JPH0124751B2 - - Google Patents

Description

[Detailed Description of the Invention] The present inventor previously disclosed in Japanese Patent Application No. 58-231250,
Water-cement ratio is 28-37%, fine aggregate ratio is 4-9%
(volume ratio), and has an air-dry specific gravity of 1.3 or less, has lower thermal conductivity than ordinary concrete, and has an excellent soundproofing performance.

This concrete with an extremely low fine aggregate ratio does not have a good appearance and has poor water permeability, but depending on the mix, a small amount of mortar is left over to provide fluidity and vibration during concrete pouring. In this way, the lower bottom surface of the cast material and a portion of the outer circumferential end surface near the lower surface are covered with excess mortar, making it possible to provide an appearance similar to that of ordinary concrete. In this case, the portions that require surface finishing are the top surface to be poured and the outer peripheral end surface near the top surface.

Raised concrete with an extremely low fine aggregate ratio finishes drying shrinkage more quickly than normal concrete, so if regular mortar is used for surface finishing, drying shrinkage between the rammed concrete of the main body and the surface finish layer will occur. Cracks are likely to appear on the finished surface due to the difference in

The present invention has been proposed to solve these problems, and involves pouring concrete with excess mortar into a formwork, which has cement-based auxiliary stands attached to the inner circumferential surface of the side plates of the formwork. The bottom surface of the poured concrete and the outer peripheral end surface of the lower part of the auxiliary table are covered with surplus mortar, and after the poured concrete has hardened until it can be removed from the mold, the coarse aggregate of the poured concrete on the outer peripheral end surface of the upper part of the auxiliary table is covered with surplus mortar. The present invention relates to a method for finishing the surface of raised concrete, which is characterized by filling the spaces between the concrete with non-shrinking mortar and then finishing the top surface of the poured concrete with non-shrinking mortar in a semi-solid state.

In the present invention, a cement-based auxiliary stand is attached to the inner peripheral surface of the side plate of the formwork in which the raised concrete is poured, and the raised concrete mixed so that there is a surplus of mortar components is poured into the formwork, and the excess mortar is poured into the formwork. The lower bottom surface of the poured concrete and the outer peripheral end surface below the auxiliary platform are covered with the mortar so that each surface has the same appearance as a normal concrete surface.

When the poured concrete has hardened to the extent that it can be removed from the mold, non-shrinkage mortar is filled into the spaces between the coarse aggregates of the poured concrete on the outer end surface of the poured concrete located above the auxiliary table. , finish the same side. At this time, the auxiliary table prevents the mortar from penetrating into the gaps formed between the coarse aggregates in the concrete body and damaging its properties. Since the auxiliary stand is made of a cement material, it has great affinity with mortar and can be integrated with it.

However, in the present invention, the upper surface of the poured concrete is then surface-finished with semi-solid non-shrinkage mortar. By using non-shrinkage mortar in a semi-solid state with poor fluidity as a finishing material, it becomes difficult for the finishing material to enter the voids of the concrete body, and therefore it is difficult to apply force during finishing work. This makes surface finishing work easier. Since each of the mortars described above is made of non-shrinkage mortar, cracks may occur on the surface of the raised concrete.According to the present invention, the surface of the raised concrete has the same appearance as ordinary concrete, and the same surface The present invention has many advantages, such as the fact that the layer is integrated with the main concrete body, so there is no risk of cracking, and according to the present invention, the surface finishing is done as part of the manufacturing process of the raised concrete member, so the construction period is shortened. It has the following advantages.

The present invention will be described below with reference to the illustrated embodiments.

Reference numeral 1 denotes a rectangular frame-shaped auxiliary stand made of cement-based material, which is attached to the inner circumferential surface of the side plate 2 of the formwork A via an adhesive or a spacer.

When the raised concrete 3 mixed with a surplus mortar component is poured into the formwork A, the surplus mortar 4 is poured into the poured concrete 3.
The lower bottom surface and the outer peripheral end surface below the auxiliary stand 1 are covered, and each surface has the same appearance as a normal concrete surface.

Next, when the poured concrete 3 hardens until it can be removed from the mold, non-shrinkage mortar 5 is applied to the outer end surface of the poured concrete 3 above the auxiliary table 2.
Fill it and finish the same surface.

Next, a semi-solid mortar 6 is placed on the top surface of the poured concrete 3 by mixing and kneading non-shrinkage mortar and then kneading it again without adding water for 2 to 4 hours.
After the surface finishing material has hardened, it is removed from the mold.

The raised concrete parts formed in this way have the same appearance as ordinary concrete products, and the non-shrinkage mortar used as a finishing material can be colored and the texture can be changed, so the finished product is The product retains its desired color and texture semi-permanently without the need for repairs.

The auxiliary stand 1 is formed to have a cross-sectional shape with a curved protrusion that protrudes into the raised concrete 3, and is used as a finishing material with good fluidity to prevent the mortar 5 from entering the raised concrete 3. is formed.

Next, an example of a composition having a surplus mortar component will be given.

Early strength cement 275Kg Fine aggregate 33.2 61Kg Coarse aggregate 630.2 889Kg Fine aggregate ratio 5% Water-cement ratio 36% Bulking agent 400 Superplasticizer 4000c.c. (Note 1) The aggregate is artificial lightweight aggregate Bilton (product name) :
Expanded shale was fired and crushed (manufactured by Sumitomo Metal Mining Co., Ltd.).

(Note 2) Perlite C type was used as the filler in a lightly packed state.

(Note 3) Mighty FD (trade name: a surfactant whose main component is naphthalene sulfonate (manufactured by Kao Soap Co., Ltd.) was used as the fluidizing agent.The fluidizing agent reduces the water-cement ratio, and It was used to make the amount of mortar surrounding the coarse aggregate more or less uniform.

(Note 4) Volume is absolute volume, and weight is surface dry weight. The coarse aggregate was used in a surface dry state.

Although the present invention has been described above with reference to embodiments, the present invention is, of course, not limited to such embodiments, and can be modified in various ways without departing from the spirit of the present invention. .

[Brief explanation of drawings]

Figures 1 and 2 are longitudinal sectional views showing the implementation status of each embodiment of the surface finishing method for raised concrete according to the present invention, Figure 3 is a slope view of the auxiliary platform, and Figure 4 is a view of the formwork. FIG. 3 is a perspective view showing a state in which an auxiliary stand is attached. 1... Auxiliary stand, 2... Formwork side plate, 3... Raised concrete, 4... Non-shrinkage mortar, 5...
Non-shrinking mortar, 6... Non-shrinking mortar in a semi-solid state.

Claims (1)

[Claims] 1. In a formwork with a cement-based auxiliary stand attached to the inner peripheral surface of the side plate of the formwork, cast concrete with excess mortar component is poured, and the surplus mortar is used to cast the bottom surface of the concrete and the outer peripheral end surface of the lower part of the auxiliary stand. Then, after the poured concrete has hardened until it can be removed from the mold, non-shrinkage mortar is filled into the space between the coarse aggregate of the poured concrete on the outer peripheral end surface of the upper part of the auxiliary table, and then the top surface of the poured concrete is covered with A method for finishing the surface of raised concrete, which is characterized by applying a surface finish with non-shrinking mortar in a semi-solid state.