As a socially conscious engineer I have a passion for sustainability. This is something I have had from a young age, where I tried to file a patent for a green energy generating device. As I prepare to move from a student life to a professional one, I want to ensure I end up working in a role focused on reducing carbon emissions from the construction industry.
To fulfil the Paris agreements and to hit net zero carbon emissions the construction industry needs to implement change. Currently building and construction are responsible for 39% of all carbon emissions in the world, with operational emissions (from energy used to heat, cool and light buildings) accounting for 28%. The remaining 11% comes from embodied carbon emissions, or ‘upfront’ carbon that is associated with materials and construction processes throughout the whole building lifecycle.
However, it is not all doom and gloom; over the last ten years there has been a huge development in technology and materials which can challenge this. There has also been a change in focus. Rather than just considering the embodied carbon within a construction project, the whole life cost and carbon emissions are being considered. The change in approach will hopefully allow buildings to be developed that will become more and more ‘green’.
Luckily, buildings with a lower whole life carbon emission are also buildings that are cheaper to run. This is because these buildings are much more efficient, requiring less energy to operate. This makes ‘green projects’ much more commercially viable.
Throughout my multi-disciplinary project lead by Professor Rod Jones, we have been challenged to develop and design a new forensic science building to be built on campus. As part of it we have been challenged to make this building as green as possible. As it is a publicly funded building, we have a duty as designers to design a building of the ‘future’. It is the duty of public buildings to lead the way in these technologies.
As a higher education building, we are designing it to have a life span over 75 years. This is challenging because we need to anticipate how the use of the building could change and the implications this could have for the structural capacity. Currently building codes require us to design the laboratory floors and plant room to resist high loadings of 7.5kN/m2. As a designer I need to consider how this could change, whether the University will want to install heavier equipment or the plant room needs to be modified to house giant batteries to store off-peak renewable energy or a hydrogen based energy supply. To address this, I might choose to design these floors to take loadings of 10kN/m2.
While designing this building I spent a large amount of time reading about emerging technologies that are arming engineers with new tools to fight climate change. I wanted to note some of the most innovative that I came across in this blog.
Concrete has gotten a bad reputation recently due to the high amount of embodied carbon within it. This is due to the processes required to get the raw materials. However, with the addition of admixtures concrete can be made more sustainable. These admixtures are usually waste products from other industrial processes, these admixtures improve the properties of the concrete and store waste products.
Finally, reinforced concrete structures have an advantage to steel, they are much better when it comes to fire protection and vibration control. This means concrete buildings can over a whole life provide green benefits.
My research has mostly been based in concrete as my multi-disciplinary project is being constructed in concrete.
The Concrete Battery
Most of us would be familiar with how hot pavement can get on a summer’s day. This is because the concrete absorbs heat and can store it. It seems a concrete battery may be the key to cheap large scale energy storage.
Companies like the Norwegian company NEST have developed a special concrete called Heatcrete that can be used as a solid-state thermal energy storage (TES). Heatcrete demonstrates superior thermal performance than other concretes.
The system consists of steel heat exchangers cast into concrete cells with water flowing through the exchangers. This allows heat to be stored during hot periods and then drawn out during colder period.
Following on from the concrete battery, concrete is very insulating and offers building designers some unique energy saving properties. The exposed concrete is able to absorb heat which it can then radiate into the building. This provides the building with ‘thermal mass’ and allows the structural components to have a dual purpose.
Check the image of the Three River Academy and see if you can spot the thermal mass.
Variable Dense Concrete
By “printing” concrete with variable density as it would allow the properties of the concrete itself to vary continuously. This would produce structures that are both lighter and stronger than conventional concrete, by making it porous in the centre and solid on the exterior, just like bones.
I hope you enjoyed my blog on sustainable construction. I hope it provided food for thought and allowed you an insight as to how the construction industry and design process is beginning to challenge its reputation for being ‘unsustainable’. Having almost graduated I am very excited to take this research and implement into projects that I work on.