Page 89 - Machinery Component Maintenance

74 Machinery Component Maintenance and Repair

otherwise, a gradient in coefficients of thermal expansion may be created
between the top and bottom of the grout. The diameter of the largest par-
ticles should be no more than 1/10 to 1/15 the thickness of the grout under
the load bearing surface of the machinery. The largest particle size in
most commercial epoxy grouts is about l/8 in. Epoxy grout manufactur-
ers usually recommend a minimum grout thickness of 1112 in.
Because the adhesive components are organic materials, the viscosities
change with temperature. More aggregate is sometimes required when
preparing mortar in hot climates than is required when mixing at conven-
tional room temperatures. The proper consistency or viscosity of the
mortar is observed when the divot falls free and does not cling to a clean
mortar hoe when a gentle chop is made in the mix.
When utilizing a concrete mixer or a mortar mixer for preparing the
grout, it is important that mixing after aggregate addition be carried out
only long enough to coat all aggregate particles uniformly. Otherwise, a
froth may be generated from air whipped into the mix. Ideal mixer
speeds are usually about 20 rpm.

Job Planning

If the equipment is being installed in original construction, grouting
should be scheduled for a time compatible with critical path sequences. If
the equipment to be grouted is in service, it may be advantageous to
schedule regrouting during a normal downtime or during a turnaround
period. In either case, work planning should be carried out in detail well
in advance of the actual time the work is to be done. Proper planning
reduces job site problems.
The equipment manufacturer should be informed well in advance in
order to alert his service personnel if their presence is required to super-
vise leveling and alignment prior to grouting. The grout manufacturer
should also be alerted if field supervision of grouting is expected. Early
communication with these parties will allow them to make necessary ar-
rangements with minimum inconvenience. Last minute notification sel-
dom accomplishes these objectives.
A clear understanding of what is expected from a contractor will mini-
mize extra charges which usually arise after the work is complete. Con-
tract details should include provisions identifying parties responsible for
furnishing utilities, materials, etc. The extent of work should also be ac-
curately defined. For example, responsibility for disposal of waste,
dressing and painting the foundation, backing-off on the jack screws, and
torquing the anchor bolts should be considered.