JPS63225564A - Cement admixing material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to cement admixtures, and more specifically, the present invention relates to cement admixtures that eliminate the viscosity of mortar and concrete (hereinafter simply referred to as concrete), This invention relates to a cement admixture based on a high-performance water reducing agent that prevents corrosion, etc., and promotes its general use in general civil engineering/architectural structures and concrete loading.

[Conventional technology and its problems]

Conventionally, high-performance water reducers have a tendency to retard setting and cause air entrainment even when added to cement in relatively large amounts, compared to ordinary water reducers such as lignin sulfone salts and polyols, which are commonly used in ready-mixed concrete factories. It has the good properties of being able to easily form high-strength concrete with low water loss and high water loss.

However, in the case of t-concrete with the addition of a high-performance water-reducing agent, when compared with the case of high-performance concrete with the addition of a normal water-reducing agent, completely different t-characteristics are exhibited in unhardened concrete. Specifically, (1) It is highly viscous like starch syrup. (2) The following problems occur during construction, such as non-pleasing (floating water).

In other words, due to the property of strong viscosity, if the construction site is sloped, there is a problem that the concrete may sag or slide downwards, making it impossible to perform the work. This poses a problem in that water in the concrete dries out before the concrete hardens, causing drying cracks due to plastic shrinkage. The timing of this much-coveted phenomenon varies depending on the outside temperature, humidity, and wind force at the time of construction, but it usually occurs as quickly as 1 degree in 20 to 30 minutes.
The desired width is as large as 2 to 5 meters. Furthermore, due to its strong viscosity and non-puzzling properties, coarse aggregate does not float to the surface of the concrete, and when it dries, a skin forms on the concrete surface, making it difficult to press the concrete with a trowel. However, the problem arises that the surface finish becomes poor. On the other hand, even if you try to improve the finish by pouring water on the concrete surface, the floating of the aggregate in the concrete is mainly due to the strong viscosity, so the aggregate cannot sink. On the other hand, the high-performance water reducer in the concrete floats to the surface, causing uneven coloring and worsening the surface finish (smoothness and uneven coloring).

As mentioned above, high-performance water reducers are extremely superior to ordinary water reducers when producing high-strength concrete, but on the other hand, they have the problems mentioned above. It is not widely used as a general-purpose product in concrete products factories, and it is not widely used in concrete product factories because it causes drying cracks during pre-laying and poor surface finish for products with large casting areas, such as cast members during pre-preparation. However, there was a strong need for a solution to this problem.

However, there is currently no technology that directly solves these problems and promotes the general use of high-performance water reducers. We conducted intensive studies from the viewpoints of eliminating the viscosity of concrete, fixing dry cracks before hardening, and improving the surface finish of concrete. By blending these with inorganic #A of alkali metals and alkaline earth metals, we obtained the knowledge that the above-mentioned problems could be solved and completed the present invention. Means for achieving this] That is, the first aspect of the present invention is to use a high performance water reducing agent, bentonite,
A cement admixture containing one or more inorganic substances selected from the group consisting of phlogopite, graphite, boron nitride, zeolite, activated carbon, coal shell, diatomaceous earth, pearlite, and acpulgite. The second aspect of the present invention is a cement admixture containing an alkali inorganic salt.

The present invention will be explained in detail below.

The high performance water reducing agent of the present invention refers to polyalyl-based lylyl sulfonate, melamine formalin resin sulfonate, and the like. Generally, commercially available high-performance water reducers have one of the above as their main ingredients, but even those that do not have the above as their main ingredients have strong viscosity and non-puzzling properties. It can be used as a superplasticizer of the invention.

Examples of polyalkylaryl sulfonate salts include naphthalene sulfonic acid formalin condensate, methylnaphthalene sulfonic acid formalin condensate, and anthracene sulfonic acid formalin condensate. Name "Mighty 100", "Mighty 150"
J' etc., Daiichi Kogyo Seiyaku c stock), product name "Cellflow 11"
0PJ etc., Takemoto Yushi c stock), product name "Pole Fine 5"
1ONJ, etc., Deyu Kokusaku Pulp C Co., Ltd.) Product name: Sunflor S Tama r Sunflow P8RJ, etc., Denki Kagaku Kogyo 1 Co., Ltd.),
There are product names such as r FT-500J, and melamine formalin resin sulfonate series include Showa 111 stock), product names "Melment F-104, r Melment F-20J"
, Nisso Master Builders Co., Ltd., product name rNL-40
00J etc. are mentioned.

The blending amount of these high performance water reducing agents is 0.25 to 5% by weight based on cement, calculated as solid content. If it is less than 0.25% by weight, the original effects such as water reduction properties as a high-performance water reducing agent cannot be expected, and even if it exceeds 5% by weight, no improvement in water reduction rate can be expected and it is not economically viable. Undesirable. The preferred amount is 0.35 to 3% by weight, and the most preferred amount is 0.4% by weight.
It is 5 to 2% by weight.

According to the present invention, one or more inorganic substances selected from the group consisting of bentonite, phlogopite, graphite, talc, boron nitride, zeolite, activated carbon, coal shell, diatomite, pearlite, and attapulgite are hereinafter simply referred to as inorganic substances. )
When mixed with a high performance water reducing agent and added to concrete, it has the role of lowering the viscosity of concrete, preventing water evaporation, suppressing the occurrence of scratches, and at the same time improving surface finish. It is.

Bentonite (including organic bentonite), phlogopite, talc, and the like have a crystal structure f in which atoms are arranged particularly densely and the t-planes are arranged parallel to each other with a rather weak bonding force.

In addition, zeolites, coal shells, etc. have relatively high porosity and have a large adsorption capacity, and can exhibit the following characteristics.

It is preferable that the amount of inorganic material added to cement is approximately 0.1 to 15% by weight, but depending on the type of inorganic material, concrete temperature, and amount of high performance water reducing agent,
Since the facultative blending amount of inorganic substances varies, it cannot be uniformly prescribed. Even taking into account various variable factors, if the amount is less than 0.1% by weight, no effect can be expected, and if it exceeds 15% by weight, the water reduction rate of the high performance water reducing agent may be extremely reduced, so it is preferable. do not have.

For example, 1.0% by weight of high performance water reducer based on cement,
When the concrete temperature is t20°C, bentonite exhibits a 1.0 to 6 weight light effect on cement, although this varies depending on the degree of swelling, and zeolite exhibits a 5 to 10 weight range. Also, if the temperature is higher than this, the effect can be exerted with a small amount, and if the temperature is lower, the opposite is true.

The inorganic substance is not particularly limited in terms of particle size, for example, it must be 5μ or less,
The particle size of the commercially available product can be used as is, and there is no need to make any special adjustments. For example, with bentonite, if the degree of swelling is the same, there is no difference in effectiveness and durability even if the bentonite is made of 200 mesh or 400 mesh.

Alkaline inorganic salt (hereinafter simply referred to as inorganic salt) is Ll.
Alkali metals such as Na-K, alkaline earth metals such as Ca and Mg, carbonates, bicarbonates, sulfates, bisulfites, sulfites, bisulfites, nitrates, nitrites, chlorides,
Hydroxides, silicates, aluminates, phosphates, borates, thiosulfates a! Examples include salts, rhodanates, Na-alums, and the like. Among these, the preferable one is Ll・N
a.K carbon #I salt bicarbonate, silicate, aluminate,
These are hydroxides, alums, and Mg sulfates.

These inorganic salts have the role of promoting the effects of inorganic substances, and their blending amount is at most 1.0% by weight based on K.
(anhydrous equivalent). If the blending amount exceeds this range, the blending effect may not be improved any further, or the inorganic substances may cause false setting or rapid setting, which is not preferable. A particularly preferred range is 0.1 to 0.5% by weight.

The mixing method and compounding method of each material of the present invention are not particularly limited, and each material may be mixed in advance within the range of blending amount to cement and added, or a high performance water reducing agent may be added. If it is in liquid form, it may be used as a slurry composition by adding an appropriate amount of water, or even if each material is added separately during concrete construction, the effect will not change at all.

The cement to which the cement admixture of the present invention is added includes:
In addition to various portland cements and mixed cements, examples include hydraulic materials based on slag powder, modified portland cement and alumina cement, etc., as well as gypsum, dolomite silaster, etc.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples.

Example 1 Based on the concrete formulation shown in Table 1, the types and amounts of high-performance water reducing agents and inorganic substances were varied, and concrete was kneaded and tested for viscosity and dryness. In addition, the smoothness due to the trowel finish was visually observed.

The viscosity measurements were carried out using a Wilstick type plastometer +- shown in the drawing with only the sample container modified for use with concrete.

This device and test method are as shown in the drawings.
11>, and after filling the sample container 3 with concrete and smoothing it, add the color 4.
Set it on the jointing device 5 degrees. Next, fix it once with screw 5 so that the tip of the plunger is in contact with the concrete surface at the center of the sample container.

After that, select an appropriate way) t- and put it on. - Release the fixation of the plunger, and the plunger will be 10cIIL and 5a.
Two types of weights are selected so that they penetrate to around R and stop, and the weight weight when the 7.5α Zojinja penetrates and stops is determined by proportional calculation.

It is determined that the viscosity has disappeared.

The coveted observation is concrete, 100100LX5
Packed in a wooden box with 0Wx10 squeezed out by 10 Clll from both sides of the center so that the desired item is placed in the center of the butterfly shape.
I immediately finished the work with a trowel and left it indoors, and also observed the state of the finish.

Table-1 Materials/cement used: Denki Kagaku Kogyo 1 Co., Ltd.) Ordinary Portolan P cement/Sand: Himeyo, Niigata Prefecture, river sand/crushed stone: Same as above, crushed stone, high performance for the concrete mix in Table-1 When a water reducing agent is added, a smaller unit amount of water is required to obtain the same slump, but without the need to correct cement, sand, crushed stone, etc.
Simply reduce the unit water volume to match the slump. Further, all of the cement admixtures of the present invention added to cement are added by weight.

Concrete is marked with a forced mixing stain with a capacity of 1001 - 60
A! Minute Conch IJ-) 'f: Knead for 3 minutes and perform the prescribed test. The results are shown in Table 2.

All of the high performance water reducing agents and inorganic substances used in Table 2 are commercially available and easily available.

Materials used High performance water reducing agent-8: "Cellflow 110PJ powder, -
Realkylaryl sulfonate β-B: “Mighty 100J# ##
-C: "Mighty 150" liquid (solid content 42 width),
! y-p: r Ball Fine 51ONJ liquid (solid content: 44), polyalyl allyl sulfonate system #-H: "Sunflow PER120J liquid, (
solid content 44 cm), I # -F: rFT-500J liquid (solid content 45%), β # - (): "Melment T-10J powder, melamine formalin resin sulfonate, z -H: "Melment F -20J#, ##
-x: l"self o -CA155P J powder, lylylsulfonate-based inorganic substance in polyalcohol -a-1: Bentonite, swelling degree 15 according to manufacturer's nominal ACC method # -a-2: # % # 25
## -b: Phlogopite powder (pulverized scrap mica) # -c # Graphite 1 - + 1: Talc (talc) -e: Boron nitride #, -f: Zeolite 1 - g: Activated carbon # - h: Coal shell (pulverized to 200 mesh) I -1: Diatomaceous earth (crystal form: Kossinodisc type) -j: Pearlite tt - To: modified bentonite # -1: Attapulgite 1 paper Powder for coating) The concrete temperature is 20℃, and the Penetra ♂ lity measurement is 20℃.
℃ room, and the desired observation is 30℃, RI'160
% and observed after 5 hours in the room.

As is clear from Table 2, if only a high performance water reducing agent is used, the viscosity of the concrete will increase as the amount of water reducing agent increases.
It is shown that the weight of the ninth weight to be penetrated by the plunger T7.5cm increases, it is easier to enter the plunger, the width of the crease is large, and the finishing quality is also poor.

In the case of round yarn made by blending the high performance water reducing agent and inorganic substance of the present invention, the high performance water reducer has a weight ratio of 0.25 or more to the cement, and the inorganic substance has a weight ratio of 0.1 or more to the cement, although this varies depending on the type. The weight of the plunger that penetrates 7.5α becomes smaller. In other words, the gateposts of Nku'J-to have lowered the desired resistance (when the viscosity of the concrete is lowered, it is difficult to form a skin on the concrete surface even when it dries) and finishability. improves.

In addition, in the present invention, even if the high-performance water reducing agent is blended in an amount exceeding 5% by weight, no improvement in the water reduction rate is expected, and furthermore, even if the inorganic substance is blended in an amount exceeding 15% by weight, the water/cement ratio increases. It can be easily inferred that the improvement effect aimed at by the present invention cannot be expected solely by this.

Note that Experiments/161 to 9 are comparative examples. The finish is 3 levels: ``S'' has a rough texture on the surface of the mortar, and ``O'' has a fine mortar texture that looks clean.

Example 2 A plunger penetration test was conducted under the same conditions as in Example 1 by adding different types and amounts of inorganic salts to the formulation of Experiment 420. The results are shown in Table-3.

In addition, inorganic salts are mixed with cement according to their external weight, those with crystallized water are converted to anhydride, and commercially available first class reagents are used. %20 of the present invention was tested six times, and compared with this, when inorganic salt was used in combination with the following:
When the plunger penetrates 7.5 cIt and stops, the weight weight becomes even smaller. In other words, it is understood that the viscosity further disappears.

〔Effect of the invention〕

As mentioned above, by using the cement admixture of the present invention, the problems that arise when a high-performance water reducing agent is added alone are (1) high viscosity (2) drying required before hardening ( 3) Covers problems such as poor finishing properties, and provides concrete that does not sag on slopes with plastic, has high resistance to drying, and has a good surface finish, making it the basis of high-performance water reducing agents. It does not significantly impair the water reduction rate.

[Brief explanation of the drawing]

The drawing is a schematic diagram of an apparatus for measuring sagging property (penetration) of the present invention. 4: Color, 2: Weight, 5: Screw, 6: Scale.

Claims (2)

[Claims] (1) High performance water reducing agent, bentonite, phlogopite, graphite,
A cement admixture comprising one or more inorganic substances selected from the group consisting of talc, boron nitride, zeolite, activated carbon, coal shell, diatomaceous earth, perlite, and attapulgite. (2) High performance water reducing agent, bentonite, phlogopite, graphite,
A cement mixture comprising one or more inorganic substances selected from the group consisting of talc, boron nitride, zeolite, activated carbon, coal shell, diatomaceous earth, perlite, and attapulgite, and an alkali inorganic salt. Material.