When it comes to demolishing buildings, there are almost as many ways to take them apart as put them up. We knock them down, blow them to bits, and build machines to take them apart. But what about a robot that eats buildings? Omer Haciomeroglu of Sweden’s Umeå Institute of Design has come up with the concept ERO concrete de-construction robot, which uses high-pressure water jets to strip concrete from rebar and recycle it on the spot.
Reinforced concrete consists of concrete poured on a mesh of steel rebar. This provides a great deal of strength, but it also makes demolition a slow, difficult process involving a great deal of smashing, bashing, and crushing. This brute force method is even used by advanced demolition robots that rely on jack hammers and shovels. The end result is a process that requires huge amounts of power, lengthy separation of crushed concrete and twisted rebar, and the machinery and transportation to achieve this.
There’s also a great deal of water involved because fire hoses are needed to continually douse the area to suppress dust. At the end, the waste material still needs to be transported out of town for disposal or to recycling at depots where the concrete and the last of the rebar need to be separated and the concrete crushed for reuse.
ERO is a winning concept design in the Student Designs category of the 2013 International Design Excellence Award and replaces several machines with a single autonomous robot type. It demolishes buildings by eating or “erasing” them section by section and layer by layer with an articulated arm equipped with a water-jet/vacuum head.
In operations, a fleet of EROs would be be deployed at a demolition site. The robots would move about on omni-directional tracks developed by Osaka University. These are cylindrical treads that propel the robot forward and back like a caterpillar tractor or rotate on their axis to make the robot crab sideways. According to Haciomeroglu, this allows ERO to dispense with hydraulic stabilizers and simplifies design.
The robots would scan the site, plan out their own routes, and then fan out to erase the building. They would do this by means of hydro demolition. This is a technique currently used for repairing reinforced concrete structures. EROS uses high-pressure water jets to hammer into the cracks in the concrete, pulverizing it and stripping it away by means of a vacuum system. What’s left is clean rebar that even has the rust stripped off. The more or less intact steel can be easily cut up for reuse or sent off for scrap.
Meanwhile, the water is recycled by a centrifugal decanter to separate it from the solids and the stripped concrete is separated into aggregate and cement and bagged by ERO, while turbulence dynamos reclaim part of the energy used in the process. The resulting bagged and labelled material is sent directly to concrete pre-cast stations nearby to produce new building blocks.