JPH10167797A - Hydraulic composition for injecting into floor panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hydraulic composition capable of keeping excellent fluidity over a long period, free from volume shrinkage, reduced in deflection amount, free from crack and improved in initial strength by including gypsum, cement, a plasticizer, a setting retarder and an accelerator. SOLUTION: This hydraulic composition is obtained by compounding 100 pts.wt. of a mixture of 2-70wt.% α-hemihydrate gypsum or β-hemihydrate gypsum produced as a by-product when phosphoric acid is produced by wet phosphoric acid production method using phosphate rock and sulfuric acid with 98-30wt.% cement such as fly ash cement or alumina cement with 0.05-5 pts.wt. oxycarboxylic acid-based and/or polycarboxylic acid-based plasticizer, 0.01-2 pts.wt. setting retarder of hydroxycarboxylic acids and 0.01-1 pt.wt. accelerator such as an alkali metal (bi)carbonate. Floor panel capable of controlling amplification of walking sound, excellent in damping effect and sound absorbing effect, free from sound-removing process and pollution of panel and enabling correspondence every strength by mixed ratio of cement to gypsum while keeping the thickness of steel plate constant is obtained thereby.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel floor panel used as a free access floor for laying a large number of sheets on a foundation floor such as a concrete slab of a building to form a floor. And a hydraulic composition for injection.

[0002]

2. Description of the Related Art Floor panels are made of inorganic materials such as aluminum, steel, concrete and the like, synthetic resins, and wood. These are formed in a square shape and are laid directly on the floor or in a state of being supported at a predetermined height by support legs. The free access floor was developed for the purpose of wiring under the computer room, and is now widely used as an OA floor in general offices such as intelligent buildings. 20 for floorboard
A load of about 0 to 500 kg is applied. A steel panel generally has a hollow structure in which top and bottom components are integrated by welding or clinching (Japanese Patent Application Laid-Open No. 59-55962). The floor panel generates an amplified form of walking sound due to vibrations during walking on the floor.To reduce this, and to reinforce the top plate,
There is one in which concrete is poured into the entire hollow portion of the panel. Concrete-injected steel floor panels require a large equipment cost because concrete is later injected into pre-bonded floor panels, and complete injection requires advanced technology and management. Further, since the liquid is injected from a small hole, fluidity becomes a problem, and there is a restriction on the composition of the material to be injected.

[0003] Concrete-injected steel panels are:
Further, the concrete and the top plate are peeled off during use due to the hardening shrinkage of the concrete, so that there is a problem that an abnormal sound is generated and a vibration damping and sound absorbing effect is largely reduced. One of the ways to prevent the floor noise that occurs when walking on this floor,
A process is used in which the upper surface of the floor panel is conditioned with a rubber roll at a constant pressure to take a sound in advance (sound taking process). Further, since a load of about 200 to 500 kg is applied to the floorboard, deflection, cracks, cracks, and the like are generated. General handling conditions for the strength of the concrete used require curing in water or in an autoclave to promote the strength.Concrete used in the panel injection type is injected once and then sealed, so the curing conditions Setting is generally difficult. Therefore, it takes a long time to develop the concrete strength after injection, and the hydration reaction of the cement is not completed. As a problem, a breathing phenomenon occurs inside the panel after injection,
Separated moisture is stained out from a joint portion (caulked portion) of the panel processing, and the product is contaminated, so that a manual wiping operation is required. In addition, it takes about two weeks to achieve a certain strength, and a product warehouse during that time is also required.

As a solution to these problems, Japanese Unexamined Patent Publication No. Sho 64-64 discloses a method in which inorganic particles are filled and solidified by centrifugal injection together with a binder into a floor plate comprising a top plate and a bottom plate.
Japanese Patent Application Laid-Open No. 71969/1995, and a molded article using inorganic hollow particles as an aggregate in a floor plate composed of a top plate and a bottom plate (Japanese Patent Publication No. 5-43022). In any of these, a molded body using concrete or inorganic hollow particles as an aggregate is present in almost the entire area of the gap between the top plate and the bottom plate. Therefore, there is room for improvement in terms of weight, vibration suppression and sound absorbing effects. On the other hand, the actual building floor is subject to large and small loads,
Products are classified for high-strength and low-strength applications. As one of the methods, the thickness of the panel steel plate is changed to meet the required performance. But with this method,
For strength applications, not only is the steel plate thick and disadvantageous in terms of cost, but it also involves various problems such as affecting the panel workability.

[0005]

The present invention is excellent in fluidity, maintains its performance for a long time, has no volumetric shrinkage, has a high initial strength, reduces the amount of deflection, and is effective for cracks and the like. In addition, it regulates the amplification of walking sound, has excellent vibration suppression and sound absorption effects, does not have a sound pickup process or panel contamination, keeps the steel plate thickness constant, and can respond to strength by mixing ratio of cement and gypsum. A hydraulic composition for injecting floor panels having a high level was found.

[0006]

According to the present invention, the above characteristics have been found by mixing gypsum and cement in a specific ratio. That is, the present invention relates to a hydraulic composition for floor panel injection comprising gypsum, cement, a fluidizing agent, a retarder and an accelerator.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The gypsum is not particularly limited, and any of natural gypsum and chemical gypsum can be used. Specifically, α-form, β-form of hemihydrate gypsum, α-form, β-form of anhydrous gypsum, etc., are produced as by-products when phosphoric acid is produced by a wet phosphoric acid production method using phosphate rock and sulfuric acid. It is preferable to use α-hemihydrate gypsum or β-hemihydrate gypsum. Further, α-hemihydrate gypsum to which an inorganic alkali is added after drying the α-hemihydrate gypsum is more preferable. The α hemihydrate gypsum has high strength without shrinkage, high durability without cracking and peeling off from the panel board. It also controls amplification of walking sound, has excellent vibration damping and sound absorbing effects, and is extremely productive. It is highly plaster.

As the cement, various cements such as Portland cement, blast furnace cement, fly ash cement, silica cement and alumina cement can be used. The mixing ratio of gypsum to cement is preferably 2 to 70 parts by weight of gypsum and 98 to 30 parts by weight of cement, and more preferably 5 to 50 parts by weight of gypsum and 95 to 50 parts by weight of cement. If the amount of the gypsum is less than 2 parts by weight or the amount of the cement exceeds 98 parts by weight, a decrease in strength due to insufficient curing, cracks due to drying and shrinkage, peeling, and the like are not preferred.

The fluidizing agent is not particularly limited.
The following can be used: For example, an oxycarboxylic acid type and / or a polycarboxylic acid type imparts good fluidity to cement, and the amount of addition is 0.05 to 5 parts by weight based on 100 parts by weight of the total of gypsum and cement. Preferably, more preferably, 0.1 to 2 parts by weight is suitable.
If the amount is less than 0.05 part by weight, a high-fluidity water-soluble slurry having a flow of 200 mm or more cannot be obtained at an appropriate amount of water. It is not preferable because it gives. In addition, salts of highly condensed β-naphthalenesulfonic acid formaldehyde, salts of melaminesulfonic acid formaldehyde condensate, salts of aminosulfonic acid condensate, and lignin-based fluidizing agents are used. Of these, an oxycarboxylic acid type and / or polycarboxylic acid type having high fluidity and having a setting retarding effect is particularly preferable.

[0010] Even if it is possible to impart high fluidity to the hydraulic composition by using only the components of gypsum, cement, and a fluidizing agent, since the fluidity greatly decreases with time, it is difficult to reach every corner of the floor panel. The liquidity is lost before it is reached, which is practically inconvenient. Therefore, in the present invention, in order to reduce the deterioration with time of high fluidity, hydroxycarboxylic acid and / or salts thereof (hereinafter, referred to as hydroxycarboxylic acids) as a retarder, and alkali metal salts and / or as accelerators. An alkali metal bicarbonate (hereinafter, referred to as an alkali metal carbonate or the like) is further used in combination.

The amount of the hydroxycarboxylic acid added as a retarder is 0.01 to 2 parts by weight, preferably 0.05 to 1.0 part by weight, based on 100 parts by weight of the total of gypsum and cement.
Parts by weight are preferred. If the added amount is less than 0.01 part by weight, a practical effect of preventing a decrease in fluidity cannot be obtained, which is not preferable. On the other hand, if it exceeds 2 parts by weight, the setting time becomes extremely long, and the strength expression is also deteriorated.

Examples of hydroxycarboxylic acids include malic acid, sodium malate, potassium malate, lithium malate, tartaric acid, sodium tartrate, potassium tartrate, lithium tartrate, citric acid, sodium citrate, thulium citrate, citric acid Lithium and the like can be mentioned. Among these, citric acid and its salts are particularly preferred.

The amount of the alkali metal carbonate used as an accelerator is 0.01 to 1 part by weight, preferably 0.05 to 0.1 part by weight, based on 100 parts by weight of the total of gypsum and cement.
3 parts by weight are preferred. If the amount is less than 0.01 part by weight, the effect of accelerating the curing is small, and if it exceeds 1 part by weight, the curing speed is too high, the workability is deteriorated, and the water resistance is also adversely affected. The role of alkali metal carbonates
In addition to promoting the effect of preventing the fluidity from deteriorating with time, the rise in strength from the start of curing is increased, and such effects are not sufficient if the amount used is other than the above. Examples of the alkali metal of carbonate or bicarbonate include lithium, sodium, potassium and the like.

The alkali to be added to the α-hemihydrate gypsum is not particularly limited as long as it is both organic and inorganic. N, which is preferably an inorganic compound,
hydroxides such as aOH, KOH, Ca (OH) ₂ , CaC
Carbonates such as O ₃ and K ₂ CO ₃ and basic oxides such as Na ₂ O, CaO, and MgO that form hydroxides in an aqueous solution;
Ammonia gas / solution may be mentioned, and two or more kinds may be mixed. As a matter of course, as the inorganic alkali, a hardening inorganic material exhibiting alkalinity such as cement may be added and mixed.

An aggregate may be added to the composition having the above ratio, if necessary, and an appropriate amount of water may be added to obtain a hydraulic composition (mortar) for injecting floor panels having desired performance. it can. Incidentally, the hydraulic composition of the present invention, silica sand, calcium carbonate, fly ash, by blending an inorganic filler such as blast furnace slag, it is possible to obtain the effect of increasing the economic effect and further improve the wear resistance. it can.
The amount used is about 5 to 50 parts by weight, preferably 10 to 100 parts by weight of gypsum and / or cement.
-30 parts by weight. In addition, the prior art is
It is also possible to use inorganic particles and / or inorganic hollow particles as an aggregate (perlite, expanded shirasu, etc.).

[0016]

The present invention will be described below in detail with reference to examples. Parts represent parts by weight unless otherwise specified. Example 1 α-hemihydrate gypsum (hereinafter referred to as α) in which 0.4 part of alkali (slaked lime) is added to 100 parts of α-hemihydrate gypsum by-produced when phosphoric acid is produced by wet phosphoric acid production using phosphate rock and sulfuric acid. 60 parts of hemihydrate gypsum slurry), 40 parts of ordinary portland cement, 2 parts of "Mariarim AKM60F" (trade name of Takemoto Yushi Co., Ltd.) containing polycarboxylic acid (maleic anhydride) as a fluidizing agent as a main component, citric acid One part of sodium, 0.2 part of sodium carbonate, 30 parts of perlite and 50 parts of water were blended, and stirred at 1500 rpm for 20 seconds using a stirrer. The non-impact flow of these slurries, the flow over time, and the strength were measured. The results are shown in Table 2.

The evaluation of each physical property was measured as follows. (1) Flow: Using a flow cone specified in JIS R5201, placed on a smooth acrylic resin plate, the kneaded slurry was poured into the flow cone, and the spreading diameter in a no-impact state was measured. The time-dependent flow was measured in the same manner 30 minutes after kneading with stirring. *: Does not flow. (2) Fillability: A container made of steel plate, a 50 x 50 x 3 cm sealed type container with a hole with a diameter of 2 cm at the top and a mortar inlet, and a 2 mm hole on the same surface with an air vent. It was created. Using a hammer, this container was used to make several projections and depressions of an appropriate size. A slurry was supplied to the inside of the container for a certain period of time (15 seconds) using a mono pump, and the hole was plugged and sealed. After curing for 14 days in a room at a temperature of 60 ° C. and a relative humidity of 60%, several sections were cut, and the cross section was visually inspected to determine the extent of the gap. Judgment standard ○: No gap ×: With gap (3) Deflection measurement: Using a steel plate with a thickness of 1.2 mm and 0.8 mm, a mortar with a hole of 2 cm in diameter opened at the top of a 50 × 50 × 3 cm sealed container Inlet and 2 on the same surface
A steel plate panel container with a hole of mm and air vent was prepared. The slurry is supplied to the inside of the steel plate panel container for a certain period of time (15 seconds) using a Mohno pump, the hole is plugged and sealed, and after curing in a room at a temperature of 20 ° C. and a relative humidity of 60% for 14 days, Tawami The measurement was performed. As shown in Fig. 1, the measurement method was performed at a specified location (Fig. 2) on the panel steel plate.
A 0 mm indenter was placed, a load of 5000 N (Newton) was applied from above, a deflection was measured, and the average was taken. (4) Flexural strength: Performed according to JIS R 9112. A test piece (30 × 40 × 1 cm) was heated at a temperature of 20
Cured in a room at 60 ° C and a relative humidity of 60% for 14 days, placed on a support (35 cm wide) of a bending strength tester (Marubishi Scientific Machinery Co., Ltd. GBL-500), and aligned the suspension with the center of the specimen. The suspension is pressurized at 250 N / min. The force at which the specimen cracks is defined as the bending strength. (5) Floor noise: The entire surface of the product panel is mechanically habituated for a certain period of time with a rubber roll having a certain pressure, and the sound generated during that period is determined by human hearing. (6) Contamination of the product panel: The appearance of the product is visually judged.

Example 2 The same procedure as in Example 1 was conducted except that 60 parts of α-hemihydrate gypsum was changed to 40 parts and 40 parts of ordinary Portland cement was changed to 60 parts. The composition is shown in Table 1, and the evaluation of physical properties is shown in Table 2.

Example 3 The procedure of Example 1 was repeated, except that the α-hemihydrate gypsum was changed to 60 parts and the ordinary Portland cement was changed to 40 parts to 80 parts. The composition is shown in Table 1, and the evaluation of physical properties is shown in Table 2.

Example 4 60 parts of α hemihydrate gypsum was replaced by 30 parts of β hemihydrate gypsum, 40 parts of ordinary Portland cement was changed to 70 parts, 2 parts of fluidizer were changed to 4 parts, and retarder was changed to 1.5 parts. The procedure was performed in the same manner as in Example 1 except that 50 parts of water was changed to 60 parts. The composition is shown in Table 1, and the evaluation of physical properties is shown in Table 2.

Comparative Example 1 The procedure of Example 1 was repeated, except that the fluidizing agent was changed to 0 parts. The composition is shown in Table 1, and the evaluation of physical properties is shown in Table 2.

Comparative Example 2 The procedure of Example 1 was repeated except that the amount of the retarder was changed to 0 parts. The composition is shown in Table 1, and the evaluation of physical properties is shown in Table 2.

Comparative Example 3 The procedure of Example 1 was repeated except that the amount of the accelerator was changed to 0 parts. The composition is shown in Table 1, and the evaluation of physical properties is shown in Table 2.

Comparative Example 4 The procedure of Example 1 was repeated, except that the α-hemihydrate gypsum of Example 1 and the ordinary Portland cement were changed to 60 parts and 100 parts of the ordinary Portland cement, respectively. The composition is shown in Table 1, and the evaluation of physical properties is shown in Table 2. Comparative example 5 It carried out similarly to Example 1 except having set the fluidizing agent of Example 4 to 0 part. The composition is shown in Table 1, and the evaluation of physical properties is shown in Table 2.

[0025]

[Table 1]

[0026]

[Table 2] ♯: using 1.2 mm and 0.8 mm steel plates

[0027]

According to the constitution of the present invention, since the fluidity is high and the decrease in the fluidity with time is small, the pumping and injection into the inside of the floor panel are easy, and the filling property and workability are greatly improved. In addition, by mainly using gypsum, the curing speed after injection and filling is high, there is no volume shrinkage, and the initial strength is high, so that the top plate of the floor panel and the filler are separated, the amount of deflection is small, and cracking occurs. It has excellent durability against cracks and the like.

[0028]

[Brief description of the drawings]

[Figure 1] Tawami measurement method

[Figure 2] Sketch from top

[Explanation of symbols]

 1 Indenter 2 Specimen 3 Support

Continuation of the front page (51) Int.Cl. ⁶ Identification code FI C04B 24:06 22:10) 111: 62 (72) Inventor Hirotaka Yoshida 7-1-1, Hikoshimasakomachi, Shimonoseki-shi, Yamaguchi Prefecture Mitsui Toatsu Chemicals Inside the corporation

Claims (11)

[Claims] 1. A hydraulic composition for floor panel injection comprising gypsum, cement, a superplasticizer, a retarder and an accelerator. 2. The hydraulic composition according to claim 1, wherein the gypsum is α-hemihydrate gypsum by-produced when phosphoric acid is produced by wet phosphoric acid production using phosphate rock and sulfuric acid. 3. The hydraulic property according to claim 1, wherein the gypsum is α-hemihydrate gypsum in which an alkali is added to α-hemihydrate gypsum by-produced when phosphoric acid is produced by wet phosphoric acid production using phosphate rock and sulfuric acid. Composition. 4. The hydraulic composition according to claim 1, wherein the gypsum is β-hemihydrate gypsum. 5. The hydraulic composition according to claim 1, comprising 2 to 70 parts by weight of gypsum and 98 to 30 parts by weight of cement based on 100 parts by weight of the total of gypsum and cement. 6. The hydraulic composition according to claim 1, wherein the fluidizing agent is an oxycarboxylic acid type and / or a polycarboxylic acid type. 7. A method according to claim 1, wherein 0.05 to 5 parts by weight of a fluidizing agent is used based on 100 parts by weight of the total of gypsum and cement.
The hydraulic composition as described in the above. 8. The method according to claim 1, wherein the retarder is hydroxycarboxylic acid and / or
2. The hydraulic composition according to claim 1, which is a salt thereof. 9. The hydraulic composition according to claim 1, wherein 0.01 to 2 parts by weight of a retarder is used based on 100 parts by weight of the total of gypsum and cement. 10. The hydraulic composition according to claim 1, wherein the accelerator is an alkali metal carbonate and / or an alkali metal bicarbonate. 11. The hydraulic composition according to claim 1, wherein the accelerator is used in an amount of 0.01 to 1 part by weight based on 100 parts by weight of the total of gypsum and cement.