A new kind of ‘smart cement’ could be used for more durable roads and cities.

Roads require serious maintenance, costing billions of dollars across Australia each year. 

But these costs could be saved by new research from the US. A team of engineers have introduced nanoparticles into ordinary cement to create a smarter, more durable and highly functional cement.

Studies had already shown that nanomaterials reduce the carbon footprint of cement composites, but until now, little was known about its impact on fracture behavior.

“As a fracture mechanics expert by training, I wanted to understand how to change cement production to enhance the fracture response,” says environmental engineering professor Ange-Therese Akono from Northwestern University. 

Traditional fracture testing, in which a series of light beams is cast onto a large block of material, involves lots of time and materials and seldom leads to the discovery of new materials.

By using an innovative method called scratch testing, Dr Akono's lab efficiently formed predictions on the material's properties in a fraction of the time. 

The method tests fracture response by applying a conical probe with increasing vertical force against the surface of microscopic bits of cement. 

“I was able to look at many different materials at the same time,” Dr Akono said. 

“My method is applied directly at the micrometer and nanometer scales, which saves a considerable amount of time. And then based on this, we can understand how materials behave, how they crack and ultimately predict their resistance to fracture.”

Predictions formed through scratch tests also allow engineers to make changes to materials that enhance their performance at the larger scale. 

In the latest paper, graphene nanoplatelets were used to improve the resistance to fracture of ordinary cement. 

Incorporating a small amount of the nanomaterial also was shown to improve water transport properties including pore structure and water penetration resistance, with reported relative decreases of 76 per cent and 78 per cent, respectively.

Implications of the study span many fields, including building construction, road maintenance, sensor and generator optimisation and structural health monitoring.