JP4462474B2 - Aqueous permeable composition and method for surface strengthening of concrete - Google Patents

Description

【００２３】
評価方法
撥水性／水１０ミリリッターを散布して、撥水状態を観察する。
透水性／ＪＩＳＡ６９０９のＢ法（２４時間）により測定する。
試験体を水平に保持し、ロート状の透水試験器具をシリコーンシーリーング材により止めつけ、４８時間以上放置したのち、２０±２℃の水を試験体の表面から高さ２５０ｍｍまで入れ、その時の水頭の高さと２４時間後の水頭の高さとの差を求める。
中性化／５％の炭酸ガスを含む雰囲気に、２０℃、６０％ＲＨの環境において３０日放置したのち、表面の中性化を下記の道路公団規格（ＪＨＳ３１１−１９９２）により測定する。
道路公団規格（ＪＨＳ３１１−１９９２）
コンクリートコアの割裂面を測定面として使用し、▲１▼測定面にフェノールフタレン１％エタノール溶液を噴霧する。▲２▼着色及び非着色部分の境界をマジックで記入する。含水率が高いコンクリートの場合は読み取りを２日後に行う。▲３▼表面から中性化深さの最大および最小を測定する。▲４▼境界を透明なビニールシートにトレースする。▲５▼非着色部分の面積を測定する。
計算
Ｃ＝ Ａ／Ｌ
Ｃ： 平均中性化深さ ｍｍ
Ａ： 非着色部分の面積 ｍｍ^２
Ｌ： 測定表面の長さ ｍｍ
耐磨耗性／ＪＩＳＫ７２０４に規定の測定法による。磨耗輪Ｈ２２、荷重１ｋｇ、１０００回転の条件における磨耗重量を測定する。
【００２４】
【発明の効果】
本発明になる水性浸透性組成物は、珪酸ソーダ並びにメチルケイ酸カリウムとを含有するもので、コンクリートに対して速やかに浸透し、珪酸ソーダがコンクリート中のＣａ、Ｍｇなど多価金属化合物と反応して珪酸塩を形成して空隙を充填するとともに、メチルケイ酸カリウムが空気中の炭酸ガスと反応してポリシリケートが形成する。このためコンクリートの空隙充填効果と撥水性が得られるとともに透水性が低くなるため、構造物の防水性を大幅に向上させることができる。
また、コンクリート表面が強化されて耐磨耗性などが大幅に向上する。前記実施例、比較例で確認されるように、従来の水ガラスにより表面処理されたコンクリートが雨水等により水洗された場合、耐磨耗性が大幅に低下するが、本発明の水性浸透性処理剤により処理した場合には、雨水等により水洗されても耐磨耗性が低下することがない。このため駐車場の床など水洗作業がされる場所への使用には効果的である。
同時にメチルケイ酸カリウムが空気中の炭酸ガスと反応してポリシリケートを形成するためにコンクリートの中性化が抑制され、前記のようなコンクリート構造物の劣化やヒビの発生を無くすことができコンクリート構造物の長寿命化に役立つ。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an aqueous permeable composition used for reinforcing a surface of concrete, mortar, concrete block or the like and a method for reinforcing the surface of concrete.
[0002]
[Patent Document 1]
JP-A-2002-338375 [Patent Document 2]
Japanese Patent Application Laid-Open No. 2001-207118
[Prior art]
Floors made of concrete, mortar, concrete blocks, etc. are inevitably deteriorated over time due to erosion due to loads, chemicals, and abrasion due to friction. In recent years, a pump car has been widely used for concrete driving work. Although placing concrete with a pump car simplifies construction, it is easy to place in a soft-kneaded state with increased water content to make it easier to drive. If the amount of water is greater than a predetermined amount, the shrinkage of the concrete is increased, which tends to cause cracks, and as a result, air and rainwater penetrate. On the other hand, when the amount of water is larger than a predetermined amount, air remains after the water is diffused and air or rainwater penetrates. In addition, the concrete structure is cracked because the foundation part is about 15 ° C in the ground, but the rooftop or outdoors are exposed to a large temperature cycle such as solar radiation in summer and cold radiation in winter. . When rainwater or air penetrates into concrete through such cracks or bubbles, the alkali component reacts with carbon dioxide and neutralization proceeds. ”Will decrease”, “Rainwater penetrates and the rust and corrosion of the rebar progress further”, “Some parts of the structure fall off due to cracking, and the appearance is damaged”. It was.
[0004]
As a method of avoiding such deterioration and neutralization, a method of covering the surface with an epoxy resin, a urethane resin, an acrylic resin, or the like has been attempted. However, since such surface reinforcement is a polymer substance, it does not have sufficient permeability to concrete, mortar, etc., and even if the surface of the structure is coated, problems such as coating deterioration, peeling, and swelling There is.
[0005]
On the other hand, concrete surface reinforcement by silicate such as water glass is known. Silicates such as water glass are excellent in permeability to concrete, mortar, etc., but since the raw material is silicate with a molar ratio of silicon to alkali of 4 or less, the alkalinity is strong and stays in the voids in the concrete. There is a concern that cracking occurs due to the alkali-aggregate reaction, and the alkali of the accumulated water is high, so that the carbonation rate of concrete increases and the neutralization is promoted.
In addition, when water is applied in a state where the reaction with calcium of silicate such as water glass is insufficient, there is no water repellency, and it takes time to obtain an effect with delayed effect, Since the protective layer is formed by combining with an alkali component of cement (such as calcium hydroxide), there is a problem that the effect cannot be obtained with old concrete from which calcium hydroxide has disappeared.
[0006]
In addition, methods using silicofluoride compounds such as magnesium silicofluoride and zinc hexafluoride were also adopted, but they are toxic because of the fluorine compounds, causing environmental pollution, and corrosive. There was a problem such as. Further, the fluoro compound has a problem that it is difficult to obtain an effect on old concrete for the same reason as the silicate.
[0007]
[Problems to be solved by the invention]
An aqueous osmotic composition that is excellent in permeability to concrete, mortar, etc., and has improved points such as neutralization and deterioration, and does not dissolve even when splashed with water. It provides a surface strengthening method for objects and concrete.
[0008]
[Means for Solving the Problems]
The present invention relates to an aqueous permeable composition comprising sodium silicate and potassium methyl silicate, which has been developed in order to solve the above-mentioned problems, and a surface strengthening method for concrete, which will be described in detail below.
[0009]
Sodium silicate employed in the present invention is one represented by Na2_rei-XSi_〇, molar ratio, Si_〇 ₂ / NA ₂ O are mentioned those of 2 / 1-1 / 4.
Sodium silicate reacts with polyvalent metal ions such as Ca, Mg, Al and Ba in cement such as concrete and mortar to form insoluble silicate metal hydrate, metal hydroxide, etc., concrete, mortar, etc. The space inside can be filled to improve the strength.
[0010]
Methyl potassium silicate is used as an aqueous solution of about 54 wt% obtained by dissolving potassium methyl silicate CH ₃ Si (OH) ₂ OK in water, and is used as a methyl silicate polymer containing about 34 wt%. Potassium methyl silicate reacts with carbon dioxide in the air to form polymethyl silicate (CH ₃ SiO _3/2 ), thereby obtaining water repellency.
[0011]
The blending ratio of sodium silicate and potassium methylsilicate is 100/1 to 100/20. If it is less than 100/1, the water repellency is insufficient, which is not preferable. On the other hand, if it is 100/20 or more, repellency becomes remarkable, which is not preferable.
The concentration is suitably 5 to 40% by weight. If it is 5% by weight or less, even though the penetration into concrete, mortar and the like is good, the strengthening effect which is the original purpose cannot be expected. On the other hand, if the concentration is 40% by weight or more, the concentration is too high, and the tendency of insufficient permeability to concrete, mortar, etc. is observed, which is not preferable.
[0012]
In addition, if necessary, for coloring, various pigments such as known inorganic pigments such as titanium oxide, carbon black, chromium oxide, gun blue, azo pigments, condensed multiple-reduction pigments, quinacridone pigments, cyanine blue, cyanine green, etc. A desired hue can be imparted using an organic pigment or a known organic coloring compound, ink, natural or synthetic dye alone or in combination of two or more.
[0013]
The aqueous osmotic composition prepared by mixing such a compounding material is applied to a surface of concrete, mortar, etc. in an amount of 0.1 to 0.5 kg / m 2 by an application means such as a brush, a roller brush, a mop, or a spool. Strengthening is planned.
Moreover, it is preferable that the coating is applied a plurality of times rather than once so as to penetrate into concrete, mortar or the like.
[0014]
Structures finished from concrete, such as floors, mortar, etc. are used in a state where the aqueous permeable composition is applied and reinforced, or waterproofed with a resin waterproof layer, fiber reinforced resin layer, etc. It can be used as a surface-enhanced state on a floor, a parking lot floor, a factory or warehouse floor.
[0015]
Hereinafter, the present invention will be described in detail according to examples and comparative examples. The blending ratio is described in parts by weight. Note that the present invention is not limited to the right.
[0016]
Example 1
Concrete 30 days after placing a 26.5% aqueous permeable composition of No. 3 water glass (solid content 50%) 50 parts, potassium methylsilicate aqueous solution (solid content 50%) 3 parts, water 47 parts The surface was coated with 0.3 kg / m ² brush. Table 1 shows the results of the evaluation tests described below for those cured for 10 days after application (without washing) and those cured for 9 days after being immersed in water for 1 hour after curing for 1 day. It was on the street.
[0017]
Example 2
Table 1 shows the results of an evaluation test performed in the same manner as in Example 1 except that 8 parts of the potassium methyl silicate aqueous solution and 42 parts of water were used.
[0018]
Example 3
Table 1 shows the results of an evaluation test conducted in the same manner as in Example 1, except that 30 parts of No. 3 water glass and 67 parts of water were used.
[0019]
Comparative Example 1
An aqueous permeable composition having a concentration of 25% was prepared by mixing 50 parts of No. 3 water glass and 50 parts of water, and the results of the evaluation test as in Example 1 are shown in Table 1.
[0020]
Comparative Example 2
An aqueous permeable composition having a concentration of 15% prepared by mixing 30 parts of No. 3 water glass and 70 parts of water was prepared. The results of the evaluation test as in Example 1 are shown in Table 1.
[0021]
Comparative Example 3
The concrete cured for 30 days after placing was designated as Comparative Example 3.
[0022]
[Table 1]

[0023]
Evaluation method Water repellency / spray 10 ml of water to observe the water repellency.
Water permeability / Measured by B method (24 hours) of JIS A6909.
Hold the test piece horizontally, fix the funnel-shaped water permeability tester with a silicone sealing material, leave it for 48 hours or more, and then add 20 ± 2 ° C water to the height of 250 mm from the surface of the test piece. Find the difference between the head height and the head height after 24 hours.
Neutralization: After leaving in an atmosphere containing carbon dioxide gas at 5 ° C. for 30 days in an environment of 20 ° C. and 60% RH, the neutralization of the surface is measured according to the following Highway Public Corporation Standard (JHS 311-1992).
Highway public corporation standard (JHS311-1992)
Using the split surface of the concrete core as the measurement surface, (1) spray 1% phenolphthalene ethanol solution on the measurement surface. (2) Mark the boundary between colored and uncolored parts with magic. In the case of concrete with a high water content, take a reading after 2 days. (3) Measure the maximum and minimum neutralization depth from the surface. (4) Trace the boundary to a transparent vinyl sheet. (5) Measure the area of the non-colored part.
Calculation C = A / L
C: Average neutralization depth mm
A: Area of non-colored part mm ²
L: Length of measurement surface mm
Abrasion resistance / according to measurement method specified in JISK7204. The wear weight under the conditions of wear wheel H22, load of 1 kg, and 1000 rotations is measured.
[0024]
【The invention's effect】
The aqueous permeable composition according to the present invention contains sodium silicate and potassium methyl silicate, and quickly penetrates into the concrete, and the sodium silicate reacts with a polyvalent metal compound such as Ca and Mg in the concrete. As a result, silicate is formed to fill the voids, and potassium methylsilicate reacts with carbon dioxide in the air to form polysilicate. For this reason, the void filling effect and water repellency of concrete are obtained, and the water permeability is lowered, so that the waterproofness of the structure can be greatly improved.
In addition, the concrete surface is strengthened and the wear resistance and the like are greatly improved. As confirmed in the examples and comparative examples, when the concrete surface-treated with the conventional water glass is washed with rain water or the like, the wear resistance is greatly reduced, but the aqueous permeability treatment of the present invention. In the case of treatment with an agent, the wear resistance does not deteriorate even when washed with rain water or the like. For this reason, it is effective for use in places where water washing operations such as parking lot floors are performed.
At the same time, potassium methylsilicate reacts with carbon dioxide in the air to form polysilicate, so that the neutralization of the concrete is suppressed, and the concrete structure can be prevented from deteriorating and cracking as described above. Helps extend the life of things.

Claims (2)

A composition for reinforcing a permeable concrete surface , comprising sodium silicate and potassium methyl silicate in a blending ratio of 100: 1 to 100: 20 and having a concentration of 5 to 40% by weight . A method for reinforcing the surface of concrete, comprising applying the composition according to claim 1 .