JP3239135B2 - Treatment method of concrete joint surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating a concrete joint surface.

[0002]

2. Description of the Related Art When constructing a concrete joint surface, a horizontal joint surface is used when the cast concrete has a young age, the latencies of the joint surface, poor quality concrete layers, and loose aggregate grains. Unless such factors are completely removed, a good bonding state cannot be obtained. Therefore, in order to ensure a good joining state, a method of shaving the concrete surface with high-pressure washing water has been used.

[0003] On the other hand, on the vertical joint surface, since the surface treatment is performed in a state where the cast concrete is already hardened, the surface is shaved with a wire brush, or a roughening treatment such as pitching is adopted. . However, in such a joint surface treatment method, the concrete surface is physically roughened by water pressure, impact, or the like, so that the roughening treatment becomes difficult and is insufficient to secure a good joint state. It was not a treatment method.

[0004] Therefore, as a method of facilitating the treatment of the joint surface, a setting retarder for delaying the setting of the cement is sprayed on the horizontal joint surface to delay the time of washing out or to shorten the period during which work is possible. A way to make it longer has been suggested. Also,
On the vertical joint surface, apply a highly viscous setting retarder to the inner surface of the formwork, or attach a paper, cloth or plastic sheet coated or impregnated with the setting retarder to the inner surface of the formwork. Methods to improve the performance have been proposed.

[0005] However, such a conventional method for processing a joint surface has the following technical problems.

[0006]

That is, in the above-mentioned conventional processing method, the setting retarder has a property of dissolving in water, so that at the construction site, the setting retarder flows out due to rainwater or water sprinkling. , Can not be washed out,
Alternatively, in the treatment of the vertical joint surface, there has been a problem that the setting retarder elutes in the bleeding water in the concrete and a portion other than a predetermined place is washed out.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a method capable of reliably processing a joint surface in on-site construction. is there.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a method of applying or adhering a setting retarder to one of the joint surfaces of concrete and curing the concrete for a predetermined period of time. In the method for treating a joint joint surface to be washed with water, the setting retarder may be an unsaturated polyether.
It was made of a material that contained stell, was not dissolved in water, and was hydrolyzed in alkaline water to exhibit the setting retardation of cement. According to this configuration, the setting retarder does not dissolve in water, is hydrolyzed with alkaline water, and has the property of exhibiting the setting retardation of cement, so that rainwater and watering, and further, The setting retarder does not flow out or elute with respect to the bleeding water. The setting retarder is a main component and a glycol and a dibasic acid, an unsaturated polyester having a weight average molecular weight of 300 to 25,000, relative to the unsaturated polycarboxylic ester le 100 parts by weight, 1 to 50 parts by weight of styrene Those crosslinked with a system monomer can be employed. In this case, the glycol of the unsaturated polyester is mainly composed of a dihydric alcohol such as ethylene glycol or propylene glycol or a polyoxyalkylene glycol which is a polymer thereof.
Accounts for 100% by weight. In the setting retarder of the present invention, the unsaturated polyester resin is hydrolyzed by the alkali contained in the cement to produce a polyester oligomer and further a glycol and a dibasic acid, which generally suppress the hydration reaction of the cement. Further, according to the retarder, the decomposition product generated by the hydrolysis is adsorbed on the surface of the cement particles, the effect of suppressing the hydration reaction of the cement is maintained for a long time, for example, It can be washed out even with a long age of 28 days. In the setting retarder, when the weight average molecular weight of the unsaturated polyester is 300 or less,
There is a disadvantage that the setting delay effect is reduced.
The unsaturated polyester has a weight average molecular weight of 2500.
If it is 0 or more, there is an inconvenience that the addition and mixing of a styrene-based monomer described below becomes difficult due to an increase in melt viscosity. The styrene-based monomer is added as a crosslinking component for curing the unsaturated polyester, which is often oily, and improves the mechanical properties of the unsaturated polyester as a resin, and also serves as a retarder. It is added for the purpose of controlling water resistance,
Other examples include methyl acrylate, ethyl acrylate, butyl acrylate, alkyl acrylate, hydroxyethyl acrylate, and methacrylates thereof, and one or more of them can be used as a polymerization monomer. In this case, when a styrene-based monomer is selected, the amount of the added
If the amount is less than 1 part by weight, the mechanical properties and water resistance of the unsaturated polyester will be insufficiently improved.
On the other hand, if the added amount is 50 parts by weight or more based on 100 parts by weight of the unsaturated polyester, there is a disadvantage that the retarding effect of the retarder becomes insufficient. The curing of the unsaturated polyester resin is carried out by radical polymerization such as organic peroxide, by simultaneously polymerizing styrene and crosslinking with the unsaturated polyester, and curing is possible at room temperature, but within about 1 hour. In order to cure in a short time, it may be performed under a temperature condition of about 60 to 200 ° C.
In order to further promote crosslinking, a curing accelerator such as an organic acid salt of cobalt can be used in combination. Further, in the present invention, the joining surface can be formed by a mold having an uneven shape. When such a mold is adopted, the joining surface becomes uneven, and a setting retarder is interposed in the joining surface of the uneven shape, and this portion is washed out,
Since the roughening treatment is performed, the integration between the leading concrete and the succeeding concrete can be improved, the shear strength of the joint surface is improved, the length of the water permeation flow path is increased, and the water tightness is also improved.

[0009]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 6
1 shows an embodiment of a method for treating a concrete joint surface according to the present invention. The embodiment shown in the figure is an example in which the processing method of the present invention is applied to a vertical joint surface. In the method of processing the joint surface, first, the preceding concrete A is cast using the formwork 10 before the processing of the joint surface.

The formwork 10 of this embodiment includes a pair of side plates 10a and 10b which are installed to face each other, and an end plate 10c which is installed on the joint surface side. On the inner surface side of the end plate 10c, an uneven portion 10d for providing unevenness on the joining surface is provided over the entire length along the longitudinal direction. In addition, the uneven portion 10
On the surface of d, a setting retarder 12 formed in a thin plate shape is provided over the entire surface.

The setting retarder 12 is, for example, adhered by an adhesive or fixed by a metal stitcher or the like. The setting retarder on the setting retarder film is shown in Table 1 below. Thus, it does not dissolve in water but is hydrolyzed with respect to an alkali, thereby exhibiting the setting retardation of the cement. The retarder 12 used in this embodiment, the main component and a glycol and a dibasic acid, weight average molecular weight of the unsaturated polyester of 2000, the unsaturated polycarboxylic S.
Against Te le 100 parts by weight, was used with the addition of styrene monomer, 5 parts by weight.

The amount of the decomposition retardant 12 decomposed and dissolved in the alkaline water was confirmed by adding 50 mg of the plate retarder 12 to pH.
Was immersed in alkaline water at room temperature, taken out every hour, and its weight was measured to determine the elution amount.

[0013]

[Table 1] After placing concrete in such a formwork 10 (see FIG. 2) and forming the preceding concrete A, after a predetermined curing period, as shown in FIG. 3, the end plate 10c is removed. The exposed surface B was exposed. Exposed joint surface B
The, as shown in the figure, uneven surface having a shape corresponding to the concave-convex portion 1 0d is formed, the nozzle 14 to the DaTsugi surface B
High pressure water D was sprayed through to wash the joint surface B and subjected to a washing process (see FIG. 4).

The joint surface B subjected to the washing process is shown in FIG.
As shown in FIG. 5, an uneven shape corresponding to the uneven portion 10d of the mold 10 is formed, and a setting retarder 12 is interposed in the joint surface B of the uneven shape to wash out this portion, whereby It becomes the state where the troll process was performed. And
Thereafter, the side plates 10a and 10b of the mold 10 are removed,
A formwork having the same structure is placed on the side of the preceding concrete A, and concrete is cast to form the succeeding concrete C (see FIG. 6).

When the joint surface B of the preceding and succeeding concretes A and C is treated in the above-described steps, the joint surface B to be washed by spraying the high-pressure water D does not dissolve in water, but does not dissolve in alkali. Since the setting retarder 12 which expresses the setting retardation property to the cement is interposed only after the hydrolysis, the roughening treatment with the high-pressure water D can be easily performed, and at the same time, rainwater, water sprinkling, and bleeding water In contrast, the setting retarder 12 does not flow out or elute.

For this reason, the portion where the setting retarder 12 is provided can be roughened accurately and accurately.
Further, in the case of the present embodiment, the joint surface B is formed by the uneven portion 10d.
Is formed by the formwork 10 provided with the joint, the joining surface B becomes uneven, and a setting retarder 12 is interposed in the joining surface B having the uneven shape, and this portion is washed out, so that the roughening treatment is performed. Is applied, the integration between the preceding and following concretes A and C can be improved, the shear strength of the joint surface B can be improved, the length of the water permeation flow path can be increased, and the watertightness can be improved.

Tables 2 and 3 below show comparison data obtained when the joint setting surface was washed out using the setting retarder 12 of the present invention and three types of commercially available setting retarders. The commercially available setting retarder is a sheet-shaped product containing a polysaccharide and lignin as main components (trade name: Zerviment, manufactured by Sunflow Co., Ltd.), and has a washing depth of 2 mm (A). Three types were prepared, one for 4 mm (B) and one for 6 mm (C).

The setting retarder 12 of the present invention and a commercially available setting retarder are each cut into a size of 9 cm × 9 cm,
This was adhered to a vertical joint surface of concrete, cured for the same period, and then washed out under the same conditions.

[0019]

[Table 2]

[0020]

[Table 3] As is clear from the results shown in Table 2, in the setting retarder 12 of the present invention, the area to be washed out (9 cm × 9 cm)
= 81 cm ² ), it was able to be washed out in almost the same size, whereas with a commercial setting retarder, it was washed out in a larger area than the area (81 cm ² ) to be washed out. In the setting retarder 12 of the present invention, necessary portions can be accurately washed out.

Further, as is clear from the results shown in Table 3, the setting retarder 12 of the present invention shows a little change in the washing depth even when the material age is long, and is sufficient even at a material age of 28 days. On the other hand, in the case of commercially available coagulants, the washing depth becomes very shallow as the number of days of age increases, and a sufficient washing depth cannot be obtained. The reason for this is that in the setting retarder 12 used in the present invention, the unsaturated polyester resin is hydrolyzed by the alkali of the cement to form a glycol component and a dibasic acid component or an oligomer thereof, and these are synthesized. Inhibits the hydration reaction of cement and, as a result, inhibits the hardening of concrete.

Furthermore, the effect of inhibiting the hydration reaction of cement is maintained for a long time by the adsorption of the hydrolysis products comprising the monomers and oligomers of the unsaturated polyester resin on the surface of the semene particles. It is estimated that even a long-term age of 28 days can be sufficiently washed out. In the above embodiment, the case where the present invention is applied to the vertical joint surface B is illustrated.
The invention is not limited to this, and can be applied to, for example, a horizontal joint surface. Further, the setting retarder 12 for the concrete joint surface of the present invention is not limited to the thin plate-like one shown in the above embodiment, but may be any of various types such as granules, liquids, sheets, rods, and pellets. For example, when it is in a liquid state, it can be applied to the inner surface of a mold.

[0023]

As described above in detail in the embodiments,
According to the method for treating a concrete joint surface according to the present invention, without taking measures against rainwater and water sprinkling, a setting retarder can be accurately installed at a necessary place, and thus a setting retarder is applied or attached. The position can be cleaned accurately.

According to the second aspect of the present invention, the material age 28
Even in the case of long-term ages such as days, it can be easily washed out. Further, according to the configuration of the third aspect, the integration between the leading concrete and the succeeding concrete can be improved, the shear strength of the joint surface is improved, the length of the water permeation flow path is increased, and the water tightness is also improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a formwork used in an embodiment of a method for treating a concrete casting surface according to the present invention.

FIG. 2 is an explanatory view of a prior concrete placing process of the processing method.

FIG. 3 is an explanatory view of a mold releasing step performed subsequent to the step of FIG. 2;

FIG. 4 is an explanatory view of a cleaning step performed subsequent to the step of FIG. 3;

FIG. 5 is an explanatory diagram of a joint surface obtained in the cleaning step of FIG. 4;

FIG. 6 is an explanatory view of a joint surface formed by concrete pouring performed subsequently to FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Formwork 10a, 10b Side plate 10c End plate 10d Concavo-convex part 12 Setting retarder 14 Nozzle A Preceding concrete B Joint surface C Following concrete D High pressure water

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Kawashima 4-640 Shimoseito, Kiyose-shi, Tokyo Inside Obayashi Corporation Technical Research Institute, Inc. (72) Inventor Yoshiyuki Ikemoto 1-19-5 Toranomon, Minato-ku, Tokyo Daise (56) References JP-A-4-222771 (JP, A) JP-A-54-159443 (JP, A) JP-A-8-309717 (JP, A) JP-A-5-12545 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) E04G 21/02 103 C04B 13/00

Claims (3)

(57) [Claims] 1. A method for treating a concrete joint surface, comprising applying or sticking a setting retarder to one of the joint surfaces of concrete and curing the concrete surface for a predetermined period of time, and then washing the concrete surface with high-pressure water. Is a method of treating a concrete joint surface, which comprises unsaturated polyester, does not dissolve in water, and is hydrolyzed in alkaline water to develop the setting retardation of cement. 2. The setting retarder contains glycol and a dibasic acid as main components, and has a weight average molecular weight of 300 to 2500.
0 unsaturated polyester, the unsaturated polyester 1
2. The method for treating a concrete joint surface according to claim 1, wherein the styrene monomer is crosslinked with 1 to 50 parts by weight based on 00 parts by weight. 3. The method for treating a concrete joint surface according to claim 1, wherein the joint surface is formed by a formwork having an uneven shape.