Improving concrete can extend service of nation’s infrastructure
Video: Dwight Look College of Engineering
Concrete is the most used material in the world after water; what ensures its performance is the cement paste that binds the other ingredients. If concrete lasts longer, then infrastructure such as roads, bridges and dams will last longer, and will save billions of dollars for taxpayers and investors.
Zachary Grasley, associate professor and Peter C. Forster Faculty Fellow I in the Department of Civil Engineering, conducts research to extend the life of cement. In 2015, he published an article on cement longevity in the journal Materials and Structure that is recognized as outstanding.
“Making concrete more durable and resilient has enormous societal impacts,” said Grasley. “It will lessen the pressure on finite natural resources needed to meet our growing demand for concrete infrastructure. The models we create help us to understand how and why concrete deforms the way that it does, which gives us insight into how to better engineer its performance.”
His research is a combined experimental and modeling approach rooted in fundamental sciences and aimed at improving concrete infrastructure. It involves new material development, novel experiments to measure important properties related to durability and resiliency, and advanced models to uncover mechanisms and predict performance of concrete in real structures.
“Viscoelastic materials are like the Tempur-Pedic mattress,” said Grasley. “Those materials have a couple of very important characteristics. One is the ‘elastic’ part of that term. It’s reversible, recoverable, and goes back to the way it is supposed to do that. The ‘visco’ part of that term means it comes back slowly. If you leave a column sitting on a concrete surface, gradually you will see that surface sink under the weight over time. If you can tailor those properties, you can reduce the stress on your concrete, meaning less repair is necessary.”
Materials with tailored viscoelastic properties can better absorb an impact or force. Moving forward, if concrete is designed with specific viscoelastic properties, it may delay or even prevent damage from taking place, thereby saving a great deal of money on repair and maintenance.
The new materials, experiments and models Grasley’s group is developing will ultimately have wide-ranging applications. They may one day be used for 3-D printing of structures or structural elements or rapid repairs of infrastructure. The experiments could be used for quality control or quality assurance to help improve concrete durability in pavements and bridges. The models may one day be integrated into a design and analysis tool that allows optimized simultaneous structure and material designs.