Page 101 - Machinery Component Maintenance

84 Machinery Component Maintenance and Repair

Table 3-4
Typical Physical Properties of Epoxy Grouts

Compressive strengths
After curin ,7 days at 77" F. and
testing at 7'3 F.. .................. 8,000 - 10,000 psi.
After curing 7 days at 77" F., heating
for 8 hrs. at 160' F. and testing at
160OF .......................... 1,000 - 3,000 psi.
After curing 7 days at 77" F., heating
for 7 days at 160' F. and testing at
160" F .......................... 4,000 - 7,000 psi.
After curing 7 days at 77" F., heatin Q
for 7 days at 160" F., cooling to 77
F. and testing at 77" F.. .......... 12,000 - 18,000 psi.
~~
Tensile strengths
After curing at 77" F for 7 days. ..... 1,600 - 2,000 psi.
~~
After curing 7 days at 77" F., heatin5
to 160" F. for 7 days, cooling to 77
F. and testing at 77" F.. .......... 2,300 - 3,000 psi.
~~
Linear coefficient of thermal expansion
Unfilled grout cured for 7 days at
77" F. and tested at 77" F.. ....... 6 - 8 x in./in."F.
Filled grout cured for 7 days at
77" F. and tested at 77' F.. ....... 1.2--.Ox IO-5in./in."F.
Bond strength
Cured at 77" F. for 7 days at tested
at 77" F.. ....................... 200 - 400 psi.
~~
Modulus of elasticity
Cured at 77 ' F. for 7 days and
tested at 77" F.. ................. 320,000 psi.

stands to reason that epoxy chocks would be much less abrasion resistant
than steel chocks.
While there are numerous reports of "satisfactory installations" in-
volving integral gas engine compressors on epoxy chocks, the fact is that
this technique has not been utilized long enough to ascertain life expec-
tancy. The authors are not aware of any installations where the anchor
bolts have been retorqued after several months of operation or where fol-
low-up data have been taken from bench marks or other datum points
such as tooling balls. In other words, the creep characteristics of epoxy
chocks have not at this time been evaluated to the satisfaction of the au-
thors. Further, some manufacturers do not provide test temperatures for