Building costs account for over 13 percent of world GDP at over $11 trillion a year – but construction and growth have lagged behind relative to other industries. Around the same time, for example, the impact on the local atmosphere is seen by the fact that cement production alone accounts for 8% of global CO2 emissions. Sustainability and the CO2 footprint of the industry are crucial concerns that need to be tackled rapidly in order to accommodate the rising demand for building while minimizing environmental risks.
The solution to these problems could well be inside the CO2 itself.
Productivity constraints could be solved by the rapid and large-scale introduction of automation into the industry. Traditionally, automation has increased productivity in many industries, but this is usually paired with job losses. This will be different in the construction industry, which is currently facing a global shortage of available labour. The introduction of robotics technology enables 3D printing of building materials, enhanced prefabrication of building components, and can help to assemble whole buildings.
Overall, this makes for creative building projects, at a lower cost, and eliminates physical burden on construction workers by providing additional roles for the installation and management of tools.
While 3D concrete printing has been studied for some time, advances in concrete materials will benefit from improved printability, such as increased speed of production while retaining structural integrity. In addition, advanced concrete must have properties such as higher mechanical stability, smart thermal behavior, air filtration and self-repair capability. But, first and foremost, in the present context, these goods need to offer better production capabilities and better carbon footprint.
New materials can become essential resources for building change. There is an opportunity to focus research and development on concrete and concrete composite materials that use CO2 capture as an ingredient. This CO2 could be extracted directly from the air, but it can also be obtained from power plants or cement plants. In this situation, CO2 will be indefinitely extracted in a mineralized state and will also help to address the effects of climate change.
CO2 will become an enabling raw material for the building industry and beyond in a number of ways. First, it is possible to use CO2 in the treatment of cement in the manner in which water is traditionally used. Emerging commercial demos are noted for prefabricated modules as well as for concrete that is poured at building sites. Second, industrial waste products, such as steel slag, fly ash from power plants or mine tailings, can be reacted with CO2 to form carbonate materials that are ideal components for concrete. Third, plant fibers and plant-derived polymers may be converted into concrete materials.
Concrete is a flexible medium for which many properties will have to adapt in order to comply with specific applications. Engineered cement composites (ECCs) are a type of concrete materials that incorporate the strength of concrete with the ductility of metals. This is partly accomplished by the incorporation of polymer fibers into a concrete mixture. Like any concrete, ECC will contain CO2 as mentioned above and may provide additional possibilities for carbon sequestration with the use of natural fibres instead of polymer fibers.
There are substantial challenges to the full-scale deployment of CO2-based composites for competitive construction methods. The work required involves the design and testing of new components, as well as the reworking and expansion of the supply chain. This involves the development of adequate demand for these products in a historically risk-averse setting and thus needs appropriate policy support.
Lessons learnt from the Fourth Industrial Revolution will also benefit the building industry. Environmental, economic and – in exchange – social gains are worth the initiative. Overall, CO2-based building materials provide an avenue for the reduction of gigatons of CO2. This group of carbon trapped goods is the only one that provides lasting removal options as opposed to other cases of CO2 use. This will also be of vital importance to the global carbon neutral world as they enable the manufacture of carbon-containing materials such as fuels, chemicals and polymers without introducing more carbon to the system.