Scientists Create A More Durable Cement By Incorporating Nanoparticles

Cement is one of the most commonly used construction materials in the entire world. It used to build everything from homes and offices to roads that we drive down every day. The challenge with cement is that despite its strength, it can be turned into a potholed mess by ice and snow, and it often requires significant amounts of money to maintain each year. In fact, it's estimated that each lane-mile of road in the US costs about $24,000 per year to maintain.

Engineers have developed more robust cement by increasing the amount of carbon in the material, but adding carbon makes the material lose some of its desirable mechanical properties. However, researchers at Northwestern University have found that by introducing nanoparticles into ordinary cement, they have formed a smarter, more durable, and highly functional product.

With the global use of cement, the industry producing it accounts for about eight percent of all human-caused greenhouse gas emissions. Scientists are keen to make the material last longer to help reduce some of that greenhouse gas emission. According to researchers on the new study, nanomaterials could reduce the carbon footprint of cement composites, but little was known about the impact of introducing nanomaterials on fracture behavior.

Northwestern University civil and environmental engineering professor Ange-Therese Akono and her team used an innovative testing method known as scratch testing. The researchers formed predictions of the material properties in a fraction of the time using the scratch testing method. That method tests fracture response by applying a conical probe with increasing vertical force against the surface of microscopic bits of cement.

The method was developed by Akono during her Ph.D. work and required less material while allowing acceleration of discovery of new materials. Akono says she was able to look at different materials at the same time. The method is applied directly at the micrometer and nanometer scales saving time. The information gathered from the test method allows researchers to understand how materials behave, how they crack and predict their resistance to fracture.

Using the process, the team was able to show that by incorporating a small amount of the nanomaterial, the water transport properties of the cement, including pore structure and water penetration resistance, saw relative decreases of 76 percent and 78 percent respectively. The results of the study have implications in a variety of fields, including construction and road maintenance.