Concrete

We've already heard about experimental self-healing concrete, that can repair cracks within itself. Now, scientists have gone a step further, utilizing bacteria to create building materials that can be grown on-site – and that regenerate when broken.

A new solar-powered catalyst made of graphene and titanium dioxide nanoparticles can pluck pollutants out of the air, much more efficiently than others. The catalyst could be coated onto building or street surfaces to improve air quality in cities.

Like anything else, concrete structures get dirty over time, and it's a hassle to clean them. Such chores may soon no longer be necessary, however, as scientists have developed what they claim is a self-cleaning concrete that isn't heavy – or weak.

Concrete is a mix of cement, an aggregate such as gravel, and water. For added strength, steel fibers are often added. Now, scientists are claiming that a new type of fiber-reinforced concrete could soon serve as a lighter and greener alternative.

Buildings that are constructed with military or civil defense applications in mind need to be tough. It was with this in mind that a new form of concrete was recently developed, that is far more resistant to cracking than regular types.

Concrete is made of a combination of cement, an aggregate such as gravel, and water. If that mixture dries too fast, then cracks can form within it as it cures. Now, however, scientists have determined that the use of coal-ash spheres can help keep that from happening.

Making cement is one of the biggest contributors of carbon emissions. Now MIT researchers have developed a new method that can clean up the process.

​While many of us might think that concrete structures such as bridges simply stand unaided for decades at a time, the fact is that they require maintenance as often as once every five years. An experimental new type of rebar, however, could drastically change that.

​Although glass is thought of as being eco-friendly because it's recyclable, the fact is that a lot of it doesn't get recycled. Now, however, scientists are suggesting that glass waste could be used to make concrete that's stronger and cheaper.

Casa B, by Italian firm Architrend Architecture, is a recently-completed concrete townhouse that's fronted by a glazed facade. In a novel touch that brings to mind Casa Brutale, the home also has a glass-bottomed swimming pool up top.

​When calcium chloride de-icer is spread on sidewalks or roads, it reacts with the calcium hydroxide in concrete, creating calcium oxychloride. Also known as CAOXY, this substance expands within the concrete, causing it to crack. Adding bacteria, however, may keep that from happening.

Utilizing tape to repair concrete structures may seem like some hillbilly fix-it joke, but in fact that's just what fiber reinforced polymer (FRP) sheets are used for. Now, scientists have developed a better FRP, that halves the number of people and amount of time required for application.