The new solution uses sparks to recycle concrete

Concrete (a mixture of cement, aggregate and water) has a very durable and high strength properties and has become a popular material especially in the construction industry. However, the use of concrete causes some negative side. Thousands of roads, bridges and bridges are being built every year, and many new buildings have been dismantled and new construction has poured into tons of crushed concrete, which has become a challenge. In 2010 alone Germany dumped 130 million tons of concrete waste in construction.

But apart from dealing with environmental impacts. Cement producers account for 8 to 15 percent of global CO ₂ emissions a year. Recycled concrete is still limited, as the current shredding method produces a lot of dust, and only uses degraded concrete. But recently a team of researchers from the Concrete Technology Group in Holzkirchen, Germany, has come up with a new approach to recycling concrete that is as efficient as ever. Their formula is to use the discharge.

Discharge usually occurs in air and water, but rarely in solids. However, German researchers used the results of a forgotten research from the 1940s, a short period of time (less than 500 nanoseconds) that sparked electricity through the water. and toward the solid. After entering the concrete, the sparks will travel along the least obstructed road, the boundary between the aggregate (rock, gravel) and cement and break the bond. This process will cause the concrete to break down and separate into cement and aggregate.

Holzkirchen scientists are now able to carry out this separation process with a capacity of about 1 ton per hour. Their goal is to achieve an optimum productivity of 20 tons per hour and bring the recycling system to market in the next two years.

If this project proves fruitful, we will achieve great progress in the field of concrete recycling, which will require less new cement production and thus reduce CO ₂ emissions. greenhouse effect.