Engineers designed the infrastructure that surrounds us today, giving us the basic necessities, comfort, connectivity, and convenience that we all take for granted. But transportation, the built environment, and electricity can carry a high environmental price.
Today’s engineering challenge is learning how to sustainably build more infrastructure and deliver more power while reducing the carbon footprint. According to Christian Ravotta, the global manager of engineering for Bechtel’s Infrastructure business unit, this requires a shift in thinking and stronger engagement in the design stage of projects.
"Sustainability has always been in our thinking," Christian said. “But now we’re moving from a place where we were meeting statutory or customer requirements like the LEED and Envision certifications to challenging ourselves to do much, much better.”
Doing much better means challenging all aspects of a project’s design, from energy efficiency to embodied carbon content in ubiquitous materials like cement, asphalt, and steel, including finding applications to replace historical materials like steel with those incorporating carbon and polymer fibers. It requires nimbler and more creative thinking – inviting engineers to collaborate with customers and stakeholders to solve problems and shape the boundaries of what’s possible.
As Christian explains, "There are no easy answers; each project has different needs and opportunities depending on where and what it is. We also need a willing supply chain—we can’t do this alone." For Christian and his team, this means seeking out the manufacturers who are making improvements and incorporating more sustainability into their production.
Beginning change with the building blocks
With a greater emphasis on innovations in sustainability, Christian's global team, made up of 325 engineers, is focused on future technologies, assessing effective, sustainable products and solutions.
“Engineers are naturally interested in sustainable design,” Christian said. “But now that there’s increasing market pull for low-carbon solutions, we’ve got to take that innate interest and look for the opportunities to become actively engaged. We also have to think cross-functionally to help capitalize on opportunities in procurement and construction.”
“Part of the team’s sustainability initiatives involve looking at each stage of a project’s execution and reducing the carbon footprint by using local and recycled materials, the optimal selection of type and strength of elements, the design of appropriate concrete mixes with lowest cement content, and utilizing automation during production and placement,” said Javeed Munshi and Wayne Bergstrom, both engineers and Bechtel Fellows on Christian’s team. The team has also developed multiple guidelines and procedures focused on implementing sustainable design and construction innovations while allowing for flexibility in approach.
Project innovations
With construction and buildings sectors reported to be responsible for around 40% of carbon emissions globally, the EPC industry has the biggest decarbonization challenge of all.
“If ordinary Portland cement—the key ingredient in concrete—were a country, it would be the fourth largest emitter of carbon in the world, responsible for approximately 7% of global emission," Swatti Taywade, a sustainability project manager, said.
Given her focus on sustainability, Swatti looks at every aspect and how to optimize mix through cement substitutes, such as using low carbon cements, promoting local sourcing of materials, and using recycled aggregate and water when she’s on a project. She’s also targeting asphalt by assessing alternative materials, promoting reuse and recycling, and weaving in the principles of a circular economy.
“Roads are big offenders so resource conservation and optimizing road design are important as well as encouraging the use of construction waste materials, low energy asphalt technologies, and innovative recycled materials and mixes,” Swatti said.
According to Rushil Patel, a chief construction engineer, it’s not all about the materials. “The way we build plays a big role, too,” he said. “For example, modularization and pre-assembly can reduce the amount of equipment we need in parallel on site, reducing emissions. We also need to alert our customers and respond rapidly to opportunities in the market, including supply chain issues and evolving carbon reduction requirements.”
However, Swatti said, construction emissions are only a part of the story. Almost 30% of global emissions come from energy use once buildings or infrastructure are in operations. It’s important to design with low end-use emissions in mind.
“Providing cost-effective solutions is a mixing bowl of aspirations, objectives, strategies, action plans, engagement, and reality checks,” Swatti said. “And the recipe is only successful if everyone including owners, engineers, construction and procurement teams, the supply chain, subject matter experts, waste recyclers, research labs, and universities work together.”