Future Forward: Materials Help Move Beyond Rehabilitation to Ongoing Sustainability
Nemkumar (Nemy) Banthia, PhD, PEng, is a distinguished university scholar at the University of British Columbia and was appointed as a Senior Canada Research Chair in Infrastructure Rehabilitation and Sustainability. He also is scientific director of the India-Canada Centre for Innovative Multidisciplinary Partnerships to Accelerate Community Transformation and Sustainability (IC-IMPACTS).
He earned a Master of Technology degree in Structural Engineering at the Indian Institute of Technology, New Delhi, and a Ph.D. from the University of British Columbia. Banthia is a fellow of the American Concrete Institute (where he received the Wason Medal), the Canadian Society for Civil Engineering (where he received the Horst Leipholz Medal), the Indian Concrete Institute, the Canadian Academy of Engineering, and the Royal Society of Canada.
IC-IMPACTS is an innovative partnership between Canadian and Indian institutions to promote and mobilize new technologies to improve water quality, increase the safety and sustainability of critical civil infrastructure, and improve health across both nations.
Banthia’s research has focused on cement- and polymer-based fiber-reinforced composites, with particular emphasis on testing and standardization, fracture behavior, strain-rate effects, durability and development of sustainable materials. He is credited for his contributions to the fundamental understanding of sprayed concrete, including particle and fiber kinematics, rebound modeling, in-situ quality control and performance characterization.
With specialization in the material side and a background in structural engineering, Banthia helps bridge materials science and its application in structures. He takes the nano and micro innovations in materials science and applies those to improve structural performance.
Banthia sees the fragmentation of our fields as a problem in civil engineering, hindering us from having a holistic view of our structures.
“If we design a bridge for a 100-year lifespan, and the average life is 37 years, then we need a new approach,” says Banthia. “While we pretend that we understand how the bridge performs or how materials interact with loads or how structures interact with materials, we don’t do a good job of it. If you’re doing a good job of optimizing materials and creating advanced designs, we should be able to at least design what we think we are designing.”
Assessment and Monitoring
With this insight in mind, Banthia’s research has expanded into condition-assessment tools and monitoring.
“If you recall the overpass that collapsed in Montreal in 2006, it was inspected that same week,” notes Banthia. “What it tells you immediately is that our condition-assessment tools are very poor. We have no idea what condition some of these old structures are in.”
The moment you have real data from a real structure, you can truly understand the next one you design.
His research is exploring the periodic assessment of bridges with new tools such as scanning with short-pulse radiography, electromagnetic methods and thermographs as well as ongoing monitoring with sensors. Hundreds of embedded sensors made of concrete and carbon nanotubes hooked to a transmission source give real-time and ongoing readings. With continual data, analysts they can provide a sense of how the bridge is performing overall.
“Sensors give you design rationale,” adds Banthia. “There are a lot of knowns in our design factors: you multiply the live load by a factor or the dead load by a factor. The factors account for uncertainty, because we don’t really know. If you had the data, then you would design better for uncertainty and reduce the multiplication factors to design what is needed. The sensors will tell you how materials are behaving, and then we can reduce the factors coming from uncertainty on material performance. We are wasting a lot of material in our structures now due to uncertainty.”
Sense of Sustainability
Banthia equates sustainability in infrastructure to using building materials that have a low carbon footprint, and making sure the buildings are durable and last a long time.
“Materials that have come from different industrial sources and absorb waste products that would have ended up in a landfill are a start,” notes Banthia. “Nothing is sustainable if the structures last just 50 years. If you’re demolishing and building new structures, the resources are far greater than building the right way with durable systems so the building lasts much longer.”
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