New test invented to gauge cement durability

Professor Nishant Garg, standing, and graduate student Hossein Kabir used computer vision to develop a fast and convenient method for testing cement durability that can be used in the field or laboratory. PHOTO: Michelle Hassel

An Indian American professor and his student have developed a new test that can predict the durability of cement in seconds to minutes – rather than the hours it takes using current methods.

The engineers at the University of Illinois Urbana-Champaign include Professor Nishant Garg and student Hossein Kabir, the University said in a news item on its website July 5, 2023.

The test measures the behavior of water droplets on cement surfaces using computer vision on a device that costs less than $200. The researchers said the new study could help the cement industry move toward rapid and automated quality control of their materials.

The results of the study, led by Prof. Garg are reported in the journal npj Materials Degradation.

“Concrete is one of the most consumed materials on our planet, second only to water,” Garg is quoted saying in the article. “Over time, the concrete used to build our infrastructure degrades over time via exposure to deicing salts; freeze and thaw cycles; and ingress of water – all of which can lead to corrosion of the rebar that is used to strengthen the structures. Ultimately, this leads to failure, sometimes catastrophically, as seen in the 2021 condominium collapse in Surfside, Florida, where 98 lives were lost.”

Garg noted that a key test used to predict the durability of cement is its ability to absorb water –the more porous the cement paste is, the more water it will absorb, ultimately leading to corrosion of the embedded rebar in reinforced concrete.

The new device uses computer vision to see how quickly a single water droplet is absorbed into the surface within the first few seconds or minute, making it far less tedious than the existing method, and it can be performed on the fly in the field or in the lab.

“We performed the new test on more than 60 unique samples, and there’s a fairly good correlation between our results and the results from the conventional ASTM test method,” Garg said. “So we are now proposing our new testing method as an alternative to test the durability of cementitious systems in a few seconds.”

The department of civil and environmental engineering at Illinois supported this research, the news report said.



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