JP2004189569A - Compound for elastic cement mortar - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compound for elastic cement mortar which has good workability in daubing on a concrete substrate and which prevents an attached tile from cracking or peeling off by absorbing the behavior of the concrete substrate after hardening of the mortar. <P>SOLUTION: A polymer dispersion for mixing with cement or a re-emulsifying powder resin of 5-50 wt.% in terms of solid content, and a lightweight aggregate with a particle size of 0.075-1.2 mm of 20 volume% or less to the total quantity of the mixture are added to the cement, so that the elongation-distortion factor of the mortar layer is kept at not less than twice (200 μm or more) of the normal behavior range (100 μm) of the concrete substrate and the static elastic modulus is kept at not more than 1/2 (10,000 N/mm<SP>2</SP>) of that of the conventional tiling cement mortar. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００８】
（比較試験）
各供試体について伸び歪み率・引張強さ、静弾性係数、圧縮強さ、接着強さ、耐久性試験後接着強さ及びタイル剥落防止性能などについて測定すると共に特性試験をしたところ表２及び図１のような結果が得られた。
【０００９】
（試験項目の内容）
「伸び歪み・引張強さ」：ＡＳＴＭ Ｃ１９０−８５の試験方法に準拠し、ブリケットによる引張試験を行い伸び歪み率を測定した。
「静弾性係数」：ＪＳＣＥ−Ｇ５０２に準じ、５０φ×１００ｍｍの円柱供試体を用い、単軸圧縮載荷により１／３応力点と５０με時の応力点を結ぶ割線弾性係数より求めた。
「曲げ・圧縮強さ」：ＪＩＳ Ａ６２０３（セメント混和用ポリマーディスパージョン及び再乳化形粉末樹脂）に準拠して測定した。
「接着強さ」：ＪＩＳ Ａ５３０３（鉄筋コンクリートＵ形）１種に適合するコンクリート製Ｕ字溝蓋の上面に、吸水調整材として「ＮＳハイフレックスＨＦ−１０００（日本化成社製）」の５倍希釈液を１回刷毛塗り乾燥後、その上に試料モルタルを金鏝により塗付け、タイル「ＩＮＡＸ製ＹＭ−２５５（４５×９５×６）ｍｍ」を張付けた。
２８日後に接着強さを測定した。
「耐久性後接着強さ」：ＪＩＳ Ａ５３０３の１種に適合するコンクリート製Ｕ字溝蓋の上面に、吸水調整材として「ＮＳハイフレックスＨＦ−１０００（日本化成社製）」の５倍希釈液を１回刷毛塗り乾燥後、その上に試料モルタルを金鏝により塗付け、タイル「ＩＮＡＸ製ＹＭ−２５５（４５×９５×６）ｍｍ」を張付けた。
材齢２８日後、２０℃水中１８時間、−２０℃気中３時間、５０℃気中３時間を１サイクルとして、１０サイクル行った後、接着強さを測定した。
「作業性」：コンクリート壁（１ｍ^２以上）に各試料モルタルを金鏝で塗付け、作業者の官能により塗付け時の作業性と前記タイルの張付け時のタイルのズレについて評価を行った。
「タイル剥落防止性能」：所定の割合（ｆｃ＝４４Ｎ／ｍｍ^２，Ｗ／Ｃ＝４３．５％）で打設したコンクリート角柱（１００×１００×３５０）ｍｍの一面に厚さ１ｍｍの下塗りを施した後、更に４ｍｍ厚の上塗りを行って張付けモルタルとし、その上に５０角モザイクタイル（４５×４５×６）ｍｍを密着張りした。
湿空２４時間、気中で２７日間養生した後、万能試験機によりコンクリートが破壊するまで単軸圧縮載荷し、中央部のコンクリート表面とタイル表面の歪を測定した。
【００１０】
（試験結果）
【表２】

【００１１】
（評価）
引張強さ：引張強さは比較例品より低下するが、伸び歪み率は、いずれの実施例品も、２００μ以上であって比較例品の２倍以上である。
静弾性係数：モルタルの柔らかさを示す静弾性係数は、１０，０００Ｎ／ｍｍ^２より遥かに低く、従来の張付けモルタルの約１／４である。
圧縮強さと接着強さ：圧縮強さは比較例品の１／２程度であるが、接着強さは同等かそれ以上である。
耐久性試験後接着強さ：１．６Ｎ／ｍｍ^２以上であるから実用上十分な接着耐久性を維持する。
作業性：タイルのズレがほとんど無く、塗り付け作業性が極めてよい。
タイル剥落防止性能：図１の軸方向歪み追従性試験結果から判るように、実施例品はコンクリートに生じている歪に対し、タイルに生じている歪が少ない。
このことは、低い静弾性係数の実施例モルタルが応力の緩和・吸収性能を発揮していることを示している。
また、タイル歪が最大値を超えた後の減少過程が、緩やかであることは、実施例モルタル配合物が靭性に富み脆性破壊を生じていないことを示している。
【００１２】
本発明におけるタイルの浮き・剥落防止効果は、モルタルにガラス転移温度が−５０〜１０℃のセメント混和用ポリマーディスパージョン又は再乳化形粉末樹脂がセメントに対し、固形分換算で５〜５０重量％混合されると共に粒径０．０７５〜１．２ｍｍの軽量骨材が全材料に対し、２０容量％を超えない範囲で添加され、モルタル配合物の伸び歪み率を２００μ以上とし、静弾性係数を１０，０００Ｎ／ｍｍ^２以下としたことに基づくものである。なお、軽量骨材の添加は静弾性係数が抑える効果と共に作業性を良好にする効果がある。
【００１３】
【発明の効果】
本発明によるモルタルは、コンクリート下地材に直接塗り付けする際の鏝作業が容易になり、またタイル張付け時にズレを生じないから張付け作業が効率よく行える。
更に、接着強さも従来品と同等である上、伸び歪み率２００μ以上、静弾性係数１０，０００Ｎ／ｍｍ^２以下にされていることにより接着耐久性が向上し、下地材の乾燥収縮や膨張・収縮などの挙動を緩和吸収し又はこれに追随して張付けタイルを保護するので長期に亘ってタイルの浮き・剥落事故を防止できる。
本発明モルタルは、タイル張付け材の他、下地補修材、下塗材及び仕上塗材として利用できる。
【図面の簡単な説明】
【図１】コンクリート歪に対するタイル歪の関係を示すグラフ[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a compound for elastic cement mortar having excellent weather resistance, deformation followability and adhesive durability, and having high adhesive strength.
[0002]
[Prior art]
When tiles are applied to concrete or other base materials, materials with higher strength and higher rigidity have been conventionally used as preferable materials.However, due to temperature changes due to solar radiation and behavior due to drying shrinkage of the base material, the adhesive interface of the tile is It has been known that, in such a case, the adhesive strength is gradually reduced due to repeated shear stress, and that cracking and fatigue fracture are more likely to occur.
In light of this reflection, there has been proposed a lightweight mortar for tile application in which both the compressive strength and the Young's modulus are reduced to 1/2 or less of those of the prior art using artificial lightweight foamed fine aggregate (see Patent Documents 1 and (0009)). Since the proposal is mainly aimed at improving the application work and reducing the Young's modulus by reducing the weight of the mortar (see Patent Document 1, (0014)), the mortar has low elongation performance, a large amount of water absorption, and the mortar itself. However, there is a drawback that the strength of the steel is reduced.
[0003]
[Patent Document 1]
JP 10-299220 A
[Problems to be solved by the invention]
The present invention provides a cement mortar composition capable of preventing cracks, floating and peeling of a tile to be stuck, and has an elongation and strain rate of a mortar layer of at least twice the normal behavior range (100 μ) of a base material. (200μ or more) and the coefficient of static elasticity is not more than 1/2 (10,000 N / mm ² ) of the conventional tile-attached cement mortar. An object of the present invention is to provide an elastic cement mortar capable of exhibiting good workability.
[0005]
[Means for Solving the Problems]
The elastic cement mortar composition of the present invention is prepared by mixing 5 to 50% by weight of a cement-dispersed polymer dispersion or a re-emulsifying type powder resin with respect to cement in terms of solid content. 0.075 to 1.2 mm of a lightweight aggregate is added in an amount not exceeding 20% by volume based on the total amount of the compounded material. As the lightweight aggregate, organic and / or inorganic materials can be used. However, when the thickness is 0.075 mm or less, the amount of water increases and the mortar strength decreases. ５5 mm and cannot be adopted. Further, when added in an amount of 20% by volume or more, the strength is reduced.
Furthermore, polyvinyl alcohol, fiber (vinylon fiber), polyester fiber, and acrylic fiber having a fiber length of 2 to 10 mm are used to improve the elongation strain rate of the mortar and eliminate slippage during application, and to prevent cracking and peeling of the mortar after curing. It is preferable to add short fibers such as nylon fibers, carbon fibers, steel fibers, and alkali-resistant glass fibers in the range of 0.2% by weight to 2.0% by weight based on the cement amount. If it is mixed in an amount of 2.0% by weight or more, kneading of the mortar becomes difficult, and fibers are exposed at joints when tiled.
The amount of water for kneading mortar is usually 20 to 35% by weight based on the material.
After curing, the mortar of the compound of the present invention has an elongation strain rate of 200 μ or more and a static elasticity coefficient of 10,000 N / mm ² or less, and thus has an improved ability to alleviate and absorb shear peeling stress generated at the tile bonding interface.
In the present invention, the polymer dispersion and the re-emulsifying type powder resin to be mixed with the cement can be a general cement admixture such as ethylene vinyl acetate, vinyl acetate veoba, acrylate copolymer, styrene butadiene rubber (SBR), and elongation strain. In order to maintain the modulus and the coefficient of static elasticity in the above ranges, those having a glass transition temperature of −50 to 10 ° C. are used.
[0006]
【Example】
(Examples and Comparative Examples)
The mortar was adjusted for each of the examples and comparative examples shown in Table 1, and a sample was prepared using a part thereof.
[0007]
[Table 1]

[0008]
(Comparative test)
Each specimen was measured for elongation strain rate / tensile strength, static elastic modulus, compressive strength, adhesive strength, adhesive strength after endurance test, tile peeling prevention performance, etc. A result like 1 was obtained.
[0009]
(Contents of test items)
"Elongation strain / tensile strength": In accordance with the test method of ASTM C190-85, a tensile test using briquettes was performed to measure an elongation strain rate.
"Static elastic modulus": In accordance with JSCE-G502, using a cylindrical sample of 50 mm x 100 mm, it was determined from a secant elastic coefficient connecting a 1/3 stress point and a stress point at 50 με by uniaxial compression loading.
"Bending / compression strength": Measured in accordance with JIS A6203 (polymer dispersion for cement admixture and re-emulsifying powder resin).
"Adhesive strength": 5-fold dilution of "NS Hyflex HF-1000 (manufactured by Nippon Kasei Co., Ltd.)" as a water absorption adjusting material on the upper surface of a concrete U-shaped groove lid conforming to JIS A5303 (reinforced concrete U type). After the solution was brush-dried once and dried, a sample mortar was applied thereon with a gold iron, and a tile “YM-255 (45 × 95 × 6) mm manufactured by INAX” was attached.
After 28 days, the adhesive strength was measured.
"Adhesive strength after durability": A 5-fold dilution of "NS High Flex HF-1000 (manufactured by Nippon Kasei)" as a water absorption adjusting material on the upper surface of a concrete U-shaped groove cover conforming to JIS A5303. Was brush-dried once, and then a sample mortar was applied thereon with a gold iron, and a tile “YM-255 (45 × 95 × 6) mm manufactured by INAX” was attached.
After 28 days of material age, the adhesive strength was measured after 10 cycles, each cycle consisting of 18 hours in 20 ° C. water, 3 hours in -20 ° C. air, and 3 hours in 50 ° C. air.
"Workability": the concrete wall (1m ² or more) smeared each sample mortar with gold iron, were evaluated for the deviation at the time of the tile sticking of the workability and the tile at the time of smeared by the operator of the functional.
"Tile flaking prevention performance": a primer of a predetermined ratio ^{(fc = 44N / mm 2,} W / C = 43.5%) in pouring concrete prisms (100 × 100 × 350) 1mm thick on one surface of mm After the application, a 4 mm-thick top coat was further applied to form a mortar, on which 50-mm square mosaic tile (45 × 45 × 6) mm was adhered.
After curing in the air for 24 hours in the moist air for 27 days, the specimen was uniaxially compressed and loaded by a universal testing machine until the concrete was broken, and the strain on the concrete surface and the tile surface in the center was measured.
[0010]
(Test results)
[Table 2]

[0011]
(Evaluation)
Tensile strength: The tensile strength is lower than that of the comparative example, but the elongation strain rate of each of the examples is 200 μ or more, which is twice or more that of the comparative example.
Static modulus: The static modulus, which indicates the softness of the mortar, is much lower than 10,000 N / mm ^2, which is about の of that of the conventional mortar.
Compressive strength and adhesive strength: The compressive strength is about half that of the comparative example, but the adhesive strength is equal to or higher.
Since the adhesive strength after the durability test is 1.6 N / mm ² or more, practically sufficient adhesive durability is maintained.
Workability: There is almost no displacement of the tile, and the workability of application is extremely good.
Tile spalling prevention performance: As can be seen from the results of the axial strain follow-up test shown in FIG. 1, the example product has less tile distortion than concrete distortion.
This indicates that the example mortar having a low static elastic modulus exhibits a stress relaxation / absorption performance.
Also, the gradual decrease process after the tile strain exceeds the maximum value indicates that the example mortar composition is rich in toughness and does not cause brittle fracture.
[0012]
The effect of preventing the tiles from floating and peeling in the present invention is as follows: the mortar has a glass transition temperature of -50 to 10 ° C, and the polymer dispersion for cement admixture or the re-emulsifying powder resin is 5 to 50% by weight in terms of solid content with respect to cement. While being mixed, a lightweight aggregate having a particle size of 0.075 to 1.2 mm is added to the total material in an amount not exceeding 20% by volume, the elongation strain rate of the mortar composition is set to 200 μ or more, and the static elastic modulus is set to This is based on a value of 10,000 N / mm ² or less. The addition of the lightweight aggregate has the effect of suppressing static elasticity and improving the workability.
[0013]
【The invention's effect】
The mortar according to the present invention facilitates trowel work when directly applying to a concrete base material, and does not cause displacement at the time of tile laying, so that the mortar can be efficiently performed.
Furthermore, the adhesive strength is the same as that of the conventional product, and the elongation strain rate is 200 μ or more and the static elastic modulus is 10,000 N / mm ² or less, so that the adhesive durability is improved, and the drying and shrinkage and expansion / Since the behavior such as shrinkage is alleviated or absorbed or the tile attached is protected in accordance therewith, it is possible to prevent the tile from floating or falling off for a long period of time.
The mortar of the present invention can be used as a base repair material, an undercoat material, and a finish coating material, in addition to the tile adhering material.
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between tile strain and concrete strain.

Claims (2)

A polymer dispersion or a re-emulsifiable powder resin for admixing a cement having a glass transition temperature of -50 to 10 ° C is mixed with the cement in an amount of 5 to 50% by weight in terms of solid content, and has a particle size of 0.075 to 1.2 mm. A compound for elastic cement mortar in which lightweight aggregate is added in an amount not exceeding 20% by volume based on all materials. The mortar composition according to claim 1, wherein short fibers having a fiber length of 2 to 10 mm are added in an amount of 0.2 to 2.0% by weight based on the cement amount.

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