Study links cement particle shape and construction costs

Engineers at the University of Illinois Urbana-Champaign have developed a low-cost test that could help the construction industry save money. The new technique uses a $500 microscope-based framework to measure cement particle size and shape — both critical to cement and concrete quality — at a fraction of the cost of currently used laser diffraction equipment, which costs roughly $50,000 or more.  

Unlike conventional laser-based equipment, which measures only cement particle size, the alternative microscope-based approach can also assess particle shape. Shape matters because it can affect how cement behaves when mixed with water. Rough, angular particles may make a mixture stickier and harder to pour and work with, while rounder particles can flow more easily.

The method, developed by civil and environmental engineering professor Nishant Garg and U. of I.  graduate students Tausif Elahi and Bayezid Baten, defines a new metric the team calls SSM, short for “size and shape metric,” that assigns a value to the size, shape and fineness of cement particles. A higher SSM number indicates a population of particles associated with greater resistance to flow.

The study findings are published in the journal Powder Technology, along with an open-access dataset of approximately 7,200 images. This work builds on Garg’s previous studies that improved testing efficiency for cementitious materials, including a five-minute ultra-rapid reactivity test as well as an automated droplet test for durability.

“Concrete is the most used material on Earth just behind water,” Garg said. “It starts off as a slurry that workers must pour and spread on site. If that slurry is sticky and difficult to work with, it can slow down a project, adding a significant cost and time burden.”

In the lab, the team suspends cement powders in a nonreactive liquid and uses a sonication device to break up the powder agglomeration, ensuring a homogeneous suspension. They then drop the liquid onto a glass slide and, once dried, capture hundreds of photomicrographs, which they run through computer-image processing to measure particle size and shape across the images.

“The resulting SSM data can be plotted against a property called yield stress, which is essentially how much stress is needed to make a material flow,” Garg said. “We also envision using SSM to provide a quantitative basis to measure other properties of cement such as hydration kinetics, strength development and flow resistance to establish a unified connection between what we see under the microscope and how that relates to macroscopic, real-world behavior.”

The team reports that the new process still involves considerable manual work and does not account for the cement’s chemical makeup. In future work, they aim to automate the process and potentially combine it with chemical analysis techniques. Longer term, the researchers hope to develop affordable and automated testing devices for wider industrial use.

 “We want to accelerate and automate,” Garg said. “In summary, we think we can bring this tech to the market by creating an automated system that will incorporate the microscope, imaging and processing that may ultimately cost a fraction of conventional laser diffraction-based instruments.”

Garg’s group has been developing accelerated and automated testing methods for cement and concrete-based materials over the past few years. One of their patent-pending methods, their five-minute ultra-rapid reactivity test, can predict the performance of supplementary cementitious materials within a few minutes as opposed to several days to weeks with conventional methods. This test is currently being commercialized by the startup Rapid Analytix Division, or RAD, that is spinning out of Garg’s lab.

The Grainger Engineering Graduate Fellowship and the Illinois Distinguished Fellowship supported this study.

Editor’s note:   

To reach Nishant Garg, email garg-group@illinois.edu. The paper “Size and shape metric (SSM): An image-based descriptor for linking particle morphology to performance of cementitious powders via low-cost microscopy” is available online. DOI: 10.1016/j.powtec.2026.123350. Civil and environmental engineering is part of The Grainger College of Engineering.