JPH0515659B2 - - Google Patents
Info
- Publication number
- JPH0515659B2 JPH0515659B2 JP6109485A JP6109485A JPH0515659B2 JP H0515659 B2 JPH0515659 B2 JP H0515659B2 JP 6109485 A JP6109485 A JP 6109485A JP 6109485 A JP6109485 A JP 6109485A JP H0515659 B2 JPH0515659 B2 JP H0515659B2
- Authority
- JP
- Japan
- Prior art keywords
- weight
- parts
- cement
- efflorescence
- water
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Landscapes
- Curing Cements, Concrete, And Artificial Stone (AREA)
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明はセメント系硬化物の白華防止方法に関
する。
（従来の技術）
セメント系硬化物たとえばコンクリートやモル
タルの建造物の白華とは、外部から浸透した雨水
等が内外壁の壁面から蒸発する際にコンクリート
内部の主に水酸化カルシウムを主成分とする成分
を表面に溶出し、これが空気に触れ、不溶性の炭
酸カルシウムとなる現象であり、この白華により
建造物の外観が著しく損われる。
セメント系硬化物のこのような白華現象に関し
ては、古くから多くの学者により研究されてお
り、この成因挙動は明らかにされているが、この
防止方法については今だすぐれたものは見出され
ていない。
現在、白華防止方法として、白華成分と反応
する物質の添加、防水剤の添加、減水剤の添
加、表面塗膜の形成等が知られている。とし
てはフライアツシユ、高炉鉱滓、水ガラス、炭酸
塩等、としてはステアリン酸塩、流動パラフイ
ン、アスフアルト系物質等が例示されている。し
かし、これらはいずれも白華防止に若干の効果は
あるものの満足できるものではない。
また、減水剤の添加は、これにより界面エネル
ギーを低下させてセメント粒子の凝集力を抑制
し、分散を助け、濡れ易くし、セメントの水和作
用の効果を高めるとともに、単位水量を減少させ
ることができ、これにより体積全体がち密化し、
水の移動路が減少し、もつて白華の生成を減少さ
せることをねらつたものである。しかしこれも効
果は小さい。
表面塗膜形成方法としては、塩化ビニル、塩化
ビニリデン、メラミン樹脂、アクリル樹脂、油ペ
イント系物質等の塗布および吹付け等が示されて
いるが、この塗膜形成のための施工作業が大変で
あり、コスト高となるのをさけることができな
い。
（発明の構成）
本発明者らは、かかる従来の不利な点を解決す
べく鋭意研究を重ねた結果、本発明に到達したも
ので、これはセメント100重量部当り、塩化カル
シウム0.05〜0.3重量部、ラウリル硫酸ナトリウ
ム0.001〜0.02重量部、およびオレイン酸ナトリ
ウム０〜３重量部を添加することを特徴とするセ
メント系硬化物の白華防止方法に関する。さらに
これに水溶性セルロースエーテルを添加する該白
華防止方法を提供するものである。
（発明の効果）
本発明によれば従来の不利をともなうことな
く、下記のようなすぐれた効果を得ることができ
る。
(1) 本発明で使用される添加剤の組合せは市販の
白華防止剤にくらべ、白華防止効果はさらに大
きい。
(2) 保水性および作業性のよいセメント系混練物
を得ることができる。
(3) 本発明によるセメント系混練物はタイル張り
用にも使用でき、白華の生じない接着性のよい
硬化物を得ることができる。
(4) 本発明によるセメント系硬化物は防水性があ
り、水の浸透量が少なく、中性化が遅延し耐久
性がすぐれている。
以下本発明を詳細に説明する。
本発明では塩化カルシウムとラウリル硫酸ナト
リウムとの併用が重要であり、この相乗作用によ
り前記効果が達成される。塩化カルシウムの添加
量はセメント100重量部当り0.05〜0.3重量部好ま
しくは0.1〜0.2重量部であり、この範囲よりも多
くても少なくても白華量は増す。なお、塩化カル
シウムはこれを含有するセメント系混練物が鉄筋
に接触する場合は、鉄筋の発錆に関与するので、
必要最小限にとどめるべきである。
ラウリル硫酸ナトリウムの添加量はセメント
100重量部当り0.001〜0.02重量部好ましくは0.002
〜0.01重量部であり、この添加量以外では白華防
止に寄与しない。
オレイン酸ナトリウムの添加量はセメント100
重量部当り０〜３重量部であり、必須成分とされ
るものではないが、この添加により防水性がで
て、白華防止効果が向上するので、セメント100
重量部当り0.5〜２重量部使用することが望まし
い。なお、この添加量は３重量部以上増量しても
防水性はほとんど変らない。この添加量を増量す
るとタイル等の接着性に悪影響が生じるので、防
水性がもたらされる範囲で最小限にとどめるべき
である。
本発明は上記した成分にさらに水溶性セルロー
スエーテルを添加する前記白華防止方法を提供す
るもので、ここに使用する水溶性セルロースエー
テルとしては、メチルセルロース、ヒドロキシプ
ロピルメチルセルロース、ヒドロキシエチルエチ
ルセルロース、ヒドロキシエチルセルロース、ヒ
ドロキシプロピルセルロース等が例示される。こ
れらのセルロースエーテルの添加量は0.01〜0.5
重量部の範囲とすることが望ましく、保水性、作
業性等にすぐれた効果がみられる。
本発明に使用されるセメントは普通ポルトラン
ドセメントが主体であるが、ほかにフライアツシ
ユセメント、高炉セメント等のセメントや、石
膏、消石灰、炭酸カルシウム、ペントナイト、粘
土等を併用してもよい。
さらに骨材としては、川砂、山砂、けい砂、寒
水砂、軽量骨材などが用いられる。このほか必要
に応じて、減水剤、AE剤、消泡剤、硬化促進剤、
収縮低減剤、エマルジヨン、繊維物質等を配合し
ても差支えない。
次に具体的実施例をあげる。
実施例
表に示すとおりの配合のセメントモルタルにつ
いて、下記の白華試験および吸水量（防水性）の
測定を行つた。結果は表に示すとおりであつた。
〔白華試験〕
各配合のセメントモルタルについて、たて×よ
こ×厚さ＝100×100×20mmの試験片を作成し、３
日養生後水中に厚さの10mmを浸漬し、７℃×50％
RH、風速0.1〜0.2ｍ／秒内に14日放置し、白華
を観察した。
（白華量判定）
◎……なし
○……少
△……中
×……多
〔吸水量（防止性）の測定〕
JIS Ｒ 5201中の強さ試験の試験片作成法に準
拠し、各セメントモルタルについて、40×40×
160mmの試験片を作成し、５日養生後、試験片の
半分の20mmを浸水し、経時毎の吸水量（重量％）
を求めた。
ただし、表中で用いた略記号は下記のとおり。
Γ90SH4000：信越化学工業(株)製商品名、ヒドロ
キシプロピルメチルセルロース
Γ市販品Ａ：脂肪酸塩系のもの
Γ市販品Ｂ：ステアリン酸カルシウム
【表】DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for preventing efflorescence of cement-based cured materials. (Prior art) Efflorescence on cement-based hardened materials, such as concrete and mortar buildings, is caused by rainwater that seeps in from the outside and evaporates from the inner and outer walls of the concrete. This is a phenomenon in which efflorescent components are eluted to the surface, which, when exposed to air, turns into insoluble calcium carbonate, and this efflorescence significantly impairs the appearance of buildings. The efflorescence phenomenon of cement-based hardened materials has been studied by many scholars for a long time, and the behavior that causes it has been clarified, but no good method for preventing it has yet been found. Not yet. Currently, known methods for preventing efflorescence include the addition of substances that react with efflorescence components, the addition of waterproofing agents, the addition of water-reducing agents, and the formation of surface coatings. Examples include fly ash, blast furnace slag, water glass, carbonates, etc., and examples include stearate, liquid paraffin, asphalt-based substances, etc. However, although these are all somewhat effective in preventing efflorescence, they are not satisfactory. In addition, the addition of a water reducing agent can reduce the interfacial energy, suppress the cohesive force of cement particles, aid dispersion, make it easier to wet, enhance the hydration effect of cement, and reduce the unit water volume. This makes the entire volume denser,
The aim is to reduce the movement path of water and thereby reduce the formation of efflorescence. However, this effect is also small. As a method for forming a surface coating film, coating and spraying of vinyl chloride, vinylidene chloride, melamine resin, acrylic resin, oil paint-based substances, etc. have been suggested, but the construction work for forming this coating film is difficult. However, high costs cannot be avoided. (Structure of the Invention) The present inventors have conducted extensive research to solve the disadvantages of the conventional art, and as a result, they have arrived at the present invention. The present invention relates to a method for preventing efflorescence of cement-based cured products, which comprises adding 0.001 to 0.02 parts by weight of sodium lauryl sulfate, and 0 to 3 parts by weight of sodium oleate. Furthermore, the present invention provides a method for preventing efflorescence, which comprises adding water-soluble cellulose ether thereto. (Effects of the Invention) According to the present invention, the following excellent effects can be obtained without the disadvantages of the conventional art. (1) The combination of additives used in the present invention has a greater efflorescence prevention effect than commercially available efflorescence inhibitors. (2) A cement-based kneaded material with good water retention and workability can be obtained. (3) The cement-based kneaded product according to the present invention can also be used for tiling, and a cured product with good adhesiveness that does not cause efflorescence can be obtained. (4) The cement-based cured product according to the present invention is waterproof, has a small amount of water penetration, slows carbonation, and has excellent durability. The present invention will be explained in detail below. In the present invention, it is important to use calcium chloride and sodium lauryl sulfate in combination, and the above effects are achieved through their synergistic action. The amount of calcium chloride added is 0.05 to 0.3 parts by weight, preferably 0.1 to 0.2 parts by weight, per 100 parts by weight of cement, and the amount of efflorescence will increase even if it is more or less than this range. In addition, calcium chloride is involved in rusting of reinforcing bars when a cement-based mixture containing it comes into contact with reinforcing bars.
It should be kept to the minimum necessary. Addition amount of sodium lauryl sulfate is cement
0.001 to 0.02 parts by weight per 100 parts by weight, preferably 0.002 parts by weight
~0.01 part by weight, and amounts other than this do not contribute to preventing efflorescence. Addition amount of sodium oleate is cement 100
It is 0 to 3 parts by weight per part by weight, and although it is not considered an essential component, its addition increases waterproofness and improves the efflorescence prevention effect.
It is desirable to use 0.5 to 2 parts by weight per part by weight. Note that even if the amount added is increased by 3 parts by weight or more, the waterproof property hardly changes. If the amount added is increased, it will have an adverse effect on the adhesion of tiles, etc., so it should be kept to a minimum as long as waterproofness is achieved. The present invention provides the method for preventing efflorescence by further adding water-soluble cellulose ether to the above-mentioned components, and the water-soluble cellulose ether used here includes methylcellulose, hydroxypropylmethylcellulose, hydroxyethylethylcellulose, hydroxyethylcellulose, Examples include hydroxypropyl cellulose. The amount of these cellulose ethers added is 0.01 to 0.5
It is desirable to keep the amount within the range of parts by weight, and excellent effects on water retention, workability, etc. can be seen. The cement used in the present invention is usually Portland cement, but other cements such as fly ash cement and blast furnace cement, gypsum, slaked lime, calcium carbonate, pentonite, clay, etc. may also be used in combination. Further, as the aggregate, river sand, mountain sand, silica sand, cold water sand, lightweight aggregate, etc. are used. In addition, water reducing agents, AE agents, antifoaming agents, curing accelerators,
Shrinkage reducing agents, emulsions, fiber substances, etc. may be added. Next, a specific example will be given. Example The following efflorescence test and measurement of water absorption (waterproofness) were performed on cement mortars having the formulations shown in the table. The results were as shown in the table. [Efflorescence test] For each blend of cement mortar, test pieces of length x width x thickness = 100 x 100 x 20 mm were prepared, and 3
After curing for a day, soak 10mm thick in water at 7℃ x 50%.
It was left for 14 days at RH and a wind speed of 0.1 to 0.2 m/sec, and efflorescence was observed. (Determination of amount of efflorescence) ◎...None ○...Low △...Medium About cement mortar, 40×40×
A 160 mm test piece was prepared, and after curing for 5 days, half of the test piece (20 mm) was immersed in water, and the amount of water absorbed over time (weight%) was measured.
I asked for However, the abbreviations used in the table are as follows. Γ90SH4000: Shin-Etsu Chemical Co., Ltd. trade name, hydroxypropyl methylcellulose Γ Commercial product A: Fatty acid salt Γ Commercial product B: Calcium stearate [Table]
Claims (1)
0.05〜0.3重量部、ラウリル硫酸ナトリウム0.001
〜0.02重量部、およびオレイン酸ナトリウム０〜
３重量部を添加することを特徴とするセメント系
硬化物の白華防止方法。 ２ セメント100重量部当り、塩化カルシウム
0.05〜0.3重量部、ラウリル硫酸ナトリウム0.001
〜0.02重量部、水溶性セルロースエーテル0.01〜
0.5重量部、およびオレイン酸ナトリウム０〜３
重量部を添加することを特徴とするセメント系硬
化物の白華防止方法。[Claims] 1 Calcium chloride per 100 parts by weight of cement
0.05-0.3 parts by weight, sodium lauryl sulfate 0.001
~0.02 parts by weight, and 0~ sodium oleate
A method for preventing efflorescence of a cement-based cured material, characterized by adding 3 parts by weight. 2 Calcium chloride per 100 parts by weight of cement
0.05-0.3 parts by weight, sodium lauryl sulfate 0.001
~0.02 parts by weight, water-soluble cellulose ether 0.01~
0.5 parts by weight, and 0-3 parts of sodium oleate
A method for preventing efflorescence of a cement-based cured material, characterized by adding parts by weight.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6109485A JPS61219747A (en) | 1985-03-26 | 1985-03-26 | Prevention of efflorescence for cementitious hardened matter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6109485A JPS61219747A (en) | 1985-03-26 | 1985-03-26 | Prevention of efflorescence for cementitious hardened matter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61219747A JPS61219747A (en) | 1986-09-30 |
| JPH0515659B2 true JPH0515659B2 (en) | 1993-03-02 |
Family
ID=13161147
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6109485A Granted JPS61219747A (en) | 1985-03-26 | 1985-03-26 | Prevention of efflorescence for cementitious hardened matter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61219747A (en) |
-
1985
- 1985-03-26 JP JP6109485A patent/JPS61219747A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61219747A (en) | 1986-09-30 |
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