JP2020105039A

JP2020105039A - Curing method for cement-based cured product

Info

Publication number: JP2020105039A
Application number: JP2018243276A
Authority: JP
Inventors: 敦花井; Atsushi Hanai; 克年長谷川; Katsutoshi Hasegawa
Original assignee: DAINIPPON CONSTRUCTION; Dai Nippon Construction
Current assignee: DAINIPPON CONSTRUCTION; Dai Nippon Construction
Priority date: 2018-12-26
Filing date: 2018-12-26
Publication date: 2020-07-09

Abstract

To provide a method which can be easily applied to a cement-based cured product, and which can improve the surface hardness and surface denseness of the cured product.SOLUTION: The cement composition after implantation is subjected to flooding curing in a diluted water of a nonionic surfactant containing copolymer of ethylene oxide and propylene oxide.SELECTED DRAWING: Figure 1

Description

本発明は、セメント系硬化体の養生方法に関する。詳しくは、エチレンオキシドとプロピレンオキシドの共重合体を含む表面硬度向上剤の希釈水により、セメント組成物を湛水養生することで、セメント系硬化体の表面硬度の向上と透気係数を向上させる養生方法に関する。 The present invention relates to a method for curing a cement-based hardened body. Specifically, by curing the cement composition with water by diluting the surface hardness improver containing a copolymer of ethylene oxide and propylene oxide, the surface hardness and the air permeability coefficient of the cement-based cured product are improved. Regarding the method.

セメントペースト、モルタル、コンクリート等のセメント系硬化体は、土木構造物、建築構造物及びコンクリート製品等に広く使用されている。セメント系硬化体の製造に用いる水は、作業性を確保するために水和反応等に供される理論必要量を超える量の水を使用する。この過剰な水の蒸発がセメント系硬化体の乾燥収縮を進行させ、ひび割れを発生させる。一方で、コンクリート構造物は、耐久性、美観等の点から、長期に渡りひび割れが発生しないこと、表面硬度が高いこと、表面の緻密性が高いこと等のコンクリートの表面品質の向上が求められている。 Cement-based hardened materials such as cement paste, mortar and concrete are widely used in civil engineering structures, building structures, concrete products and the like. As the water used for producing the cement-based hardened product, an amount of water exceeding the theoretically required amount used for the hydration reaction or the like is used to ensure workability. The evaporation of this excess water accelerates the drying shrinkage of the cement-based hardened product, causing cracking. On the other hand, in terms of durability, aesthetics, etc., concrete structures are required to improve the surface quality of concrete, such as long-term non-cracking, high surface hardness, and high surface compactness. ing.

こうした乾燥に伴うセメント系硬化体のひび割れを防止するために、従来、収縮低減剤が使用されている。収縮低減剤は一般に、セメント系硬化体の製造の際、セメント組成物に混和する方法が採られる。 In order to prevent cracking of the cement-based hardened product due to such drying, a shrinkage reducing agent has been conventionally used. The shrinkage reducing agent is generally incorporated into the cement composition during the production of the hardened cementitious material.

この方法に用いる、市販の収縮低減剤は何れも予め混和使用に適する組成に調製されたものである。しかし、モルタルやコンクリート等の製造時における収縮低減剤の直接混和は、連行空気が安定しないことが多いため品質管理が難しくなることが多い。また、混和使用以外の使用の目的で収縮低減剤を硬化途中のセメント硬化体に塗布する方法も知られている（特許文献１及び特許文献２）。 All commercially available shrinkage reducing agents used in this method have been prepared in advance to have a composition suitable for admixture. However, direct mixing of the shrinkage-reducing agent during the production of mortar, concrete, etc. often makes quality control difficult because the entrained air is often unstable. Further, there is also known a method of applying a shrinkage reducing agent to a cement hardened body during curing for purposes other than admixture use (Patent Documents 1 and 2).

特許文献１には、打設した硬化前のセメントコンクリートを表面仕上げする際に、その表面に乾燥収縮低減剤即ち非イオン性界面活性剤を散布することで、ひび割れを防止する方法が記載されている。 Patent Document 1 describes a method of preventing cracks by spraying a drying shrinkage reducing agent, that is, a nonionic surfactant, on the surface of cement concrete before hardening which has been set. There is.

特許文献２には、セメント系硬化体の表面に、セメント系硬化体の凝結反応の終結後から材齢７日の期間に収縮低減剤を塗布、散布又は吹付けすることで、セメント硬化体の圧縮強度の増加及び乾燥収縮の低減を図る方法が記載されている。 In Patent Document 2, a shrinkage-reducing agent is applied, sprayed or sprayed on the surface of a hardened cementitious material during the period of 7 days after the completion of the setting reaction of the hardened cementitious material. A method for increasing the compressive strength and reducing the drying shrinkage is described.

しかし、特許文献１に記載の方法では、硬化後にセメント硬化体の表面が脆弱になり、また低温度環境下では硬化不良が生じるなど、コンクリートの強度や耐久性を低下させるという問題が発生するとの指摘が特許文献２の明細書中の段落［０００４］及び特許文献３の明細書中の段落［０００７］に記載されており、既に知られている。
また、特許文献２に記載の方法では、段落［００２４］において、「収縮低減剤を表面最終仕上げ作業時に塗布すると表面に脆弱層が生じ、表面硬度が低下する。一方、収縮低減剤を終結後の硬化コンクリートに塗布した場合には無塗布と同等の表面硬度が得られた」と記載されている。この記載は、段落［００２４］の表３の試験結果（比較例６乃至比較例９及び実施例８）に基づくものであって、比較例７乃至比較例９即ちコンクリートを表面仕上げする際に収縮低減剤を塗布する特許文献１の記載の方法では、表面に脆弱層が生じ、表面硬度が低下することを示している。さらに、実施例８即ち収縮低減剤を終結後の硬化コンクリートに塗布する方法は、無塗布に比べてわずかに劣る表面硬度を示し、表面硬度を向上させるものではないことが知られている。 However, in the method described in Patent Document 1, there is a problem that the surface of the hardened cement body becomes brittle after hardening, and hardening failure occurs in a low temperature environment, and the strength and durability of the concrete are lowered. The indication is described in paragraph [0004] in the specification of Patent Document 2 and paragraph [0007] in the specification of Patent Document 3 and is already known.
In addition, in the method described in Patent Document 2, in paragraph [0024], "When a shrinkage-reducing agent is applied during the surface final finishing operation, a brittle layer is formed on the surface to reduce the surface hardness. When it was applied to the hardened concrete, the surface hardness equivalent to that of no application was obtained." This description is based on the test results (Comparative Examples 6 to 9 and Example 8) in Table 3 of Paragraph [0024], and the shrinkage occurs when Comparative Examples 7 to 9 or concrete is surface-finished. The method described in Patent Document 1 in which the reducing agent is applied shows that a brittle layer is formed on the surface and the surface hardness is reduced. Further, it is known that Example 8, that is, the method of applying the shrinkage-reducing agent to the hardened concrete after termination shows a surface hardness slightly inferior to that without the application and does not improve the surface hardness.

特開２００６−１４３４８１号公報JP 2006-143481 A 特開２００９−１４９４７６号公報JP, 2009-149476, A 特開２０１７−１１４７１４号公報JP, 2017-114714, A

これまでの非イオン性界面活性剤は、セメント硬化体の乾燥収縮の低減及び表面のひび割れを防止するために使用されるものであって、セメント系硬化体への適用の効果に関して、表面硬度については低下するか又は無塗布とほぼ変わらないと報告されているのみである。さらに表層透気係数の向上即ち表面の緻密性を向上させる効果についてはその報告例は本発明者の知る限りない。
従って、セメント系硬化体の表面硬度を向上させること及び表面の緻密性を向上させることに加えて、施工が煩雑ではない方法の開発が求められていた。さらに、上記の方法に使用される非イオン性界面活性剤の収縮低減剤の中で表面硬度向上剤として機能する薬剤が求められていた。 Conventional nonionic surfactants are used to reduce drying shrinkage and prevent surface cracking of hardened cement products. Regarding the effect of application to hardened cement products, regarding surface hardness Is reported to be reduced or about the same as no coating. The inventors of the present invention are not aware of any reported examples of the effect of improving the air permeability coefficient of the surface layer, that is, improving the denseness of the surface.
Therefore, in addition to improving the surface hardness of the cement-based cured product and improving the surface compactness, there has been a demand for the development of a method in which the construction is not complicated. Further, among the shrinkage reducing agents for nonionic surfactants used in the above method, there has been a demand for agents that function as surface hardness improvers.

本発明は、上記課題を解決するもので、セメント系硬化体に対して簡便に施工することができ、硬化体への施工によりその表面硬度を向上でき、かつ、表面の緻密性を向上させる方法を提供することにある。
また、上記方法に使用する表面硬度向上剤を提供することにある。 The present invention is to solve the above-mentioned problems, and can be easily applied to a cement-based hardened product, the surface hardness of which can be improved by applying the hardened product, and a method for improving the surface compactness. To provide.
Another object is to provide a surface hardness improver used in the above method.

本発明者は、上記課題を解決するために鋭意検討を行った結果、エチレンオキシドとプロピレンオキシドの共重合体を含む非イオン性界面活性剤が表面硬度向上剤として機能することを見出した。これに続いて、本発明者は、上記表面硬度向上剤の希釈水にて打ち込み後のセメント組成物を湛水養生することで、セメント系硬化体の表面硬度を向上させることに加えて表面の緻密性を向上させることができる新たな養生方法を見出し、本発明を完成させた。 As a result of earnest studies to solve the above problems, the present inventor has found that a nonionic surfactant containing a copolymer of ethylene oxide and propylene oxide functions as a surface hardness improver. Subsequently, the present inventor, by flooding curing the cement composition after driving with the dilution water of the surface hardness improver, in addition to improving the surface hardness of the cement-based cured product The present invention has been completed by discovering a new curing method that can improve the compactness.

即ち、本発明は、以下の態様からなる。
（１）セメント組成物を、打込み後、エチレンオキシドとプロピレンオキシドの共重合体を含む表面硬度向上剤の希釈水により湛水養生することを特徴とするセメント系硬化体の養生方法。
（２）上記表面硬度向上剤の希釈水の濃度が５質量％乃至１０質量％である（１）に記載のセメント系硬化体の養生方法。
（３）上記湛水養生を打込み後、材齢７日乃至２８日の期間続ける（１）又は（２）に記載のセメント系硬化体の養生方法。
（４）上記セメント組成物の水セメント比が５８％以下である（１）乃至（３）のいずれか一に記載のセメント系硬化体の養生方法。
（５）セメント系硬化体の表面硬度を湛水養生により向上させるための、エチレンオキシドとプロピレンオキシドの共重合体を含む表面硬度向上剤。 That is, the present invention comprises the following aspects.
(1) A method for curing a cement-based hardened product, which comprises, after implanting, a cement composition, which is water-filled with a surface hardness improver containing a copolymer of ethylene oxide and propylene oxide and diluted with water.
(2) The method for curing a cement-based hardened product according to (1), wherein the surface water hardness improver has a concentration of diluting water of 5% by mass to 10% by mass.
(3) The method for curing a cement-based cured product according to (1) or (2), which is continued for 7 to 28 days after the impregnation with water.
(4) The method for curing a cement-based cured product according to any one of (1) to (3), wherein the cement composition has a water-cement ratio of 58% or less.
(5) A surface hardness improver containing a copolymer of ethylene oxide and propylene oxide for improving the surface hardness of a cement-based hardened body by flooding curing.

本発明の方法を用いることにより、セメント系硬化体の表面硬度の向上及び表面の緻密性を向上させることができる。
本発明の表面硬度向上剤は、収縮低減剤が表面を脆弱にさせるか又はあくまで表面硬度の低下防止のみであった従来の収縮低減剤の効果とは全く異質な正反対の効果を発現させるものである。
本発明の方法は、施工作業も湛水養生の養生水に表面硬度向上剤を混和するだけであって簡単であり、施工性に優れる。 By using the method of the present invention, it is possible to improve the surface hardness and the surface compactness of the cement-based hardened product.
The surface hardness improver of the present invention is one that causes the shrinkage-reducing agent to weaken the surface, or exerts a completely opposite effect, which is completely different from the effect of the conventional shrinkage-reducing agent, which merely prevents the reduction of the surface hardness. is there.
The method of the present invention is simple in construction work since it is only required to mix the surface hardness improver with the curing water for flooding curing, and is excellent in workability.

図１は、試験例１における表面硬度増加比（％）を示すグラフである。［２４ＢＢ２８Ｓは、第２表に記載の配合｛24-8-25BB(膨張材）C；274kg/ｍ³+膨張剤；20kg/ｍ³、W/C；54.5％｝にて形成されるコンクリートを第２表に記載の各種養生水｛水道水（標準水）、希釈水イ（５％）又は希釈水ロ（５％）｝にて材齢２８日間養生したコンクリートの水道水養生（標準水養生）に対する養生水の種類による表面硬度増加比を示す。３６Ｈ７Ｓは、第３表に記載の配合（36-10-25H C；370kg/ｍ³、W/C；40.5%）にて形成されるコンクリートを第３表に記載の各種養生水｛水道水（標準水）、希釈水イ（５％）又は希釈水ロ（５％）｝にて材齢７日間養生したコンクリートの水道水養生（標準水養生）に対する養生水の種類による表面硬度増加比を示す。３６Ｈ２８Ｓは、第４表に記載の配合（36-10-25H C；370kg/ｍ³、W/C；40.5%）にて形成されるコンクリートを第４表に記載の各種養生水｛水道水（標準水）、希釈水イ（５％）又は希釈水ロ（５％）｝にて材齢２８日間養生したコンクリートの水道水養生（標準水養生）に対する養生水の種類による表面硬度増加比を示す。］FIG. 1 is a graph showing the surface hardness increase ratio (%) in Test Example 1. [24BB28S is concrete formed with the composition shown in Table 2 {24-8-25BB (expanding material) C; 274 kg/m ³ +expanding agent; 20 kg/m ³ , W/C; 54.5%}. Tap water curing (concrete water curing) for concrete aged 28 days with various curing water described in Table 2 {tap water (standard water), diluting water (5%) or diluting water (5%)} ) Shows the increase ratio of surface hardness depending on the type of curing water. 36H7S is a concrete formed with the composition (36-10-25H C; 370 kg/m ³ , W/C; 40.5%) described in Table 3 and various curing water (tap water (tap water ( Standard water), dilution water (5%) or dilution water (5%)} shows the surface hardness increase ratio by the type of curing water to tap water curing (standard water curing) of concrete aged for 7 days. .. 36H28S is a concrete formed by the composition (36-10-25H C; 370 kg/m ³ , W/C; 40.5%) described in Table 4 and various curing water (tap water (tap water ( Standard water), dilution water (5%) or dilution water (5%)} shows the ratio of increase in surface hardness depending on the type of curing water with respect to tap water curing (standard water curing) of concrete aged for 28 days. .. ] 図２は、試験例１における圧縮強度増加比（％）を示すグラフである。［２４ＢＢ７Ｉは、第１表に記載の配合｛24-8-25BB(膨張材）C；274kg/ｍ³+膨張剤；20kg/ｍ³、W/C；54.5％｝にて形成されるコンクリートを第１表に記載の各種養生水｛水道水（標準水）、希釈水イ（５％）又は希釈水ロ（５％）｝にて材齢７日間養生したコンクリートの水道水養生（標準水養生）に対する養生水の種類による圧縮強度増加比を示す。２４ＢＢ２８Ｉは、第２表に記載の配合｛24-8-25BB(膨張材）C；274kg/ｍ³+膨張剤；20kg/ｍ³、W/C；54.5％｝にて形成されるコンクリートを第２表に記載の各種養生水｛水道水（標準水）、希釈水イ（５％）又は希釈水ロ（５％）｝にて材齢２８日間養生したコンクリートの水道水養生（標準水養生）に対する養生水の種類による圧縮強度増加比を示す。３６Ｈ７Ｉは、第３表に記載の配合（36-10-25H C；370kg/ｍ³、W/C；40.5%）にて形成されるコンクリートを第３表に記載の各種養生水｛水道水（標準水）、希釈水イ（５％）又は希釈水ロ（５％）｝にて材齢７日間養生したコンクリートの水道水養生（標準水養生）に対する養生水の種類による圧縮強度増加比を示す。３６Ｈ２８Ｉは、第４表に記載の配合（36-10-25H C；370kg/ｍ³、W/C；40.5%）にて形成されるコンクリートを第４表に記載の各種養生水｛水道水（標準水）、希釈水イ（５％）又は希釈水ロ（５％）｝にて材齢２８日間養生したコンクリートの水道水養生（標準水養生）に対する養生水の種類による圧縮強度増加比を示す。］FIG. 2 is a graph showing the compressive strength increase ratio (%) in Test Example 1. [24BB7I is concrete formed with the composition shown in Table 1 {24-8-25BB (expanding material) C; 274 kg/m ³ +expanding agent; 20 kg/m ³ , W/C; 54.5%}. Tap water curing (concrete water curing) of concrete aged for 7 days with various curing water described in Table 1 {tap water (standard water), dilution water (5%) or dilution water (5%)} ) Indicates the ratio of increase in compressive strength depending on the type of curing water. 24BB28I is the concrete formed with the composition shown in Table 2 {24-8-25BB (expansion material) C; 274 kg/m ³ +expansion agent; 20 kg/m ³ , W/C; 54.5%}. 2 Tap water curing (standard water curing) of concrete cured for 28 days with various curing water listed in Table 2 (tap water (standard water), dilution water (5%) or dilution water (5%)) Shows the ratio of increase in compressive strength depending on the type of curing water. 36H7I is the concrete formed by the composition (36-10-25H C; 370 kg/m ³ , W/C; 40.5%) described in Table 3 and various curing water described in Table 3 (tap water ( Standard water), dilution water (5%) or dilution water (5%)} shows the compression strength increase ratio by the type of curing water to the tap water curing (standard water curing) of concrete aged for 7 days. .. 36H28I is concrete formed by the composition (36-10-25H C; 370 kg/m ³ , W/C; 40.5%) described in Table 4 and various curing water described in Table 4 {tap water ( Standard water), dilution water (5%) or dilution water (5%)} shows the compression strength increase ratio by the type of curing water to the tap water curing (standard water curing) of concrete aged for 28 days. .. ] 図３は、試験例２における水道水養生（標準水養生）に対する表面硬度向上剤の希釈水ロ（５％又は１０％）養生の表面硬度増加比（％）及び圧縮強度増加比（％）（材齢７日間）を示すグラフである。［２４Ｎ７Ｓは、第５表に記載の比較例９及び実施例５乃至実施例６の配合（24-12-25NC；291kg/ｍ³、W/C；57.7%）にて形成されるコンクリートを第５表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢７日間養生したコンクリートの表面硬度増加比を示す。３６Ｎ７Ｓは、第５表に記載の比較例１０及び実施例７乃至実施例８の配合（36-12-25NC；376kg/ｍ³、W/C；44.4%）にて形成されるコンクリートを第５表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢７日間養生したコンクリートの表面硬度増加比を示す。３６Ｈ７Ｓは、第５表に記載の比較例１１及び実施例９乃至実施例１０の配合（36-12-25HC；398kg/ｍ³、W/C；43.2%）にて形成されるコンクリートを第５表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢７日間養生したコンクリートの表面硬度増加比を示す。２４Ｎ７Ｉは、第５表に記載の比較例９及び実施例５乃至実施例６の配合（24-12-25NC；291kg/ｍ³、W/C；57.7%）にて形成されるコンクリートを第５表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢７日間養生したコンクリートの圧縮強度増加比を示す。３６Ｎ７Ｉは、第５表に記載の比較例１０及び実施例７乃至実施例８の配合（36-12-25NC；376kg/ｍ³、W/C；44.4%）にて形成されるコンクリートを第５表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢７日間養生したコンクリートの圧縮強度増加比を示す。３６Ｈ７Ｉは、第５表に記載の比較例１１及び実施例９乃至実施例１０の配合（36-12-25HC；398kg/ｍ³、W/C；43.2%）にて形成されるコンクリートを第５表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢７日間養生したコンクリートの圧縮強度増加比を示す。］FIG. 3 shows the surface hardness increasing ratio (%) and the compressive strength increasing ratio (%) of the dilution water (5% or 10%) of the surface hardness improver for the tap water curing (standard water curing) in Test Example 2. It is a graph which shows material age 7 days). [24N7S is a concrete formed by the composition of Comparative Example 9 and Examples 5 to 6 (24-12-25NC; 291 kg/m ³ , W/C; 57.7%) shown in Table 5. Table 5 shows the surface hardness increase ratio of concrete aged for 7 days with various curing waters {tap water (standard water), dilution water (10%) or dilution water (5%)} shown in Table 5. 36N7S is a concrete formed with the mixture of Comparative Example 10 and Examples 7 to 8 (36-12-25NC; 376 kg/m ³ , W/C; 44.4%) listed in Table 5 The surface hardness increase ratio of concrete aged for 7 days with various curing waters listed in the table {tap water (standard water), dilution water (10%) or dilution water (5%)} is shown. 36H7S is concrete formed with the composition of Comparative Example 11 and Examples 9 to 10 (36-12-25HC; 398 kg/m ³ , W/C; 43.2%) described in Table 5 The surface hardness increase ratio of concrete aged for 7 days with various curing waters listed in the table {tap water (standard water), dilution water (10%) or dilution water (5%)} is shown. 24N7I is a concrete formed with the mixture of Comparative Example 9 and Examples 5 to 6 (24-12-25NC; 291 kg/m ³ , W/C; 57.7%) listed in Table 5 The compressive strength increase ratio of concrete aged for 7 days with various curing water {tap water (standard water), dilution water (10%) or dilution water (5%)} shown in the table is shown. 36N7I is concrete formed with the composition of Comparative Example 10 and Examples 7 to 8 (36-12-25NC; 376 kg/m ³ , W/C; 44.4%) described in Table 5 The compressive strength increase ratio of concrete aged for 7 days with various curing water {tap water (standard water), dilution water (10%) or dilution water (5%)} shown in the table is shown. 36H7I is a concrete formed with the composition of Comparative Example 11 and Examples 9 to 10 (36-12-25HC; 398 kg/m ³ , W/C; 43.2%) listed in Table 5 The compressive strength increase ratio of concrete aged for 7 days with various curing water {tap water (standard water), dilution water (10%) or dilution water (5%)} shown in the table is shown. ] 図４は、試験例２における水道水養生（標準水養生）に対する表面硬度向上剤の希釈水ロ（５％又は１０％）養生の表面硬度増加比（％）及び圧縮強度増加比（％）（材齢２８日間）を示すグラフである。［２４Ｎ２８Ｓは、第６表に記載の比較例１２及び実施例１１乃至実施例１２の配合（24-12-25NC；291kg/ｍ³、W/C；57.7%）にて形成されるコンクリートを第６表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢２８日間養生したコンクリートの表面硬度増加比を示す。３６Ｎ２８Ｓは、第６表に記載の比較例１３及び実施例１３乃至実施例１４の配合（36-12-25NC；376kg/ｍ³、W/C；44.4%）にて形成されるコンクリートを第６表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢２８日間養生したコンクリートの表面硬度増加比を示す。３６Ｈ２８Ｓは、第６表に記載の比較例１４及び実施例１５乃至実施例１６の配合（36-12-25HC；398kg/ｍ³、W/C；43.2%）にて形成されるコンクリートを第６表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢２８日間養生したコンクリートの表面硬度増加比を示す。２４Ｎ２８Ｉは、第６表に記載の比較例１２及び実施例１１乃至実施例１２の配合（24-12-25NC；291kg/ｍ³、W/C；57.7%）にて形成されるコンクリートを第６表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢２８日間養生したコンクリートの圧縮強度増加比を示す。３６Ｎ２８Ｉは、第６表に記載の比較例１３及び実施例１３乃至実施例１４の配合（36-12-25NC；376kg/ｍ³、W/C；44.4%）にて形成されるコンクリートを第６表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢２８日間養生したコンクリートの圧縮強度増加比を示す。３６Ｈ２８Ｉは、第６表に記載の比較例１４及び実施例１５乃至実施例１６の配合（36-12-25HC；398kg/ｍ³、W/C；43.2%）にて形成されるコンクリートを第６表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢２８日間養生したコンクリートの圧縮強度増加比を示す。］FIG. 4 shows the surface hardness increasing ratio (%) and the compressive strength increasing ratio (%) of the dilution water (5% or 10%) of the surface hardness improver for the tap water curing (standard water curing) in Test Example 2. It is a graph showing material age 28 days). [24N28S is the concrete formed by the composition of Comparative Example 12 and Examples 11 to 12 (24-12-25NC; 291 kg/m ³ , W/C; 57.7%) listed in Table 6. Table 6 shows the surface hardness increase ratio of concrete aged for 28 days with various curing water {tap water (standard water), dilution water (10%) or dilution water (5%)} shown in Table 6. 36N28S is a concrete formed with the composition of Comparative Example 13 and Examples 13 to 14 (36-12-25NC; 376 kg/m ³ , W/C; 44.4%) listed in Table 6 to 6th. The surface hardness increase ratio of concrete aged for 28 days with various curing water {tap water (standard water), diluting water (10%) or diluting water (5%)} shown in the table is shown. 36H28S is the sixth concrete formed by the mixture of Comparative Example 14 and Examples 15 to 16 (36-12-25HC; 398 kg/m ³ , W/C; 43.2%) shown in Table 6. The surface hardness increase ratio of concrete aged for 28 days with various curing water {tap water (standard water), diluting water (10%) or diluting water (5%)} shown in the table is shown. 24N28I is the sixth concrete formed by the mixture of Comparative Example 12 and Examples 11 to 12 (24-12-25NC; 291 kg/m ³ , W/C; 57.7%) shown in Table 6. The compressive strength increase ratio of concrete aged for 28 days with various types of curing water (tap water (standard water), dilution water (10%) or dilution water (5%)) shown in the table is shown. 36N28I is the sixth concrete formed by the composition of Comparative Example 13 and Examples 13 to 14 (36-12-25NC; 376 kg/m ³ , W/C; 44.4%) shown in Table 6. The compressive strength increase ratio of concrete aged for 28 days with various types of curing water (tap water (standard water), dilution water (10%) or dilution water (5%)) shown in the table is shown. 36H28I is the sixth concrete formed by the composition of Comparative Example 14 and Examples 15 to 16 (36-12-25HC; 398 kg/m ³ , W/C; 43.2%) shown in Table 6. The compressive strength increase ratio of concrete aged for 28 days with various types of curing water (tap water (standard water), dilution water (10%) or dilution water (5%)) shown in the table is shown. ] 図５は、試験例２における水道水養生（標準水養生）に対する表面硬度向上剤の希釈水ロ（５％又は１０％）養生の表面硬度増加比（％）及び圧縮強度増加比（％）｛養生水ロによる養生（材齢７日間）及び気中養生２１日（計材齢２８日）｝を示すグラフである。［２４Ｎ(７＋２１)Ｓは、第７表に記載の比較例１５及び実施例１７乃至実施例１８の配合（24-12-25NC；291kg/ｍ³、W/C；57.7%）にて形成されるコンクリートを第７表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢７日間養生した後、気中養生を２１日間（計材齢２８日間）行ったコンクリートの表面硬度増加比を示す。３６Ｎ(７＋２１)Ｓは、第７表に記載の比較例１６及び実施例１９の配合（36-12-25NC；376kg/ｍ³、W/C；44.4%）にて形成されるコンクリートを第７表に記載の養生水｛水道水（標準水）、又は希釈水ロ（５％）｝にて材齢７日間養生した後、気中養生を２１日間（計材齢２８日間）行ったコンクリートの表面硬度増加比を示す。３６Ｈ(７＋２１)Ｓは、第７表に記載の比較例１７及び実施例２０乃至実施例２１の配合（36-12-25HC；398kg/ｍ³、W/C；43.2%）にて形成されるコンクリートを第７表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢７日間養生した後、気中養生を２１日間（計材齢２８日間）行ったコンクリートの表面硬度増加比を示す。２４Ｎ(７＋２１)Ｉは、第７表に記載の比較例１５及び実施例１７乃至実施例１８の配合（24-12-25NC；291kg/ｍ³、W/C；57.7%）にて形成されるコンクリートを第７表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢７日間養生した後、気中養生を２１日間（計材齢２８日間）行ったコンクリートの圧縮強度増加比を示す。３６Ｎ(７＋２１)Ｉは、第７表に記載の比較例１６及び実施例１９の配合（36-12-25NC；376kg/ｍ³、W/C；44.4%）にて形成されるコンクリートを第７表に記載の養生水｛水道水（標準水）、又は希釈水ロ（５％）｝にて材齢７日間養生した後、気中養生を２１日間（計材齢２８日間）行ったコンクリートの圧縮強度増加比を示す。３６Ｈ(７＋２１)Ｉは、第７表に記載の比較例１７及び実施例２０乃至実施例２１の配合（36-12-25HC；398kg/ｍ³、W/C；43.2%）にて形成されるコンクリートを第７表に記載の各種養生水｛水道水（標準水）、希釈水ロ（１０％）又は希釈水ロ（５％）｝にて材齢７日間養生した後、気中養生を２１日間（計材齢２８日間）行ったコンクリートの圧縮強度増加比を示す。］FIG. 5 is a ratio (%) of increasing surface hardness and a ratio (%) of increasing compressive strength (%) for diluting water (5% or 10%) of the surface hardness improver to tap water curing (standard water curing) in Test Example 2. It is a graph which shows curing by curing water (7 days old material) and 21 days in air (total material age 28 days)}. [24N(7+21)S is formed by the composition of Comparative Example 15 and Examples 17 to 18 (24-12-25NC; 291 kg/m ³ , W/C; 57.7%) shown in Table 7. The concrete is cured with various curing waters listed in Table 7 (tap water (standard water), dilution water b (10%) or dilution water b (5%)) for 7 days and then air-cured. The increase ratio of the surface hardness of concrete after 21 days (28 days of material age) is shown. 36N(7+21)S is the concrete formed with the composition of Comparative Example 16 and Example 19 (36-12-25NC; 376 kg/m ³ , W/C; 44.4%) listed in Table 7. After curing for 7 days with curing water (tap water (standard water) or dilution water (5%)) listed in the table, air-curing for 21 days (total material age 28 days) The surface hardness increase ratio is shown. 36H(7+21)S is formed by the composition of Comparative Example 17 and Examples 20 to 21 shown in Table 7 (36-12-25HC; 398 kg/m ³ , W/C; 43.2%). The concrete was aged with various curing waters listed in Table 7 (tap water (standard water), dilution water b (10%) or dilution water b (5%)) for 7 days, and then aerial curing 21 The increase ratio of the surface hardness of the concrete carried out for a day (28 days of material age) is shown. 24N(7+21)I is formed by the composition of Comparative Example 15 and Examples 17 to 18 (24-12-25NC; 291 kg/m ³ , W/C; 57.7%) shown in Table 7. The concrete was aged with various curing waters listed in Table 7 (tap water (standard water), dilution water b (10%) or dilution water b (5%)) for 7 days, and then aerial curing 21 The compressive strength increase ratio of the concrete carried out for a day (28 days of material age) is shown. 36N(7+21)I is concrete formed by the composition of Comparative Example 16 and Example 19 (36-12-25NC; 376 kg/m ³ , W/C; 44.4%) described in Table 7. After curing for 7 days with curing water (tap water (standard water) or dilution water (5%)) listed in the table, air-curing for 21 days (total material age 28 days) The compression strength increase ratio is shown. 36H(7+21)I is formed by the formulation of Comparative Example 17 and Examples 20 to 21 shown in Table 7 (36-12-25HC; 398 kg/m ³ , W/C; 43.2%). The concrete was aged with various curing waters listed in Table 7 (tap water (standard water), dilution water b (10%) or dilution water b (5%)) for 7 days, and then aerial curing 21 The compressive strength increase ratio of the concrete carried out for a day (28 days of material age) is shown. ] 図６は、試験例３（比較例１８乃至１９及び実施例２２乃至２３）における水道水養生及び希釈水ロ（５％）養生によるコンクリートの透気係数を示すグラフである。FIG. 6 is a graph showing the air permeability coefficient of concrete in test example 3 (comparative examples 18 to 19 and examples 22 to 23) by curing tap water and diluting water (5%).

本発明は、セメント組成物を、打込み後、エチレンオキシドとプロピレンオキシドの共重合体を含む表面硬度向上剤の希釈水により湛水養生することを特徴とするセメント系硬化体の養生方法及び該方法に使用される表面硬度向上剤を対象とする。
更に詳細に本発明を説明する。 The present invention provides a method for curing a cement-based hardened product and a method for curing a cement-based hardened product, which is characterized in that after the cement composition is injected, it is water-filled by diluting a surface hardness improver containing a copolymer of ethylene oxide and propylene oxide. The target is the surface hardness improver used.
The present invention will be described in more detail.

本発明のセメント系硬化体の養生方法に使用する、セメント組成物は、セメントペースト、モルタル、コンクリート等のセメントを結合相形成成分とする水硬性組成物であれば何れのものでも良い。結合相形成成分としてのセメントも特に限定されず、例えば、普通、早強、超早強、中庸熱、低熱、耐硫酸塩などの各種ポルトランドセメント、高炉スラグ、フライアッシュ、シリカ等が混合された混合セメント、白色セメント、アルミナセメント、エコセメント、フィラーセメントなどの特殊セメントなどを挙げることができる。また、結合相形成成分以外の含有成分も特に限定されるものではなく、例えば細骨材や粗骨材、その他モルタルやコンクリートで使用できる各種混和剤・材を含んでも構わない。 The cement composition used in the method for curing a cement-based hardened product of the present invention may be any hydraulic composition as long as it is a cement composition such as cement paste, mortar or concrete, which contains cement as a binder phase forming component. Cement as a binder phase forming component is not particularly limited, for example, normal, early strength, super early strength, moderate heat, low heat, various portland cement such as sulfate resistance, blast furnace slag, fly ash, silica, etc. were mixed. Specific cements such as mixed cements, white cements, alumina cements, eco cements, and filler cements can be mentioned. The components other than the binder phase forming component are not particularly limited, and may include, for example, fine aggregates, coarse aggregates, and various admixtures/materials that can be used in mortar and concrete.

本発明のセメント系硬化体の養生方法において、打込み後とは、一般に、養生工程の前に行う、打込み、締固め、仕上げからなる工程の終了後であることを示すが、急速硬化性のセメント組成物などを用いたときは、締固め及び仕上げの過程の前又は途中において、本発明による養生方法を開始してもよい。打込みとは、均質に製造され、現場まで運搬されたセメント組成物を、均質なまま型枠の中に投入する行為であって、締固めとは、振動を与えてセメント組成物に巻き込まれた余分な気泡を抜く行為を示す。締固めを行う方法として３つの方法、セメント組成物の内部に振動機（バイブレータ）を挿入して締め固める内部振動方式、型枠の外側から振動を与えて締め固める型枠振動方式、道路舗装や床などの表面を締め固める表面振動方式があるが、本発明ではいずれの方法も採りえる。また、仕上げとは、荒均し作業、定規ずり作業、及び最終仕上げからなる。荒均し作業とは、例えば、スコップやトンボなどを使用し、大雑把に、打ち込んだセメント組成物の表面の凹凸を均すものであり、定規ずり作業とは、セメント組成物の高さを決めるものであり、仕上げ精度に影響し、セメント組成物面に多少足跡がつくぐらいに固まった頃、例えば、トンボや木ゴテなどを使用して行い、さらに、セメント組成物の表面を均すものであり、最終仕上げ作業とは、定規ずり後に、硬化の状態を見ながら行うもので、トロウエルなどの機械コテや、木ゴテ、又は金ゴテなどを用いて所定の寸法精度を得る作業であり、コテむらなどを無くす金ゴテを使用して仕上げ面のむらの補正を行う場合がある。本発明では、打込み後、下記の表面硬度向上剤の希釈水で湛水養生する。 In the method for curing a cement-based hardened material of the present invention, the term "after implantation" generally means that after the step of implanting, compacting, and finishing, which is performed before the curing step, the cement is a rapid hardening cement. When a composition or the like is used, the curing method according to the present invention may be started before or during the compaction and finishing processes. Implanting is the act of putting a cement composition that has been homogeneously manufactured and transported to the site into the mold while maintaining its homogeneity, and compaction is that the cement composition was vibrated and caught in the cement composition. Indicates the act of removing excess bubbles. There are three methods for compaction: an internal vibration method in which a vibrator (vibrator) is inserted into the cement composition for compaction, a form vibration method in which vibration is applied from the outside of the formwork for compaction, road paving or Although there is a surface vibration method for compacting the surface of a floor or the like, any method can be adopted in the present invention. Further, finishing includes roughing work, ruler cutting work, and final finishing work. The roughening operation is, for example, roughly using a scoop or a dragonfly to even out the unevenness of the surface of the cement composition that has been driven in.The ruler cutting operation determines the height of the cement composition. It affects the finishing accuracy, and when the cement composition has hardened to the extent that it has a slight footprint, for example, using a dragonfly or a wooden iron, and further leveling the surface of the cement composition. Yes, the final finishing work is performed after observing the state of hardening after ruler cutting, and it is the work of obtaining a predetermined dimensional accuracy using a mechanical iron such as a trowel, a wooden iron, or a gold iron. There are cases where unevenness on the finished surface is corrected using a gold iron that eliminates unevenness. In the present invention, after the implantation, the surface is hardened by flooding with the following dilution water of the surface hardness improving agent.

本発明のセメント系硬化体の養生方法で使用する、表面硬度向上剤とは、非イオン性界面活性剤の一種であり、具体的には、エチレンオキシドとプロピレンオキシドの共重合体を主成分とする界面活性剤であり、エチレンオキシドが低分子量エチレンオキシドである
ことがより好ましい。共重合体の重合形式は、例えばブロック重合、ランダム重合等のいずれの形式でもかまわない。たとえばデンカ株式会社製の商品名「デンカエスケーガード」などの市販品を用いることができる。 The surface hardness improver used in the method for curing a cement-based cured product of the present invention is a kind of nonionic surfactant, and specifically, contains a copolymer of ethylene oxide and propylene oxide as a main component. More preferably, it is a surfactant and the ethylene oxide is a low molecular weight ethylene oxide. The polymerization method of the copolymer may be any method such as block polymerization or random polymerization. For example, a commercial product such as the product name "Denka SK-Guard" manufactured by DENKA CORPORATION can be used.

本発明の養生方法における、希釈水により湛水養生するとは、段落［００１８］に記載した表面硬度向上剤を水で希釈して希釈水とし、これを養生水として用いて、湛水養生するものである。湛水養生とは、セメント組成物を型枠に打込み後、セメント組成物の表面に養生水を張る養生方法であることを示す。本発明は打込み後に表面硬度向上剤の希釈水で養生する点において、セメント系硬化体の凝結反応の終結後から材齢７日の期間に収縮低減剤を塗布、散布又は吹き付けをする特許文献２に記載の発明とは異なる。本発明の養生方法ではセメント系硬化体の表面硬度の向上効果並びに表面緻密性の向上効果が得られるが、特許文献２に記載の方法では斯様な効果が実質奏しない。本発明の養生方法では、希釈水の濃度は１０質量％以下とするものであって、好ましくは５質量％乃至１０質量％であり、さらに好ましくは５質量％である。５質量％乃至１０質量％の希釈水を製造する方法、時期については、例えば、予め希釈水の濃度が５質量乃至１０質量％になるように表面硬度向上剤を水で希釈して必要量の希釈水を製造し、これを養生の際に、一般的に用いられる水道水（標準水）の代わりに養生水として用いる方法が採れる。また、例えば打込み後のセメント組成物の型枠の大きさから養生に必要な養生水を見積もり、水道水を張った後、５質量乃至１０質量％になるように表面硬度向上剤を加えてもよいし、表面硬度向上剤を先に加えてその後、水道水を加えて希釈し、５質量乃至１０質量％の必要量の希釈水としてもよい。また、打込み後のセメント組成物の表面から張り出す養生水の高さは１乃至１０ｃｍが好ましい。養生水の高さについて好ましい態様は、気候条件によって変化する。さらに、型枠の種類は、打込むセメント硬化体の周囲をあらかじめ高くできるものであればよく、特に制限されない。例えば材質での分類上においては、鋼製型枠、木製型枠等が用いることができ、製造後のセメント硬化体の表面状態から分類される型枠の種類では、化粧型枠等を用いることができる。湛水養生する際の温度（養生水の温度及び外気温）は特に制限されないが、概ね５℃から３５℃が望ましい。 In the curing method of the present invention, the term "submergence curing with dilution water" means that the surface hardness improver described in paragraph [0018] is diluted with water to obtain dilution water, and this is used as curing water to perform submersion curing. Is. The submerged curing refers to a curing method in which after the cement composition is cast into a mold, curing water is poured on the surface of the cement composition. According to the present invention, a shrinkage-reducing agent is applied, sprayed or sprayed within a period of 7 days after the completion of the setting reaction of the cement-based hardened material, in that it is cured with dilution water of the surface hardness improver after the driving. Different from the invention described in (1). With the curing method of the present invention, the effect of improving the surface hardness and the effect of improving the surface denseness of the cement-based cured product can be obtained, but the method described in Patent Document 2 does not substantially exhibit such an effect. In the curing method of the present invention, the concentration of diluting water is 10% by mass or less, preferably 5% by mass to 10% by mass, and more preferably 5% by mass. Regarding the method and timing of producing 5% by mass to 10% by mass of dilution water, for example, the surface hardness improver is diluted with water so that the concentration of the dilution water is 5% by mass to 10% by mass. A method of producing diluted water and using it as curing water instead of tap water (standard water) that is generally used during curing is adopted. Further, for example, the curing water required for curing is estimated from the size of the mold of the cement composition after driving, and after adding tap water, a surface hardness improver may be added so as to be 5% by mass to 10% by mass. Alternatively, the surface hardness improver may be added first, and then tap water may be added to dilute the water to obtain a required amount of dilution water of 5% to 10% by mass. Further, the height of the curing water that projects from the surface of the cement composition after driving is preferably 1 to 10 cm. The preferred embodiment for the height of the curing water varies depending on the climatic conditions. Further, the type of the mold is not particularly limited as long as it can raise the circumference of the hardened cement body in advance. For example, in terms of material classification, steel molds, wooden molds, etc. can be used. For types of molds classified according to the surface condition of the hardened cement after manufacturing, use decorative molds, etc. You can The temperature for curing the submerged water (the temperature of the curing water and the outside air temperature) is not particularly limited, but is preferably 5°C to 35°C.

本発明の養生方法おける湛水養生の期間は、材齢２８日間以下とするものであって、好ましくは７日間乃至２８日間であり、さらに好ましくは、７日間である。本発明における材齢とは、一般的な材齢と同じくセメント組成物を型枠に打込んだ時点（打設時点）からの経過期間をいう。打設日は材齢には含まない。２８日間を超えての養生は、表面硬度及び透気係数を２８日間以下の養生のそれらと比較して向上させるものではなく不経済である。また、湛水養生の期間を材齢２８日間以下続ければ、その後、気中養生等の養生を行ってもかまわない。この場合は、湛水養生と気中養生等の養生を組み合わせた期間が材齢２８日間以下となることが好ましい。 The period of flooding curing in the curing method of the present invention is 28 days or less, preferably 7 to 28 days, and more preferably 7 days. The age in the present invention means the elapsed time from the time when the cement composition is driven into the mold (the time of driving), as in the general age. The date of placing is not included in the material age. Curing for more than 28 days is uneconomical as it does not improve surface hardness and air permeability compared to those for curing for 28 days or less. Further, if the period of flooding curing is 28 days or less, the curing may be performed in the air or the like thereafter. In this case, it is preferable that the combined period of flooding and air curing be 28 days or less.

本発明で使用するセメント組成物の水セメント比は一般に５８％以下のものである。水セメント比が６０％程度の上限値が設定されることが多いセメント組成物が通常適用される、例えばトンネルの覆工や砂防ダム提体の施行において湛水養生は一般に適する方法と云えず、従って本発明の養生方法は斯様な施行において有利な方法とはならない。 The water-cement ratio of the cement composition used in the present invention is generally 58% or less. A cement composition in which a water-cement ratio is often set to an upper limit value of about 60% is usually applied. For example, in the case of lining tunnels or implementing erosion control dam bodies, submerged curing cannot be said to be a generally suitable method. Therefore, the curing method of the present invention is not an advantageous method in such an implementation.

以下、実施例及び比較例からなる試験例により本発明をさらに詳細に説明するが、本発明は、下記の試験例に何ら制限されるものではない。 Hereinafter, the present invention will be described in more detail with reference to test examples including examples and comparative examples, but the present invention is not limited to the following test examples.

第１表乃至第９表及び図１乃至図６において、
ＢＢ：高炉セメントＢ種
Ｎ：普通ポルトランドセメント
Ｈ：早強ポルトランドセメント
Ｃ：セメント
Ｗ：水
膨張剤：ハイパーエクスパン（太平洋マテリアル株式会社製）
希釈水イ(５％)：５％ＡＥ剤希釈水
希釈水ロ(５％)：５％表面硬度向上剤｛デンカエスケーガード（デンカ株式会社製、エチレンオキサイドとプロピレンオキサイドの共重合体）｝希釈水
希釈水ロ(１０％)：１０％表面硬度向上剤｛デンカエスケーガード（デンカ株式会社製、エチレンオキサイドとプロピレンオキサイドの共重合体）｝希釈水
Ａａｖｅ：圧縮強度の平均値
Ｓａｖｅ:表面硬度の平均値
を示す。 In Tables 1 to 9 and FIGS. 1 to 6,
BB: Blast furnace cement Class B N: Normal Portland cement H: Early strength Portland cement C: Cement W: Water swelling agent: Hyperexpan (Pacific Materials Co., Ltd.)
Diluting water (5%): 5% AE agent Diluting water Diluting water (5%): 5% Surface hardness improver {Denka ESC Guard (Denka Co., Ltd., a copolymer of ethylene oxide and propylene oxide)} Dilution Water-diluted water (10%): 10% Surface hardness improver {Denka SK-Guard (Denka Corporation, copolymer of ethylene oxide and propylene oxide)} Diluted water A ave: Average compressive strength S ave: Surface The average value of hardness is shown.

［試験例１］
試験例１（比較例１乃至比較例８及び実施例１乃至実施例４）では、第１表乃至第４表に記載の配合（水セメント比５４．５％及び４０．５％）のコンクリートからなる供試体の表面硬度及び表面硬度増加比並びに圧縮強度及び圧縮強度増加比の確認を行った。 [Test Example 1]
In Test Example 1 (Comparative Examples 1 to 8 and Example 1 to Example 4), concrete having the composition (water cement ratio 54.5% and 40.5%) described in Tables 1 to 4 was used. The surface hardness and the surface hardness increase ratio, and the compressive strength and the compressive strength increase ratio of each of the test pieces were confirmed.

＜表面硬度（試験例１）＞
コンクリートを直径１００ｍｍ、高さ２００ｍｍの円柱状の供試体になるように化粧型枠に打設し、打込み後、供試体の表面に高さ２ｃｍまで、第１表乃至第４表に記載の養生水｛水道水、希釈水イ(５％)又は希釈水ロ(５％)｝を張り湛水養生（材齢７日間又は材齢２８日間）を行った。表面硬度試験は、土木学会規準のＪＳＣＥ−Ｇ５０４「硬化コンクリートのテストハンマー強度の試験方法」に記載されている試験方法に基づき、シュミットハンマーを用いて、互いに３０ｍｍ以上の間隔を持った２０点にて供試体の反発度を測定し、その後、打撃方法や供試体の状況に応じた補正を実施し、補正後の値を推定表面硬度とした。表面硬度及び表面硬度増加比を第１表乃至第４表に、表面硬度増加比を図１に示す。 <Surface hardness (Test example 1)>
Concrete was cast into a decorative formwork so as to form a cylindrical test piece having a diameter of 100 mm and a height of 200 mm, and after the casting, the surface of the test piece was cured up to a height of 2 cm, as shown in Tables 1 to 4. Water {tap water, diluting water (5%) or diluting water (5%)} was applied and flooding was carried out (age 7 days or age 28 days). The surface hardness test is based on the test method described in JSCE-G 504 “Test method for test hammer strength of hardened concrete” of JSCE standard, using a Schmidt hammer, and 20 points spaced from each other by 30 mm or more. The degree of repulsion of the test piece was measured by, and thereafter, correction was performed according to the impact method and the condition of the test piece, and the value after correction was taken as the estimated surface hardness. The surface hardness and the surface hardness increase ratio are shown in Tables 1 to 4, and the surface hardness increase ratio is shown in FIG.

＜圧縮強度（試験例１）＞
段落［００２５］に記載の方法で作成した供試体を用いて圧縮強度を測定した。圧縮強度試験はＪＩＳＡ１１０８（コンクリートの圧縮強度試験方法）に準拠し、圧縮強度を測定した。圧縮強度及び圧縮強度増加比を第１表乃至第４表に、圧縮強度増加比を図２に示す。 <Compressive strength (Test example 1)>
The compressive strength was measured using the test piece prepared by the method described in paragraph [0025]. The compressive strength test was performed according to JIS A 1108 (concrete compressive strength test method) to measure the compressive strength. The compression strength and the compression strength increase ratio are shown in Tables 1 to 4, and the compression strength increase ratio is shown in FIG.

＜試験例１の結果＞
表面硬度について、図１及び第１表乃至第４表の結果から表面硬度向上剤を希釈した希釈水ロ（５％）にて養生した場合（実施例２乃至実施例４）、コンクリートの配合及び材齢期間にかかわらず、表面硬度向上剤を混和していない水道水の養生に比べて表面硬度が向上する。一方で、ＡＥ剤を希釈した希釈水イ（５％）にて養生した場合（比較例４、比較例６及び比較例８）は、表面硬度の向上は見られない。また、コンクリートの水セメント比に着目すると（実施例２及び実施例４）、水セメント比が小さいコンクリートの方が表面硬度の向上効果が高い。
圧縮強度について、図２及び第１表乃至第４表の結果から、表面硬度向上剤を希釈した
希釈水ロ（５％）にて養生した場合（実施例２乃至実施例４）、顕著な強度向上及び強度低下の傾向は見られない。また、表面硬度の増加比と圧縮強度の増加比に相関は見られない。 <Results of Test Example 1>
Regarding the surface hardness, from the results shown in FIG. 1 and Tables 1 to 4, when the surface hardness improver was diluted with diluted water (5%) (Examples 2 to 4), the concrete mix and Regardless of the age of the material, the surface hardness is improved compared to the curing of tap water in which the surface hardness improver is not mixed. On the other hand, no improvement in surface hardness is observed when curing is performed with dilution water (5%) diluted with the AE agent (Comparative Example 4, Comparative Example 6 and Comparative Example 8). Further, focusing on the water-cement ratio of concrete (Examples 2 and 4), the concrete having a small water-cement ratio has a higher effect of improving the surface hardness.
Regarding the compressive strength, from the results of FIG. 2 and Tables 1 to 4, remarkable strength was obtained when the surface hardness improver was cured with diluted water (5%) (Examples 2 to 4). There is no tendency for improvement and reduction in strength. Further, there is no correlation between the increase ratio of surface hardness and the increase ratio of compressive strength.

［試験例２］
試験例２（比較例９乃至比較例１７及び実施例５乃至実施例２１）では、第１表乃至第４表に記載の配合（水セメント比５７．７％、４４．４％及び４３．２％）のコンクリートからなる供試体の表面硬度及び表面硬度増加比並びに圧縮強度及び圧縮強度増加比の確認を行った。 [Test Example 2]
In Test Example 2 (Comparative Examples 9 to 17 and Examples 5 to 21), the formulations (water cement ratios 57.7%, 44.4% and 43.2) shown in Tables 1 to 4 were used. %) of the specimen made of concrete was confirmed for the surface hardness and the surface hardness increase ratio, and the compressive strength and the compressive strength increase ratio.

＜表面硬度（試験例２）＞
コンクリートを直径１００ｍｍ、高さ２００ｍｍの円柱状の供試体になるように化粧型枠に打設し、打込み後、供試体の表面に高さ２ｃｍまで、第５表乃至第７表に記載の養生水（水道水、希釈水ロ(１０％)又は希釈水ロ(５％)）を張り「湛水養生（材齢７日間）」若しくは「湛水養生（材齢２８日間）」又は「湛水養生（材齢７日間）その後気中養生（２１日間）」を行った。表面硬度試験は、段落［００２５］に記載の方法と同様に行った。表面硬度及び表面硬度増加比を第５表乃至第７表に、表面硬度増加比を図３乃至図５に示す。 <Surface hardness (Test example 2)>
Concrete was cast into a decorative formwork so as to form a cylindrical test piece having a diameter of 100 mm and a height of 200 mm, and after the casting, the surface of the test piece was cured up to a height of 2 cm, as shown in Tables 5 to 7. Fill with water (tap water, diluted water b (10%) or diluted water b (5%)), "submerged water curing (7 days old)" or "submerged water curing (28 days old)" or "pouring water" Curing (7 days old) and then air curing (21 days)". The surface hardness test was performed in the same manner as the method described in paragraph [0025]. The surface hardness and the surface hardness increase ratio are shown in Tables 5 to 7, and the surface hardness increase ratio is shown in FIGS. 3 to 5.

＜圧縮強度（試験例２）＞
段落［００３３］に記載の方法で作成した供試体を用いて圧縮強度を測定した。圧縮強度試験は段落［００２６］に記載の方法と同様にＪＩＳＡ１１０８（コンクリートの圧縮強度試験方法）に準拠し、圧縮強度を測定した。圧縮強度及び圧縮強度増加比を第５表乃至第７表に、圧縮強度増加比を図３乃至図５に示す。 <Compressive strength (Test example 2)>
The compressive strength was measured using the test piece prepared by the method described in paragraph [0033]. The compressive strength test was performed in accordance with JIS A 1108 (concrete compressive strength test method) as in the method described in paragraph [0026]. The compression strength and the compression strength increase ratio are shown in Tables 5 to 7, and the compression strength increase ratio is shown in FIGS. 3 to 5.

＜試験例２の結果＞
表面硬度について、図３乃至図５及び第５表乃至第７表の結果から表面硬度向上剤を希釈した希釈水ロ（５％）及び希釈水ロ（１０％）にて養生した場合（実施例５乃至実施例２１）、コンクリートの配合及び材齢期間にかかわらず、表面硬度向上剤を混和していない水道水の養生（比較例９乃至比較例１７）に比べて表面硬度が向上する。また、表面硬度向上剤の希釈濃度に着目すると、希釈水ロ（１０％）（実施例５、実施例７、実施例９、実施例１１、実施例１３、実施例１５、実施例１７及び実施例２０）より希釈水ロ（５％）（実施例６、実施例８、実施例１０、実施例１２、実施例１４、実施例１６、実施例１８及び実施例２１）で養生した供試体の方が、表面硬度の向上が見られる。一方で、養生期間に着目すると、材齢７日間（実施例５乃至実施例１０）及び材齢２８日間（実施例１１乃至実施例１６）で養生した供試体の方が材齢７日間その後気中養生２１日間（実施例１７乃至実施例２１）よりも供試体の表面硬度の向上が見られる。
圧縮強度について、図３乃至図５及び第５表乃至第７表の結果から表面硬度向上剤を希釈した希釈水ロ（５％）及び希釈水ロ（１０％）にて養生した場合（実施例５乃至実施例２１）、顕著な強度向上及び強度低下は見られない。また、表面硬度の増加比と圧縮強度の増加比に相関は見られない。 <Results of Test Example 2>
Regarding the surface hardness, from the results shown in FIGS. 3 to 5 and Tables 5 to 7, when the surface hardness improver was diluted with diluted water (5%) and diluted water (10%) (Examples) 5 to Example 21), the surface hardness is improved as compared with the curing of tap water in which the surface hardness improver is not mixed (Comparative Examples 9 to 17), regardless of the mixing ratio of concrete and age period. Further, focusing attention on the dilution concentration of the surface hardness improver, dilution water (10%) (Example 5, Example 7, Example 9, Example 11, Example 13, Example 15, Example 17, and Example). Example 20) of diluted water (5%) (Example 6, Example 8, Example 10, Example 12, Example 14, Example 16, Example 18, and Example 21) In this case, the surface hardness is improved. On the other hand, focusing on the curing period, the specimens aged at 7 days of age (Examples 5 to 10) and 28 days of age (Examples 11 to 16) have 7 days of age. The surface hardness of the test piece is improved more than that of the medium curing for 21 days (Examples 17 to 21).
Regarding the compressive strength, from the results of FIGS. 3 to 5 and Tables 5 to 7, when the surface hardness improver was diluted with diluted water (5%) and diluted water (10%) (Examples) 5 to Example 21), no significant improvement in strength or reduction in strength is observed. Further, there is no correlation between the increase ratio of surface hardness and the increase ratio of compressive strength.

［試験例３］
試験例３（比較例１８乃至比較例１９及び実施例２２乃至実施例２３）では、第９表に記載の配合（水セメント比４３．２％）のコンクリートからなる供試体の表層透気係数の確認を行った。 [Test Example 3]
In Test Example 3 (Comparative Examples 18 to 19 and Examples 22 to 23), the surface layer air permeability coefficient of the test piece made of concrete having the composition (water cement ratio 43.2%) described in Table 9 was measured. I confirmed.

＜表層透気試験（試験例３）＞
コンクリートを長さ５００ｍｍ、幅１００ｍｍ、高さ２５０ｍｍの直方体状の供試体になるように化粧型枠に打設し、打込み後、供試体の表面に高さ２ｃｍまで、第９表に記載の養生水｛水道水又は希釈水ロ(５％)｝を張り湛水養生（材齢７日間若しくは又は材齢２８日間）」を行った。表層透気試験は国土交通省東北地方整備局の「コンクリート構造物の品質確保の手引き（案）（橋脚、橋台、函渠、擁壁編）」に記載されているトレント法（R.J.Torrent: A two-chamber vacuum cell for measuring the coefficient of permeability to air of the concrete cover on site, Mater.Struct.,Vol.25, No.150, pp.358-365,July 1992）に基づき、各供試体において３箇所（左側、中央、右側）の表層透気係数ｋＴ（×10^-16ｍ²）を算出し、合わせて表面水率（含水率）を測定した。
なお、表層透気試験に用いるトレント法は、ダブルチャンバーの吸引によってコンクリート表層を真空状態にし、その後吸引を停止し、チャンバー内の気圧が回復するまでの時間から一次元方向の表層透気係数ｋＴ（×10^-16ｍ²）を算出する手法である。また、表層透気試験の結果は、コンクリートの含水率に影響を受けることが知られている。表層透気係数によって、コンクリート構造物の表面の密実性や緻密性の状態は、一般的に第８表に示すようにグレーディングできる。 <Surface Air Permeation Test (Test Example 3)>
Concrete is cast into a decorative formwork to form a rectangular parallelepiped test piece with a length of 500 mm, a width of 100 mm, and a height of 250 mm, and after curing, the surface of the test piece is cured up to a height of 2 cm, as shown in Table 9. Water {tap water or diluted water (5%)} was added and flooded with water (age 7 days or age 28 days). The surface air permeability test is based on the Trent method (RJ Torrent: A two) described in the "Guide for Quality Assurance of Concrete Structures (Draft) (Bridge Piers, Abutments, Hakocks, Retaining Walls)" by the Tohoku Regional Development Bureau, Ministry of Land, Infrastructure, Transport and Tourism. -chamber vacuum cell for measuring the coefficient of permeability to air of the concrete cover on site, Mater.Struct., Vol.25, No.150, pp.358-365, July 1992) The surface air permeability coefficient kT (×10 ⁻¹⁶ m ² ) on the left side, the center, and the right side was calculated and combined to measure the surface water content (water content).
The Trent method used for the surface air permeability test is that the concrete surface layer is evacuated by the suction of the double chamber, the suction is stopped after that, and the air permeability coefficient kT in the one-dimensional direction from the time until the atmospheric pressure in the chamber is recovered. This is a method of calculating (×10 ^-16 m ² ). It is known that the results of the surface air permeability test are affected by the water content of concrete. Depending on the surface air permeability coefficient, the solidity or denseness of the surface of the concrete structure can be generally graded as shown in Table 8.

試験例３にて算出した表層透気係数ｋＴ（×10^-16ｍ²）を第９表及び図６に示す。 The surface air permeability coefficient kT (×10 ^-16 m ² ) calculated in Test Example 3 is shown in Table 9 and FIG.

＜試験例３の結果＞
表層透気係数について、図６及び第９表の結果から表面硬度向上剤を希釈した希釈水ロ（５％）にて養生した場合（実施例２２乃至実施例２３）、材齢期間にかかわらず、表面硬度向上剤を混和していない水道水の養生（比較例１８乃至比較例１９）に比べて０．００１×１０^−１６程度透気係数が小さい結果が得られた。つまり表面の緻密性が向上している。一方で、養生期間に着目すると、材齢７日間（実施例２２）と材齢２８日間（実施例２３）では、透気係数の向上に差は見られなかった。 <Results of Test Example 3>
Regarding the surface air permeability coefficient, from the results shown in FIG. 6 and Table 9, when the surface hardness improver was cured with diluted water b (5%) (Examples 22 to 23), regardless of the age period. In comparison with the curing of tap water containing no surface hardness improver (Comparative Examples 18 to 19), the air permeability coefficient was smaller by about 0.001×10 ⁻¹⁶ . That is, the denseness of the surface is improved. On the other hand, focusing on the curing period, there was no difference in the improvement of the air permeability coefficient between the material age of 7 days (Example 22) and the material age of 28 days (Example 23).

Claims

A method for curing a cement-based hardened product, which comprises curing a cement composition with water after diluting with water for diluting a surface hardness improver containing a copolymer of ethylene oxide and propylene oxide.

The method for curing a cement-based hardened product according to claim 1, wherein the concentration of the diluting water of the surface hardness improver is 5% by mass to 10% by mass.

The method for curing a cement-based hardened product according to claim 1 or 2, which is continued for a period of 7 to 28 days after the impregnation with water.

The method for curing a cement-based hardened product according to any one of claims 1 to 3, wherein a water-cement ratio of the cement composition is 58% or less.

A surface hardness improver containing a copolymer of ethylene oxide and propylene oxide for improving the surface hardness of a cement-based hardened body by flooding curing.