Alphatec – Grouting Specialists
Once the holes had been flushed clean, high-strength reinforcing steel bars (DYWIDAG rods) were inserted into these holes with copper tubing attached. The top of the hole was then sealed for pressure resistance of up to 300 bar. ALPHATEC® 300 injection grout was pumped into the holes until flow out was observed from the vent tube. The vent was crimped shut, and pressure applied to the hole to push the resin into all separations, cold joints, fissures, stress cracks, shrinkage cracks, honeycombs and any other void or imperfection intersected by the hole. Evidence of coverage was seen at various places around the foundation and the pressure was maintained on each hole until the site supervisor was satisfied that optimal coverage had been achieved. The injected resin cured in approximately 24 hours and the protruding tubes were cut off. The repaired foundation will show much greater resistance to movement, and its ability to damp out vibrations will be greatly enhanced by this repair.
Additional injection work was done on the crankcase and frame extension anchor bolts, after the main chipping work was complete. No evidence of loose bolts was found.
Two of the suspect pipe support plinths were repaired by pressure injection, since the baseplates appeared to be relatively well grouted. The plinths, however, were not properly fastened to the underlying concrete mat and the injection work has solved this problem.
Figure 4: Alignment
Grout Removal
The existing grout and underlying damaged concrete was removed by pneumatic chippers to a depth of approximately 150 mm beneath the motor baseplates. Work on the compressor was delayed due to problems removing piping and wiring.
As this picture shows, the method of installing the baseplates left a lot to be desired, with multiple shims, and gaps between baseplate and grout. The grout was removed in sections, with at least 50 % of the original grout being left in place while the initial supports were put in place. The baseplate was supported by the ALPHAPAD® system, consisting of specially designed hydraulic jacks, with a ball joint incorporated to ensure parallel support on the underside of the machine flange.
HYDROCARBON WORLD – VOLUME 6 ISSUE 2 15
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84