Note: Descriptions are shown in the official language in which they were submitted.
1 "COMPOSITION AND METHOD FOR MAKING SELF ADHERING
2 CONCRETE AND SYNTHETIC SEDIMENTARY ROCK FROM CEMENTITIOUS
3 MATERIALS"
4
STATEMENT OF FEDERALLY SPONSORED RESEARCH
6 No Federally sponsored research was used
7 STATEMENT OF NAMES OF PARTIES OF JOINT RESEARCH
8 No joint research parties were involved in this invention
9 INCORPORATION BY REFERENCE
a) Polycarboxylate superplasticizer admixtures: Effect on hydration,
11 microstructure and rheological behavior in cement pastes
12 b) Unlocking the secrets of Al-tobermorite in Roman seawater
13 concrete
14 c) Silica Fume User Manual
d) The Geometry and Petrogenesis of Dolomite Hydrocarbon
16 Reservoirs
17 STATEMENT of DISCLOSURES
18 The patent claims that a novel method of using common concrete
19 materials and additives can result in a new materials and physical
phenomenon. The
inventor Evan Vokes knew of no prior art that pertained to this invention and
is not
21 an improvement of existing technology. This was further confirmed by
multiple
22 searches by Parlee law for the original provisional patent. There are no
known
1
CA 3019731 2018-10-03
1 commercial or patent claims offered by others technology that assisted in
9 development of this novel idea as all manufacturers claims do not include
this
3 phenomenon. There was no public disclosure or offer for sale. I did work
with some
4 industry people to obtain unique materials and information that are hard
to
procureon a need to know basis but only Altamix has seen part of the process.
6 BACKGROUND of INVENTION
7 TECHNICAL FIELD
Embodiments herein relate to cement compositions and more
9 particularly to compositions for bonding said compositions to other
cement or
creation of new products from these cement compositions.
11
2
CA 3019731 2018-10-03
1
2 BACKGROUND
3 There
is sometime a need to adhere a new concrete composition to
4
existing surfaces including too old, cured cement.. To date the use of polymer
adhesives to approximate adhesion or bonding cement-to-cement has been a
6
challenge, resulting in variable success at best. The applicant noticed that
although
7 new
concrete is considered to be chemically dead to old concrete, he had
personally
8 observed chance adhesions in past years but no literature or products were
9
reflective of this phenomenon as it is accepted as an engineering tenant that
concrete does not bond to existing concrete.
11 As
discussed in a December 1997 article "Effective Use of Bonding
12
Agents", a Construction Technology Update No. 11, by Mr. Noel P. Mailvaganam
of
13 the
National Research Council of Canada (the NRC Article), two of the critical
14 factors
affecting the bonding between new and old concrete are (i) the strength and
integrity of the old surface and (ii) the cleanliness of the old surface. As
one has
16 come to
expect, the surface condition plays a critical role in bond development,
17
although the strength of the bond also depends on other factors such
compaction of
18 the new
concrete and proper surface preparation that takes into account the density
19 of the
base concrete. Known surface preparation includes acid etching of the base
concrete, while mechanical cleaning will be essential if the old concrete
contains a
21 weak or
deteriorated surface. The NRC Article identifies the main types of bonding
22 agents used in the construction industry as latex emulsions and epoxies.
The NRC
3
CA 3019731 2018-10-03
1 Article notes that while good adhesion may be obtained without a bonding
agent,
2 generally a bonding layer consisting of cement and sand slurry,
cement/latex slurry
3 or epoxy increases bond strength.
4 The NRC Article identifies latex bonding agents including Styrene
Butadiene (SBR) latex and Polyvinyl acetate latex (PVA).
6 Styrene butadiene (SBR) latex, which is compatible with
cementitious
7 compounds, is a copolymer. This type of latex shows good stability in the
presence
8 of multivalent cations such as calcium (Ca2+) and aluminum (A13+), and is
9 unaffected by the addition of relatively large amounts of electrolytes
(e.g., CaCl2).
SBR latex may coagulate if subjected to high temperatures, freezing
temperatures,
11 or severe mechanical action for prolonged periods of time.
12 Two main types of PVAs are used in repair: non-re-emulsifiable and
13 emulsifiable. Non-re-emulsifiable PVA forms a film that offers good
water resistance,
14 ultraviolet stability, and aging characteristics. Because of its
compatibility with
cement, it is widely used as a bonding agent and as a binder for cementitious
water-
16 based paints and waterproofing coatings. Emulsifiable PVA produces a
film that can
17 be softened and re-tackified with water. This type of latex permits the
application of a
18 film to a surface long before the subsequent application of a water-
based overlay. Its
19 use is limited to specific applications where the possible infiltration
of moisture to the
bond line is precluded. It is most widely used as a bonding agent for plaster,
and to
21 bond finish or base-coat gypsum, or Portland cement plaster, to interior
surfaces of
22 cured cast-in- place concrete. Acrylic ester resins are polymers and
copolymers of
4
CA 3019731 2018-10-03
1 the esters of acrylic and methacrylic acids. Their physical properties
range from soft
2 elastomers to hard plastics. This type of emulsion is used in
cementitious
3 compounds in much the same manner as SBR latex. Epoxy emulsions are
produced
4 from liquid epoxy resin mixed with the curing agent. In addition to
serving as an
emulsifying agent, the curing agent also serves as a wetting agent. From the
time of
6 mixing until gellation occurs, the emulsions are stable and can be
diluted with water.
7 Pot life can be varied from 1 to 6 hours depending on the curing agent
selected and
8 on the amount of water added. Most epoxy emulsions are prepared on the
job site
9 just before use because phase separation occurs in prepackaged emulsions.
Equal
parts of epoxy and curing agent are mixed, then blended for 2 to 5 minutes and
11 allowed to set for 15 minutes to enable polymerization to begin. While
the mixture is
12 being mechanically agitated, water is added slowly to form the emulsion.
As an
13 alternative to these liquid-based systems, which require on-site
measurement and
14 pre-dilution, it is now possible to obtain factory-blended powders
containing a
mixture of cement, spray-dried latex powders, sand and other additives, which
are
16 simply mixed with water on site. The resultant "stipple" finish provides
a good "key"
17 for repair mortar or overlays. The stippled grout coat minimizes the
loss of water
18 from the overlay to the substrate, preventing desiccation of the cement and
the
19 resultant poor bond. Although the grout coat does provide points of
anchorage for
bonding, the application of the repair mortar or overlay while this key coat
is still
21 tacky is strongly recommended.
5
CA 3019731 2018-10-03
1 Various
epoxy products are available for the bonding of freshly placed
2
concrete to cured concrete and of concrete to steel. Most products contain
resins
3 that
are 100% solids. They may or may not contain fillers, such as calcium
4
carbonate or silica flour, and other additives to enhance a particular
property or
reduce cost. Products are available in a variety of consistencies, ranging
from a
6 highly
filled paste (for overhead work) to liquids with a viscosity of 100 cp (0.1 Pa-
s),
7 which
is similar to that of water. Because the formulations can combine different
8 resins,
hardeners and modifiers to produce a great variety of end products, the user
9 and specifier need guidance on the options available to them. The ASTM
standard
ASTM 0881-78 "Epoxy-resin-based Bonding Systems for Concrete" is quite
11
informative in this respect. It is a performance specification based on end
use and
12 there
are no specific limits on chemical composition. Instead, the material selected
13 must
meet requirements related to physical properties such as viscosity, bond
14
strength, shrinkage and thermal compatibility. The specification classifies
the epoxy-
resin bonding system by type, grade and class. The type is determined by end
use
16 (see
ASTM C881, Table 1, "Physical Requirements of Bonding Systems"). Systems
17 can be summarized as follows: Type I, for bonding hardened concrete and
other
18
materials to hardened concrete; Type II, for bonding freshly mixed concrete to
19
hardened concrete; Type Ill, for bonding skid-resistant materials to hardened
concrete (or for use as a binder in epoxy mortars or concretes).
21 The NRC
Article concludes that critical factors governing the
22
achievement of an effective repair is good adhesion at the interface of the
repair
6
CA 3019731 2018-10-03
1
material and the concrete substrate and that a proper bond between the repair
2
material and the substrate can be obtained by surface preparation,
consolidation
3 and
curing ¨ all without the use of bonding agents. However, bonding agents play a
4 significant role where it is critical to ensure bond at the interface.
Applicant understands from the above that the primary bonding
6
mechanism of the above is mechanical and thus is inherently less competent
that
7 the base concrete and susceptible to water migration damage. Regardless if
one
8 applies an epoxy or a latex based admixture, the use of polymer admixtures
is
9 limited
to specific applications where the possible infiltration of moisture to the
bond
line is precluded. Therefore, there is interest in the industry to seek
mechanisms for
11 bonding that overcome the issues associated with bonding agents.
17 There
exists an overlay industry where a thick layer of concrete is
13 poured
directly on top of existing concrete. There also exists a wealth of
information
14 on the
internet about its limited usefulness and applicability which precludes the
necessity of discussion in the context of VokeStone.
16
17 SUMMARY
18
Generally, in embodiments disclosed herein, a bonding mechanism is
19
disclosed which results in an improved interface. In concrete-to-concrete
embodiments, the interface can be more competent than that of the base
concrete.
21
Applicant has effected a change from the conventional hydration bonds of semi
22
amorphous Calcium Silica Hydrates to the precipitation of carbonates and with
7
CA 3019731 2018-10-03
1 further
treatment to the precipitation of minerals in the composition and at
interfaces
2 to
existing structure and across interfaces to existing concrete or within the
volume
3 of concrete.
4
Applicant's research was initially directed to the top-coating, recoating
or repairing the surface of prior concrete floor surfaces through the
application of an
6 added cementitious composition. Applicant attempted both new combinations of
7 additives, added to the new concrete, and to new methodologies for enhancing
8
bonding. Further, for floor finishing embodiments, Applicant was aware of the
9
objectives and potential conflict between ease of finishing the new concrete
and its
ability to bond with the old concrete.
11 In
embodiments, Applicant has determined that a cementitious
12
composition exhibiting, bonding characteristics and a surface quality superior
to that
13 of base
concrete, comprises Portland cement, pozzolanic material and sand
14
combined with a superplasticizer such as Poly Carboxyl Ether. The interface
between the new composition and the old base concrete may be initially
mechanical
16 but,
over time, develops a full chemical bonding interface to form. Used for
flooring
17 and
other surface requiring enhanced finishing, the resulting cement can be
finished.
18
Further, the surface retainer reinforcing micro bars in the finished surface
for a safe
19 and
uniform finished surface without releasing micro bar ends to project out of
the
surface. Further adhesion advantage is achieved when aggregate in the parent
or
21 base
material is exposed which does not induce sub-surface damage using
22
techniques, such as through mechanical abrasion or weathering, In other
8
CA 3019731 2018-10-03
1 embodiments, the composition has proved to exhibit a strong bond to other
materials
2 including steel or expanded polystyrene but no adhesion to polymers such
as ABS
3 or polyethylene. The composition is also formable and amenable to post-
forming
4 finishing.
The most viable of the overlay mix designs demonstrate long range
6 crystallinity with a rock matrix of silicates and carbonates, typically
quartz, calcite
7 and dolomite, while other phases are both possible. The chemical reactions
of the
8 mix design is unverified at this time but data analysis appears to be
controlled by
9 PCE which mechanical testing showed a medium correlation between strength
and
POE across the same ratios of aggregate, pozzolan and Portland. Tests also
11 showed that sodium silicate did not determine the initial adhesion as
tests without
12 the PMT admixture but XRD of these mixtures did show that the interface was
13 magnesium calcium carbonate, which is not the crystalline mineral that
the
14 chemically similar dolomite is. Sodium silicates long term actions of
promoting the
conversion of magnesium calcium carbonate into Dolomite as well as the other
16 mineral conversions attest to its usefulness of commercialization
considerations. As
17 matrix strength rises, the sand component becomes indistinguishable from
the basic
18 cement matrix when sodium silicate is added. The formation of these
phases pushes
19 the long range crystal order across the bonding interface over time.
While
mechanical bond is exhibited in days, full chemical bonds developed well into
the
21 parent material within a week or more slowly over time dependent on
chemical and
22 water composition used.
9
CA 3019731 2018-10-03
1 As conventional concrete is hydrated amorphous rings, the strength
of
2 traditional concrete relies on the aggregate strength. In this case, we
use much more
3 sand than traditional mix designs and utilize precipitated mineral matrix
to provide
4 strength.
Applicant will use this rock as a synthetic "sedimentary" rock under the
6 trademark VokeStoneTM (Evan Vokes).
7 As a result, embodiments of cementitious compositions result in
the
8 following features:
9 a) Unprecedented adhesion of concrete to concrete by
precipitation reaction.
11 b) Functionally structural thin overlays or bond coats are
possible.
12 c) Functional in-situ concrete repairs are possible.
13 d) Synthetic rock (VokeStoneTM) is created in embodiments
having
14 low permeability, high strength; and
e) Pre-formed cement-derived products may be created.
16
17 BRIEF DESCRIPTION OF THE DRAWINGS
18 Figures 1A and 1B are a flow chart of stagewise admixing of
19 components to obtain the desired formulation and products that result
therefrom;
Figure 2A is a secondary electron image, from an SEM, at a bonded
21 interface of new sodium silicate enhanced composition to an old
concrete;
CA 3019731 2018-10-03
1 Figure
2B is an X-Ray map from an SEM at a bonded interface of new
2 sodium silicate enhanced composition to an old concrete;
3 Figure
3 is a table of the crystalline components for a new sodium
4 silicate enhanced composition to an old concrete;
Figure 4 is an X-Ray diffraction image of the bonding interface of an
6 embodiment of the new composition and the cement matrix of old concrete;
7 Figure
5 is an X-Ray diffraction image of the bonding interface of an
8 embodiment of the new composition and a discrete aggregate face in old
concrete.
9
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
11 As
stated above, in embodiments, one form of cementitious
12 compositions comprises Portland Cement, pozzolanic material and sand
combined
13 with a
superplasticizer such as Poly Carboxyl Ether and the use of a proprietary
14 sodium
silicate derivative, Pozzonlanic Mix Treatment,(PMT) in some compositions.
Some understanding of the standard engineering nature of concrete is required
to
16 point
out the differences. Concrete may be defined as an aggregate held in place by
17 a
matrix of semi amorphous hydrated rings of Calcium Silica Hydroxides. It is
well
18 known
that the strength of concrete is the strength of the aggregate. This accepted
19 engineering tenant is very different than what VokeStone has achieved
21
Portland cement ¨ provides CaO or lime portion needed for binding
22 clay and silicates together. A European standard defines Portland cement as
a
11
CA 3019731 2018-10-03
1
hydraulic material which shall consist of at least two-thirds by mass of
calcium
2
silicates (3 CaO=Si02 and 2 CaO=Si02), the remainder consisting of aluminum-
and
3 iron-
containing clinker phases and other compounds. It is well established that
4
Portland cements are the chemical reagent that makes concrete possible, In the
case of VokeStone; we are concerned with the difference between the Alite and
6 Belite allomorphs of this commodity notated in cement science as CS3 and CS2
7
respectively. The Belite allomorph is the preferred cement for VokeStone and
is
8 often
referred to as Sulfate resistant Portland. The Alite allomorph is more common
9 in
industry, where it is known a general purpose Portland, since it sets much
faster
but there are other considerations related to the chemistry and morphology
that must
11 be
considered for VokeStone. Alite has been successfully tested but Belite is the
12 more functional allomorph.
13
14 Adding
Pozzolanic materials to concrete is recognized as binding clays
and silicates to the CaO. ASTM 0618 prescribes that a pozzolan should contain
16 SiO2 +
Al2O3 + Fe2O3 70 wt.%. Fly ash is often used in combination with
17
Portland cement (in the order of 30% by wt) as a pozzolan to produce hydraulic
18 cement
or hydraulic plaster and a replacement or partial replacement for Portland
19 cement
in concrete production. Sales literature often identifies to use of Pozzolan's
to ensure the setting of concrete and plaster and provide concrete with more
21
protection from wet conditions and chemical attack but Pozzolans can damage
22
concrete just as easily. At the risk of oversimplification for the purposes of
this
12
CA 3019731 2018-10-03
1
embodiment, Industrial Pozzolan products are essentially reactive fine silica
with
2
heterogeneous allomorphs. Fly ash is the most common and is characterized as
fine
3 silica
with a high degree of crystallinity. Conversely, the chemically similar Silica
4 Fume is
typically produced by rapid cooling so that a mainly amorphous quenched
glass or simply stated limited crystallinity. Blast Furnace slag pozzolans are
similar
6
although the method of production is radically different. In practice all the
Pozzolans
7 are heterogeneous. As an example, fly ash is a heterogeneous material. SiO2,
8 A1203,
Fe2O3 and occasionally CaO are the main chemical components present in
9 fly
ashes; but the Pozzolan relationship VokeStone needs appears to be is the
total
presence of both amorphous and crystalline silica phases as well as magnesium
11
content. Specifying materials used to get to this goal are not as important as
what
12 the full combinations of materials are.
13 For
instance the mineralogy of fly ash is very diverse. There are two
14 types of fly ash:
- Class F fly ash. This fly ash is pozzolanic in nature, and contains
16 less
than 7% lime (CaO). Possessing pozzolanic properties, the
17 glassy
silica and alumina of Class F fly ash requires a cementing
18 agent, such as Portland cement, and
19 - Class
C fly ash generally contains more than 20% lime (CaO).
Unlike Class F, self-cementing Class C fly ash does not require an
21
activator. Alkali and sulfate (SO4) contents are generally higher in
22 Class C fly ashes
13
CA 3019731 2018-10-03
1 For
VokeStone, there is no guarantee that these materials that meet
2 the ASTM standards for both classes of flyash would work. Rather they must
be
3
investigated for the correct properties as one of the ingredients of VokeStone
is not
4 required to be present in the ASTM standard analysis.
All the dry ingredients were subjected to XRay Florescence as XRay
6
Diffraction gives little information on what elements are present. The finding
is that
7 the
undeclared Magnesium content was significant in many samples. It is safe to
say
8 that the correlation between material combinations that maximized magnesium
9
content, and adhesion was very strong.. All these raw materials were less than
5%
magnesium whereas magnesium carbonates themselves are 13% magnesium.
11 There
is no kinetic chemical path for the raw materials to form magnesium
12
carbonates on their own even if the path is thermodynamically favored so
reagents
13 and catalysts are required.
14
Superplasticizer - also known as high-range water-reducers, are
chemical admixtures including polymers used where well-dispersed particle
16
suspension is required. A current embodiment includes polycarboxylate ether-
based
17
superplasticizers (PCEs) which are discussed in detail for industry accepted
use in
18 January
2005 paper by F. Puertas Polycarboxylate superplasticizers admixtures:
19 Effect on hydration, microstructure and rheological behavior in cement
pastes.
The paper summarizes known effects of PCE demonstrating the
21
industry accepted method that a relatively low dosage (0.15-0.3% by cement
14
CA 3019731 2018-10-03
1 weight) the PCE superplasticizers allow a water reduction up to 40%, due
to their
2 chemical structure which enables good particle dispersion.
3 In this
application the PCE is used at a very high rate of 3.0-4.5% by
4 cement
mass or 1.6-16.0% by water mass. The optimum engineering ratio of
Portland cement type product to water is defined as a W/C ratio of 0.25 by
mass. It
6 would be assumed that water alone, is the factor that determines strength of
7 standard concrete matrixes that support the aggregate, hence the accepted
8 engineering tenant is that lowering the water content is an essential
variable when
9 seeking to increase the strength of the resulting product. In the case of
VokeStone
lowering the water did not exclusively result in the strongest test results,
rather,
11 water/cement rations between 0.30-0.36 in conjunction with PCE doses
over 10:1
12 water to PCE ratios resulted in the maximum compressive strengths. There
are an
13 infinite number of mid steps that can be achieved with water to cement
to PCE
14 ratios.
PCE has another very strong effect where it keeps Ca2+ ions from
16 reacting. This effect appears to be important as the observation is that
the
17 thermodynamically less preferable MgCO3 (-1095kJ/mol) complexes to
precipitate
18 before the less desirable CaCO3 (-1206kJ/mol).
19 Sodium
silicate, or water glass, generally has the form of
Na2(Si02)nO. In liquid form, for ease of mixing, Sodium silicate is a mixture
of
21 caustic soda, quartz sand, and water are mixed than fed into a reactor,
where steam
22 is
introduced. The reaction is n SiO2 + 2 NaOH Na2O=nSi02 + H20. Sodium
CA 3019731 2018-10-03
1 silicate can help to reduce porosity in masonry products. Sodium silicate
is typically
2 only applied as a surface treatment. A chemical reaction occurs with the
excess
3 Ca(OH)2 (portlandite) present in the existing concrete that permanently
binds the
4 silicates with the surface, making them far more durable and water
repellent. This
treatment generally is applied only after the initial cure has taken place.
6 Sand was found to be a very important component for the VokeStone.
7 It was observed that without sand, the cream of the mix would not react
and harden.
8 Further testing showed that pure silica sands that were deficient in
Magnesium
9 content did not perform to expectations. The mechanisms of crystal growth
are well
established and it appears that the sand in conjunction with the fine silica
provide
11 nucleation sites for crystal growth. There is an unknown if the sand is
required to
12 nucleate precipitation of magnesium compounds or if there is an overall
critical value
13 of magnesium content required for the reactions to proceed. It is
unknown if doping
14 the mixture with Magnesium compounds would overcome the limitation.
One of the resultant components, Dolomite is a calcium magnesium
16 carbonate with a chemical composition of CaMg(CO3)2 and a heat of
formation of -
17 2660KJ/mol but there exist no laboratory experiments to prove the formation
of
18 Dolomite from the theoretical precipitation to reality. This geoscience
subject
19 referred to as the Dolomite Enigma was reviewed extensively by
Braithwaite in the
Geological Societies 2004 title, The Geometry and Petrogenesis of Dolomite
21 Hydrocarbon Reservoirs. Not only does this reference to the Dolomite
Enigma
22 remain current but the problem is widespread in Geosciences. There is no
term to
16
CA 3019731 2018-10-03
1 describe the conversion of chemical compounds into mineral. A quick
google search
2 will show that one of the few man made minerals that mimics nature is
diamond.
3 While Calcite is a known product of sodium silicate cement chemistries,
the
4 presence of Quartz that was not present in the precursor materials so the
presence
of quartz with no know chemical path is also an enigma in VokeStone. The
presence
6 of the quartz is harder to comprehend as so many of the precursor materials
are
7 silicates whereas, magnesium is easier to follow the chemistry path to
crystallization.
8 VokeStone appears to have a strong correlation to solving the Dolomite
enigma.
9 The parent or base material the overlays were developed on had a
concrete admixture containing high quantities of sulfur precluded finishing
the
11 surface. Both mechanical methods of scarifying and diamond grinding of
the surface
12 resulting in unreliable or complete failure of embedded micro rebar
reinforcements to
13 grind off flush with the concrete itself. Further, epoxy and urethane
coverings were
14 investigated and were confirmed as unsuitable for effective restoration
of a
functional work surface. Accordingly, compositions with sulfur are
discouraged.
16 Once mechanical surface remediation failed, different silicate-
based
17 products were tested. Commercial admixtures were tested, using Portland
Cement,
18 Sand and aggregate particularly in embodiments touted as suitable for
forming thin
19 coatings bonded to old concrete. Successful adhesion was not achieved.
With reference to the flow chart of Figs 1A and 1B and as discussed,
21 embodiments of a self-consolidating, cementitious composition are
provided
22 comprising Portland cement, pozzolanic materials, sand and
superplasticizer. On
17
CA 3019731 2018-10-03
1 curing, a synthetic stone with a precipitated interface results. The use
of aggregate
2 is of economic necessity as the mix design is very expensive compared to
industry
3 standard concrete mixes. At the time of this application, Applicant
understands the
4 precipitated interface to be largely composed of quartz and carbonate
materials but
thermodynamically other precipitates are possible. The initial result is a
bond layer
6 that exhibits at least mechanical bond interface superior to prior
interfaces. There
7 are numerous chemical and mechanical variations that can be applied to
change the
8 performance to make it more application specific. For instance, the
addition of
9 greater amounts of sand and silica fume, further enhance the surface
finish through
techniques including float and troweling. Crack load carrying may be improved
by
11 reinforcement such as micro reinforcement bars.
12 In improved concrete-to-concrete interfaces, additives from the
sodium
13 silicate family can be added to enhance chemical bonds through
precipitation and
14 crystallization at the bond interface. Over time, sodium silicate
containing mixes will
chemically bond across the interface. Once bonded, the Interface and parent
16 material are now the same crystalline, chemically similar structure. PMT
is preferred
17 chemical available from Enhance ICD (Canada) Inc, and is provided in
liquid form,
18 but other companies offer similar proprietary admixtures. Investigation
during the
19 provisional application showed that the PMT additive claim is that it
accelerates
"rigidity" and "densifies". A further manufacturer caution is that PMT should
not be
21 mixed with polycarboxylate admixtures but no reason was given for this
statement.
22 Commonly, the experience of users with PMT is that there is no bleed
water, mix is
18
CA 3019731 2018-10-03
1
extremely workable, sets up faster, successive coats or pours can commence
2 sooner,
and forms can be stripped earlier. These are the same functional properties
3 claimed
by vendors of POE as both compounds have a proven record of increasing
4 the
utilization rate of Portland cement. It is well known that Sodium silicate
effects
water seals by forcing the precipitation of Calcium carbonate on existing
concrete by
6
scavenging unreacted Portland to form a Calcite crystal structure that seals
porosity.
7
8 Part
way through the development process, the vendor of PMT sent a
9 lab
result to extol the strength virtues of PMT that showed that trace minerals of
Jennerite and Tobermorite had formed in one of their tests. When I sent my
samples
11 for
XRD, I asked them to specifically look for these minerals. The answer from XRD
12 was VokeStone is substantially different as these minerals were never
observed.
13
14 In more
detail of the path of the invention, after all industry ideas to
repair the floor were exhausted, the inventor started with cement materials
that were
16 used to
cast the original floor, CSA type 50 Portland, Sand and 10mm aggregate.
17
Combinations of POE and PMT were tried but no success was obtained. Research
18
indicated that a flyash and silica fume may have been useful but are difficult
to
19 obtain
in less than bulk loads of product. Subsequently, a unique cementitious
composition was implemented utilizing a bag of commercial type GU Portland
21 cement,
a bag of commercial SAKRETE (Registered trademark of Sakrete of North
22
America, LLC), a super plasticizer and sodium silicates. Applicant was
informed by
19
CA 3019731 2018-10-03
1 the vendor that commercial yet proprietary formulations SAKRETE also
include
2 about 30 % pozzolanic materials with an included plasticizer but very low
3 percentages of Portland. Accordingly, the SAKRETE component was only used
to
4 supply a simple source of Fly ash equivalent useful in the research when
mixed with
additional general purpose Portland to bring the cement component up to a
6 reasonable level. This resulted in the first successful adhesion but no
useable
7 surface and removal was characterized by the preferential removal of the
parent
8 material as opposed to removal of the overlay.
9 For control, after successful proof of concept testing, and
further
research, Type F fly ash (from LaFarge North America Inc.) was obtained and
was
11 subsequently used as an additive on remaining tests. As set forth above,
many
12 further set of samples were prepared utilizing a type F fly ash and
LaFarge CSA type
13 50 Portland. Ultimately compositions were established that successfully
adhered.
14 Adherence was deemed successful when the sample was removable from the
parent concrete floor three days subsequent to application; only by chipping,
with a
16 portion of the floor removed therewith.
17 Such successful samples had a hard black layer at the new/old
18 interface. The hard black layer would form whether or not the sodium
silicate
19 derivative was used. While surface adhesion was reliably achieved,
surface finish
was not achieved at the same time, where the two properties remained mutually
21 exclusive through several rounds of testing. Surface finishing was
improved with the
22 adjustment of additional elements. Namely, silica fume, (a pozzolanic
material) and
CA 3019731 2018-10-03
1 a very high sand ratio aided in surface finish at the same time as
adhesion across a
2 wide range of water and chemical compositions.
3 As above, pozzolans (first located near Pozzuoli, Italy) are
understood
4 to be a broad class of siliceous or siliceous and aluminous materials
which, in
themselves, possess little or no cementitious value but which will, in finely
divided
6 form and in the presence of water, react chemically with calcium hydroxide
at
7 ordinary temperature to form compounds possessing cementitious properties.
8 Successful concrete, first used by the Ancient Romans (Roman Concrete), used
9 volcanic ash (pozzolanic materials) as a key component and different effects
came
from different deposits.. An excellent reference, Unlocking the secrets of Al-
11 tobermorite in Roman seawater concrete by Marie D. Jackson etal in
October 2013
12 details how the various Roman concretes were based on different amounts of
13 crystalline or amorphous volcanic product and while the product was
slightly
14 crystalline, the strengths were low by modern standards. The conclusion
was that
seawater was the active ingredient but no evidence was supplied of how they
came
16 to this conclusion. While no one has exactly replicated Roman Cements,
Pliny the
17 younger and current materials science give the clues that make this
invention
18 possible. While the Roman concrete cannot be considered prior art as it
is so
19 different, in materials science there are two tenants that can be
invoked: a)
amorphous materials are considered reactive in the presence of the correct
catalyst.
21 b) crystalline materials serve as nucleation sites to further grow
crystal structures.
21
CA 3019731 2018-10-03
1 A form
of pozzolanic material is silica fume, also known as microsilica.
2 Silica
Fume is an amorphous (non-crystalline) polymorph of silicon dioxide, silica It
3 is an
ultrafine powder collected as a by-product of the silicon and ferrosilicon
alloy
4
production and consists of spherical particles with an average particle
diameter of
150 nm.
6 Through
the addition of silica fume, surface hardness and finishing
7
improved and, at the same time, adhesion was improved. As set forth in Table
2.4,
8 section
2.4, Silica Fume Users Manual by the Silica Fume Association April 2005
9 silica fume has the highest amorphous 5i02 (85-97%) and therefore reactive
content, of the common cement, binders and enhancers.
11 In
enhancing the bond from a predominantly mechanical to a chemical
12 bond
interface, time was a factor. Typically in concrete construction, it is
understood
13 that
concrete strength increases over time as hydration occurs. Herein, the bond
14
interface adhesion develops over time. Two brands of Silica fume were tested
and
the brand with higher Magnesium content was significantly more effective than
the
16 brand with the more amorphous nature so the amorphous nature alone is not
the
17 only factor.
18 While
researching surface finish, Applicant determined that poor initial
19 results
of the bond layer to a destructive bond test, improved over time when the
swatches from Test 15 a&b were left on the floor due to time constraints.
21
Previously, initial performance was only evaluated after three days which was
22
determined by the hardening degree of the overlay but poor adhesion results of
22
CA 3019731 2018-10-03
1 samples left for three days were markedly improved and successful at 10
days and
2 later experiments showed that some compositions took over a month to
adhere. The
3 implication is that many of the earlier tests, deemed failures would have
been
4 successful if left for longer time periods. The later interface clearly
included a
crystalline phase.
6 Further, the interface, dark or black in appearance, was noted to
be
7 substantially continuous and that sand was hard to discern from the rest
of the
8 matrix. Holding broken interface samples to the sun showed that the
matrix showed
9 reflectivity of crystalline materials, the same as the cleaved
aggregates.
In bonding to other old concrete surfaces, it was determined that the
11 overlay experienced reduced adhesion resulting from attempts to bond to
the
12 existing concrete cream layers. Although the shear stress required to
break the
13 bond would exceed the industry accepted 200kPa permanence threshold. Even
14 adhering to an existing concrete cream layer would be considered a
permanent
repair, the interface readily tears off when subjected to shear stress on an
industrial
16 scale such as point loads from common floor jacks.
17
18 Removal of the cream layers of parent materials adds a level of
19 complexity. If the existing cream layer is scarified, Scanning Electron
Microscope
SEM images of the interface showed damaged in areas below the grind level.
21 Alternatively, pouring new compositions on exposed aggregate where the
cream
22 layer was removed on other samples showed good adhesion whether naturally
23
CA 3019731 2018-10-03
1 removed
or mechanically removed. Proper installation should include removal of the
2
hardened cream layer whether by less coarse means including, shot blasting,
3 diamond grinding or through natural weathering.
4 The
physical manifestations of the bond have many unique
implications. As shown in Fig 2A, an SEM from a Scanning Electron microscope
of a
6 bonded
interface of a base composition and pre-existing concrete, further comprises
7 a
sodium silicate additive, in this case PMT from Enhance ICD (Canada) Inc. The
8 older
parent concrete is shown at the right and new composition to the left, the
9
crystalline nature of the chemically bonded interface clearly illustrated as
the mottled
and lighter gray area along an interface trending downward and right from left
top
11 corner to the bottom middle.
12 Fig. 2B
is an X-ray map from an SEM of the same interface of a
13 bonded
interface, with the old concrete at the right and new composition to the left,
14 the
dissolution of the concentrated Ca in the parent material, shows the
crystallinity
moving left across the interface, from new to old, and consuming free Ca,
resulting
16 in
crystalline interface bonding. The upper right, in the old concrete
illustrates that
17 most of the Calcium remains unused.
18 As
shown in the Table of Fig. 3, a Spectrum Phase ID Report is
19
provided for the composition at a concrete interface of a sodium silicate
enhanced
formulation bonded to old concrete. The results demonstrate each component
21
presenting as crystalline for a completely crystalline interface. X-Ray
diffraction only
22 shows crystalline forms and while there is subjectivity in quantifying in
24
CA 3019731 2018-10-03
1 XRD, the sums of the wt. .% totals 100. The correct methodology to
absolute mineral
2 quantification is thin section but it is not required in this
application.
3
4 As explained early in this application, conventional concrete is semi
amorphous
(non-crystalline) rings of calcium silica hydrate that support an aggregate.
The table
6 illustrates VokeStone as an almost complete conversion of a relatively
normal
7 concrete mix to synthetic sedimentary rock comprising Dolomite, Quartz,
Calcite and
8 Calcium Silicate Hydrate as the major phases as evidenced by XRD scans
showing
9 strong reflection lines with high crystallographic identifications and
little background
noise as compared to amorphous materials as evidenced by XRD of the precursor
11 materials.
12 Fig. 4 is an XRD plot of a concrete sample with partial admixture
load
13 of the current embodiments. This is an embodiment of the composition
without the
14 sodium silicate additive. Superior adherence is provided but is not
fully crystalline
across the interface. The interface illustrates carbonates, precipitated early
in the
16 reaction. The samples are absent the PMT admixture but still adhere to
the parent
17 concrete.
18 While the sodium silicate free compositions are quite different
than the
19 preferred sodium silicate containing compositions of this group of
mixes, they are
still commercially viable for concrete bonding. Chemically they are the same
as
21 VokeStone but crystallization is different.
CA 3019731 2018-10-03
1
Applicant noted while pouring the nominal one inch thick overlays in
2 the Styrofoam forms, some cement paste escaped the forms due to the uneven
3 nature
of the floor with no entrained sand. This cement paste did harden and bind to
4 the
parent floor but it took many months during the provisional period. This
cement
paste did not support timely precipitation without elevated levels of sand. In
other
6 words, the successful compositions required sand to enable crystal growth in
a
7 timely fashion.
8
9 In Fig.
5, an XRD plot is shown of a second location in the sample of
Fig. 4, the interface being unique located at the face of aggregate in the
parent
11
material. The results evidence the crystalline nature that is also observable
with the
12 naked eye when separated from the aggregate. The chemical reaction that
makes
13 the
material consistent through the matrix resulted in less Calcium Manganese
14 Carbonate at the rock interface rather than at the richer cement
interface.
Other observations from the SEM included that problematic sulfur was
13
confirmed as present in the parent material, but the rest of the chemical
composition
17 was
uniform in the overlay, the interface and the surface of the parent material.
The
18 free Calcium of the parent material was absent from the interface and a
uniform
19
Calcium, Silicon, and Carbon distribution was present. Applicant believes that
carbon chains in the plasticizers force a useful precipitation of carbonates
into
21 mineral form without adversely affecting the concrete. This reaction is
22
thermodynamically probable as the PCE is known in literature to suppress Ca2+
ions
26
CA 3019731 2018-10-03
1 from reacting for a time period whereas the PMT will react to form
carbonates
2 immediately.
3 The XRD
results indicated this was in a form akin to an artificial
4 sedimentary rock and the same crystal phases were present both sides and
across
the interface. Dolomite, Quartz and Calcite composed almost 100% of the new
6 concrete of the overlay, and in the parent material surface. While
calcite is a natural
7 expected product of sodium silicate reactions in concrete, quartz and
dolomite were
8 not. Further testing of an early sample that did not contain silicates,
showed that the
9 black interface development was almost all carbonate crystal structures
but not fully
developed into the Dolstone minerals.
11 The
adhesion phenomenon was interesting but unknown until mechanical
12 testing was conducted. The proof was when the official ASTM pull test on
July 28
13 proved that the adhesion phenomenon was real science July 28th, test
compression
14 samples which had been prepared in standard ASTM sized 4 inch x 8 inch
plastic
tubes, were tested at different ages. During the destructive compression test,
the
16 resulting samples exhibited very high strengths and stone-like
characteristics. When
17 they finally failed, the samples formed shards instead of crumbling,
more consistent
18 with a stone than with traditional concrete. As strength was a not
primary
19 consideration, no specific strength objectives were expected, however
some of the
samples tested high as 75MPa at 14 days which indicates that a hard wearing
21 surface is produced..
27
CA 3019731 2018-10-03
1 One embodiment of the relative proportions of a cementitious
2 composition comprise
3 - 10 kg of Portland cement
4 - 25 kg of Sand
- lkg of Silica fume or equivalent pozzolanic material
6 - 1 kg of fly ash (type F)
7 - 50-500 ml of superplastizer (PCE)
8 - 25-50m1 of SodiumSilicate (PMT) and
9 - 2 ¨ 4.5 kg water.
Optionally, the composition can also include aggregate, in the order of
11 up to about 15 kg small aggregate to 10 kg of the Portland cement to
make the
12 preferred thin overlay variation of VokeStone.
13 Late in the initial testing process, a round of testing was
completed
14 with a commercial bulk mix of CSA type 10 and 15% fly ash. The
precipitating and
adherence effect was present but much reduced. There appears to be a
16 fundamental difference between CSA types 10 and 50 that were tested, which
17 certainly shows that the type of Portland can affect the outcome of
adhesion. The
18 tests were a reproduction of the original Sakrete and Portland mix that
adhered,
19 hence, these cements would have been predominately CS3 containing CSA
type 10
Portland cement so we know that the other forms of Portland cement work but
the
21 best results come from the predominately CS2 cements also known as
sulfate
22 resisting cements.
28
CA 3019731 2018-10-03
1 In
summary, using application combination of common Portland
2 Cement,
Pozzolanic materials and Sand combined with a superplasticizer (Poly
3
Carboxyl Ether), a rudimentary mechanical bond layer is formed. The adhesive
bond
4 layer
is within the carbonate family. Bond layers of this simple chemistry are most
useful when used as a bond layer with or without subsequent overlays of more
6
traditional concrete mixtures. The use of both crystalline and amorphous
Pozzolanic
7 materials and sand are combined resulting in engineered variability in the
8
performance of the end products. A wide variation of compositions have shown
that
9 bond
layer will adhere to conventional concrete tested. However a cream finish,
common on finished concrete surfaces, exhibits little structural use and a
tendency
11 to
disbond which reducing the overall effectiveness of the overlay. A preferred
12 method
is to expose the aggregate in the parent material, whether by mechanical
13
abrasion or existing weathering. Forms of suitable mechanical abrasion or
exposure
14 include
shot blasting or diamond grinding, as other more aggressive methods such
as scarifying result in a lower surface integrity of the parent material.
16 Using
the same chemistry described above, a thin layer of two times
17 thicker than the largest aggregate diameter or much thicker may be poured
on a
18 floor.
The hardness of this layer is directly related to compressive strength which
19 has
been dependent on a ratio of water to cement and, with the proportion of
superplasticizers to total water content, and the use of silicate chemistry,
results in
21
observed strengths of 75MPa in 14 days. Careful control of aggregates and wet
29
CA 3019731 2018-10-03
1 troweling, to ensure sand comes to surface and reduce surface porosity,
results in a
2 hard surface. This surface may be further hardened with select silicate
treatments.
3 The thin overlays described above are quite complex from the
4 engineering point of view. There are three interrelated properties that
must
simultaneously happen to make a successful thin overlay. The interface must
bond
6 and be able to transfer shear stress. The resultant surface must be
commercially
7 useable by the end user. The volume of the overlay must be of sufficient
strength to
8 spread point loads without crushing the matrix.
9 Long range crystallinity is demonstrated with a natural rock matrix
of
silicates and carbonates, typically quartz, calcite and dolomite. In the case
of
11 VokeStone, the same highly crystalline silicates and carbonates are
formed, typically
12 quartz calcite and dolomite. Functionally, when sodium silicates are
added, the sand
13 portion becomes indistinguishable from the basic cement matrix and even
holding
14 broken sections to bright light reveals the crystalline nature. The
formation of these
phases will push the long range crystal order across an interface over a
period of
16 time. Observations have shown that for mixes that did not exhibit
mechanical bonds
17 in three days, full chemical bonds were developed well into the parent
material within
18 a week. The observation arose when test swatches 15a and 15b failed the
three day
19 adhesion test, it was left on the floor for two weeks, when it was
discovered that it
had fully adhered. Some compositions take a very long time, such as a month or
21 more to develop but over time, still make fully crystalline interfaces
when no
22 mechanical bond was initially present. The previously described
mechanical
CA 3019731 2018-10-03
1 interfaces are analogous to metallurgical results produced in brazing
metal surfaces
2 but the chemical interface described is akin to welding metal surfaces.
3 The
process of how the chemical products of the reaction become
4 crystals analogous to minerals should be described as mineralization.
There is a
problem with the use of this term as Geoscience never addresses how minerals
are
6 created, only what can observe at this time. The basic principle is that
natural rocks
7 and minerals are created over eons so there was no need to define a dynamic
8
process. Hence what should be the correct term for a dynamic process,
9 "mineralization", has been used instead to describe the mineral ore value
of natural
rock formations. Describing a process that is not in a reference book or paper
is a
11 challenge.
12 While
most recipes for the product are self-leveling allowing very flat
13 surfaces to be produced, the product can be used in other ways as well.
The product
14 lends itself to formwork and can be used both as a new product but also
for repair as
it adheres well to steel as well as concrete. The basic chemical nature of the
16 carbonates protects steel from corrosion if water movement does not
occur.
17 The
very nature of VokeStone adhesive bonding characteristics lend
18 itself to extension of previous cement work or adhesion to partially
cured "green"
19 concrete during long time lapses result in partial cures during large
pours whereas
interfaces with this new product can become mechanically indistinguishable
from
21 previous layers. This allows the transfer of stresses across a bond
which allows the
22 Vokestone to act as an extension of the parent material. .
31
CA 3019731 2018-10-03
1 Of interest to industry is VokeStone will present a superior
method of
2 grouting machinery for the above reasons. The use of epoxy grout does not
offer
3 many of the distinct advantages of VokeStone as it can only mechanically
adhere to
4 interfaces. The chemical adhesion and self-leveling characteristics of
variations of
VokeStone provide superior performance in vibration applications. Proof of
concept
6 of this was the use of the VokeStone technology to grout a tile wall with
a
7 commercial sanded grout. The process allowed easier application of the
grout but
8 the resultant mixture is far harder and more inert than standard grouts.
The
9 properties of hard and more inert were manifest as the hardened product
is not
removable during post construction phases. The chemical changes have rendered
11 the grout lines to be superior to standard soft permeable grouts. These
are the
12 same desirable properties that industrial grouts try to achieve.
13 Chemical and Thaw Resistance.
14 The accepted damage mechanism from freeze thaw action on
concrete is the expansion of water that wicks into voids in concrete. Water
that
16 expands in pores, voids and cracks exhibits very high tensile stresses,
exactly the
17 property concrete is poor at resisting. The use of water sealers on the
surface only
18 partially deals with these problems and can create a barrier that allows
damaging
19 water to collect which will result in further acceleration of damage.
Chlorides have
long been known to actively participate in degradation mechanisms as they
depress
21 the freezing point of water allowing water migration at temperatures
that will
22 exacerbate the freeze thaw damage
32
CA 3019731 2018-10-03
1 Herein,
the material disclosed herein demonstrates very strong
2 resistance to free migration of water which makes it resistant to damage
from
3 soluble
salts such as chlorides. That material is also resistant to the action of
freeze
4 thaw as
samples put into and removed from a freezer in both wet and dry conditions
over three day cycles for 2 months did not experience any degradation and the
6
interfaces were not damaged as expected with mechanical bonds. There appears
to
7 be no
capillary action of liquid water possible and would be considered to be very
8 low
permeability. The low permeability indicates that some water vapor would move
9 through
VokeStone making permeability similar to natural dolomite, or limestone. An
outdoors demonstrator was poured in August 2016 and has been through many
11 natural
freeze thaw cycles as the site of the research in in a chinook zone. At the
12 time of filing, the degraded concrete still has a well adhered VokeStone
coating.
13
14 Production of artificial Sedimentary rock.
The production of artificial sedimentary rock is another benefit of the
16
process, which depending on PCE loading of mixture can result in carbonate and
17
silicate rocks of very high crystallinity. These products that may be divided
into two
18 groups:
Art and Architectural products and Structural products. Art Products are
19
produced for the high quality surface finish common in monument and
construction
industries Functional Structural products are cement structures that need low
21
permeability such as tanks or containment ponds. Thick sections have been
poured
22 with
the bulk properties appearing homogenous throughout the mixture depth in low
33
CA 3019731 2018-10-03
1 water content mixes. Fractures of the materials, generally show sharp
edges
2 common to crystalline material as opposed to the normal granular crush of
concrete
3 test samples
4 There is a limitation where there is a float layer that forms that
must be
engineered out or allowed to form in an area where it does not affect the
final
6 product.
7 The surface finish for the Art aspect of the material shows as the
.8 concentration of PCE increases. A range of high quality surface finish
modes up to
9 and including similar appearances to fine grained granite demonstrate a
very fine
finish can be achieve by pouring directly against plastic which is very
suitable for
11 monuments such as markers, remembrance or other monuments. Tests have
shown
12 the higher PCE variations of VokeStone would lend themselves to the
intricate
13 details of sculpture and architecture very well.
14
Concrete does not normally lend itself to containment of liquids unless
16 it is lined. Tanks or other non-pressure type vessels have been produced
as
17 commodities for generations but the commonality is that they all leak
due to water
18 ingress or egress. Waterglass surface treatments have been used for long
periods of
19 times to attempt to control this problem. Tanks built out of VokeStone
would be low
permeability from the outset and could be built to very high strength levels
to reduce
21 the amount of concrete used. Cisterns, large diameter water pipes and
Septic tanks
22 are classic examples where in one circumstance we try to keep potable
water in and
34
CA 3019731 2018-10-03
1 the other where we try keep the effluent out of groundwater so
permeability is a
2 significant question. Similarly, various formulations of VokeStone,
material would be
3 of particular value in the storage of salts and nuclear waste. Whether
cast in insitu,
4 or precast, VokeStone can be applied to many engineering applications
35
CA 3019731 2018-10-03
