Note: Descriptions are shown in the official language in which they were submitted.
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PI-0177 Cognate TITLE
Inorganic Grouting Systems For Use
In Anchoring A Bolt In A Hole
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to inor-
ganic grouting systems and a compartmented package
for use therewith in a method of anchoring a
reinforcing member in a hole, e.g., in a mine roof,
wherein reactive inorganic components are intro-
duced into a hole and allowed to react and harden
thereln around a reinforcing member so as to fix it
firmly in the hole.
Description of the Prior Art
Anchor bolts are employed in various
fields of engineering, for example as strength-
ening or reinforcing members in rock formations and
in structural bodies. The bolts are inserted into
drill holes in the formation or body, and often
are fixed or anchored therein, at their inner end
or over substantially their entire length, by means
of a reactive grouting composition which hardens
around the bolt. When used in a mine roof, bolts
grouted in this manner help significantly to
prevent mine roof failure. Because unsupported rock
.
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strata have a tendency to move vertically and
laterally, and this motion is what commonly causes
the roof to fail, it is important that bolts be
installed as soon as possible in a newly e~posed
roof and that the required strength provided by
the hardening of the grouting composition be
developed rapidly, e.g., in a matter of a few
minutes, or within an hour or so, depending on the
type of mine. Rapid hardening also contributes to
the efficiency of the bolt installation operation.
As a practical matter, the hardening or
setting time of a bolt grouting composition must be
sufficient to allow the reactive components thereof
to be mixed and positioned around the bolt in the
hole, e.g., at least about 15 seconds, depending on
anchoring length, both in the case in which the
components are delivered separately into the hole
and combined therein and mixed, e.g., by the rota-
tion of the bolt, as well as when the components
are delivered into the hole in combined and mixed
form either before or after bolt insertion. Beyond
this necessary working time, the rate at which the
composition approaches its ultimate strength should
be as high as possible, e.g., for coal mine roof
support the grout should attain about 80~ of its
pull strength in an hour Gr less, and the ultimate
pull strength should be at least about 175 kilograms
per centimeter of anchoring length. Thus, the
over-riding need in grouting systems for rock bolt
anchoring is sufficient working time combined with
high ultimate pull strength attained as rapidly s
is re~uired for a given use.
Reactive compositions which have been used
in rock bolt anchoring include inorganic cement
mortars and hardenable synthetic resins, and these
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have been introduced into the drill holes through
a feed pipe, or in cartridged rorm. In the latter
case, the reactive components, e.g., a polymerizable
resin formulation and a catalyst which catalyzes
the curing of the resin, are introduced into the
hole in separate cartridges or in separate compart-
ments of the same cartridge. A rigid bolt pene-
trates, and the.eby ruptures, the cartridge(s) and
the package contents are mixed by rotation of the
bolt. The grouting mixture hardens around the bolt
so as to anchor it in place.
In the case of inorganic cements, the
pumping of a prepared cement mortar into a hole
after a bolt is in position therein has been des-
cribed, as has the driving of a bolt into cement
mortar in a hole. In the former case, complete
and uniform filling of the space around the bolt
is difficult to ensure; and, in the latter case,
the bolt has to be installed immediately after the
mortar has been introduced, so that it is not
feasible to fill a large number of holes with the
mortar first and subsequently to introduce the
bolts, a more efficient procedure.
Cartridged cement systems for anchoring
rock bolts are described in U.S. Re. 25,869, British
Patents 1,293,619 and 1,293,620, and German OLS
2,207,076. In these systems the components of a
cement mortar are introduced into a drill hole in
separate compartments of an easily destructible
cartridge. One component of the system, i.e., a
cement that sets by hydration, is placed in one of
the compartments in the dry particulate state,
i.e., as a dry powder or grit; and the other com-
ponent, i.e., water, is placed in the other compart-
ment. The cartridge is broken and the components
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are mixed by driving and rQtating the bolt therein.
The cartridged system has the advantage that ~olts
can be installed in the holes at any time after the
introduction of the reactive components because the
components are kept separated until the installation
of the bolt. Also, such a system requires no complex
pumping equipment at the site of use.
U.S. Re. 25,869 discloses the use of a
glass cylinder filled with a dry Portland cement/
sand mixture which has embedded therein a glass
capsule containing water and a rapid-hardening agent,
e.g., calcium chloride, to shorten the hardening time.
British Patents 1,293,619 and 1,293,620
describe the use of a cartridge consisting of inner
and outer rigid brittle tubes having at least one
end that is readily frangible, the space between the
two tubes containing a mixture of Portland cement and
high alumina cement, and the inner tube containing
water. The addition of an aggregate, e.g., sand or
copper slag, a natural gum and salt compound, and
a wetting agent to the water also is disclosed.
In German OLS 2,207,076, the particulate
material in one compartment is gypsum, preferably
mixed with a strength-enhancing cement, to which an
inert filler such as styrofoam may be added. The
use of alginates, polyvinyl alcohol, polyacrylic acid,
carboxymethylcellulose, and metallic soaps as
gelling agents to increase the viscosity of the water
in the other compartment also is disclosed.
Although inorganic grouting systems are
economically attractive in contrast to resin-catalyst
systems, and generally are not plagued with such
problems as instability on storage as are resin
catalyst systems, cement grouting systems wherein one
of the components is a dry cement may present certain
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difficulties in use, especially when applied to the
fixing of bolts in drill holes. When compartmented
cartridges are used, the bolt must be inserted into
the cartridge and penetrate its full length if the
components are to be mixed properly. This insertion
is more difficult to achieve with cartridges con-
taining a dry cement component. The magnitude of the
force required to achieve the necessary insertion may
exceed the capability of standard bolting equipment
available in the working location, e.g., in a mine.
Also, the insertion force required with such car-
tridges may cause the bolt to buckle.
Another problem with the cartridged dry
cement component system of the prior art is that the
cement component is easily vulnerable to premature
hardening should ambient moisture or water from the
other compartment penetrate the cartridge seals or
packaging material, a situation which could arise on
storage or during transportation of cartridges.
Lastly, the prior art bolt-anchoring systems employ-
ing inorganic cement are not well-suited for use in
the uncartridged form, where compact pumping equipment
and accurate metering are desirable to deliver the
components to the drill hole.
U.S. Patent 3,324,663 describes the
reinforcement of rock formations with a two-component
resin composition based on (a) an unsaturated poly-
merizable polyester (alkyd) resin mixed with a mono-
meric polymerizable ethylenic compound and (b) a
cross-linking peroxide catalyst system. ~ water-
reactive filler such as Portland cement or p'aster
of Paris (S-10 percent of the final composition) is
incorporated in either the resin component or
the catalyst component, and water is incorporated in
the component not containing the water-reactive filler.
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The water-reactive filler and water are used to
modify the basic resin/catalyst system, the
presence of water during the curing of the resin
being disclosed as causing an imperfect cure and
minimizing shrinkage. Water-reactive fillers (up
to 5 percent) have been disclosed (U.S. Patent
2,288,321) to shorten the curing time of alkyd
resins by reacting with the water formed during
curing.
In the grouting system of U.S. Patent
3,324,663, the reactants essential for the for~ation
of a hardened grout are totally organic, i.e., an
alkyd resin and a liquid ethylenic monomer, and
they are cartridged together in the same compartment,
lS i.e., premixed, the resin being dissolved in the
ethylenic monomer and reacting therewith when the
separately packaged catalyst is mixed in. Only
about 5-10 percent of the total composition is
water-reactive filler. The preponderance of resin
and catalyst in this system, and the basic resin-
curing reaction that occurs, over-ride and obscure
any possible secondary reaction involving the water-
reactive filler.
With regard to specific inorganic grouting
compositions, cements that set up by hydration
are the best-known. However, it is known that
certain oxide/phosphate compositions can react
extremely rapidly to form hard products. These
compositions contain high-surface-area magnesium
oxide, and/or monoammonium phosphate. The reaction
with phosphoric acid also has been reported to be
extremely rapid. While rapid reaction of the
components of a grouting composition for anchoring
rock bolts for coal mines is a desirable property
(provided that the composition does not set before
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it can be mixed and emplaced), it is essential that
compositions for this use develop high strength
early and attain a high ultimate strength within a
reasonable period of time, e.g., in an hour or so,
to provide an umbrella of safety in a mine roof.
The prior art does not describe or suggest oxide/
phosphate grouting compositions that meet these
requirements, e.g., compositions that permit suffi-
cient time for emplacing and mixing yet attain a
pull strength of at least about 175 kilograms per
centimeter of anchoring length in an hour or less.
The hardening reaction that occurs when
magnesium oxide and phosphates are combined has been
employed for various purposes, e.g., to produce a
lS binder system for foundry aggregate or refractory
materials, to patch or repair cracks in roadways,
etc. In these systems the reactants have a low rate
of reaction, and are characterized by a long setting
time (long pot life or working time) and slow
strength development, usually over a period of days.
Long pot life allows the mixture of reactive com-
ponents to be shaped, e.g., by casting, and permits
the performance of large jobs with a single mix.
For example, U.S. Patent 3,923,534 discloses
refractory compositions in which a magnesia of low
reactivity (fused or hard-burnt magnesia) is used as
a setting agent in combination with water and a
water-soluble aluminum phosphate binding agent for
a re~ractory filler such as silica or alumina. The
wet refractory composition is said to be useful in
concrete mixes, as a mortar or grouting, or as a
castable composition. Low-reactivity magnesia is
used in a minor amount relative to the aluminum
phosphate, and the binding agent is a complex
phosphate containing aluminum and phosphorus in a
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1/1 ratio. These compositions set in hours or
even days, allowing large mixes to be used but
consequently providing no significant supporti~e
strength over such periods. In addition to lacking
early strength, the described compositions develop
very little mechanical strength on standing at room
temperature even for several days after setting,
and require heating, for example, heating in use, to
attain a useful mechanical strength.
U.S. Patent 3,923,525 relates to binder
compositions for foundry aggregate, the binder system
being obtained from an aluminum phosphate containing
boron, an alkaline earth material, and water. The
composition of the aggregate-binder foundry mix is
such as to allow it to be molded or shaped and there-
after cured to form a porous self-supporting structure
having good collapsibility and shake-out properties.
Only a small amount of binder is used, generally less
than about 10 percent, and frequently within the
range of about 0.5 to about 7 percent, by weight, based
on the weight of the aggregate. Most often, the binder
content range by weight is from about 1 to about 5
percent of the aggregate weight. This is sufficient
to allow the binder to be distributed on the aggregate
particles, and the coated particles to be molded into
the desired shape. These foundry mixes require 1 to 4
hours to cure, and the cured shapes are weak enough
to be collapsible and readily broken down for removal
from a casting.
The method of patching described in U.S.
Patent 3,821,006 employs a two-component system of
an inert particulate aggregate such as sand and a
reactive mixture of an acid phosphate salt and
magnesium oxide particles of the "dead-burned" type.
Acid phosphate salts disclosed are monoammonium
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g
ph~spAate, monosodium phosphate, anà monomagnesium
phosphate. None of the disclosed compositions made
from these salts hav~ the high early strengths
required for rock bolt anchoring in mine roofs. For
example, a composition made from monomagnesium
phosphate is reported to have developed a compressive
strength of only 29 kilograms per square centimeter
after 2 hours, and 60 kilograms per square centimeter
after 24 hours.
Ammonium phosphate as a binder for magnesium
oxide is also described in U.S. Patents 3,960,580,
3,879,209, and 3,285,758. The cements based on magne-
sium oxide and dry, solid monoammonium phosphate (or
an aqueous solution of ammonium polyphosphates) of
U.S. Patent 3,960,580 contain an oxy-boron compound
such as sodium borate to extend their setting time.
The compressive strength of these cements even after
2 hours is low, and their maximum strength is not
attained for many days. U.S. Patent 3,879,209 des-
cribes a process for repairing roadways, etc. with
a composition comprising a magnesia aggregate wetted
with a solution of ammonium phosphate containing ortho-
phosphates, pyrophosphate, and polyphosphates, the
latter including tripolyphosphate and higher polyphos-
phates. This composition also develops strengthslowly, i.e., over a period of days. The ammonium
component is described as essential for this composi-
tion, as phosphorus oxide components alone, such as
phosphorus pentoxide, are disclosed as not giving
the desired results. The same ammonium phosphate
solution is described in U.S. Patent 3,285,758, which
also mentions the unsuitability of phosphoric acid
and magnesium phosphate as well.
German OLS 2,553,140 describes a process for
producing a cement by reacting aqueous orthophosphoric
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acid with a chemical combination of oxides such as
magnesium orthosilicate (2MgO-SiO2). The cement com-
positions described have long setting times (9-90
minutes) and their compressive strengths are measured
usually after one month.
SUMMARY OF THE INVENTION
The present invention provides improved
grouting systems for use in anchoring a reinforcing
member in a hole by the reaction of the mixed com-
ponents of a hardenable inorganic grouting compositionso as to form a hardened grout around the reinforcing
member, the improved systems having, in one case, a
cement component in slush form to impart lubricity
to the grouting composition for easy insertion and
rotation of a reinforcing member, and, in another
case, a high-early-strength phosphate grouting
composition, particularly suitable for use in coal
mine roofs, that achieves a pull strength level of at
least about 175 kg/cm anchoring length within an
hour, and usually within 5-10 minutes.
In one embodiment of the invention, an
inorganic grouting system includes a composition
comprising controlled amounts of a first component
(a) comprising a slush or sludgy mass of a particu-
late inorganic cement, e.g., a cement that sets byhydration, and a liquid, such as a hydrocarbon,
which is non-reactive therewith, and a second
component (b), separated from the first, comprising
a liquid, e.g., water, which is reactive with the
inorganic cement in the first component, the
inorganic cement constituting more than 10 percent
of the total weight of components (a) and (b), and
components (a) and (b) being adapted to be brought
together and intimately mixed so as to react rapidly
to form a hardened grout of sufficient strength to
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firmly anchor the reinforcing member to the wall of
the hole. A particulate aggregate such as sand
preferably is present in one or both of the com-
ponents in an amount such as to constitute about
from 20 to 80 percent of the total weight of
components (a) and (b). A non-uniform fine sand is
most preferred. In this system, the grouting com-
position preferably is forced into an annulus formed
between the reinforcing member and the wall of the
hole by the introduction of the reinforcing member
into the grouting composition before any substantial
hardening of the composition has occurred, the mixed
components of the composition reacting in the annulus
to form a hardened grout.
In a method of anchoring a reinforcing member
in a hole by means of this improved grouting system,
(1) two components of a hardenable inorganic grouting
composition are delivered into the hole in controlled
amounts, the first of these components, (a),comprising
a slush of a particulate inorganic cement and a liquid
which is non-reactive therewith, and the second, (b),
comprising a liquid which is reactive with the
inorganic cement, the inorganic cement constituting
more than 10 percent of the total weight of compo-
nents (a) and (b); and (2) a reinforcing member isintroduced into the grouting compos tion in the hole
before any substantial hardening of the composition
has occurred, whereby grouting composition is forced
into an annulus formed between the reinforcing member
and the wall of the hole; components (a) and (b)
being delivered into the hole in a separated or
freshly brought-together condition and intimately
mixed whereby they react rapidly around the reinforc-
ing member to form a hardened grout of sufficient
strength to firmly anchor the reinforcing member to
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the wall of the hole. Preferably, the two components
are delivered into the hole separately, most
prefera~ly by virtue of their being maintained in a
frangible compartmented package adapted to be
inserted into the hole and subsequently broken
therein by the penetration of the reinforcing member
therethrough, and the components are brought together
and mixed by rotation of the reinforcing member.
The invention also provides such a package containing
(a) in a first compartment, a slush or sludgy mass
comprising a particulate inorganic cement in a liquid
which is nonreactive therewith, and (b) in a second
compartment, separated from the first, a liquid which
is reactive with the inorganic cement in the first
compartment, the inorganic cement constituting more
than 10 percent of the weight of the total package
contents. A particulate aggregate such as sand
preferably is present in the first and/or second com-
partments in an amount such as to constitute up to
about 80 percent of the weight of the total package
contents.
In a preferred grouting system and anchoring
method of the invention, which finds particular use
in the reinforcement of mine roofs wherein the
grouting composition has to set up fast enough to
provide high strength in a very short time, grouting
compositions are employed which harden relatively
rapidly, e.g., compositions containing calcined
gypsum or Very High Early Strength cement (described
in U.S. Patent 3,860,433) in the first component and
water in the second component, or wherein the cement
in the first component is an alkaline earth metal
oxide or hydroxide and the second component contains
a phosphoric acid or phosphate solutior
The term "inorganic cement" as used herein
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to describe the particulate solid reactant in the
first component or package compartment denotes a
particulate inorganic composition that sets up and
hardens to a strong, dense monolithic solid upon
being mixed with a liquid and allowed to stand.
The term includes hydraulic cements, i.e., those
that are capable of setting and hardening without
contact with the atmosphere due to the interaction
of the constituents of the cement rather than by the
evaporation of a liquid vehicle or by reaction with
atmospheric carbon dioxide or oxygen. Examples of
such cements are Portland cements, high-alumina
cements, pozzolanas, and gypsum plasters, which
set up when mixed with water; lead oxide, which
sets up when mixed with glycerin; as well as the
more rapid-setting metal oxide or hydroxide com-
positions, e.g., magnesium oxide, which set up
rapidly when mixed with phosphoric acid or phos-
phate solutions.
The term "slush" as used herein to describe
the first component of the grouting composition
denotes a solid-liquid combination of mud-like or
sludgy consistency. The term includes solid-
liquid combinations of varying degrees of mobility,
but in all cases denotes combinations that are
readily pumpable.
The term "liquid" as used herein to des-
cribe the second component of the grouting compo-
sition which is reactive with the inorganic cement
in the first component is used in the conventional
sense to denote single-phase materials as well as
solutions. Also, the reactivity of this liquid
with respect to the cement may be produced in situ
when the components are brought together, as will
be described hereinafter.
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14
The nonreactivity of the liquid in the
slush which constitutes the first component or which
is present in the first package compartment refers
to the substantial lnertness of this liquid with
S respect to the solid cement and other materials
present therein. Such liquid may, however, be
reactive with a material in the second component or
compartment, and may have some influence on the
setting time and ultimate strength of the grout.
In another embodiment, the present inven-
tion provides a high-early-strength phosphate
grouting system for use in a hole in combination with
a reinforcing member wherein a hardened grout is
formed around the reinforcing member in the hole by
the reaction of the mixed components of a hardenable
inorganic grouting composition, said grouting compo-
sition comprising
(a) an acidic reactive component comprising
at least one acidic oxy phosphorus compound selected
from the group consisting of phosphoric acids, e.g.,
H3PO4, anhydrides of phosphoric acids, e.g., P2O5,
and salts of phosphoric acids with multivalent,
preferably trivalent, metal cations, preferably
Al(H2Po4)3;
(b) a basic reactive component comprising
at least one particulate basic compound of a Group II
or Group III metal capable of reacting with the oxy
phosphorus compound in the presence of water to form
a monolithic solid, preferably an alkaline earth
metal compound selected from the group consisting
of magnesium oxide,magnesium hydroxide, magnesium
silicate, magnesium aluminate, and calcium aluminate;
and
tc) an aqueous component;
3~ these components being present in or outside a hole
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in a separated condition such that any substan.ial
hardening reaction between the basic and acidic
components is prevented, and when present outside
the hole being adapted to be delivered into the hole
separately or in a freshly combined condition; the
basic metal compound(s) having a particle surface
area of about from 0.1 to 40, preferably less than
about 30, square meters per gram and constituting
about from 5 to 35 percent of the total weight of the
grouting composition, with the proviso that when the
surface area is less than 1 square meter per gram
more than about 95 percent of the particles pass
through a 200 mesh screen (U.S. Standard Sieve Series);
the ratio of the moles of the basic metal compound(s)
to the moles of phosphorus pentoxide on which the
oxy phosphorus compound is based being in the range
of about from 2/1 to 17/1; the amount of water present
in the composition constituting about from 3 to 20
percent of the total weight of the grouting composi-
tion; a particulate aggregate being present in thecomposition in an amount such as to constitute about
from 30 to 70 percent of the total weight of the
composition; and the components, when mixed, reacting
without the application of heat thereto to form a
hardened grout having a pull strength of at least
about 175 kilograms per centimeter of anchoring length
within an hour.
In a preferred embodiment, the acidic
reactive component and at least a portion of the
aqueous component are combined together in the form
of an aqueous solution or mixture of a phosphoric
acid or a phosphoric acid salt, and this solution or
mixture is kept separate from the basic reactive
component until use.
In this high-early-strength system, use
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of the reactive components in the form of a slush
also is desirable to achieve lubricity in the system
for the easy insertion and rotation of a reinforcing
member, and to make the component pumpable through
small-diameter passageways. Hydrocarbons, polyols,
and water are suitable slush-forming liquids.
BRIEF DESCRIPTION OF THE DRAWING
In the accompanying drawing, which illus-
trates specific embodiments of the compartmented
package and inorganic grouting systems o~ the inven-
tion,
FIG. l is a perspective view of a portion
of a compartmented package of the invention, which
package has been cross-sectioned in the transverse
direction so as to reveal more fully the internal
structure thereof; and
FIG. 2 is a plot of shear strength vs.
time of a cement-water system of the invention.
DETAILED DESCRIPTION
In a method and system of this invention,
an inorganic cement, e.g., a cement that sets by
hydration or a metal oxide, is maintained in the form
of a slush or sludgy mass together with a liquid
with which it does not react, e.g., an inert
nonaqueous liquid, preferably a hydrocarbon, in the
case of a cement that sets by hydration; and the
slush is brought together and mixed, preferably in
a drill hole, with a reactive liquid, e.g., water in
the case of a cement that sets by hydration, and
allowed to react in the hole around a reinforcing
member. Cement in slush form has several advantages
over the dry cement used in previous rock bolt
packages. First, the nonreactive liquid imparts
lubricity to the cement so that, when the two
components of the grouting composition are packaged
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17
in a compartmented cartridge, a bolt can be inserted
into the cartridge easily and rapidly. Also, the
nonreactive liquid, if substantially immiscible with
the reactive liquid, helps to reduce tne possibility
of the premature setting of the cement as a result
of contact with the reactive liquid or its vapors,
e.g., ambient moisture, during storage or handling,
thereby affording a longer shelf life to the car-
tridged system. In addition, use of the cement in
slush form enables the cement component to be
metered accurately and handled in compact pumps for
ease of packaging in high-speed form-fill machinery
as well as for on-site feed operations. The
cement component in slush form also is advantageous
in that it is adapted to be delivered intermittently
in relatively small quantities as is required for
bolt anchoring in holes.
The combining of the inorganic cement with
a nonreactive liquid in accordance with one embodi-
ment of the present invention, while effectivelyisolating and fluidizing the cement prior to use,
surprisingly does not interfere with the interaction
of the cement and reactive liquid after the grouting
components have been mixed, relatively short setting
times, rapid strength development, and high ultimate
strengths being attainable despite the initial
presence of the nonreactive liquid around the
particles of cement in the slush. The fact that the
present slush system provides the rapid setting and
strength development that is so important for mine
roof support is indeed unexpected when consideration
is given to the slush form of the cement used, and
the behavior of cement-oil combinations in such
processes as the cementing of wells, well casings,
or earth formations. For example, in the process
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for sealing off water-bearing formations adjacent
to oil- or gas-bearing for~ations, known as
"squeeze cementing", and described, for example, in
U.S. Patent 2,800,363, a cement slurry is pumped
into a well until it is adjacent the water-bearing
formation, and is held there in a static condition
for about five minutes ("hesitation step") to allow
water from the water-bea~ing formation to come into
contact with the slurry. Then high pressure is
exerted on the slurry to squeeze it into the hydro-
carbon-bearing and water-bearing formations. The
slurry in the water-bearing formation hardens to
selectively seal off that formation. In the
"squeeze cementing" process and the well-cementing
lS process of U.S. Patent 2,878,875 oil or a water-in-
oil emulsion has been used in place of water in
the cement slurry in order to delay the setting
time of the cement. The development of strength in
the cement in the described well-sealing process has
been reported to require several days' time, an indica-
tion that cement-oil slurries should be avoided in
processes requiring a rapid setting of the cement.
In the high-early-strength phosphate
grouting system of the invention, ~articulate
materials in the grouting composition, e.g., the
basic metal compound, aggregate, or the oxy phos-
phorus compound, may be present in the dry state,
but preferably they are present in the form of a
solution, slurry, or slush with a liquid with which
they are nonreactive to any substantial degree. If
water is kept separate from the oxy phosphorus
compound, the latter and any aggregate which may
be combined therewith form a slurry or slush with
a nonaqueous liquid, preferably a hydrocarbon.
Preferably, however, in the acidic component,
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phosphoric acid or a metal phosphate is present
in aqueous solution or as a slurry or slush with
water, which slurry or slush may also contain
aggregate. The basic metal compound and any
aggregate present therewith preferably form a
slurry or slush with a nonaqueous liquid such
as a hydrocarbon or polyol, or with water or a
water-containing liquid, water being used if the
oxy phosphorus compound is separate from the basic
metal compound and if the basic metal compound is
sufficiently nonreactive with water that the basic
component is not rendered resistant to bolt pene-
tration by the occurrence of a hardening reaction
therein. Magnesium oxide, for example, can be
used in a slush with water or a water-containing
mixture such as an aqueous glycol. A reaction
may begin to take place between the oxide and
water after some time depending on such factors
as the calcination or fusion temperature of the
oxide, the oxide/water ratio, oxide particle
size, storage temperature, etc. This produces
magnesium hydroxide, also a basic metal compound
as defined herein for use in the basic reactive
component. Thus, in a packaged system some change
in the consistency of the basic component may be
noted after a certain period of time, e.g., after
about several hours to several days, when magnesium
oxide and water are present therein, but this does
not involve hardening to the degree that bolt
penetration becomes difficult. Also in a system
wherein a freshly made magnesium oxide/water
component is pumped into a hole, bolt insertion
and reaction with the acidic component would occur
before hydration of the oxide. Thus, in the sense
defined above, water is a substantially nonreactive
19
Z~
~ o
slush-forming liquid for magnesium oxide.
A wide variety of liquids can be used as
slush-forming liquids in the grouting compositions.
The specific choice in any given case will be made
on the basis of the nature of the particulate
ingredient, usually the cement or basic metal com-
pound, any effect the particular liquid may have on
the setting and strength-development time, and the
cost of the liquid. Liquid hydrocarbons and mixtures
containing such hydrocarbons are particularly
advantageous from the point of view of setting time
as well as cost, and therefore are preferred. A
substantially nonvolatile liquid is preferred to
assure stability under varying conditions of storage
and use. For this reason, liquids boiling above
about 25C at atmospheric pressure are preferred.
Thus, preferred hydrocarbon slush-forming liquids
are 5-25 carbon atom aliphatic hydrocarbons such as
hexanes, heptanes, and octanes; and aromatic hydro-
carbons such as benzene and alkyl benzenes, e.g.,toluene and xylene. Aromatic or aliphatic hydrocar-
bon mixtures such as gasoline, naphtha, kerosene,
paraffin oil, diesel fuel, fuel oils, lubricating
oils, vegetable oils, e.g., linseed, tung, cottonseed,
corn, and peanut oils, and crudes such as petroleum
and shale oil also can be employed. For use in
coal mines, the liquid in the slush must have a
flash point above 38C and should be low in volatile
aromatics.
Although low-viscosity slush-forming liquids
are preferred, thick liquids such as medium- or high-
viscosity process oils, asphalt, grease, e.g., hydro-
carbon oils thickened with soaps or other viscosity
modifiers; animal fats, e.g., lard; and hydrogenated
vegetable oils also can be used alone or combined with
ll~ZS.~6
21
lower-viscosity liquids.
The slush-forming liquid also can be an
alcohol, e.g., methanol, isopropanol, butanol, sec-
butyl alcohol, amyl alcohol, a polyol such as glycol,
or glycerol; a ketone, e.g., acetone or methyl ethyl
ketone; cellosolve; an ester, e.g., dibutyl
phthalate or acetyl tributyl citrate; dimethyl
sulfoxide; or dimethylformamide; but the setting
time of grouts made from slushes with these compounds
may be much longer than that from slushes with
hydrocarbons.
A particulate aggregate, preferably sand,
may be present in a controlled amount as a filler in
one or both of the components of the grouting com-
position, e.g., cement/water or basic/acidiccomponents. In general, aggregate greatly enhances
the strength of the hardened grout and also reduces
the amount of cement or basic metal compound required.
Other aggregate materials which can be used include
particles of competent rocks or rock-forming
minerals such as granite, basalt, dolomite, andesite,
feldspars, amphiboles, pyroxenes, olivine, gabbro,
rhyolite, syenite, diorite, dolerite, peridotite,
trachyte, obsidian, quartz, etc., as well as
materials such as slag, cinders, fly ash, glass
cullet, and fibrous materials such as chopped metal
(preferably steel) wire, glass fibers, asbestos,
cotton, and polyester and aramide fibers. Sands
having different particle shapes and sizes can be
used. Because of the need to be packed in a narrow
annulus, the particles should have a minimum dimen-
sion no larger than about 3 mm. Mixtures of dif-
ferent aggregates also can be used.
For a given system, the shear strength of
the hardened grout increases with increasing
21
S6
22
aggregate content up to about 60-70 percent by
weight based on the total weight of the grouting
composition. At the same time, however, mixing
of the components becomes increasingly difficult
as the aggregate content increases. Also, too
high an aggregate content, e.g., 90 percent or
more based on the total weight of the grout results
in a friable, impact-sensitive product whlch is of
no use for anchoring a reinforcing member in a hole.
Therefore, while an aggregate content of up to about
80 percent can be employed, a content above about
70 percent is not preferred on the basis of ease
of mixing and because there is little if any shear
strength increase to be gained by exceeding 70
percent. Also, an aggregate/cement weight ratio in
the range ofabout from 1/1 to 4/1 is preferred.
Usually at least about 20 percent, and preferably
at least about 40 percent, of the total weight of
the grouting composition will be aggregate.
The manner in which the aggregate is
distributed between the reaction components has no
significant effect on the shear strength of the
hardened grout. Thus, 100 percent of the aggregate
can be in the cement slush or basic component, or
100 percent in the component separated therefrom.
Alternatively, aggregate can be distributed in any
other proportions, e.g., 1/1, between two separated
components. The specific aggregate distribution in
any given case usually will be selected on the basis
of that which glves a desired viscosity balance and
ease of mixing. In a system in which the components
are pumped and mixed at the site of use, it may be
more convenient to include the aggregate in only
one of the components.
In the inorganic grouting systems of
2556
23
this invention a 2referred aggregate in the grouting
composition is non-uniform or graded sand, i.e., sand
having, in a size cut which includes 90 percent or
more of the particles, maximum and minimum sizes that
deviate by more than about 20 percent from the median
particle size of the cut. It has been found that
graded sand produces bolt-anchoring grouts having
higher shear strengths than those made from composi-
tions containing uniform sand. Inasmuch as graded
sands having a 30 percent or more particle size
deviation are commonly available, these often will
find use in the present system. Although it is not
intended that the invention be limited by theoretical
considerations, it is believed that the advantageous
effect of graded sand in the composition, as contrasted
to uniform sand, may be related to a better distribu-
tion and packing of sand particles.
In the present grouting systems, the sand
preferably is substantially free, and in any case
contains no more than about lO, and preferably no
more than about 5, percent by volume, of particles
larger than about 600 microns. Compositions contain-
ing more particles of this size have to have a higher
liquids/solids ratio to facilitate pumping, e.g.,
during packaging operations, and the liquid content
necessary for pumpability may result in a weaker grout.
With particles larger than about 600 microns, there
is a greater likelihood that the sar.d particles will
be able to pierce through film cartridges of the
grout, especially at the ends of the cartridge where
the film is gathered together and held in place by
a metal clip, thus resulting in leakage. Larger
than 600-micron particles also are deleterious to
the composition in that they make the insertion of a
bolt difficult. Such particles have a greater
S6
24
tendency to settle out of a slush, slurry or liquid,
thereby causing cartridged grouts to be harder and
st~ffer in one area than in another, and making it
difficult for a bolt to be inserted therein. Bolt
insertion also is easier when the sand has round,
rather than jagged, particles, and therefore round-
particle sands are preferred.
When the components of the grouting compo-
sition used in the phosphate grouting system of the
invention are combined and mixed, the reactive
materials therein react rapidly around a reinforcing
member to form a hardened grout of sufficient strength
to firmly anchor the reinforcing member in a hole in
rock strata so as to provide supportive strength to
the strata. In quantitative terms, rapid reaction,
in this case, means that the phosphate grouting com-
position hardens in less than 30 minutes, usually in
about 1-2 minutes, and reaches at least about 80% of
its ultimate pull strength in less than 30-60 minutes,
usually in less than 10 minutes. Firm anchorage
means that the ultimate pull strength of the hardened
grout is at least about 175 kilograms per centimeter
of anchorage length.
The rapid attainment of high pull strength
that characterizes the present phosphate grouting
system depends on a unique combination of features of
the grouting composition, including the surface area
and content of the particulate basic metal compound(s),
with respect to the total grouting composition and
also with respect to the oxy phosphorus compound(s)
the water content, the aggregate content, and in a
preferred case, the presence of an oxy phosphorus
compound (trivalent metal salt of phosphoric acid)
that forms a cross-linked ?olymeric network in the
hardening reaction. The reactive entity in the
24
ll~Z556
acidic component is a phosphoric acid or an
anhydride thereof, or an acid salt of a phosphoric
acid with a multivalent, preferably trivalent,
metal cation. This entity reacts with the reactive
entity in the basic component which is a basic
Group II or III metal compound that is capable of
reacting with the phosphoric acid or an anhydride
or salt thereof to form a monolithic solid. Such
compounds include, for example, alkaline earth
metal oxides and hydroxides, e.g., magnesium oxide,
magnesium hydroxide, and calcium oxide; aluminum
oxide and hydroxide; ferric hydroxide; alkaline
earth metal aluminates, e.g., magnesium aluminate
and calcium aluminate; and magnesium silicate.
lS Magnesium oxide and hydroxide are preferred on the
basis of availability. Aluminum oxide, e.g.,
A12O3 3H2O, desirably is used in mixture with
magnesium oxide or hydroxide, especially when the
oxy phosphorus compound is phosphoric acid, H3PO4.
With such mixtures, up to about 13%, and preferably
about from 5 to 7% of the grouting composition, is
aluminum oxide.
When the acidic, basic, and aqueous com-
ponents are combined and mixed, the phosphoric acid
or phosphate reacts with the particulate basic
metal compound in the presence of the water to form
a hardened structure wherein the particles of
aggregate and any unreacted portions of the par-
ticles of the basic metal compound are bound
together. It has been found that monovalent salts
of phosphoric acid, e.g., the ammonium phosphates
which figure prominently in the prior art on
patching systems, etc., do not develop the early
pull strength required for bolt anchoring, and
it is believed that this shortcoming is due, at least
25~6
26
in ?art, to the inability of such salts to form a
three-dimensional polymeric network crosslinked by
a multivalent metal ion, e.g., Al 3. ~or this
reason, salts of phosphoric acids with trivalent
metal cations, e.g., Al 3, are preferred phosphoric
acid salts in the acidic component. Phcsphoric acid
(and P2O5), and acid alumlnum salts thereof, espe-
cially the common aluminum dihydrogen ?hosphate and
AlH3(PO4)2-H3PO4, are most preferred on the basis
of availability.
In the present system, the grouting
composition is in its pre-mixed form, and for this
reason the acidic, basic, and aqueous components are
present in a separated state. Separation of these
components is such that one component is excluded
from the presence of the other two, which in turn
may be together or also separate. In most cases,
it will be more convenient, and therefore preferred,
to have the phosphoric acid or phosphate present in
its hydrous form, i.e., as an aqueous solution or
slurry, and in such cases the combined acidic and
aqueous components will be maintained separate from
the basic component, which can also contain water
and/or a nonaqueous liquid. Alternativel~, a sub-
stantially anhydrous acidic component, e.g., onecontaining P2O5, can be combined with a substantially
anhydrous basic component, and these combined com-
ponents kept separate from the aqueous component; or
the basic and aqueous components can be combined and
kept separate from the substantially anhydrous acidic
component. In both of the latter cases, the sub-
stantially anhydrous components can be slurries or
slushes with nonaqueous liquids.
The particulate basic metal compound, e.g.,
magnesium oxide, has a surface area in the range of
26
556
27
up to about 40 square meters ~er gram, and con-
stitutes about from 5 to 35 percent of the total
weight of the grouting composition. Grouts
having less than about 5 percent OL the basic metal
compound do not develop a sufficiently high ultimate
pull strength regardless of the setting time. A
preferred minimum is about 8 percent. There appears
to be no advantage in exceeding a basic metal com-
pound content of about 35 percent, and on an econo-
mical basis more than about 25 percent generally willnot be used. These percentages refer to the total
of all such reactive basic metal compounds present.
The preferred basic metal compound has a
surface area of less than about 30, and most prefer-
ably 1 to 20, square meters per gram. This meansthat the preferred magnesium oxide is the so-called
"chemical grade" magnesium oxide, prepared by
calcining magnesium carbonate at temperatures in the
900-1200C range. Calcined-grade tsurface area gen-
erally well below 1 square meter per gram) and fused(surrace area below about 0.1 square meter per gram)
magnesium oxide also can be used, however. For a
given concentration of the basic metal compound, the
selected surface area thereof should be sufficiently
low to assure the necessary working time (e.g.,
about 15-45 seconds to allow insertion of a bolt
into the grout and mixing), but sufficiently high
to give a hardened grout of a desired strength in
the desired time. Generally, this means that high
concentrations are used with low surface areas and
vice versa. With low-surface area compounds, e.g.,
below about 1 square meter per gram, more than about
95 percent of the particles should pass through a
200-mesh screen (U.S. Standard Sieve Series) to
assure an acceptable reaction rate. High-surface-
5~6
28area i~gO preferably is used with aluminum phosphate.
High early strength also requires that the
basic metal compound concentration be sufficiently
hish with respect to the amount of phosphoric acid
(or its anhydride) or metal phosphate present in the
acidic component. The molar ratio, for example, of
the basic metal compound in the oxide form to the
oxy phosphorus compound in the form of P2O5 should
be at least about 2/1, preferably at least about
4/1. Generally, there is no advantage to exceeding
this ratio to any large degree, e.g., above about
17/1, inasmuch as a cheaper filler can be used to
increase the solids content without deleterious
effect.
As was mentioned previously, a phosphoric
acid or a metal phosphate preferably will be present
in the hyd~ous form, i.e., as an aqueous solution or
slurry, and in this embodiment the aqueous component
will, at least in part, be found combined with the
acidic component. In this case, the basic component
must be maintained separate from the acidic component,
and may or may not contain water.
Water is needed in the grouting composition
so that the acidic oxy phosphorus compound will be in
the form of a well-dispersed system which allows for
mobility of ions. At least about 3 percent of the
total weight of the grouting composition will be water,
larger concentrations being used with compositions
containing larger amounts of oxy phosphorus compound.
However, the water content of the composition has to
be controlled so as not to exceed about 20 percent
by weight, or the rate of strength development will be
deleteriously affected. Accordingly, the concentration
of aqueous phosphoric acid or aqueous metal phosphate
in the acidic component is at least about 60 percent
28
11~2S56
29
by weight. This concentration can be much higher,
e.g., when water is also present in the basic com-
ponent. Supersaturated aluminum phosphate solutions
and the solid-liquid mixtures which result when
crystallization ta.~es place from these metastable
solutions are preferred over less concentrated
solutions because they produce stronger grouts.
The hardened grout produced around the
reinforcing member in the method of this invention
forms as a result of the reaction between inorganic
reactants. Organic resin-curing systems are not
required, and the reactants which undergo a
hardening reaction therefore are substantially
all-inorganic. The development of strength in the
hardened grout sufficient to anchor a bolt securely
in place in a hole in a mine roof, and provision
of the components in a form such that they can be
delivered and mixed conveniently, require a balance
of the content of inorganic cement, slush-forming
liquid, reactive liquid, and aggregate, if present.
On this basis, although it is possible to make a
marginally satisfactory grout from compositions
containing 5-10 percent of a cement that sets by
hydration, in order to provide maximum strength
capability it is preferred that the amount of such
cement constitute more than 10 percent of the total
weight of the composition. Sufficient reactive
liquid should be present to react with such cement,
e.g., sufficient to give a water/cement weight
ratio of at least about 0.1, and preferably at
least about 0.3. In order to be able to allow for
the incorporation of a sufficient amount of aggre-
gate and reactive li~uid into this system, the
amount of cement will not exceed about 80 percent
of the total weight of the two components; and a
29
556
maximum cem~nt content of about 50 percent is
preferred inasmuch as no advantage in terms of final
strength is seen in exceeding this amount.
The specific amounts of liquids used in
the composition will depend on the amount of solids
present, ease of delivery, mixing, etc. From
strength considerations, it is undesirable to exceed
significantly the stoichiometric amount of reactive
liquid and the amount of slush-forming liquid
required to give the necessary lubricity and
deliverability (e.g., pumpability). A liquids/solids
weight ratio of the combined components in the range
of about from 0.1 to 0.6 is satisfactory from the
viewpoint of strength, and handling and mixing con-
siderations. In accordance with these considerations,
the water/cement weight ratio in cement systems that
set by hydration generally will not exceed about 1.0,
preferably 0.7; and the amount of water, based on the
total weight of the two components, will be about
from 2 to 50, and preferably 5 to 30, percent. Also,
the amount of slush forming liquid will vary about
from 5 to 50, preferably 8 to 20, percent of the
total weight of the composition; or about from 10 to
75 percent, preferably 35 to 65 percent, of the weight
of the cement.
The reactive liquid in the second compo-
nent of the grouting composition, and the acidic
component of a basic/acidic phosphate system contain-
ing aqueous phosphoric acid, preferably are in
thickened form, e.g., contain a thickening agent.
This reduces the chance that the liquid will run out
of an upward-slanting hole or soak into fissures or
pores in the hole wall. The thickening agent is a
solid material that absorbs water, is hydratable, or
is somewhat water-soluble, and can be an inorganic
Z556
31
material such as clay or fumed silica, or an organic
material. Organic thickening a~ents that can be used
include carbo~ymethylcelluloses, polyvinyl alcohols,
starches, carbo~y vinyl polymers, and other mucilages
and resins such as galactomannans (e.s., guar sum),
polyacrylamides, and polyethylene oxides. Poly-
ethylene oxide, polyacrylamide, and mixtures of the
two are preferred. These two materials not only
provide the thickening effect needed to reduce the
chance that the water will run out of an upward-
slanting hole or soak into fissures or pores in the
hole wall, but are lubricants as well, in the sense
that they facilitate the insertion of a bolt into an
aggregate-water slush, the aggregate having less
tendency to settle or pack in water containing these
materials. Moreover, the beneficial effect of these
thickener/lubricants is achieved with sufficiently
small amounts thereof that grout shear strength is
not severely compromised. In phosphoric acid systems
because of their stability therein polyethylene
oxides are preferred organic thickeners.
The amount of thickening agent in the
reactive liquid component, e.g., the acidic reactive
component, depends on the specific material used, and
specifically on the degree of thickening of the
liquid component attainable therewith, a function
generally of the molecular weight and degree of
substitution of the material, and depends also on
other solid materials which may be incorporated in
the reactive liquid component. Generally, the amount
of thickening agent will be in the range of about
from 0.1 to 1, preferably to 0.5, percent of the
total weight of the composition, the lower end of
the range being used with materials of higher mole-
cular welght and/or having more hydrophilic groups.
ll~Z556
In the case of the organic polymers, more thanabout 0.2 percent, based on the total weight of the
composition, usually will not be necessary.
One or more surface-active agents can be
incorporated into the reaction system, in either
one or both of the components. A surface-active
agent in the cement slush or in the reactive liquid
component containing suspended sand particles
produces the consistency of a smooth paste, which
results in improved ease of mixing of the components.
The surface-active agent should be soluble in the
liquid of the component in which it is used, and
should give a hydrophilic-lipophilic balance value
of about from 8 to 14, as determined according to the
methods outlined in "The Atlas HLB System", Atlas
Chemical Industries, Inc., 1952. About from 0.1 to
10, and preferably from 1 to 5, percent of surface-
active agent is used. However, since the presence
of a surface-active agent can result in a hardened
grout of lower shear strength, it is necessary to
assess what effect, if any, the surfactant under
consideration has on strength, and to balance this
finding against the advantage to be gained in ease
of mixing. Surfactants which can be used include
oleic acid, sorbitan monooleate and monolaurate,
polyoxyethylene monooleate and hexaoleate, poly-
oxyethylene sorbitan trioleate and monolaurate, and
polyoxyethylene tridecyl ether. Of these, oleic
acid is preferred both on the basis of degree of
effectiveness and cost.
The present grouting system can be used
wherever structure reinforcement is required, e.g.,
in rock bolting or roof bolting in _oal or metal
mines, or to secure bolts in holes drilled in
concrete structures. If the components of the system
ll~Z556
33
are delivered into the drill hole by pumping, they
preferably are pumped into the hole separately and
combined and mixed therein before or after bolt
insertion, Alternatively, pumped components can
be combined just outside the hole and mixed there
or in the hole. Preferably the components of the
grouting composition are delivered into the drill
hole, and the reinforcing member is introduced into
the composition before any substantial hardening of
the composition has occurred, whereby grouting com-
position is forced into an annulus formed between
the reinforcing member and the wall of the hole.
The components are thereafter mixed, preferably by
the rotation of the reinforcing member, to form the
hardened grout. A preferred system comprises a
frangible compartmented package having at least
two components in separate compartments, the package
being broken by penetration by the reinforcing mem-
ber. One such package is shown in FIG. 1. In FIG.
1, a tubular member 1 of substantially circular
transverse cross-section and a diaphragm 2 are
constructed by wrapping a single web of pliable
film material in a manner such as to form a con-
voluted tube having a partially single-ply and
partially double-ply wall, the inner ply of the
double-ply wall portion forming diaphragm 2. The
two plies of the double-ply portion are sealed
together near inner edge 3 and outer edge 4 of the
web so as to form linear junctures or seals 5 and
6, respectively. Tubular member 1, diaphragm 2,
and junctures 5 and 6 define two separate compart-
ments 7 and 8. At each end of the compartmented
tubular member, one of which is shown in FIG. 1, the
end portions of tubular member 1 and of diaphragm
2 are collectively gathered together and closed Dy
11~2556
closure means 9. Compartment 8 is filled with
Component A described in Example 1 which follows,
and compartment 7 with Component B described in the
same example.
In use, this package is inserted into a
drill hole, and a bolt is forced into the package,
tearing the film and penetrating a part, or the
full length, of the package. The components are
mixed by rotation of the bolt, and subsequently
react with hardening so as to secure the bolt in
the hole.
The invention will now be illustrated by
way of the following examples. Parts are by weight.
Example 1
A two-component reaction system of the
following composition was made:
Component A Component B
19.05% cement 0.12% polyacrylamide
28.S7~ sand 28.57% sand
11.43% oil 12.26~ water
The percentages are percent of the ingredients by
weight, based on the total combined weight of the
two components. The cement was "Very High Early
Strength" (VHE) cement, manufactured by U.S. Cypsum
Co., a fast-setting cement that sets by hydration,
described in U.S. Patent 3,860,433. This cement
contains (by weight) about 20-40% 3CaO 3A12O3-CaSO4
and about 10-35~ chemically unbound CaSO4, the
remainder being substantially ~-2CaO-SiO2. The sand
was Ottawa Silica Company's Banding Sand. This
sand has round particles, 94~ of which are in the
size range of 74 to 210 microns. The median
particle size is 142 microns, and the deviation +
48g. The sand has 99% of its particles smaller than
420 microns. The surface area of the sand is about
34
556
160 cm2~g. The polyacrylamide was "Polyhail"* 295,
made by the Stein Hall Company. The oil was kerosene.
The slush of cement, sand, and oil was kept separated
from tne thickened water/sand combination. For
strength testing, the two components were mixed to
substantial homogeneity, whereupon oil was exuded
therefrom, and the resulting ~aste-like composition
hardened.
The shear strength of the grout, measured
after 24 hours, was 336 kg/sq. cm. The method of
measure.~ent was the following:
A sample of the freshly mixed grout was
placed on polyethylene terephthalate film, and a
stainless steel rins, 15.9 mm in diameter and 2.92 mm
high, was placed on the grout. ~ piece of poly-
ethylene terephthalate film was placed over the ring,
and the latter then was pressed evenly into the grout
by means of a block of wood. The resulting '~shear
button" of the grout was placed on an InstrGn testing
machine (conforming to ASTM Method E4, Verification
of Testing Machines), and tested (24 hours after
mixing) for shear strength by the method of AsTr~
D732 (ASTM is the American Society for Testing and
Materials). In this test, a plunger was brought down
onto the grout at a rate of 12.7 mm per minute.
The shear strength was calculated from the applied
force to cause failure, according to the following
equation:
shear strength = Force
Specimen thickness ~ ~J x diam. of
punch
The grout also was evaluated after 24 hours
in terms of its average pull strength, i.e., 450 kg~cm,
accordins to the following procedure:
Freshly mixed grout was placed in a section
* denotes trade mark
556
36
of 2.54-cm threaded pipe, and a standard 1.59-cm-
diameter steel blunt reinforcing rod was inserted
into the grout. The excess grout which was squeezed
out during insertion of the rod was scraped off, and
5 the pipe-rod assembly was placed into a test fixture
mounted in an Instron Universal Testing Machine. The
rod was then pulled (24 hours after the mixing of the
grout) by applying a measured upward force to the bolt
while the pipe section of the pipe-rod assembly was
held stationary in the fixture. The force at which
the first discontinuity in the recorded force vs.
deflection curve was observed was the pull strength.
Example 2
Four dual-compartment frangible packages
in the form of 46-cm-long, 2.3-cm-diameter "chub"
cartridges as described in U.S. Patents 3,795,081
and 3,861,522 and as is shown in FIG. 1 herein, and
containing a two-component reaction system of the
invention, were made from a web of polyethylene
terepnthalate film. One compartment contained a slush
of the cement, sand, and oil described in Example 1.
The other compartment contained water and the sand
and thickener described in Example 1. The ingredients
content based on the total combined weight of the5 contents of the two compartments was as follows:
Cartridges Cartridges
a and b c and d
cement 34% 32~
oil 13% 13%
sand 31.4%* 30.2%**
water 21.6% 24.8
thickener 0.10~ 0.10
*26% in the cement slush; 5.4% in the water
**24% in the cement slush; 6.2~ in the water5 Each sealed cartridge was placed in a 2.54-cm-diameter
36
ll'iZ556
37
steel pipe having a rough wall and a welded closure
at one end (simulated drill hole). ~he pipe was held
in an upright position in a vise with the closed end
uppermost. ~ headed reinforcing rod ~bolt) 15.9 mm
in diameter was inserted into the cartridge with a
rotating upward motion, and spun at 3G0 rpm to mix
the contents of the package. A washer closed off the
bottom end of the pipe. Ambient temperature was 27~C.
After one hour the pull strength of the grout was
determined by applying force to the headed end of the
bolt in a downward direction at a rate of 1.27 cm per
minute. The results are shown in the following table:
Mixing Force
Time Required To
Cartridge (sec) Cause Slippaqe
1 5 _ _
a 7.5 10.2 x lCJ kg
b 20 12 x 1~3 kg
c 7.5 9.1 x 103 kg
d 17.5 9.2 x 103 kg
Example 3
A cement-oil slush and an aqueous sand
mixture in the proportions 28.57% cement, 14.29~ oil,
42.86~ sand, and 14.29~ water (same cement, oil, and
sand as described in Example 1) were mixed thoroughly,
and shear buttons prepared from the freshly mixed
grout as described in Example 1. The buttons were
tested for shear strength after seven different periods
of time, according to the procedure described in
Example 1. The results are shown in FIG. 2, where
shear strength is plotted vs. time on a logarithmic
scale. It is seen that this grout achieved a shear
strength of 70-140 kg/sq cm (equivalent to the strength
of coal mine roof strata) in 30 to 90 minutes, and
well over 90 percent of its full strength (equivalent
to the strength of metal mine roofs) in less than 4
hours.
2556
38
Example 4
~1) The following separate com~onents
~ere ?repared:
Component A (parts) Component B (parts)
cement (26.32) sand (19.74)
sand (19.74~ 1~ aqueous solution of
oil (14.47) polyacrylamide (19.74)
The sand and oil were the same as those used in
Example 1. Five different mixes of Com?onent A were
prepared, each with a different cement. The 24-hour
shear strength of the grout prepared by mixing each
one of the five A Components with Component B was
measured as described in Example 1. The results
were as follows:
Cement in Component A Shear Strength (kg/sq cm)
-
VHE 147
Ordinary Portland (Type II)~ 5
I'Rapid Rock"*(a) ~ 4
Huron Regu~ated Set Portland
Cement (RSPC) (b) 0
Hydrostone* Super X(C) 42
(a) Reported as producing a fast-setting (15 min)
pourable grout when mixed with water, setting
to 350 kg/sq cm in one hr (Tamms Industries Co.
TI-103, 1974)
(b~ Type III, contains calcium aluminum fluorite,
reported to be fast-setting and able to gain
strength at a rapid rate during the earlv ages
of the concrete (National Gypsum Co., Huron
Cement Div. data sheets)
(c) Calcined gypsum, U.S. Gypsum Co.
(2) Strength/setting time characteristics
of cements used in Part (1) in the absence
of oil.
Each of the cements (20 parts) listed in
* denotes trade mark
38
1142SS6
39
Part (1) above was ~ixed with 30 parts of the sand,
and an amount of water was added according to the
manufacturer's specifications to achieve maximum
strength at minimum age. The nu~ber of minutes
5 required for each oil-free grout to become hard is
given in the following table:
Cement Hardening Time
VHE ~ 20 min
Ordinary Portland~ 24 hrs
"Rapid Rock" ~10 min
Huron RSPC ~20 min
Hydrostone Super X~20 min
The following table gives the compressive
strengths (manufacturer's specifications) and 24-hour
shear strengths ~measured as described in Example 1)
for oil-free grouts made from the cements listed in
Part (1) above. The shear test specimens were pre-
pared from grouts made by mixing 10 parts of the
cement with 15 parts of sand and 3.5-4.5 parts of0 water (according to manufacturer's specifications).
Compressive Strength Shear
kg/sq cm (time inStrength
Cement hrs)_ kg/sq cm
VHE ~ 350 (24) 375
Ordinary Portland ~140 (24) 84
"Rapid Rock" 350 (1) 251
Huron RSPC ~ 210 (24) 452
Hydrostone Super X ~455 (1) (wet) 265
~945 (l)(dry)
Example 5
The effect of sand content on the 24-hour
shear strength of the grout was examined with a
system wherein 28.6 parts of the cement described in
Example 1 and 14.3 parts of-the oil described in
Example 1 formed one component, and 14.3 parts of a
39
il'~Z556
,. .,
1 percent aqueous polyacrylamide solution formed the
other component, and an amount of sand was divided
evenly between the two components. The results are
shown in the following table:
Sand Shear Strength
Parts~ % (kg/sq cm)*
214
14.9 242
26 294
46.8 737
*Measured as described in Example 1.
Example 6
A reaction system in which 18.7 percent
cement and 13.1 percent oil (same cement and oil as
in Example 1) were in Component A, 12.1 percent of a
1 percent aqueous solution of polyacrylamide was in
Component B, and 56.1 percent sand (the sand used
in Example 1) was located as indicated in the follow-
ing table, was tested for shear strength as described
20previously:
24-hr Shear Strength
kg/sq cm
100% in Component A 327
100% in Component B 288
~50% in Component A~
25~50% in Component BJ 292
These results show that the distribution of sand
between the components has no significant effect on
the shear strength of the hardened grout inasmuch
as all of the values are within + 10 percent of the
average value, a deviation possibly due to experi-
mental error in the test procedure.
Example 7
Fibrous materials were added to the cement-
oil slurry in the following experiments.
3 (a) A grout made by mixing a cement-oil
Z556
slush containing 28.19 parts V~E cement, 14.25 parts
of the oil described in Example 1, and 0.28 part
of 1.27-2.54-cm-long glasswool fibers with an
aqueous sand suspension containing 42.74 parts of
the sand described in Example 1, 14.25 parts of
water, and 0.14 part of poiyacrylamide, had a
l-day shear strength (method of Example 1) of
291 kg/sq cm. The same slurry without the glasswool
gave a grout having a l-day shear strength of 235
kg/sq cm.
(b) The 4-hour shear strengtn of a grout
made by mixing 40.61 parts ~E cement and 18.27 oil
(same as that of ~.xample 1) with 20.30 parts sand
(same as that of Example 1) and 20.30 parts of a
1 percent aqueous solution of polyacrylamide was
increased from 98 kg/sq cm to 123 Xg/sq cm by the
addition of 0.51 percent of 1.27-cm-long Kevlar~
(ara~lde) fibers to the cement slush.
Example 8
Different organic liquids were tested as
slush-forming liquids by combining 20 parts of VHE
cement with 10 parts of the liquid being tested,
adding 10 parts of water to the resulting slush,
mixing the cement and water components, and testing
the resulting grout qualitatively for hardness.
The results were as follows:
Slush-Forming Agent Grout Characteristics
pentane hard in ~7 min
hexane hard in ~7 min
heptane hard in ~7 min
benzene hard in ~5 min
toluene hard in ~-10 min
xylene hard in ~J7 min
gasoline hard in ~ 8 min
fuel oil ~2 hard in ~ 9 min
il'~ZSS6
~2
Slush-Forming Agent Grout Characteristics
kerosene hard ~n ~ 6 min
Nujoi hard in ~ 23 min
methanol hard in _ 7 hr
When the above-described procedure was
rollowed wit;~out the addition of a slush-~orming
liquid, the grout became hard in 5 minu.es.
Example 9
One of the benefits achieved by employing
the cement in the form of a slush was studied bv
comparing ,he force required to insert a bolt into
the slush as contrasted to that needed to penetrate
a dry cement. ~ 2.54 cm-inne--d ameter steel ?i?e
was filled with the cement component, and a 15.9-mm-
diameter steel reinforcing rod was moved downward
into the component in an Instron* machine at a rate
of 51 cm per minute. A force of only about 0.2 kg
was required to penetrate 2.5 cm of a slush con-
sisting of 44.44 percent cement, 33.33 percent sand,
and 22.22 percent ~apoleum* 470 (a predominately
aliphatic kerosene) or Circosol* 410 (a naphthenic
based oil made by the Sun Oil Company).
In contrast, a rorce of 1600 kg (maximum
available on the Instron machine) was required to
insert the bolt about 2.54 cm deep into a mixture
of 57.1 parts dr~ cement and 42.9 parts sand.
Example 10
The following separate components were
prepared:
Component A (parts) Component B (parts)
cement (28.57) sand (42.86)
oil (14.29) water (14.29)
The cement and oil were the same as those used in
Example 1. Three different mixes of Component B
were prepared, each with a different sand. The 24-
* denotes trade mark
42
56
43
hour shear strength of the grout prepared by mixing
each one of the three B components with Component A
was measured as described in Example 1. The
results were as follows:
Sand In Sand Shear Strength
Component B Characteristics (kg/sq cm)
Banding Sand See Example 1 246
"Sakrete"t Sand 95g 147-420j~; median
(-35 mesh)* 288JU; deviation + 45~
100% ~540 ~. Jagged. 235
Sawing Sand 95% 297-420 ~; median
(Otttawa-Silica 358~u; deviation +
Co.) 17~. 96% ~540 ~.
Round 117
*All-purpose "Sakrete" sand packaged by H. T. Camp~ell
Company, Towson, Maryland
Example 11
The procedure described in Example 10 was
repeated with seven different graded sands in
Component B. In this case, the cement content was
18.5 parts, oil 14.8 parts, sand 55.6 parts, and
water 11.1 parts. All of the sands had round
particles and were products of the Ottawa Silica
Company, Ottawa, Illinois, and described in Ottawa's
Product Data Sheet OD 3-74-0. The results were as
follows:
t denotes trade mark
43
556
~4
PARTICLE ~I7E '~) SHEAR STRE~G~
a.~D ~GE.~E3~A~ DEVI~TION ~.~. KG~SQ C.
~1) ape~ial Bond 96~ 105-297 201 48~ 100~ ~'340 223
(~! 90nd S~nd ~7~ 105-297 '01 ~8~ 100~ <5~0 255
in~ àp~c~ 6~ 2~ 280 5~ 0~ <5~0 250
Bl~nd
(d) ;0-~esh91~ 105-210 157 33~ 99~ <420 22
ie) 3andi~9 Sand 9~ 74-210 1~2 ~8~ 99~ ~20 22~
tf) 9~ aholl 96~ 74-210 112 ~8~ ~99~ <~20 231
(~) F-1~0 98~ <53-.~7 ~`100 ~7~ ~99~ <297 171
Example 12
The procedure described in Example 10 was
repeated twice, once with a graded sand, i.e., the
-35 mesh "Sakrete" described in Example 10, and once
with a uniform sand, i.e., the 297-420 micron cut from
the -35 mesh "Sakrete". The median particle size of
the uniform sand was 358 microns, and the deviation
+ 17%. The 24-hour shear strength of the grout
containing the graded sand was 472 kg/sq cm, and that
of the grout containing the uniform sand 354 kg/sq cm.
Example 13
Two different sands were tested with respect
to their settling rates in thickened water, as an
indication of their behavior in stored two-compartment
cartridges having a cement slush in one compartment
and a sand/water mixture in the other. Segregation of
the sand results in an asymmetrical package, which is
harder and stiffer in one section than in another,
making bolt insertion more difficult.
Both sands were "Sakrete". One was a
coarse sand consisting solely of particles larger
than 500 microns (53~ larger than 833 microns, 12%
larger than 2.36 mm, the remainder between 540 and
833 microns). The other was a fine sand consisting
of the -35 mesh "Sakrete" described in Example 10.
Tubes 31 cm long and having a 2.5-cm-diameter were
filled with a 1~ aqueous solution of polyacrylamide,
and the sand was added to the tubes. The settling
44
556
rate at 20C was about 20 minutes for about 90%
of the coarse sand, and about 46 minutes for about
90% of the fine sand.
Example 14
The following separate components were
prepared:
Component A (parts) Component B (parts)
cement (27.8) sand (41.6)
oil (13.9) 1% aqueous thickener
solution (16.7)
The cement, oil and sand were the same as those used
in Example 1. Different mixes of Component B were
prepared, each with a different thickener. The
24-hour shear strength of the grout prepared by
mixing each of the A Components with Component B
was measured as described in Example 1. The results
were as follows:
Thickener
Chemical Shear Strengtb
Type Cs~n~nercial Desiqnation !kq/sq cm)
Polyacrylamide Polyhall 295 (Stein Eall) 139
Polyacrylamide E~olyhall M40 (Stein Hall) 164
rolyacrylamide Polyh~ll 650 (Stein 8all) 113
Polyetbyler.e oxide Polyox~ 301 (Union Carbide) 81
Sodium carboxymethylcellulose Sodium CMC lDu Pont) 148
SGc~ium carbo~:ymethylcelluloseSodium CMC (}~ercules) 182
Methylccllulose derivative Methocel~ HD IDow) 16
Methylcellulose cerivative Methocel J5MS (Dow) 50
~lethylcellulose derivative Methocel J75YS (Dow) 27
~lethylccllulos~: derivative Methocel E41~ (Dow) 38
Methylcallulose derivative Met~,ocel 1;4M (Dow) 20
~ethyic211ulose derivative Methocel XlSM (Dow) 17
Natural gum Jaguar~ 180 (Stein Hall) 163
~atural gum Jaguar 180 (Stein Hall~67
When the above-described procedure was
repeated with no thickener, the shear strength was
333 psi.
Example 15
A 2.54-cm inner diameter steel pipe was
filled with a mixture of 75% sand (-35 mesh
"Sakrete" made by H. T. Campbell Company, Towson,
* denotes trade mark
il4Z556
46
Maryland) ~nd 25~ of a 1% aqueous solution of a
thickener, and a 15.9-mm diameter steel reinforcing
rod was moved downward into the mixture in an Instron
machine at a rate of 51 cm per minute. The force
required to insert the rod 2.54 cm was measured.
The results were as ollows:
Force Needed
For 2.54 cm
Thickener Penetration (kg)
Polyox 301 5
10 Methocel HD 22
Polyhall 295 57
Jaguar 180 91
Sodium CMC 94
Hercules CMC 149
A force of 608 kg was required when no
thickener was present, and 588 kg when no water or
thickener was present.
Examples 14 and 15 show that, of the
thickeners which permit a shear strength of 70-140
kg/sq cm to be retained, polyethylene oxide and
polyacrylamide are superior in ease of bolt pene-
tration, and thus are particularly suited for use in
cement grouts for anchoring rock bolts.
Example 16
When the procedure described in Example 15
was repeated with the use of the sand described in
Example 1 (Banding sand), a force of only 0.2 kg per
2.54 cm of insertion was required for the Polyhall
295 and the Polyox 301 solutions.
Examples 17-21
A surfactant (0.2 part) was added to a
grout of the following composition:
46
`" li ~5~6
47
Component A Component B
VHE cement (19.76 parts) sand * (29.64 parts)
sand * (29.64 parts) 1% aqueous solution of
oil * (7.90 parts) polyacrylamide 112.85 parts)
* Same as in Example 1
The grouts obtained upon mixing of Components A and
B were tested after 24 hours for shear strength as
described in Example 1. In all cases in which a
surfactant was employed, the component containing
the surfactant was a smooth paste, and mixing was
easy.
Component 24-hour S~ear
Example ~LB Contg.Stren~t~
No. Sur~-ctant Chemic~l Compound Value~ Surfac~ant kg~sc cm
15 17 none 2 5
18 Tween~ 81 Polyo~ethylene
monooliatc 10 ~ 133
19 T~ecn 85 Polvox~cthylene
sDrbit~n trioleale 11 ~ 72
2020 Sp~mt 20 Sorbit~n n~onol~ te 8.6 A 39
21 G1086 Polyoxyethylene
hexaole~te 10.2 A 5_
- evdrophilic-Lipophili~ Balance
~ Component ~ was 19.01 part~ cement 2&.S2 p~rt~ ~nd ~nd ~1.31 part~ oil
Component B w~s 28.i2 part2i s~md and 12.36 partC polyacrylam~de ~olution
~xample 22
The following components were prepared
Component A Component B
VHE cement (31.16 parts) sand * (46.74 parts)
oil * (6.23 parts) 1% aqueous solution
Span 80 ** (0.12 part) polyacrylamide
Tween 85 (0.16 part ) (15.58 parts)
* Same as in ~xample 1
** Sorbitan Monooleate
Component A (113 parts) and Component B (187 parts)
were packed into the separate compartments of the
polyethylene terephthalate film cartridqe described
in Example 2. The cartridged grout was subjected
to a pull strength test in a simulated drill hole
as described in Example 2. Twenty-four hours after
t denotes trade mark
47
" ll~Z5S6
48
the components had been mixed, the pull strength of
the hardened grout was 11 x 103 kg.
Example 23
The following two components were made:
Component A Component B
Hydrostone* (2000 parts) Water (1758 parts)
~arcol 90 N.F. (369 parts) .~ethocel 65 (35 parts)
Light Mineral HG (Dow)
Oil (Exxon)
Stearic acid (22 parts) Sodium stearate (114 parts)
*a commercial cement consisting essentially of
calcined gypsum
Component A was made by heating a mixture of the oil
and stearic acid to 57C to dissolve the stearic
acid, and mixing the resulting solution with the
hydrostone in a turbine mixer. Component B was
made by heating a mixture of the ingredients to 57C
to dissolve the sodium stearate and produce a thick
paste. When Components A and B were mixed in the
weight ratio of 6.38/1 A/B, the mixture set up into
a solid within a few minutes.
One compartment of a 61-cm-long dual-
compartment cartridge described in Example 2 was
filled with Component A and the other compartment with
Component B in the weight ratio of 6.38 parts of
Component A for every part of Component B. The
filled cartridge was stored for 10 days and then
tested for rock bolt anchoring substantially as
described in Example 2. A 76-cm-long rock bolt was
inserted into the cartridge at a rate of somewhat
less than 1.2 meters per 15 seconds, while the bolt
was spun at 450 rpm. The bolt was spun for 5 or 10
seconds after insertion.
When the grouted bolt was pull-tested after
12.5 minutes, no slippage occurred until a force of
8200 kg had been applied.
48
" ll~Z556
49
Example 24
~ grouting composition was prepared which
had the following components:
Acidic and Aqueous
Basic Component Components
13.2% MgO 18.5~ aqueous Al(H2PO4)3
solution
35.9% Sand 21% Sand
11.4% Circosol 304*
(containing 2.5% oleic
acid surfactant)
*A napthenic Petroleum oil manufactured by
the Sun Oil Company
The percentages are percent of the ingredients by
weight, based on the total combined weight of the
components, The magnesium oxide had a surface area
of 5.7 square meters per gram. The sand was Ottawa
Silica Company's Banding Sand. This sand has round
particles, 94~ of which are in the size range of
74 to 210 microns, and 99% of which are smaller than
420 microns.
The composition of the aluminum phos?hate
solution, by weight, was 11.5~ A12O3, 47.7~ P2O5, an
40.8% H2O.
The basic component (234 ?arts) was intro-
duced into one compartment, and the acidic andaqueous components (151 parts) into the other compart-
ment, of a two-compartment frangible "chub" cartridge
such as that described in U.S. Patents 3,795,081 and
3,861,522, the cartridge being made of polyethylene
terephthalate film. In the sealed compartmented
cartridge, which was 41 centimeters long and 2.3
centimeters in diameter, the basic com?onent and
acidic/aqueous component were maintained se?arate
from one another. The cartridge was cooled to 10C
(to simulate the average temperature in a mine) and
49
" ~14ZSS6
placed in a 41-cm-long, 2.54 cm-inner-diameter steel
pipe having a rough wall (coarse threads) and a
welded closure at one end (simulated drill hole).
The pipe was held in an upright position in the vise
of a Mayo* machine with the closed end uppermost.
The Mayo machine is one which is commonly used in
mines to drill holes into mine ceilings and to install
roof bolts for grouting. A 61-cm-long reinforcing rod
(bolt) having a diameter of 2 cm also was mounted in
the Mayo machine. Both the pipe (drill hole) and the
bolt were at 10C.
Upon actuation of the machine, the rod was
inserted into the cartridge with an upward motion at
a speed of 6 meters per minute at 400 rpm. During
insertion the bolt broke the polyethylene terephthalate
film. After the bolt reached the closed end of the
pipe, the bolt was spun for 35 seconds and completed
mixing of the initially separated components.
Five minutes after the bolt installation
had been completed, the pull strength of the hardened
grout was measured by applying an increasing force
to the headed end of the bolt in a downward direction.
The bolt broke at a load of 15.5 x 103 kg. Therefore,
the grout supported a load of more than 378 kg per
centimeter of anchoring length and exceeded the steel
bolt in strength.
Example 25
The procedure described in Example 24 was
repeated except that the magnesium oxide content of
the grouting composition was 17~, sand 31.5~ in
basic, 15.3% in acidic, component, Circosol 12.7%
and aluminum phosphate solution 23.6% and the
magnesium oxide surface area was 10 square meters
per gram. The chub cartridge was 51 cm long, and
* denotes trade mark
S56
contained 201 parts of the basic component and
128.5 parts cf the acidic/aqueous component. In
this case, after five minutes, the bolt broke at a
load of 21.8 x 103 kg, the yrou. havin~ su?ported
a load of more than ~27 kg per centimeter of
anchorinq length.
ExamPle 26
A grouting composition was prep2red which
had the following components:
Acid and Aqueous
Basic Component Components
-
MgO (43.62 parts) 74% aqueous solution
of H3PO4 (32.8 p2rts)
A12O3-3H2O (23.44 parts) Sand (67.12 parts)
Circosol 304 (32.12 parts) Polyethylene oxide
(0.08 part)
Oleic Acid (0.82 part)
The surface area of the magnesium oxide was 10 m2/9.
The sand was the same as that described in Example 24.
The polyethylene oxide, which served as a thickener
for phosphoric acid, was Polyox 301, having a
molecular weight of about 4,000,000.
The composition was loaded into a cartridqe
and tested as described in Example 24. The two-
component cartridge contained 82.5 parts of the basic
component and 199.5 parts of the acidic/3queous
component. The bolt was inserted into the cartri~ge
at a speed of 3 meters per minute and a thrust of
454 kg. and mixed at a torque of 68 Newton meters.
The total time required for bolt insertion and mixing
was 25-27 seconds. In the 5-minute pull test, the
bolt broke at a load of 15.2 x 103 kg, the grou.
having supported a loa2 of more than 372 kg per
centimeter of anchoring length.
Example 27
The effect of the surface area o~ magneslum
556
52
oxide ?articles on the rate of hardening of a given
grouting composition is shown in a series of
experiments made with a composition containing 13
~IgO, 7% .~12O3 3I~2O, 10~ Ci.cosol 304, 23~ H3PO4
~74~ aqueous solution), and 47~ sand, the basic
component cor.taining the MgO, A12O3-3H2O, oil, and
sand in an amount which was 20~ of the total welgh~
of the composition; and the acidic/aqueous com?onent
containing the H3PO4 solutlon and the remainder of
the sand. The composition was tested for 5-minute
pull strength as described in Example 24.
MgO Surface Area Pull Strength
2/g) (kg/cm)
1.1 0
2.6 129
4.4 243
5.6 393
6.5 643
821
Thus, at the 13~ MgO concentration level, grouts
having MgO surface areas below 4.4 m2~g requ red
longer than 5 min~tes to attain strength levels o
175 kg/cm. Above 10 m2/g, the setting rates her_ ~a
hign adequate mixing of the com?onents could not be
accomplished.
Example 28
The following experiments show that a com-
position having a small surface area MgO and low
setting rate can have its setting rate increased
increasing the MgO concentration. The experimen~s
were carried out on the composition described in
Example 24 except that the MgO content was varied,
the difference in the MgO content f~om that in
Example ~4 having been reflected in a prOpQrtionate
decrease or increase in the sand content of the basic
component described in Example 24.
11~2S56
53
5-Min Pull Stre.-gth
.~q~ (ka~cm)
250
11.6 321
i~ 536
1~ ,86
When the comDosition described in Exam?le
24 was made with MgO having a surface area of
1.1 m2/g, the 5-minute pull strength was 0 kg~cm,
but at a MgO level of 25~, the composl.ion nac a
5-minute pull strenqth of 786 Xg/cm.
Exampl_ 29
A grouting composition was prepared which
had the following components:
Acidic and Aqueous
Basic Component Components
18.0% MgO 18~ aqueous Al(H2PO4)3
solution
35.6% Sand 20~ Sand
8.4~ Circosol*
*A mixture of 48.7~ Circosol 450, 48.75% Circosol
4240, and 2.5~ oleic acid.
The MgO was of the dead-burned type, having a surface
area of 0.8 m2/g, and a median particle size of
6 microns.
When cartridged and tested according to
the procedure described in Example 24 (30 second mix
time after installation; bolt insertion at 1000 kq
thrust and mixing at 163 Newton meters torque), the
5 minute pull strength was 317 kg/cm.
Example 30
The following groutinq compositions were
prepared:
556
54
~ 3
Basic Com~onent Basic ComPonent
^~
13~ .~gO ~10 m2fg) 15.4~ `tgO (10 m~g)
10~ Oil containing 2.5% 23 3 2
oleic acid
27~ Sand 11.8~ Oil
23.7~ Sand
A_idic/Aqueous Component Acidic/Aqueous Component
q 3 4 ( 4%) q 3~4 (
27% Sand 21.9% Sand
Both compositions were tested as describe-
in Example 24, except that the pipe and bolt lengths
were 12.7 cm. Mixing time after the bolt was in
place was 30 seconds. With Compositian A, the
hardened grout, after five minutes, supported a load
of up to 786 kg/cm and then failed. Composition B
supported more than 857 kg/cm.
Examples 31-34
The effect of the water content of tAe
grouting composition (or the concentration of the
Al(H2PO4)3 solution) is shown in a series of ex?eri-
ments made with a composition containing 13% MgO,
10.4% Circosol, 57.9% sand, and 18.7% Al(H2PO4)3
solution of different concentrations.
Al(H2P4)3 soln- % Water in Strength
_ ( 2PO4)3 ~ H20 Groutinq Compn. (kq/cm)
31 71.6 28.4 5.3 714
32 69.7 30.3 5.7 393
33 67.3 32.7 6.1 321
34 47.6 52.4 9.8 71
Examples 35-39
Five different compositions were prepared
using an approximately 70% aaueous Al(H2POq)3 solu-
tion (11.2~ A1203 and 46.8~ P20~) in the acid~aqueous
component. In all cases, 61-cm-long, 2-cm-diameter
556
bolts were installed into the grout as described
in Example 24 and pull-tested 5-10 minutes after
installation. Com?ositions, mole ratios, and pull
strengths are tabulated below:
Ex. Ex. Ex. Ex. Ex.
36 37 38 39
% MgO 8.9 13.9 17.021 23
MgO Surface
Area, m2/g 20 15 10 -1 ~i
% Oil* - - 12.712.4 13.5
% Glycol** 7.9 11.4 - ~ ~
% Sand 56.0 56.7 46.849.1 53.6
(H2PO4)3
Soln. (70%) 27.2 18 23.617.5 10
Moles .~gO/P2O5 2.45 5.7 5.4 9.0 17.3
Pull Strength
(kg/cm) 242 280 357 280 182
* Circosol containing 2.5~ oleic acid; in basic
component
**In basic component
Exam~les 40-45
Grouting compositions wherein oil was not
present as a slush-forming liquid for the basic .met21
compound were prepared and tested as described in
Example 24. Details of the compositions and test
results are given in the following table:
2556
56
~cldic/Water
_~. Basic 0Ompon~nc C.~mDon~nt 5-~in, Pull Test
Slush- Oxy
Formin~ Phosphorus
`~e~al Compd.* Sand* Liquid* Compd.* Sand~ Condltions Result
41) 16.$X ?150 ~9.4~ ~q ~3-cm cartridoe 371 kgJaD
(-lSm2~g) none none ( 2 4)3 54.2X ~eighins 347.9 g;
soln. (a) 61 cm x 2 cm
thrust,
300 rpm, 6 meters/
41 12.8X MgO 38.3X 8.5Z 23.4X aq. 17.0Z 13 cm x 2 cm 357 ks/cm
(5.7 m2/g) water ( 2 4)3 bolt; mixed
1 0 soln. (b) 30 sec at 400 rpm
42 18.3Z2~gO 12% 18.8X aq. 18.2X mixed 15 sec at 256 kg/cm
(15 m /g) 32.7Z glycoL Al(H2PO4)3 320 rpm
soln, (c)
4311.9% Mg(OH)2 28.7X 9.5X 25.0~ aq. 25.0% 61 cm x 2 cm 259 kg/cm
water Al(H2P04)3 bolt; 300 rpm,
soln, (d) 7 meters/min
4414.0Z Hg(OH)2 28.0Z 7.7Z 23.77, aq. 24.4X mixed 15 sec 348 kg/cm
glycol Al(H2PO4)3 in 10 ~in
watler Soln, (d)
2 0 45 10.10Z ~go 30 30% 9 09Z 20.20X aq. 30.30X -- --
water(8) Mg (H2P04) 2
soln. (f)
*Z content i5 based on the total weight of the composltion
2 3 ' 2 5 X, H20 0.8Z
(b) A12O3 11.5%, P205 46%, H20 4 2. 5X
2 5 ( ) 2 3 ' 2 5 5 ~ 2 3 5%
(d)AlzO3 11.2Z, P205 45.6Z, H20 43.2~
(e)A1203 11%, P205 47X, H2O 34X, glycol 8X
(f) 42 9 g MgO. 401.0 g H3PO4 (85X), 556.1 g H2O per kg. soln,
(g) Thickened wlth lX polyacrylamide
In Example 45 the grout was evaluated by
a shear strength measurement made ~y the following
method:
A sample of the freshly mixed grout was
placed on polyethylene terephthalate film, and a
stainless steel ring, 15.9 mm in diameter and 2.92 mm
56
~ Z556
high, WdS placed on the grout. A ?lece o~ ?oly-
eth~-lene tere?hthalate film was placed over the rins,
and the lat~er then was ~ressed evenly into the
grout b~- means of a block of wood. The resulting
"shear bu~on" of the grout was placed or. an Instron
testinc machine (conforming to ASTM Method _4,
Verification of Testing Machines), and tested
(5 minutes a~ter mixins) for shear strength by t.he
method of ASTM D732. In this test, a plunger was
brought down onto the grout at a rate of 12.7 mm
?er minute. The shear strength was calculated from
the applied force to cause failure, according to the
following equation:
shear strength = Force k
apeclmen thlc ness x ~x dlam.
punch
The measured shear strength was 9Q kg/
sq cm.
Example 46
A grouting composition was pre?ared
containing 9.0~ magnesium oxide (10 m2/g), 14.1~
Circosol 450, 52.2~ banding sand, 11.8~ A1 (H2P04) 3
and 12.9% water. The MgO/P2O5 molar ratio was 4.
When tested as described in Example 30, the hardened
grout held a load of 572 kg/cm.
Control Experiments
_ _
In contrast, a composition containing 8.,~,
magnesium oxide (10 m2/g), 14.7% Circosol 450, 50.6
banding sand, 13-0% NH4H2PO4, and 13.0~ water
(MgO/P2O5 molar ratio= 4.4) held onl~ 45 kg/cm.
When a bolt was embedded into a mixture of
8-7~ MgO, 65 3% sand, 13.0% ~H4H2DO4, and 13,0C H2O
and tested as described in Example 30, the bolt was
dislodged with less than 5 kg. force after 10 minutes.
Exam~le 47
The following composition was ?repared:
`` ll~ZSS6
58
13~ McO (surface area 13.4 m2/g)
56.4~ banding sand
12.0~ ethylene glycol (in basic com?onent)
18.6~ Al(H2PO4)3 solution (10.5~ A12O3,
42% P2O5)
T~is grout, tested as describea in Exam?le 30, had
a pull strength of 672 kg/cm in 5 minutes.
