Building confidence with sensory waves 

Concrete is the second most used material across the world, but its strength and durability depend entirely on the proper setting and hardening of its core element: cement. Now, research from KU has developed a faster and more reliable way to monitor this hardening process and assess concrete quality. 

“Understanding the mechanical properties of cement is crucial because they directly influence the safety and durability of concrete structures,” says Tae Yeon Kim, a civil engineering researcher at KU. “The importance of these findings lies in the ability to accurately monitor cement stiffness and strength in real time using a method that doesn’t destroy the material.” 

Published in Cement and Concrete Research, the study describes the use of a technology called a solitary wave-based sensor—an advanced probe that generates moving energy beams capable of revealing the internal structure of materials. By analyzing how these beams bounce back from hardening cement, the researchers can instantly spot hidden defects and assess the material’s strength and durability.  

“Understanding the mechanical properties of cement is crucial because they directly influence the safety and durability of concrete structures.” 

Tae Yeon Kim

Unlike traditional sound and ultrasonic waves, solitary waves offer a unique advantage: they maintain their shape without weakening or coming apart as they pass through materials, producing sharper and more sensitive signals. Crucially, the wave’s speed and strength can be fine-tuned, making them highly sensitive to the mechanical and geometrical characteristics of the cement sample. 

“Accurate and reliable evaluation of the cement’s strength ensures effective structural design, quality control, and maintenance, thereby helping to prevent potential structural failures,” Kim says. In theory, the sensor could also be used to inspect the structural integrity of other materials, from plastics to human bones. 

The results of the study show the characteristics of the reflected solitary waves were highly sensitive to hydration, water-to-cement ratio, and mechanical properties. This enabled the researchers to accurately reflect the progress of the setting process. 

KU is “exceptionally well-positioned to carry out and advance innovative research of this kind,” Kim adds. The university provided the necessary expertise, state-of-the-art laboratory facilities, and funding to conduct both experimental testing and advanced computational modeling. 

While the technique is not yet ready for commercialization, it has demonstrated strong performance in laboratory conditions. The team is now working to integrate artificial intelligence to allow the probe to show the results in real time. They’re also developing portable versions of the technology, making it adaptable for use in a range of sites and locations. 

Reference

Ahmed Z. Alkhaffaf, Sangyoung Yoon, Andreas Schiffer, Tadahiro Kishida, Chan Yeob Yeun, Tae-Yeon Kim. Estimation of Young’s modulus and compressive strength of cement using a solitary wave in granular crystals. Cement and Concrete Research, 194, 2025.