Modern Materials: 2 concrete innovations and a recycled brick

‘Living’ concrete
 
Researchers at the University of Colorado, Boulder, have developed a process that uses an organic material that can be molded into shapes, including bricks (pictured above). The process combines cyanobacteria, warm water, sand, gelatin and nutrients to form microbes that help to cement the sand together. The mixture is then poured into molds to create blocks.
 
While the material is weaker than traditional concrete, 2-inch cubes are strong enough for an average-sized person to stand on and larger blocks, roughly the size of shoe boxes, could function as bricks on a construction site, the researchers said.
 
The draws of this type of living concrete is its ability to reproduce and its potential as a lower carbon alternative to concrete. The bacteria used in the process can continue to help produce more bricks while giving off less greenhouse gases than the production of traditional concrete. 
 
Recycled brick
 
Gabriela Medero, a professor at Heriot-Watt University’s School of Energy, Geoscience, Infrastructure and Society in England, claims she has found a way to make a brick from 100% recycled material. She says K-Briq, which can come in any color, behaves like a traditional clay brick.
 
The difference is that the K-Briq, made from recycled construction and demolition waste, produces one-tenth of the carbon dioxide emitted by a traditional fired brick. Medero came up with the concept 10 years ago, and has been working toward developing the sustainable block ever since. 
 
“I have spent many years researching building materials and have been concerned that modern construction techniques exploit raw materials without considering that they are amongst the largest contributors to carbon emissions,” Medero told the BBC. “The amount of waste they produce is not sustainable long term.”
 
200-year-plus concrete
 
A Japanese industrial manufacturer claims it will commercialize a technology by year's end that could make maintaining concrete much less expensive, the San Francisco Chronicle reported. IHI Corp. has developed a process to prolong reinforced concrete’s useful life to more than 200 years, twice the length of its current lifecycle. The method involves using a new IHI-developed machine, but with the same raw materials as traditional concrete, lowering repeat costs. 
 
The machine inhibits the development of air bubbles during the pouring of concrete by vibrating to remove air pockets while putting pressure on the mixture, the firm said, reducing the holes on the surface by about 70%. 
 
IHI said the technology is designed for infrastructure projects. In tests concrete exposed to rainwater and road salt breaks down slower when it has fewer holes.