26
Geotechnical News • September 2012
THE GROUT LINE
compaction grout, urethane solution
grout injection into soil, groutjack-
ing with both cementitious grouts
and urethane foam, grout rheology,
stability, and bleed, installation of self
drilling micro-piles, and testing of
soil anchors. The latest developments
in real time computer monitoring of
grouting parameters were featured by,
Atlas Copco, Sweden, and RST Instru-
ments, Canada, both of which provide
the original input data to the clients
representatives in standard format
such as Microsoft Excel. Equipment
on display or used in the demonstra-
tion included grout mixers and pumps
from Airplaco, NCIF, Atlas Copco,
Cementech , and ChemGrout. And the
grand finally this year, lifting a 10,000
pound concrete block attached to the
lift line only by friction supplied from
a special Baski down-hole packer!
The always popular penetrability
evaluation of ultrafine cement grouts
into sand deposited in transparent
columns was repeated. This event has
been an important force in the devel-
opment of ultrafine cement grouts
for the solidification of sandy soils.
Therein, various grout mixtures are
injected into the bottom of the sand
columns at a pressure of 10 psi and for
a maximum time of 20 minutes. The
relative penetrability is determined
by the distance permeated or the time
required for the grout to reach the top
of the columns. Through the years,
nine manufacturers of ultrafine cement
from five different countries have sent
their product to be evaluated. Some
have actually changed their formula-
tion when less than good performance
was experienced, and these tests have
been responsible for a substantial
advance in this developing technology.
A variety of grout materials including
cementitious, chemical solution, and
resin based were mixed and handled.
Influence of the latest material science
and admixture technology for cementi-
tious grouts was illustrated by the fill-
ing of eight foot tall transparent tubes
to evaluate various grout stability and
bleed characteristics.
The short course sponsored each year
by the Colorado School of Mines is
the only one of its kind anywhere in
the world, and has become the place
to see and be seen for those involved
in grouting. Throughout the years,
participants have come from virtually
every major organization involved
with grouting, be they government
agency, designer, supplier, or contrac-
tor. They run the gamut from relative
Photo 1:The always popular permeation of various ultrafine cement grouts
into sand columns.
Photo 2: Automatic real time recording of grouting parameters are described
by Bill Warfield of Atlas Copco during injection for a self drilling micro pile.
