When you see the colossal structure and hear how much it weighs, you really can’t imagine it being possible. Lifting a 70-tonne crusher unit that had sunk out of alignment, along with the one-metre-thick concrete foundation slab beneath it, using expansion resin. Yet that is exactly what URETEK did at Dura Vermeer Reststoffen in Vijfhuizen, North Holland.
In 2013, it became apparent that the concrete foundation slab of Dura Vermeer Reststoffen’s crusher unit was subsiding. As a result, the unit had become lopsided and parts had started to wear out significantly. To prevent excessive wear and high replacement costs, the company decided that the plant needed to be straightened out again. There were broadly two options for this: jacking up the crushing plant and then placing it on a specially made frame, or raising the concrete slab – including the crushing plant – by injecting a powerful expansion resin underneath it. Dura Vermeer opted for the second option and called upon the specialist expertise of URETEK for this.
Powerful expansion
Injection lances were installed through the one-metre-thick concrete slab, reaching just below the slab’s surface. Expansion resin was injected very precisely beneath the concrete slab of the crushing plant via these lances in order to raise the crushing plant again. To ensure this entire process was properly controlled, the ‘lifting process’ was continuously monitored using sensitive laser equipment. Ultimately, it took less than two days to fully level the crusher plant again.
Support points
The crusher plant is founded on two concrete slabs and rests on fourteen support points anchored in the concrete slabs. Measurements were taken at all these support points beforehand to determine the exact degree of misalignment. This revealed that one of the two concrete slabs had subsided unevenly, causing the axis of the discharge conveyor belt to become out of plumb. Ultimately, expansion resin was injected beneath all support points – including the concrete slab that had not subsided – to restore tension to the ground beneath both foundation slabs.
