JP4315260B1 - Method for repairing concrete placing surface and premix mortar containing water retaining material - Google Patents

Abstract

The present invention provides a technique for easily and reliably repairing bubble marks generated on a concrete casting surface, particularly a sloped concrete casting surface, using powder instead of mortar repair.
SOLUTION: When repairing bubble marks 4, 6, and 7 generated on a concrete casting surface 2, the mixed powder-containing water-retaining material-containing premix mortar 12 is pressed into the bubble marks with a sponge ridge 8 so as to push the concrete. It is applied to the installation surface, then water is applied to the application surface by spraying, and the surface is leveled with a sponge to repair the concrete placement surface. The powdery water retention material-containing premix mortar 12 is configured to include 1.25 to 75 volume parts of water retention material and 5 to 75 volume parts of fine aggregate of 0.4 mm or less with respect to 100 volume parts of cementitious material. .
[Selection] Figure 2

Description

  The present invention relates to a novel method for repairing bubble marks generated on a concrete casting surface of a cast-in-place, a concrete molded product or a concrete building, particularly a sloped concrete casting surface, and a powdery water retaining material used in the method. The present invention relates to a material-containing premix mortar.

  Vibrators are used to improve fillability when placing concrete. In this case, if the casting surface is inclined, the generated bubbles will adhere to the concrete panel surface in the middle of the rise, and the concrete casting surface Numerous large and small bubbles can occur. When a vibrator is not used, many larger bubbles are formed. Also, in the case of a vertical surface such as a box culvert or a building, a bubble mark is generated depending on the manner of placement.

Even if bubble marks occur, there is no effect on the concrete strength. In the case of buildings, there is no problem because it is hidden by painting or wallpaper. However, since outdoor structures such as sabo dams and retaining walls are made of concrete, if the degree is too high, the appearance deteriorates and the quality is mistaken, so that the processing becomes a problem. Also, in the case of a building, the finish of the surface is also a problem in the case of finishing the concrete.

  That is, in the case of structures such as sabo dams and retaining walls, the appearance is subject to evaluation as well as the finished dimensions and concrete strength, and if there are bubble marks or dirt on the concrete placement surface, the evaluation will deteriorate and adversely affect subsequent orders It will be. In addition, if there are bubble marks, there is a possibility that acid rainwater accumulates there and the acid rainwater penetrates into the concrete and weakens the concrete. In addition, in the case of a structure with a concrete finish, it becomes a product as it is, so the presence of bubble marks and dirt is not relaxed.

  Therefore, repairing the entire surface with mortar has been carried out especially when there are many bubble marks, but it takes time and money, and when mortar is coated with a thickness of about 1 mm, cracks and peeling often occur. In many cases, it is not possible to make a settlement.

In this case, as shown in Patent Documents 1 to 3, if a mortar mixed with synthetic resin, acrylic latex, or epoxy resin is used, cracking and peeling are less likely to occur even when the mortar is about 1 mm thick. However, it is very expensive and undesirable.
JP 2006-103986 A JP 2004-189564 A Japanese Patent Laid-Open No. 10-176424 Japanese Patent Laid-Open No. 06-32665 Japanese Patent No. 3644519 Japanese Patent Laid-Open No. 06-305856 JP-A-10-196115

  In addition, although the technique which coats with a mixture of bentonite and cement and raises fire resistance performance is described in patent document 4, this is what applies the thing kneaded with water to a steel frame, and is used for restoration of a concrete casting surface. It is different from what is used. In addition, Patent Documents 5 to 7 can be cited as techniques for filling a hole in the surface of a cement molded article. Patent Documents 5 to 6 are a mixture of a cement mixture with water, and Patent Document 7 is a resin. These are different from those that use powder to repair fine bubble marks on the concrete casting surface. In addition, in the case of a concrete-finished structure, the pattern of the formwork appears interesting on the concrete casting surface, but if the entire surface is repaired with mortar, the formwork pattern will disappear. is there.

  The inventor, instead of repairing the mortar, mixed cement powder or fine aggregate with it and applied it to the surface of the concrete by pushing it into a bubble mark with a sponge scissors, and tried to apply moisture by spraying. However, the cement powder did not set and flowed.

  Therefore, as a result of various researches, the present inventor has thoroughly mixed a cement mixture (bill mole # 1) marketed under the name of a commercially available ironing repair material into cement powder, and pushed the concrete into the bubble marks. When it was applied to the surface and given water with a mist sprayer, it was found that the cement and bill mole did not flow and the bubble marks were repaired cleanly. This is because the iron repair material contains some substance that absorbs and retains water, and it seems that water gradually comes out of this substance and hardens the cement. In addition, when Birmol was suspended in water, it was found that very fine sand was contained. That is, it was inferred that this substance retained moisture and formed a film of water, which was gradually solidified by supplying moisture to the cement by the action of fine aggregates.

  From this finding, the present inventor used bentonite as a substance that absorbs and retains water, mixed fine sand and given water by spraying, and it was found that cement and bentonite do not flow and are beautiful. It was found that repair of bubble marks was performed. In addition, when a drop of water was dropped on a mixture of cement and bill mole, and a mixture of cement, bentonite and sand, and viewed with a microscope, the area where the water was absorbed almost did not spread and became a hole. . However, with bentonite alone, the dripping water was not absorbed for a while and was in a rounded state. Therefore, it was speculated that bentonite absorbed water by the action of cement and sand.

  In addition to bentonite, zeolite powder or visiting stone powder mixed with cement and sand also absorbed water in the same state. Zeolite and visiting stone are known to contain montmorillonite-like substances. Other diatomaceous earth and highly water-absorbing resin also have water retention. In addition, Asagi clay and Kuroshiki powder add viscosity to the mixed powder.

  In addition, as the above-mentioned commercially available ironing repair materials (sometimes referred to as thin coating finish materials), the trade name Birmol (Toyoun Corporation ironing repair materials (# 01, # 03, DX-10, DX-) In addition to 15)), there are Union P mole (manufactured by Futase Ceramics Co., Ltd.) and tough ace (polymer cement ironing material manufactured by Lion Co., Ltd.). be able to. However, these commercially available thin coating materials and repair materials themselves are kneaded with water-based resin adhesives such as Hiflex, Refrebond, and sealer solution (applied to a thickness of about 1 mm). If it is in powder form, it is said that it is inferior in curability or hardly cured even if water is given by spraying. However, when these and cement are mixed in about half and used in powder form, an ideal one can be obtained for the repair of bubble marks.

  However, although the iron repair material described above is due to the use of Portland cement (hereinafter simply referred to as cement) or the color of other substances being mixed, the color is dark (Billmol is reddish black) ) There are many things and often does not match the color of the concrete casting surface to be restored. For this reason, white cement is used as the cement to be mixed, or color matching is performed by mixing slaked lime or calcium carbonate.

  Color matching is also performed when water retention materials such as bentonite, zeolite, diatomaceous earth, and stone powder are used alone or in combination. Also, the color changes depending on the type and mixing ratio of the aggregate, and in the case of cement (especially blast furnace cement), the color varies depending on the type and manufacturer, and the color varies depending on the material used including the water retention material. It is better to match the color by mixing white cement with slaked lime or calcium carbonate. Moreover, when darkening a color, the powder of a waiting stone, a zeolite, or a finely crushed product may be used.

  Color matching is necessary to prevent color unevenness between the concrete casting surface and the bubble trace portion when the bubble trace is repaired. This color matching is performed by adjusting the color of the concrete placing surface to be repaired, as a powder mixture or a dry product obtained by kneading a small amount of mixed powder with water (heated with a burner to dry in a few minutes). Is.

In addition, the cementitious substance said by this invention contains slaked lime, calcium carbonate, and fly ash other than cements, such as white cement, cement (Portland cement), and blast furnace cement. These, as well as the cement including CaO and SiO _2. In the case of Portland cement, there is almost no difference in color depending on the manufacturer, but in the case of blast furnace cement, those manufactured by Onoda Cement are white and those manufactured by Tokuyama Cement and Aso Cement are somewhat pale. Therefore, in the case of two later companies, the ratio of slaked lime and calcium carbonate is increased. The reason why a large amount of blast furnace cement is used in the present invention instead of ordinary cement is that the color of the blast furnace cement is somewhat white. Furthermore, since most of the outdoor structures use blast furnace cement, it depends on the compatibility.

  Commercially available thin coating materials and repair materials are premixed with very fine (about 0.2 mm or less) fine aggregate, but in the case of a mixture of water retention material such as bentonite and cement, fine aggregate If not, water absorption will be poor (it may hardly absorb water), and there will be problems such as cracks in the bubble marks buried after drying. Therefore, fine aggregate of 0.4 mm or less is mixed. If the thickness exceeds 0.4 mm, sand streaks may stick to the surface and may not fit into fine bubble marks when averaged with a sponge jar, which is not preferable. If possible, the fine aggregate is desirably 0.3 mm or less, more preferably 0.25 mm or less (0.063 mm or more).

  As the fine aggregate, fine sand may be used, but fine crushed products of zeolite or visiting stone may be used. Fine sand is quite expensive because it takes time and effort to crush, but it is soft in the case of zeolite and stone, so it is easy to crush and crush, and there is an advantage that a fine (fine) crushed product can be obtained at low cost. Furthermore, in the case of zeolite or visiting stone, it also acts as a water retaining material. Therefore, when a finely crushed product of zeolite or visiting stone is used, there is an advantage that it is not necessary to use a separate water retaining material.

  Zeolite is a substance produced under the low temperature and constant pressure conditions, mainly composed of elements present in the crust such as Si, Al, alkaline earth, etc., and has the property of adsorbing water and various gases. Kuroshiki is a tuff sandstone that forms the lower Ikimo Group of the Neogene Miocene Izumo Group. It consists of a wide variety of rock fragments and crystal fragments, and the substrate that fills them. . Among them, zeolite is also included and has the property of absorbing water permeability and water well. Moreover, the fine powder of visiting stones has the effect of preventing cracking. When bentonite is supplied with water, it forms a water film on the surface and has a cohesive force. However, even when zeolite or visiting stone is applied with water, it cannot form a water film on the surface, and absorbs water by capillary action.

  The mixing ratio of the cement, the water retaining material, and the fine aggregate is used at a ratio of 1.25 to 75 parts by volume of the water retaining material and 5 to 75 parts by volume of the fine aggregate with respect to 100 parts by volume of the cement. If the ratio of the water retaining material is small, the water retaining effect is small, and the cement is not sufficiently flowed or hardened by spraying water. When the ratio of the water retaining material is too large, the mixture is difficult to harden due to a small amount of cement. Moreover, if there is little fine aggregate, the crack of an application surface will arise or water penetration will be difficult, and sufficient hardening cannot be performed. If the proportion of fine aggregate is too large, the cement component will decrease and sufficient curing will not be obtained. In the case of a water retaining material, it is 9.1 to 75 parts by volume, excluding the superabsorbent resin. Within these ranges, implementation is possible (Tables 1 and 2). More preferably, the water retaining material is about 20 to 60 parts by volume and the fine aggregate is about 20 to 45 parts by volume with respect to 100 parts by volume. is there. Moreover, in the case of a combination of blast furnace cement and zeolite particles, there is a tendency to harden quickly.

  In the present invention, the cement and the like are shown in the capacity part because the cement and the like were weighed in a container (500 cc) in the implementation. The weight of one 500cc container is 452g for white cement, 400g for blast furnace cement, 440g for granite stones (0.3mm or less), 258g for zeolite grains (0.25-0.063mm), and shallow clay. 450 g, slaked lime 260 g, bentonite and fly ash 300 g.

  In addition, in the case of a commercially available thin coating finish or repair material, cement or fine aggregate is contained in itself, so the mixing ratio of the cement and the iron repair material is the iron repair material 33 to 100 capacity parts of cement. When the capacity is 300 parts by volume, good results are obtained (Table 1). The detailed blending ratio of the ironing repair material is not known in the trade secret, but at least 20% by volume of fine aggregate is considered. In addition, resin, paste, fiber and the like are included.

  As described above in detail, the present invention uses a sponge jar to mix powder-type water-retaining material-containing premix mortar that has been color-matched when repairing air bubble marks generated on the concrete placement surface of cast-in-place or molded products or concrete structures. It is applied to the concrete casting surface so as to be pushed into the bubble marks, then water is applied to the application surface by spraying, and then the surface is further smoothed with a sponge. The sponge cocoon is obtained by bonding a sponge or foam rubber plate having a thickness of about 2 to 6 mm to the surface of a wood or plastic handle. Sponge wrinkles are used for spreading a waterproofing material or a finishing material for troweling, finishing mortar, etc. In the present invention, other wrinkles cannot be used. However, in other cocoons, there is a tendency that the water-retaining material-containing premix mortar cannot be pushed into the bubble marks as in the case of the sponge cocoons, and the use of the sponge cocoons is more preferable.

Therefore,
(1) Apply water-preserving material-containing premix mortar with a sponge scissors to imprint on the concrete casting surface, spray water, and then level with a sponge scissors, so anyone can easily remove bubbles on the concrete casting surface. Can be repaired.
(2) The water-retaining material-containing premix mortar is mainly made of white cement, and is simply mixed with a water-retaining material such as bentonite and sand, so that it can be obtained inexpensively, easily and in large quantities.
(3) Since the bubble marks on the concrete casting surface can be easily repaired, the aesthetics of outdoor structures such as sabo dams and retaining walls are improved, and the construction technology is highly evaluated.
(4) Since the water-retaining material-containing premix mortar can be easily matched to the color of the concrete structure, the repair of the bubble marks is not noticeable at all.
(5) The color of the repaired bubble scar does not change for several years. Therefore, it is sufficient for inspection. In other words, after several years, the concrete casting surface itself has been darkened due to the effects of acid rain, so the repaired bubble marks are not noticeable.
(6) The concrete placement surface is finished cleanly.
(7) In the case of a concrete structure that is left untouched, the bubble marks can be removed neatly and the pattern of the mold remains as it is, so that the appearance intended by the designer can be maintained.
An excellent effect is obtained.

  When repairing the bubble marks on the concrete casting surface, apply the color-matched powdery water-retaining material-containing premix mortar onto the concrete casting surface by pushing it into the bubble marks with a sponge scissor, and then spray the coated surface with a spray. After adding moisture, finish the surface with a sponge jar. Finally, the entire coated surface may be covered with a sheet for curing.

(Example)
FIG. 1 is a front view showing a part of a retaining wall 1 for two concrete panels, and FIG. 2A is a schematic end view taken along the line XX in FIG. 2 (b) to FIG. 2 (d) are cut end schematic views of the same location as FIG. 2 (a), and FIG. 2 (b) is a powdered water retention material-containing premix mortar (hereinafter referred to as powdered pre-mold) Fig. 2 (c) shows a state where water is applied by spraying, Fig. 2 (d) shows a concrete placement with a sponge hammer. In this state, the surface 2 is leveled. FIG. 3 is a front view of a state where the repair of the bubble scar is completed at the same location as FIG. In addition, the code | symbol 3 of FIG.1 and FIG.3 is a drain port.

  Examples 1 to 8 are examples in which a fine aggregate was not used but a cement-based substance and a commercially available ironing repair material were used. Examples 9 to 19 are examples in which fine water sand is used as various water retention materials and fine aggregates for cementitious materials. Moreover, although Example 20 to Example 30 partially used the water retention material, many did not use a water retention material, but used the finely pulverized material of a zeolite or a visiting stone as an aggregate and a water retention material. It is an example. However, although each Example is not necessarily implemented in this order, it is inconsistent, but it is in this order as a result of being classified according to the materials used. Moreover, although each Example is an Example of a thing, Example 1 also gives the Example of each method.

First, as shown in Table 1, white cement and bill mole # 1 are mixed at a volume ratio of 6: 5, and slaked lime is mixed at a ratio of 2 to match the color of the concrete placement surface 2 of the retaining wall. And thoroughly mixed to obtain a powdery premixed mortar. If the powdered premix mortar is about 8 liters, an area (3.24 m ² ) equivalent to ^two concrete panels can be applied. This naturally includes those adhered to places other than the bubble traces on the concrete casting surface and the amount spilled from the sponge basket. The amount of the powdered premix mortar depends on the number and size of the bubble marks, the finished state of the concrete casting surface, and the like. In addition, the area for two concrete panels is an area that is just right for one application.

  Next, as shown to Fig.2 (a), when there exists the big bubble trace 4, it fills with the normal mortar 5 on the previous day until it becomes a depth of about 1-2 mm. Further, when there is an inverted-mouth type bubble mark having a narrow entrance and a wide back as indicated by reference numeral 6, the entrance portion is cut out in advance as indicated by a dotted line. In the case of the bubble mark 6 in FIG. 2A, since it is not so deep as compared with the bubble mark 4, the powdery premix mortar is applied as it is, but when it is deep, the same processing as the bubble mark 4 is performed.

Then, on the day, as shown in FIG. 2 (b), the powdered premix mortar 9 is applied by pushing the upper side of the mortar 5 and the inside of the other bubble marks 7 and the bubble marks 6 with a sponge pad 8. I will do it. The powdery premix mortar 9 also adheres to the concrete casting surface 2 other than the bubble marks 4, 6, 7. It takes about 20 to 30 minutes to apply to this area (3.24 m ² ). The sponge jar 8 is moved up and down at an angle of about 5 to 20 degrees with the longer side facing sideways.

  Next, water 11 is applied over the entire application surface with a spray 10 (FIG. 4). The amount of water is about 400 cc to 700 cc at a time (for two concrete panels). The code | symbol 12 is the powdery premix mortar containing the water | moisture content sprayed (given).

  Then, after 5 to 40 minutes, this time, the sponge bowl 8 is held vertically or horizontally, moved almost horizontally and vertically and horizontally, and the entire concrete placing surface 2, especially above the bubble marks 4, 6, 7, is leveled. To go. The code | symbol 13 is a powdery premix mortar hardened | cured material which filled the bubble trace. As a result, the concrete casting surface 14 in which the bubble marks are beautifully repaired is obtained. The leveling with the sponge wrinkle 8 is carried out when the surface of the bubble mark to which the powdered premix mortar 9 has been applied is slightly wet but has become dry to some extent. The time to start leveling varies depending on the season, the dry state of the concrete placing surface 2 and the like, and is about 5 to 40 minutes after the water is sprayed. For some reason, the color becomes blackish when leveling with a sponge candy 8 in an insufficiently dried state. When leveled in just dry condition, the entire area of the bubble marks will be glossy.

  If there is a place where the powdery premix mortar 9 has flowed or there are places where the bubble marks 4, 6, 7 are not sufficiently filled, the powdery premix mortar 9 is again applied and sprayed on that part. After -40 minutes, the part is leveled so that the surface is pressed with a sponge scissors. This completes the repair of bubble marks on the entire concrete casting surface. If there is something wrong with the second repair, repeat this operation. Furthermore, when the water spray is repeated 3 to 6 times every several minutes to several hours (during the day or the next day) after leveling with a sponge jar, water penetrates into the powdery premix mortar 9 in the bubble trace. Is fully performed and hardened reliably. In this case, the amount of water sprayed per time is about 400 to 700 cc / two concrete panels. However, in the case of a mixture of white cement and Bilmoto, if water is dripped too much, it will sag, so the number of spraying needs to be somewhat modest (2-4 times).

After the air bubble mark repair on the concrete placing surface is completed, the portion is covered with a sheet and cured. In addition, the time required for the repair work of the bubble marks is a variety of by-site such as or a base adjustment of concrete設面Dari formed a scaffold, 10m ² ~30m ² about the construction is possible in one day roughly is there. The sheet curing usually takes about 1 day in summer and about 3 days in winter to cope with rain. If it continues to rain, leave it hanging. Further, by covering with a sheet, it is promoted that the yet-dried concrete casting sweats, and this sweat also functions to cure or fix the powdered premix mortar 9. However, when there is no worry about rain, this sheet covering can be omitted. Then, after removing the sheet, it is preferable to spray the water about once.

In addition, when the concrete placement surface 2 is dry, it is preferable to wet the concrete placement surface by spraying in advance before applying the water retaining material-containing premix mortar 9. Normally, concrete is demolded 1 to 2 weeks after placing, but in that case the concrete is not yet sufficiently dry, and the water-retaining material-containing premix mortar tends to adhere to the concrete placing surface. However, when the concrete dries quickly or takes a long time after demolding (for example, one month later), the concrete placement surface is dry. Therefore, in such a case, the concrete placement surface should be moistened by spraying before applying the water-retaining material-containing premix mortar. The construction area for one day (8 hours) is about 10 to 15 m ² , although it depends on the weather, the shape of the construction place, and the like.

(Example 2 to Example 8)
From Example 2 to Example 8, as in Example 1, white cement and commercially available ironing repair materials, and other cement-based substances and water retention materials at the ratios (volume ratios) shown in Table 1 for color matching are used. The example which mixed thoroughly and obtained the powdery premix mortar is shown. The construction was performed in the same manner as in Example 1. Here, in Example 7, the proportion of the building mole is large and the color is black. And all of these showed a good bubble mark repairing state.

(Example 10 to Example 19)
From Example 10 to Example 19, as shown in Tables 1 and 2, various cement-based materials and bentonite water retention materials and fine sand of 0.3 mm or less are mainly used for color matching, as shown in Tables 1 and 2. Are sufficiently mixed at a ratio (capacity ratio) shown in the table. The construction method is the same as in Example 1. All of these also showed a good bubble mark repair state. In addition, the fine sand of Example 10 uses what was baked and refined | miniaturized.

(Example 20 to Example 30)
Next, at the ratio (volume ratio) shown in Table 2, cement-based materials and crushed zeolite products (0.25 to 0.063 mm is 90%), crushed stone stone products (0.3 mm or less), Part (Examples 21 to 24 are bentonite, Example 25 is zeolite powder (0.063 mm or less)) using a water retention material and thoroughly mixed to obtain a powdered premix mortar. In this blending example, color matching is performed on the concrete placing surface. These were also constructed in the same manner as in Example 1, but showed a good bubble mark repair state as in the other examples. In Example 20, both fine sand and sand particles are used as fine aggregates.

  Each of the above examples shows the percentages that can be implemented, but the examples shown in Examples 26 to 30 are only manufactured by mixing zeolite grains or granite stone grains with white cement and blast furnace cement. Is also simple and preferred.

  In addition, each of the embodiments described above is for the retaining wall 1, but the same can be applied to a concrete molded product such as a box culvert or a concrete structure without a beating. Since many of these are vertical compared to the retaining wall 1, the bubble marks are small and small, but their presence also deteriorates the appearance.

It is a front view which shows the part for two concrete panels in a part of retaining wall. Example 1 FIG. 2 (a) is a schematic end view taken along the line XX in FIG. 1, and FIG. 2 (b) shows a state in which the powdery premix mortar of the present invention is applied to the concrete placing surface with a sponge knot. A schematic end view, FIG. 2 (c) is a schematic end view showing a state where water is sprayed in the same manner, and FIG. 2 (d) shows a state where the surface of the concrete placing surface is leveled with a sponge punch. FIG. 2 is a schematic end view, and FIG. It is a front view which shows the state which the repair of the bubble trace was completed in the same location as FIG. Example 1

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Retaining wall 2 Concrete casting surface 3 Drain outlet 4 Large bubble trace 5 Mortar 6 Reverse-mouth type bubble trace 7 Normal bubble trace 8 Sponge bowl 9 Powdery premix mortar 10 Spraying 11 Water 12 Powdered pre-water Mixed mortar 13 Powdered premixed mortar cured product with embedded bubble marks Concrete casting surface with repaired bubble marks

Claims (8)

  When repairing bubble marks that occur on the surface of cast-in-place, concrete moldings, or concrete building surfaces, press premixed mortar containing powdered water retention material that includes fine aggregates into the bubble marks with a sponge. A method for repairing a concrete casting surface, comprising: applying to a concrete casting surface, then applying moisture to the coating surface by spraying and then leveling and curing the surface with a sponge.   After spraying and spraying and drying for 5 to 40 minutes, leveling with a sponge jar, and if there is a place where premixed mortar containing water retention material has flowed or where there are not enough air bubble marks, the water retention material is contained again in this part 2. The method for repairing a concrete casting surface according to claim 1, wherein the premixed mortar is applied and sprayed, and finally the surface is leveled with a sponge scissors.   The method for repairing a concrete casting surface according to claim 1 or 2, wherein the spraying of water is repeated 3 to 6 times every several minutes to several hours after leveling with a sponge scissors.   4. The method for repairing a concrete casting surface according to claim 1, wherein the surface is smoothed with a sponge pad and then the coated surface is covered with a vinyl sheet and cured. The water-retaining material is 1.25 to 75 parts by volume with respect to 100 parts by volume of the cement-based substance, and the fine aggregate is 0.3 mm or less, and includes 5 to 75 parts by weight of the fine aggregate. A premixed mortar containing a powdered water retention material for applying to a concrete casting surface to repair the concrete casting surface.   It is a powder mixture in which white cement, blast furnace cement, Portland cement or fly ash is appropriately combined as a cement-based material, and slaked lime and calcium carbonate, which are cement-based materials, are mixed in consideration of the color of the water retaining material and fine aggregate. The powder water-retaining material-containing premix mortar according to claim 5, wherein the color matches the color of the concrete casting surface for repairing the powder mixture.   As a water retention material, a montmorillonite-containing material having water retention properties such as bentonite, zeolite, and visitor stone powder, a superabsorbent resin, or a cement mixture containing a water retention material content commercially available as an ironing material is used. Item 7. A powdered water retention material-containing premix mortar according to item 5 or claim 6.   In the case of using finely crushed zeolite or visitor stone as fine aggregates, no other water retention material is used, and if the entire premix mortar is set to 1, the finely divided product of zeolite or visitor stone is 0 The powdery water retaining material-containing premix mortar according to claim 5, 6 or 7, which is used at a ratio of 0.048 to 0.313.

Images