At C-Probe, it is our mission to extend a structure’s whole life performance using low-carbon corrosion monitoring products. This article marks the beginning of a monthly series published on our website blog: Sustainable Resilience. Sustainable Resilience will discuss a range of topics from corrosion protection to sustainability choices and modern methods of construction, resilience in infrastructure and much more. However, it is important to firstly unpack the term Sustainable Resilience and explore what this means to the construction sector in 2021 and beyond.
The decisions we make today lay the foundations of tomorrow. The construction industry is under a lot of pressure in recent years to drastically modernise in its materials and operations, especially with committed NetZero targets set by the UK Government in 2019. As a country, we should be looking to enhance our legacy with smarter, greener structures and protection methods, as opposed to resorting to demolition of unusable buildings, with its associated loss of embodied energy and high economic and resource cost.
Sustainable resilience of a structure starts with the whole life asset performance, which takes into consideration not only the initial capital cost of a built asset but also the operational, maintenance, repair, upgrade, and eventual disposal costs. The sector needs to shift focus to the whole life performance of infrastructure and explore how to reduce costs and CO2 emissions to be more sustainable, in an economic and environmental sense.
It would make sense to start at the most prevalent structural issue that causes degradation and spiralling costs: corrosion. Corrosion is responsible for 70% of damage within the construction industry for steel and concrete structures. The idea that corrosion can be controlled from early stages and structures can be strengthened to protect it from future issues reduces the asset’s carbon footprint and avoids costly maintenance, contributing to the concept of structural resilience.
The effects of structural degradation and corrosion
Corrosion is an electrochemical process, in which we apply lots of energy in production into converting to steel forms, only for the steel to revert to their more natural, lower energy and stable state of ore (iron oxides) over time. The rust that is produced can expand in volume by 8-10-fold which increases stresses in the concrete cover, creating cracks and spalls. The obvious effects of corrosion are on a structure’s condition and aesthetic. If ‘concrete cancer’ can take its course then the structures’ usage, safety and value are significantly impacted, whilst the physical appearance begins to look aesthetically poor, rusted and eventually derelict!
Corrosion affects all aspects of life, however, if not kept under control. From a social perspective, it is extremely disruptive as building maintenance and construction leaves structures temporarily out of use. If degradation occurs in important infrastructures such as highways, electrical towers, parking structures, bridges, or heritage buildings then this has a direct effect on the people using them daily – whether this be a commute to work or school or being able to deliver services efficiently. In extreme cases, structural corrosion can result in injury or loss of life.
The environmental impact of corrosion also comes in various forms. To become more sustainable and reduce whole life costs, the need to demolish corroding buildings needs to drastically decrease. Demolition results in large amounts of waste, which then contribute to air and land pollution. If the construction occurs in a densely populated urban environment, the pollution and noise then progress to become an issue for the surrounding community.
Corrosion is the single biggest cause of spiralling cost of degradation to economies yet, whilst standards exist, there is no legislation is in place to mandate control. There is clear evidence that is has an impact on all aspects of life, so with sustainable solutions available it seems timely to develop awareness and vital to take advantage of such technology.
What do C-Probe use for low-carbon restoration?
To control corrosion, C-Probe use smart materials that build, repair, protect, strengthen, and monitor structures, so asset owners can take preventative actions to manage the future. Our smart materials centers on LoCem® – a low-carbon, alkali-activated cementitious material (AACM geopolymer), developed into a range of products over the past 10 years with Sheffield Hallam University, that can be formed as an anode in mortar and concrete forms.
So, in what ways is LoCem® a low-carbon, smart material? Firstly, its production is completely sustainable, as it is produced at our St Helen’s manufacturing facility using industrial by-product waste and with no heat. This results in over 80% less CO2 emissions compared to traditional Portland cements!
It is classed as a smart material as it can be controlled by applying current to provide Impressed Current Cathodic Protection. The effect on the steel can then be monitored and used to draw out valuable performance data for asset owners. This is part of our open network monitoring system (Achilles Suite of Structural Healthcare Systems) that provides onsite data to access online using the AiMS (Achilles Interactive Management Server). Whether it be tracking service life, or for due diligence or a monthly performance report, our smart materials enable our clients to remotely control and monitor their structure, enabling them to cut costs in unexpected maintenance repairs caused by corrosion.
In addition to this, we have manufactured it to have desired physical and mechanical characteristics that improve a structure’s durability. This includes excellent compressive and flexural strength, freeze-thaw, chemical and acid resistance as well as fire resistance for at least at least 5 hours at 1200°C.
From here, we can create systems of quality which provide resilience to structures.
Recent publications such as The National Infrastructure Strategy and The Construction Playbook have already outlined how the construction sector is progressing – acceptance of innovative solutions and corrosion management, we argue, is a key factor in this. We have worked over decades promoting structural resilience, as this is vital for improving whole life performance of structures. It is with our low-carbon, smart materials that we are not only creating smarter, more sustainable infrastructure, but also giving asset owners more control and insight into their investments.
For more information about our services and products, please contact us here. Stay tuned for monthly articles on our website blog, Sustainable Resilience!