We’re starting to see those silent cars everywhere. The electric vehicle evolution is gradually seeping onto our roads. Every month or two, we also seem to read about another wind power generation record in the UK, or some super solar cell. Pension funds and big corporations are coming under great pressure to divest from fossil fuels. The clean power revolution is well underway.
And yet the third biggest polluter of the planet - after power and transport - awaits the seismic shift that will shake it to its foundations. Indeed, cement production still accounts for roughly 8% of the world’s greenhouse gas emissions.
The problem is that creating cement is an energy-intense, polluting process with firing temperatures of 2,700 degrees Fahrenheit needed to create it, and plenty of CO2 released during processing.
Green cement and concrete are needed to reduce emissions in construction and other industries.
But there are signs that the processing could become cleaner. A recent report released by Market Research Future (MRFR) predicts that concrete (of which cement is a key ingredient) use could get appreciably greener over the next six years. It estimates that the global green concrete market size will grow at a 9.45% compound annual growth rate from 2020-27.
MRFR attributes this rise to several factors. First, there is a growing demand for green or recycled concrete (that incorporates waste components) within the construction industry. For builders, it enhances their environmental credentials and will increasingly become a business-savvy investment as governments seek to reduce carbon emissions.
Green building codes and the creation of energy-efficient infrastructure will also help propel this growth, and changing building regulations in massive markets including China, India, and the Middle East will result in many manufacturers looking to develop different material combinations. Increasingly, we’re seeing manufacturers turning to less energy-intensive manufacturing methods and investigating which waste materials could be used to create a greener cement or concrete that doesn’t compromise on performance.
Researchers at Chalmers University of Technology, in Sweden, have even been developing a rechargeable cement-based battery. If it ever comes to pass, this could be used to create buildings that store energy like giant batteries. Some manufacturers are also looking into the electrification of kilns, which isn’t feasible yet, and carbon capture and storage has long been mooted as a means to reduce industrial emissions.
Imagine an entire twenty storey concrete building that can store energy like a giant battery. This could be possible if Chalmers University’s cement-based rechargeable batteries come to fruition. | Image Credit: Yen Strandqvist/Chalmers University of Technology
The good news is that we don’t just have people all over the world working on low-carbon materials and manufacturing methods; experts in the UK are tackling the issue right now. On 2 June, speakers at the SCI’s free webinar, Ultra-low carbon concrete, a sustainable future, will examine some of the exciting initiatives underway.
These include an award winning, industry accepted ultra-low carbon alternative to traditional cement, which could result in CO2 savings of up to 78%, and the potential of using offsite manufacturing to provide commercial projects with a sustainable structural frame solution.
As with transport and power, cement is getting greener increment by increment. But with drastic climate change consequences dangling above us like the Sword of Damocles, now is the time for concrete action.
Register for Ultra-low carbon concrete, a sustainable future today at: https://bit.ly/33WfjkN.
Concrete is a common fixture in the building blocks of everyday life. Image: US Navy@Wikimedia Commons
Concrete is the most widely used construction material in the world, with use dating back to Ancient Egypt.
Predictably, our needs concerning construction and the environment have changed since then, but the abundance of concrete and its uses have not. We still use concrete to build infrastructure, but building standards have changed dramatically.
Dubai city landscape. Concrete is predominantly used in residential buildings and infrastructure. Image: Pixabay
Its immense use, from house foundations to roads, means that problems cannot easily be fixed through removal of the old and replacement with the new. Such constraints have seen researchers focus on unique ways to solve the problems that widespread use of concrete can create for industry.
In the UK, four universities have created ‘self-healing’ concrete as part of a collaborative project, known as Resilient Materials 4 Life (RM4L), to produce materials that can repair themselves. Currently, monitoring and fixing building materials costs the UK construction industry £40 billion a year.
Microcapsules are mixed through the cement which then break apart when tiny cracks begin to appear. The group have also tested shape-memory polymers that can close the cracks together closely and prevent further damage. These techniques have shown success in long-term trials and in scaled-up structural elements, said Prof Bob Lark, speaking to Materials World magazine. Lark is lead investigator for RM4L at Cardiff University.
RM4L already has 20 industry partners and there is hope that, in the future, technologies can be transferred to other materials, although it has not yet reached the commercialisation stage.
Lark said: ‘What we have to do now is improve the reliability and reduce the cost of the techniques that we have developed so far, but we also need to find other, more efficient and perhaps more tailored approaches that can ensure we address the full range of damage scenarios that structures can experience.’
Making concrete eco-friendly
The abundance of concrete globally comes with an equally large carbon footprint, with concrete production equating to 5% of the annual CO2 produced by humans. For every tonne of concrete made, we contribute one tonne of CO2 to our surroundings. It is primarily due to the vast quantity produced each year that leads to this high level of environmental damage, as concrete is otherwise a ‘low impact’ material.
This inherent characteristic has led some scientists to develop stronger types of concrete. Here, the building features and low environmental impact of the material remain the same, but because less is needed of the stronger concrete to perform the same job, carbon emissions are reduced significantly.
Another method aimed at tackling emissions is the ‘upcycling’ of concrete. At UCLA, researchers have created a closed-loop process by using carbon capture from power plants that would be used to create a 3D-printed CO2NCRETE.
‘It could be a game-changer for climate policy,’ said Prof JR DeShazo, Director at the Luskin Centre for innovation, UCLA. ‘It takes what was a problem and turns it into a benefit in products and services that are going to be very much needed and valued in places like India and China.’