Note: Descriptions are shown in the official language in which they were submitted.
1 203203
HYDRAULIC COMPOSITION, FORMED PRODUCTS THEREFROM AND
SEGREGATION REDUCTION AGENT FOR HYDRAULIC SUBSTANCES
This invention relates to hydraulic compositions,
products formed therefrom and segregation reduction
agents for hydraulic substances, which compositions
contain (3-1,3-glucan, and which exhibit high fluidity,
high filling capacity, and which are very high in
resistance to segregation and useful for such as mortar
or concrete.
Technology which imparts high fluidity to concrete
and which gives it high filling capacity and makes it
possible tQ pour the concrete without consolidation has
been disclosed as the so-called "high performance
concrete" developed by Professor Okamura of the
Department of Engineering of Tokyo University (see
Doboku Seko, October 1989). Also, viscosity improving
agents have been added to concrete to prevent
segregation of the ingredients in the mortar or
concrete.
The following problems are, however, associated
with the prior art.
(a) In the case of high performance concrete, it
is necessary to carefully select the materials in order
to produce a concrete which has a very high powder
content and moreover, small amounts of viscosity
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enhancers must be used in order to prevent separation of
the concrete while it is in the fluid state. Because of
this, very careful quality control must be exercised
over the materials being used, and strict production
control is also required. It is quite difficult to
perform on-site formulation and utilization of this type
of concrete.
(b) Concrete to which antiwashout admixtures have
been added to prevent segregation has poor fluidity, so
when it is poured into highly reinforced forms, it is
very difficult to achieve proper filling without
consolidation. Also, because it has a large unit water
content, the water density declines which lowers its
resistance to carbonation, causes a high degree of
shrinkage during drying, and which, due to the large air
bubbles within, causes lowered resistance to freezing
and thawing and thus, lowered durability.
The object of this invention is to improve upon
the above described problems and provide hydraulic
compositions, products formed thereafter and separation
reduction agents, useful for such as mortar or concrete,
which offer high fluidity, high filling capacity, and
high resistance to segregation which make it possible to
pour the concrete without consolidation and still
achieve excellent durability.
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Accordingly, the present invention relates to: 1) a
hydraulic composition comprising a hydraulic cementitious
powder; 0.01 to 1.0 wt.% (3-1,3-glucan; and 0.2 to 6.0 wt.%
a superplasticizer; 2) the formed product when water is
added to said composition and the composition is then
allowed to harden over a certain period of time; and 3) a
segregation reducing agent containing ~i-1,3-glucan which is
added to hydraulic compositions.
1o The invention will be described in greater detail with
reference to the accompanying drawings, wherein:
Figures 1 through 4 are illustrative figures showing
the conditions for the filling tests.
Figure 5 shows the filling experiment test device used
in accordance with the present invention.
The cementitious powder material used in this
invention may be cement, lime, gypsum, calcium silicate,
calcium carbonate, magnesium carbonate, magnesium
trisilicate, etc. Various types of cements such as
20 Portland cement, which contain quality improving additives
such as diatomaceous, silica, earth, blast-furnace slag,
fly ash, silica fume may be used in this invention. Very
desirable effects are obtained when an ultra-fine powder is
added as a quality improving agent
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such as silica fume, in which the silica is present in
the form of an ultra fine powder (200,000 cm2/g or
higher). In other words, this ultra fine powder has a
very high surface area and is of a size which is one
order or more smaller than normally used in cements. By
so doing, the viscosity increases and this permits the
reduction in the amount of viscosity agent used in the
composition so better filling and fluidity are obtained.
As a result of reducing the amount of viscosity agent
added to the composition, it is possible to realize
improvements in the compression strength of the set
concrete.
By using Portland cement as the cementitious
powder, it is possible to make cement slate boards; or,
by using calcium silicate as the main component of the
hydraulic powder substance and using silica,
diatomaceous earth or lime in the composition, one can
prepare calcium silicate boards. The incorporation of
slag, gypsum, or lime can similarly be used to obtain a
slag-gypsum type of board. In addition, by selecting or
combining the hydraulic powder, one can prepare gypsum
board, magnesium carbonate board, or calcium carbonate
board, etc.
The (3-1,3-glucan is a polysaccharide containing
glucose which is primarily (3-1,3- bonded. Specific
examples are curdlan, paramylon, pachyman, scleroglucan,
laminalrin and yeast glucan, etc. In this invention,
curdlan is especially preferred.
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Curdlan, as described in Volume 20 Number 10, pp
49-59 (1978) in New Food Industry is primarily composed
of (3-1,3-glucoside, a polysaccharide which coagulates
when heated. When heated in the presence of water, in
5 other words, this polysaccharide coagulates (forms a
gel) .
These polysaccharides can be produced by
microorganisms which belong to the genus AlcaliQenes
or the genus Agrobacterium. Specific examples are the
polysaccharide produced by AlcaliQenes faecalis var~
myxocrenes lOC3K which is referenced in Agricultural
Biological Chemistry, Volume 30 page 196 (1966); the
polysaccharide produced by Alcaligenes faecalis var,
myxogenes lOC3K mutated bacteria NTK-a (IFO 13140) (See
Japanese Kokoku (examined) Patent No. 48-32673/1973);
or the polysaccharides produced by Agrobacterium
radiobacter (IFO 13127 or its mutant strain U-19 (IFO
12126).
Curdlan is a polysaccharide which is produced as
described above by microorganisms, but in this
invention, one may use it as-is, in an unrefined form,
or if necessary, highly refined curdlan may also be
used.
Paramylon is also one type of (3-1,3-glucan, as
described above. It is one type of stored
polysaccharide which accumulates in the cells of
Euglena, a type of microorganism. This paramylon is
described in Carbohydrate Research, 25, 231-242 (1979)
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and in Japanese Kokai Patent Nos. 64-37297/1989 and 1-
37297/1989. Unlike curdlan, paramylon powder does not
coagulate when heated, but if necessary, it can be
treated with an alkali in order to impart this property.
It is also possible to use paramylon in an unrefined
form in this invention, but it may also be used in a
highly refined form if necessary. (3-1,3-glucan derived
from microorganisms, particularly curdlan and
paramylon, when treated with alkali as described below,
and in the presence of valence 2 or higher metal ions
such as calcium ions, magnesium ions, copper ions, iron
ions, or cobalt ions, cause the formation of a [3-1,3-
glucan metal ion cross-linked gel. Glucan in this state
of being a metal ion cross-linked gel can be obtained by
dissolving the microorganism-produced (3-1,3-glucan in an
aqueous alkali solution and then bringing it in contact
with a water-soluble organic solvent to deposit the (3-
1,3-glucan, which is preferably then neutralized to a
pH of 6-7.
Another method of obtaining the metal ion cross-
linked gel form a-1,3-glucan is to freeze an aqueous
alkali solution of the above (3-1,3-glucan and then bring
the frozen solution into contact with a water-soluble
organic solvent to deposit the (3-1,3-glucan, which is
then neutralized. The glucan obtained in this manner
may be dehydrated, if necessary, to make a dry powder.
The water-soluble organic solvent used in the above
described method for depositing the glucan is preferably
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an alcohol such as methanol. The aqueous alkali
solution used to dissolve the glucan may be one prepared
with an alkali such as sodium hydroxide, potassium
hydroxide, ammonium hydroxide, etc.
The (3-1,3-glucan obtained in this manner has, as
was previously stated, the ability to form a metal ion
cross-linked gel. For example, in this invention, a
composition which contains the calcium ion is normally a
good adjuvant for this formation.
In this invention, the [3-1,3-glucan functions as a
viscosity agent. To wit, the [3-1,3-glucan increases the
viscosity of the hydraulic composition and as a result,
it helps to prevent the segregation when pouring and it
increases the workability of the concrete.
Any of the superplasticizers which are normally
used in concrete may be used as the superplasticizer in
the hydraulic composition of this invention. In this
specific~~tion, the high range AE (air-entraining) water
reducing admixture includes a fluidity enhancing agent.
Specific examples of such are the naphthalene type
agents such as highly condensed formalin naphthalene
sulfonate; melamine type agents such as sulfonated
melaminE. formalin condensate; and the carboxylic acid
type anc! lignin type agents.
ThE~se materials are used in order to increase the
fluiditSJ of the hydraulic composition which has enhanced
viscosity and to improve filling properties. Normally,
the watE,r reduction can be reduced by about two-fold
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when compared to the conventional water reducing agent.
The hydraulic composition of this invention
normally contains the above-described type of
cementitious powder, (3-1,3-glucan, and a
superplasticizer, but depending upon the application, a
fine aggregate can be further added to make a mortar
composition, and both fine and coarse aggregates can be
included to adjust the composition for concrete
applications. Any of the materials used in the prior
art as fine and coarse aggregates may be used in the
hydraulic composition of this invention.
It is further possible with the hydraulic
composition of this invention to add additional
additives which are normally used. Examples would
include AE agents, AE water reducing agents, water
reducing agents, etc.
The mixing method used when water is added to this
hydraulic substance is basically the same as the mixing
method used in the prior art for concrete. The mixing
is normally implemented in accordance with the method
wherein water is added. The preferred method of water
addition is to make the addition in two separate stages.
This method itself may be implemented in the same way it
normally is when using a general lot or batch type
addition and mixing method. The use of this lot type
addition and mixing method improves the resistance to
separation of the hydraulic composition. This permits
one to reduce the amounts of viscosity agent and
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superplasticizer which are added to the hydraulic
composition, while still achieving the desired fluidity,
resistance to segregation, and filling ability.
The following are examples of desirable hydraulic
composition ratios which can be used in this invention.
The binding material or the binder material below means
the composition of cement and its quality improving
materials.
With respect to the binding material (the total
weight of Portland cement, fly ash and blast furnace
slag total weight with a concrete per unit volume of
250-700 t~g/m3), 0.01 to 1.0~, 0.2 to 1.09s preferably by
weight of (3-1,3-glucan and 0.5 to 3.0~, 0.2 to 6.09s,
preferably, by weight of superplasticizer would be
added.
In cases where some of the binding material has
been replaced by silica fume or other silica type ultra-
fine powder, approximately 6 to 30~ by weight of silica
type powder in the binding material is preferred. With
respect to the unit binder material weight (Portland
cement, fly ash, and blast furnace slag total weight,
with a concrete unit volume of 350 to 800 kg/m3), for
example 50 to 100 kg/m~ of unit volume of silica fume,
0.02 to 1.0~ by weight of (3-1,3-glucan and 0.5 to 3'-k by
weight ~c~f superplasticizer would be added.
Following the addition of water to the hydraulic
composition of this invention, after a certain period of
time ha,~ elapsed, it is possible to achieve a formed
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product. What is meant here by "formed product" means
any article or structure made from concrete.
The concrete and other hydraulic compositions of
this invention do not require the use of a vibrating
machine, etc. to consolidate the concrete at the time
that it is poured. Even if such a device is affixed to
the forms and used, one needs it only slightly over a
short period of time. The aggregate will not separate
and it will easily fill all of the corners and hard-to-
reach places in the forms.
Because of this, (1) the forms may be of simple
construction and light in weight, making them easily
handled and offering improved safety and maintenance;
and (2) the ability to eliminate the vibrations and the
noise from them reduces the health risks to the workers
and greatly improves the working environment.
Also, since there is no bleeding or other types of
material separation during and after pouring of the
concrete, the concrete structure or casting has
excellent uniformity and longevity.
Example 1
A hydraulic composition with the mix
proportion shown in Table 1 was prepared and then tested
for fluidity, filling properties, and resistance to
segregation.
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Table 1
Maximum Water-hind-~ Sand aggro-Unit content
size ing materialgate ratio (Kg/m3)
of coarse
aggregate ratio (%) Water Cement Blast-fur-
<mm) (%) W C nace slag
B
20 30 41 150 150 150
_ Unit content
(Kg/m3)
Fine Coarse Admixture
Fly ash aggregateaggregate(Binding
material
X WT%)
F S G Superplasti-AE water Viscosity
cizer redu- agent
cing agent
200 663 940 5(1.0) 0.75(0.15) 1.5(0.3)
(Note)
Superplasticizer: Highly condenced formalin naph thalenesulfonate is used.
AE water reducing agent: Compound polyol ligninsulfonate is used.
Viscosity agent: Curdlon is used.
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Superplasticizer: Highly condensed formalin
naphthalenesulfonate is used.
AE water reducing agent: Compound polyol
ligninsulfonate is used.
Viscosity enhancing agent: Curdlan is used.
In order to test the properties, as shown in Fig.
1, multiple reinforcing bars 21 were positioned in form
2 so that they were 35 mm apart in clear distance, and
then the hydraulic composition 1 of this invention was
poured into the form.
The height of the form was 500 mm and the width was
825 mm, with a sloping top surface, and the top surface
was partially uncovered.
In this test, the hydraulic composition 1 was
simply allowed to flow inside of the form 2. Without
using any vibrations, it was possible to achieve a
perfectly filled hydraulic composition 1 within the form
.when observed after about 99 seconds. (Figs. 1 through
4)
Next, evaluations were made of the strength and
durability of the same composition. The data obtained
appears in Table 2.
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Table 2
Material Age 7 days 28 days 91 days
Compressive
Strengh 289 429 521
(kg f/cmZ)
Freezing and thawing resistance: relative dynamic
modulus of elasticity 90~ (after 300 cycles)
Amount of drying shrinkage: 340 a (after 4 weeks had
elapsed)
The numbers above are at about the same levels as
for normal concrete, and no reduction in durability was
noted.
The resistance to salt penetration, resistance to
sea water, resistance to chemical agents, and resistance
to carbonation were better than for normal concrete.
Example 2
Commercially available, regular Portland cement
(specific surface area of 3250 cm2/g), ground granulated
blast-furnace slag (4300 cmz/g) and fly ash (3000 cm2/g)
were combined in various ways to make 5 mix proportions
as shown in the following Table 3. The slump flow
filling ability measurements were carried out.
The U-shaped container shown in Fig. 5 was used in
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these tests for filling ability.
There is a concrete filling chamber A on one side
of the container, while there was a measurement chamber
B on the other side. There were windows placed in the
lower part in between the two chambers.
Steel bars 21 were placed vertically at 35 mm
intervals through these windows and the chambers were
closed off by a shutter until the beginning of the test.
For the test, chamber A was filled with the
concrete being tested and the shutter was raised. The
height H to which the concrete rose in measurement
chamber B was measured as a basis for determining the
filling ability.
The results are shown in Table 3 in the lower right
column. It was found that, with the particle size of
binding material used in this test, the minimum amount
of unit binder (cement + blast-furnace slag powder + fly
ash) needed to obtain good fluidity and filling ability
was 400 kg/m3 (200 + 200 + 0) or higher.
Keeping in mind that these results were obtained
for multiple steel bars at 35 mm intervals in clear
distance, when the interval between the steel bars is
greater than this, it would be possible to decrease the
unit binder material to a minimum of 350 kg/m3.
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Tohln 2
Mix W C B F S G
No. <Kg/m3) <Kg/m3) <Kg/m3) <Kg/m3) (Kg/m3) <Kg/m3)
1 165 150 150 200 698 884
2 170 200 200 - 925 799
3 180 225 225 - 853 802
4 180 225 225 - 853 802
5 185 225 225 - 840 802
SP BP
Mix WT% in Bind-WT% in bindingS/A Slump flowFilling
No. ing materialmaterial (%) value (cm)Height H
(WT% in water) (mm)
1 1.35 0.36 (I.1) 45 67.5 320
2 2.0 0.34 (0.8) 55 64.0 300
3 1.7 0.6 (1.5) 53 68.5 312
4 1.7 0.64 (1.6) 53 57.5 345
5 1.6 0.66 <1.6) 53 63.3 350
W: Water
C: Portland cement
B: Ground granulated blast-furnace slag
F: Fly ash
S: Fine aggrcpate
G: Coarse aggregate
SP: Superplasticizer(Hiaghly condensed formalin naphthalenesulfonate is used)
BP: Viscosity agent <Curdlan is used)
A: (S+G)
S/A: Fine aggregate proportion
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Example 3
Silica fume was used in place of fly ash of example
2 in the mixture; the mix proportions and test results
appear in Table 4.
In Table 4, Mix No. 1 is the base mix while Mix
Nos. 2 through 5 are those which used no fly ash at
all, but which used silica fume as a substitute.
The results indicated that about 450 kg/m3 of
binder (C + B + SF) was adequate. The reason is that
with this amount of binder, the fluidity by the slump
flow test dropped somewhat, but on the other hand,
filling properties were excellent and a sufficient
filling height was achieved.
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Table 4
Mix W C B F SF S G
No. (Kg/m3)<Kg/m3) (Kg/m3) <Kg/m3) (Kg/m3)(Kg/m3) (Kg/m3)
1 165 150 150 200 - 698 884
2 180 200 200 - 50 800 845
3 185 200 200 - 50 794 839
4 190 200 200 - 75 774 818
195 200 200 - 75 767 811
SP BP
Mix WT% in Bind-WT% WT% S/A Slump Filling
No. ing materialin (Kg/m3) in (%) flow Height
binding water value H
material (cm) (mm)
1 1.35 0.36 (1.82) (1.1) 45 67.5 320
2 1.95 0.40 (1.82) (1.0) 50 53.3 320
3 1.95 0.40 (1.82) (0.98)50 55.5 313
4 2.20 0.35 (1.61) (0.87)50 55.8 310
5 2.10 0.35 (1.65) (0.85)50 54.0 333
SF: Silica fume
Other symbols are the same as in Table 3.
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As described above, this invention provides the
following effects:
(A) It makes it possible to prepare a concrete
with high resistance to segregation, high fluidity, and
excellent filling ability. Because of this, vibration
of the concrete is not necessary during casting; it can
simply be poured. This reduces the number of workers
needed; through the elimination of the vibrating
operation it conserves energy in the operation, and
eliminates the need for human intervention so that it is
possible to automate or use robots for a large part of
the concrete construction operations.
(B) In addition to this invention preventing the
segregation of materials which comes from insufficient
consolidation, it also prevents the segregation of
materials which results from excessive consolidation.
Because of this, it has high water impermeability and
durability, and results in formed concrete structures
which have uniform properties and stable quality.
(C) Since it is not necessary to strictly specify
the materials used, any materials which fulfill the
specification may be used. It does not require strict
quality control, so it may be used in a wide range of
on-site operations.
(D) It is also possible to use this invention in
preparing pre-stressed concrete without conducting
vibration.
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