Innovative Thinker | Alireza Behnejad
Planted concept
Bio-based materials should be considered on the journey to net zero emissions, Alireza Behnejad tells Sotiris Kanaris.
There are different options for the industry to consider when it comes to carbon footprint [reduction],” says University of Surrey associate professor of civil and environmental engineering Alireza Behnejad.
Behnejad: Lifecycle assessment should be carried out when construction materials are selected
“One is not to build anything, but we know that is impossible. So we need to learn to build things with less carbon footprint by either using fewer materials or using materials that are greener.”
He believes that the industry should explore the replacement of conventional construction materials, such as concrete and steel, with bio-based ones that are derived from living organisms such as plants.
Behnejad stresses that lifecycle assessment – environmental impact analysis of all stages of a product’s life – should be carried out when materials are selected.
“It’s not only about the cost for my generation, but also the cost for the next generation,” he says. “It’s important to understand where the material comes from, how it was produced, how much energy was involved and what is going to happen at the end of the structure’s life.”
He says that if a timber structure is chosen instead of a steel structure, it might cost more initially but would lead to significant savings for the next generation.
For the wider adoption of bio-based construction materials, Behnejad says that “we need the [supply of] materials, the knowledge and the appetite”.
In terms of supply, advances in materials engineering have enabled the production of a range of products such as cross-laminated timber which is increasingly popular in construction.
“We need to learn to build things with less carbon footprint by either using fewer materials or using materials that are greenerBut Behnejad says that supply can be a limitation when it comes to timber use. He believes that more research should be undertaken on how the properties of other available natural materials could improve to meet the construction industry’s demands.
Behnejad points to bamboo as an example. Several research groups are looking into the use of bamboo in construction as it grows very quickly which is key for supply. “You can have mature bamboo, which can be used in construction within three to five years, but the equivalent for timber is 20 to 30 years,” says Behnejad.
Another important factor affecting the wider use of bio-materials is the industry’s appetite for them.
Behnejad finds that there is still resilience to change.
He says: “Education has a key role to play to show that change is possible. Our younger generation should have knowledge on the different alternatives so they can choose what is best suited for their project.”
Behnejad adds that incorporating bio-based materials into more design software will also boost adoption.