Newpac rapid road trial

1
Newpac Rapid Road Trial
2
Background

• UGM in conjunction with Yuleba Minerals have been
  developing a cementitious road repair product
  call Rapid Road. The aim of the product is to
  allow the rapid and efficient repair of mine
  roadways. Rapid Road is a dry mix early set high
  strength concrete blend.

3
Trial

• Newpac Colliery was seen as an ideal site to
  trial the material. Newpac Colliery has a varying
  floor thickness and in places floor breakthrough
  has caused some large bog holes.

4

• The trial was carried out in the long wall 2 main
  gate drive heading. A bog hole as shown in figure
  1.1 was selected for the trial.

5
(No Transcript)
6

• Friday 4/5/07 The bog hole was mucked out to
  remove as many silts and clay like material as
  was possible. Air pumps were set in the bog hole
  to remove the water in preparation for the
  installation of the rapid road.

7

• Saturday 5/5/07 The water level in the bog hole
  had not changed and silts were again present in
  the water. Whilst these were far from ideal
  conditions to install the rapid road it was
  decided to proceed with the trial. The original
  plan had been to open each bulka bag and rake
  material on the floor while wetting the material
  to form a slab ranging from 150mm to 250mm thick.
  Surface trials _at_25 Deg C had given a working time
  of between 5 and 10 minutes.

8

• The revised plan was to place the material into
  the water starting at one end of the bog hole and
  work back. It was decided to start at a water
  depth of approximately 200mm and work towards the
  centre of the bog hole.

9
(No Transcript)
10

• The down side of this method was that we had to
  add enough material to fill the area until we had
  reached the top of the water. This was the only
  way we could ensure we had added enough material
  into the water, our concern being the muddy silts
  in the bog hole would adversely affect the final
  strength of rapid road.

11
(No Transcript)
12

• The 16 bags (16 T) of material were stored in an
  area just out bye of the bog hole. A crew of 4
  people including the Eimco operator took
  approximately 3 ½ hours to install the 16 bags of
  material. The crew started by bringing one bag at
  a time and then changed to bringing the bags on a
  trailer and hanging the bags from roof bolts
  allowing the crew to split them as they worked
  there way along the heading (see fig 1.3).

13
(No Transcript)
14

• The rapid road surface trials showed the material
  to be workable for 5-10 minutes. During the
  installation at Newpac the rapid road seemed to
  remain workable for up to an hour figure
  1.5(left) show the material after approximately
  30 minutes while figure 1.5(right) is after
  approximately 90 minutes.Originally 24T of rapid
  road had been delivered to site of this 8T was
  mistakenly used leaving 16T. While 16T would have
  been enough to fill the area if it had been pump,
  the 16T filled an area approximately 5 meters
  wide by 8.5 meters long and a further 30 bags
  (30T) would be needed to fill the remaining bog
  hole.

15
(No Transcript)
16

• Tuesday 8/5/07 the site was inspected (figures6)
  to see how well the rapid road material had held
  up. On inspection the rapid road was intact and
  while the area had been subject to some vehicle
  traffic the rake marks were still clearly evident
  in the surface of the rapid road. This would
  indicate that although the rapid road was used in
  very adverse conditions and that silts and clays
  in the water would have degraded its ultimate
  strength the rapid road had still obtained a
  reasonable strength.

17
Conclusion

• The testing confirmed that the current rapid road
  mix provides enough working time to place the
  material. The testing conditions were not ideal
  but did show that the rapid road formulation even
  when subject to significant silt contamination
  provides adequate strength.

18

• While installing rapid road directly into water
  worked, to gauge the mix the rapid road was mixed
  until it reached the surface of the water and it
  would be difficult to mix it to a level under the
  waters surface. This meant that even though we
  were originally going to lay a slab up to 250mm
  thick we ended up with a slab in places 500mm
  thick. Thus considerable more material is
  required and roof height was lost in the process.

19

• In future situations where the water cant be
  removed the crew and offsite engineering staff
  would propose first filling the area with crushed
  rock or iron stone up to a level approximately
  200mm bellow the desired finished surface then
  (providing the water level is bellow the desired
  floor level) apply the rapid road in accordance
  with the original installation guide to provide a
  finished slab approximately 200mm thick.

20

• Yuleba is located in Southern Queensland (near
  Roma, Surat, Miles and Chinchilla) and services
  mines in NSW and QLD
• Kerry Grover
• Greg Moore
• www.yulebaminerals.com.au