5 things you didn’t know about... a new concrete mix that resists salt damage
Credit: Drexel University. A series of concrete core samples being prepared for testing for reactivity with de-icers.
1. The new method for producing concrete uses by-products of coal furnaces, the metal industry and silicon and ferrosilicon alloys – fly ash, slag and silica fume.
2. It has proved more resistant to salt deterioration than current concrete mixes used for road and pavement surfaces.
3. Calcium chloride salt, used to de-ice roads, reacts with calcium hydroxide in concrete, forming calcium oxychloride. This can expand when formed, creating internal pressure and producing cracks in the concrete.
4. The new concrete mix contains less calcium hydroxide, therefore producing less calcium oxychloride than Portland cement, while also using recycled materials.
5. It is hoped that the new mix will allow the lifespan of concrete roads and pavements to reach the designed target of 20-40 years.
To read the paper in full visit, bit.ly/2rL3VV6
To find out more see page 7 of the upcoming July issue of Materials World.
