Concrete cancer is a term used to describe the problem of concrete spalling and cracking caused by rebar corrosion in buildings and concrete structures. When the steel reinforcing within a concrete slab starts to rust, the steel rust can expand up to 7 times its original size, which causes concrete to be displaced and become flakey. The process intensifies as the steel pushes the concrete away (referred to as concrete spalling), and more water comes into contact with the steel, which compounds the problem.
Beside flaking and cracking, other signs of spalling concrete include rust stains that appear to be coming from within the concrete, leaks, and bubbling. Often the problem is blamed on weathering or aging concrete, but the problem can be dangerous. Spalling can cause chucks of concrete to separate from structures such as buildings and bridges and present a real hazard to pedestrians passing by or traffic below.
Structural engineers have wrestled with the problem for years and recently researchers at the University of British Columbia in Canada think they have found a cure for concrete cancer. Their study suggests that a cure may involve “producing concrete using discarded glass.” Shahria Alam, an associate professor of engineering and one of the authors of the report, says, ““Every year, millions of tons of glass bypass recycling centers and end up in North American landfills.” He explains that their goal, like many engineers, is to try and make smarter building materials without having to take a new resource out of the ground.
The researchers report that “By partially replacing cement with polymer, fly ash and glass powder, we were able to produce concrete that was more than 60% stronger than what was previously believed possible.” They are looking to further test their products but hope to eventually replace up to 25% of traditional cement materials, mined from the earth with recycled glass.
The Conco Companies is one of the leading concrete contractors in the Western U.S. and offer a wide range of quality services and products. While we tackle projects both big and small, our experience includes providing the complete concrete package for the Levi’s Stadium along with other notable projects. We serve California, Washington State, Oregon, Colorado and Nevada.