the number of visitors, bounce rate, traffic source, etc. The use of these cookies is strictly limited to measuring the site's audience. These cookies do not allow the tracking of navigation on other websites and the data collected is not combined or shared with third parties.