Living concrete for structural load-bearing and biological function

Researchers at the University of Colorado Boulder have developed a new living concrete, offering green alternatives to modern building materials by literally bringing them to life. The new concrete combines sand and bacteria to build a living material that has structural load-bearing and biological function.

Concrete is the second most used material on earth after water. Its production process, however, is not sustainable. Cement, the powder to make concrete is responsible for 6% of CO2 emissions, and concrete releases CO2 when it cures.

living concrete scaffold with hydrogel to strengthen building materials

The College of Engineering and Applied Science at Colorado University Boulder team created a scaffold out of sand and hydrogel for bacteria to grow in. The hydrogel retains moisture and nutrients for the bacteria to proliferate and mineralise, a process similar to the formation of seashells in the ocean. Combining the three, the researchers created a green living material that demonstrates similar strength to cement-based mortar.

“We use photosynthetic cyanobacteria to biomineralize the scaffold, so it actually is really green. It looks like a Frankenstein-type material,” says senior author Wil Srubar, who heads the Living Materials Laboratory at the University of Colorado Boulder. “That’s exactly what we’re trying to create—something that stays alive.”

The hydrogel-sand brick is not only alive, but it also reproduces. By splitting the brick in half, the bacteria can grow into two complete bricks with the help of some extra sand, hydrogel and nutrients. Instead of manufacturing the bricks one by one, Srubar and his team demonstrated that one parent brick could reproduce up to eight bricks after three generations.

living concrete mould bacteria

“What we’re really excited about is that this challenges the conventional ways in which we manufacture structural building materials,” says Srubar. “It really demonstrates the capability of exponential material manufacturing.”

However, there is a trade-off with this green material.

The brick needs to be completely dried out to attain strength, but at the same time, drying stresses the bacteria and compromises its viability. To maintain structural function and ensure microbial survivability, the concept of optimum relative humidity and storage conditions is critical. Utilizing the humidity and temperature as physical switches, the researchers can control when the bacteria grow and when the material stays dormant to serve structural functions.

“This is a material platform that sets the stage for brand new exciting materials that can be engineered to interact and respond to their environments,” says Srubar. “We are just trying to bring building materials to life, and I think that is the nugget in this whole thing. We’re just scratching the surface and laying the foundation of a new discipline. The sky is the limit.”

The next step for Srubar and his team is to explore the numerous applications that the material platform brings. Srubar envisions introducing bacteria with different functionalities to the material platform to create new materials with biological functions, such as ones that sense and respond to toxins in the air. Other applications include building structures where there are limited resources like the desert or even another planet.

“In austere environments, these materials would perform especially well because they use light from the sun to grow and proliferate with very little exogenous material needed for their growth,” says Srubar. “It’s going to happen one way or another, and we’re not going to be trucking bags of cement all the way to Mars. I really do think that we’ll be bringing biology with us once we go.”



Latest


03 Mar 2021
10 Commandments for proper construction

With the pandemic having created a survival mode for much smaller and emerging building contractors, it is now more important…

10 Commandments for proper construction

With the pandemic having created a survival mode for much smaller and emerging building contractors, it is now more important than ever for site staff to have at least a basic knowledge of concrete behaviour and performance in construction, says John Roxburgh, senior lecturer at the School of Concrete Technology.…

02 Mar 2021
Highlighting the fire risk faced by hospitals

The biggest challenge faced by hospitals; when it comes to fire risk; is that a large number of occupants are…

Highlighting the fire risk faced by hospitals

The biggest challenge faced by hospitals; when it comes to fire risk; is that a large number of occupants are either incapacitated or immobilised. This renders them extremely vulnerable; ASP Fire CEO Michael van Niekerk highlights. Hospitals must be able to compartmentalise wards in the event of a fire so…

01 Mar 2021
Going green. How Harvey EcoTile® is transforming roofing.

A building’s green credentials are determined by a variety of factors such as water efficiency; energy efficiency; environmentally friendly materials;…

Going green. How Harvey EcoTile® is transforming roofing.

A building’s green credentials are determined by a variety of factors such as water efficiency; energy efficiency; environmentally friendly materials; waste reduction; lowering carbon emissions and sustainable development and growth. In pursuit of sustainable, revolutionary roofing, Harvey Roofing Products has developed the Harvey EcoTile®, a sustainably produced mineral composite roof…

01 Mar 2021
Cement & Concrete SA established to drive the industry to new heights

Cement & Concrete SA (CCSA) has today announced that the new consolidated industry body is open for business and is…

Cement & Concrete SA established to drive the industry to new heights

Cement & Concrete SA (CCSA) has today announced that the new consolidated industry body is open for business and is set to take the lead on all matters relating to cement and concrete in South Africa. The single non-profit entity, CCSA, was established through an extensive and thorough process of…


Top stories


23 Jan 2020
Refurbishment at North West University

As the three established divisions of Norcros SA, TAL, Johnson Tiles and Tile Africa recently played important roles in an…

Refurbishment at North West University

As the three established divisions of Norcros SA, TAL, Johnson Tiles and Tile Africa recently played important roles in an extensive tiling project at North-West University’s Potchefstroom campus in North West Province. The project entailed refurbishing the five-block Sports Village, a guest house facility providing accommodation for the public, athletes…

06 Mar 2020
7 Awe-inspiring marble use cases

Marble, an exceptionally versatile material used for centuries to create awe-inspiring art, majestic staircases, classic kitchens and resplendent flooring. With…

7 Awe-inspiring marble use cases

Marble, an exceptionally versatile material used for centuries to create awe-inspiring art, majestic staircases, classic kitchens and resplendent flooring. With today’s contemporary design trends, the wide selection of marble can be used in more ways than ever before.

05 Mar 2020
First Green Key Boutique Hotel in South Africa

21 Nettleton attains their Green Key Award from WESSA, becoming South Africa’s first boutique hotel to achieve this accolade for…

First Green Key Boutique Hotel in South Africa

21 Nettleton attains their Green Key Award from WESSA, becoming South Africa’s first boutique hotel to achieve this accolade for its efforts in sustainability. An exciting partnership between WESSA and 21 Nettleton has resulted in the private boutique hotel in Clifton, Cape Town being awarded the prestigious Green Key award.…

27 Feb 2020
The Nxuba wind farm Renewable Energy

In its ongoing efforts to showcase the potential that renewables can play in boosting the security of energy supplies in…

The Nxuba wind farm Renewable Energy

In its ongoing efforts to showcase the potential that renewables can play in boosting the security of energy supplies in South Africa, Enel Green Power (EGP) highlights its commitment to the country as it nears the completion of its Nxuba wind farm in the Eastern Cape. The company recently started…


Visit the official COVID-19 government website to stay informed: sacoronavirus.co.za