After water, concrete is the most widely used substance on Earth. Despite its attractive price-point, flexibility and durability, concrete has less than favourable environmental credentials. Largely due to the scale of its usage, it reportedly contributes approximately 5% of the world’s CO2 output.
Concrete has been in use for millennia and these days we produce over 2 billion tonnes of it annually. Therefore, reversing the tide of its global usage is a seemingly insurmountable task. If we can’t do without it, can we look to make how we use it better for everyone?
By 2050 we will be producing four times the amount of concrete we produced in the 1990s. Concrete is endemic in its usage worldwide mostly due to the fact that it’s an incredibly successful and reliable building material. It not only builds our roads, enables us to cross over, or under large bodies of water, but it can also enable us to construct buildings that are over 800m tall.
Unfortunately, there is, as yet no feasible alternative to concrete that is as durable, cost effective and can be used at such enormous scale that produces significantly less carbon. Until the time that such innovation is created, or there’s a shift in the way concrete is used globally, we must look to other controllable factors we can improve upon, for the benefit of society and the environment.
Once such area is the reinforcement carbon steel rods, or ‘rebar’, used to provide extra tension and strength to support concrete structures. Rebar has been used in construction since the 15th century and often resembles a grid-style pattern providing necessary tension to keep the concrete in place.
The construction and installation of rebar is highly skilled work, and not without its dangers. Injury resulting from rebar is reported to account for 61% of all construction accidents, with severity ranging from minor injuries to death. In addition, many workers suffer from long-term joint and muscular complaints due to being bent over constantly on site to fix the rods together using the existing metal wire twisting system.
Construction Innovation Hub is collaborating with rebar manufacturers MetLase, who are designing and manufacturing a more sustainable steel rod system, and software engineers ParaPy, who are developing a bespoke knowledge-based engineering platform designed to support the use of MetLase’s new rebar system into the design phase of builds. The collective goal of this collaboration is to develop an innovative new rebar system; demonstrate its value and ultimately encourage adoption of it across industry. A new rebar system that not only reduces carbon emissions through reducing the amount of metal used and being more efficient to construct, but also helping to improve the accuracy of the finished structure by reducing variation and droop from 1000m to approximately 40mm.
The collaborators are in the process of extensively researching this innovative approach to rebar – testing the efficacy and efficiency of the new style rods and their patented ‘twist and fix’ locking system and exploring how the knowledge-based engineering platform can enable designs using rebar to be reduced from several weeks to mere minutes.
So far, they have been able to establish that the new system of rebar would:
- Significantly improve on delivery and assembly time;
- Open up the labour pool by reducing the skill level needed to assemble;
- Reduce risk of injury;
- Improve overall quality and reliability of rebar;
- Reduce the design lead time; and
- Be suitable for use in both platform-based and traditional construction projects.
There are plans to demonstrate the new rebar system as a proof of concept within a new build structure scheduled for September 2022.