Does the future of sustainable construction lie in self-healing concrete?
Concrete is the most widely used mater...
Of all the carbon emitters that surround us every day it’s easy to overlook one of the most ubiquitous: concrete.
Concrete is the most widely used material in the construction industry, used to build our buildings, pave our roads and span our bridges, and by 2030 urban growth in China and India will place global cement output at 5bn metric tons per year, with current output already responsible for eight percent of the global emissions total, according to an article in the Guardian.
Although its environmental impact is far from benign, concrete – defined as the mixture of aggregates, water and the hydraulic powder material known as cement – is incredibly useful and widely applicable. Thanks to its durability, easily-sourced raw materials and thermal resistance, it is unlikely that an alternative building material will replace it on a large scale any time soon.
That being said, Hendrik Jonkers, a microbiologist at Delft University and a finalist at the recent 10th annual European Inventor Awards, has a plan to increase the lifespan of concrete, making it a more sustainable and thus a more viable solution for many more years to come.
His innovation, which embeds self-activating limestone-producing bacteria into the building material, is designed to decrease the amount of new concrete produced and lower maintenance and repair costs for city officials, building owners and homeowners.
“One of my colleagues, a civil engineer with no knowledge of microbiology, read about applying limestone-producing bacteria to monuments [to preserve them],” Jonkers told the Guardian. “He asked me: ‘Is it possible for buildings?’ Then my task was to find the right bacteria that could not only survive being mixed into concrete, but also actively start a self-healing process.”
Healing cracks in concrete is expensive. According to HealCON, the project working on the self-healing concrete, annual maintenance cost for bridges, tunnels and other essential infrastructure in the EU reaches €6bn (£4.2bn) a year.
The new invention comes in three forms: a spray that can be applied to existing construction for small cracks that need repairing, a repair mortar for structural repair of large damage and self-healing concrete itself, which can be mixed in quantities as needed. While the spray is commercially available, the latter two are currently in field tests. One application that Jonkers predicts will be widely useful for urban planners is highway infrastructure, where the use of de-icing salts is notoriously detrimental to concrete-paved roads.
Encouraging as it sounds, Jonkers’ self-healing concrete can’t cure very wide cracks or potholes on roads just yet; the technology is currently able to mend cracks up to 0.8mm wide. And while making better concrete is a more feasible approach to sustainable building than shifting to an entirely new building material, that doesn’t mean the innovation is a sure bet. The current cost would be prohibitive for many. A standard-priced cubic meter of concrete is €70, according to Jonkers, while the self-healing variety would cost €100.
John Alker, director of policy at the UK Green Building Council, says the success of any new green infrastructure technology relies on innovators like Jonkers being able to demonstrate the particular benefit of a product, whether that’s around cost or enabling a client to meet environmental targets.
“We’ve seen a lot of innovation around concrete as it is a highly impactful product in terms of the energy that goes into producing it and it’s simultaneously a very important construction product globally,” Alker said. But persuading the construction industry to change its behaviour will be tough, he says. “It comes down to innovative clients and developers being willing to experiment with their building and try and test these materials and prove a track record before others will follow.”
Though Jonkers is aware of the challenges of reaching wide adoption of the material, he points out that in particularly vulnerable environments – such as coastal communities or tropical regions that are increasingly experiencing extreme rainfall – some are already seeing the cost-benefit analysis of using this technology from the outset.
“We did a project in Ecuador where we made a concrete canal and irrigation system with self-healing concrete,” Jonkers said. “We are doing tests all over the world in developing countries where they realise that though this is more expensive than current tech, they see the profit because they will have to avoid repair down the line.”
What do you think about self-healing concrete? Do you think it is a viable solution for the construction industry?
Research reveals 164% rise in searches for loft conversions
Market research conducted by building supply specialist Insulation4Less has revealed that searches for ‘Loft Conversions’ rose by a staggering 164% between May and June of this year, while searches for ‘Loft Conversion Ideas’ jumped by 186% as people spend more time on home renovations this summer.
The company also found that the most popular use for a loft conversion is for an additional bedroom, while an extra bathroom was the second-highest search term. Walk-in wardrobes came in third, beating out a home office in fourth while converting a loft into a home cinema round off the top five.
According to a recent study, a loft conversion can add roughly 20% to the value of a property. With the average UK house price standing at £267,000 in January 2021, this represents an average increase in value of more than £53,400.
Johnpaul Manning, Managing Director of Insulation4Less, said: “If the last year has taught us anything, it's that having space is essential to our mental health and wellbeing, so it's no surprise that people are taking the time to focus on home improvements to help them make the most of their home.
As one of the most under-utilised areas in any property, loft conversions represent a great opportunity to maximise the use of space that not only improves quality of life but also has the capacity to add value to the home”, he said.
Manning added that it's important to remember that a loft conversion isn't just your average DIY project, and should never be done on the spur of the moment. “A significant amount of planning needs to happen to make it a reality, and an understanding that life can be disrupted while the build is taking place.
“While it's definitely a worthwhile project, I'd recommend that anyone considering a loft conversion should do some in-depth research to really understand what's needed to make it a reality”, Manning said.
Is Your Loft Suitable For a Conversion?
While loft conversions do look amazing and add an extra element to a property, not all homes may be suitable. Insulation4Less says that this is due to a variety of factors.
“It's important to make sure that your roof is structurally sound enough to handle a conversion”, the company said. Although there are different types of roof structures, they mostly fall into two distinct categories: a traditional roof, and a trussed roof.
A traditional roof: was typically found in pre-1960s houses. Rafters on traditional roofs run along its edges, leaving a good amount of free space. However, they might still need new or extra support. Trussed roofs, on the other hand, have ‘W’ shaped rafters that support the roof and the floor structure. Even though truss roofs may appear to be harder to convert, it’s not impossible; the ‘W’ shaped rafters can be replaced with an ‘A’ shape structure which creates a hollow space. While this can add additional costs, it could be a worthy investment, so take this into consideration during your planning process.
“Another thing to consider is the roof's height and pitch, and how that will impact the amount of space you’ll have. You’ll need a minimum height of 2.2m to ensure proper clearance. While you might be happy to settle for something a little shorter on paper, make sure your happy with the height you have and the effect it could have on the enjoyment of the space”, Insulation4Less advises.
The company recommends doing research before going to an architect or contractor. “Ultimately, look for other conversions on your street or in similar properties, and if you feel comfortable, ask if you can have a look and discuss how their project came together - you’ll find a wealth of information that could really help your own project in the future”.
Information credit: Insulation4Less.