JPS588602A - Manufacture of concrete product - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses concrete to which a formalin condensate-based cement water reducing agent of β-naphthalene sulfonate is added,
The present invention relates to a method of manufacturing vibratory compacted concrete products.

Conventionally, cement water reducing agents consisting of β-naphthalene sulfonic acid Na formalin condensate have been used in various types of concrete for the purpose of reducing water during concrete production. When used to manufacture culverts, U-shaped grooves, etc., air bubbles (endrapped air) that were caught inside the concrete during vibration compaction collect on the formwork surface, and after the concrete hardens, air bubbles form on the concrete surface. There was a problem with the beauty of the concrete product as there were many residues left behind.

Step 49, pour into a formwork coated with an oil-based formwork release agent,
When compacted by vibration, the concrete surface became dirty after hardening compared to concrete without this water-reducing agent, so it could not be put to practical use.

In order to improve this concrete surface condition, the present inventor investigated various formwork release agents, and found that 0β type Applying an emulsion-based formwork release agent to the concrete formwork improves the appearance of the concrete surface, and even when vibration compaction is performed, entrained air bubbles do not collect on the formwork surface, resulting in a smooth concrete surface. The present invention has been completed by discovering that

That is, the present invention provides an oil content concentration of 5 to 25% by weight in concrete formwork when producing concrete products by vibration compaction of concrete to which a formalin condensation cement water reducing agent of β-naphthalene sulfonate has been added. This method of manufacturing concrete products is characterized by applying a mold emulsion-based formwork release agent, pouring concrete, and compacting it by vibration.

The present invention will be explained in detail below.

In the present invention, the formalin condensate of β-naphthalene sulfonate added to concrete for the purpose of increasing the strength of concrete may be either Na salt or Ca salt, and may also be an alkylnaphthalene sulfonic acid or a lignin sulfonic acid. etc. may be co-condensed.

OA pear-shaped emulsion mold stripping agent is based on mineral oil or vegetable oil, and contains oil film strengthening agents such as higher fatty acids, aliphatic amines, aliphatic amides, rosin amines, rosin amide, and metal soaps, and then type, alkylphenol type (for example, NOF ■ trade name "Nirasan Nonion NB-208, 5J, rH8204, 5J"),
It is preferable to form an emulsion using a nonionic surfactant such as an ester type or sorbitan ester type (for example, Nirasan Nonion 0F-85RJ, trade name of NOF Corporation).

Commercially available Q/W emulsion mold stripping agents include:
Nichiei Kogyo Co., Ltd. product name “Mordor”, Shin-Etsu Sangyo Co., Ltd. product name “
There are examples such as "Reginer Sepun".

The φ-type emulsion-based formwork stripping agent is applied to the formwork in the form of an emulsion diluted with water, with an oil concentration of 5 to 25%.
It is desirable to prepare and apply the paste so that the amount is 9% by weight; outside this range, hardened cement paste will not easily remain on the formwork and the concrete surface condition will not be good.

The vibration compaction method for concrete can use a low-frequency vibrator, a high-frequency vibrator, etc., but preferably, a table viscillator or an external vibrator that can vibrate the entire formwork is attached to the formwork. This is a vibration compaction method.

(6) As described above, by carrying out the manufacturing method of the present invention, a high-strength concrete product with a smooth and beautiful concrete surface can be obtained.

The present invention will be explained below with reference to Examples.

Example 1 Reinforced concrete U-shape (
In manufacturing J-K8A5305), concrete with the composition shown in Table 1 was mixed, poured into a formwork coated with a formwork release agent, compacted with a table vibrator, and steam-cured. A concrete product was obtained. The formwork release agent used and the surface condition of the hardened concrete are shown in Table 2. Magnet 4 is the method of the present invention.

(5)-12- (4) (6) In the Nagi 1 test, when a concrete product was manufactured in the same way without adding a water reducing agent, the concrete surface condition after hardening was beautiful, but the slump was 10 cIN.
Since the water-cement ratio increased to 52% to make concrete, the compressive strength of the concrete was poor, and the demolding strength (6 hours) after steam curing was 120 kg/1 M2 of Nagi 1.
80Kg/ax".

Example 2 In the tests of No. 1 and No. 4, the water reducing agent was β-naphthalene sulfonic acid Na formalin metal condensate (solid content concentration 42%).
) When concrete products were produced in the same manner, except for the case of 1st floor, bubble marks were left on the concrete surface, but 4th floor had a smooth and beautiful concrete surface.

Patent applicant Denki Kagaku Kogyo Co., Ltd. 13-

Claims (1)

[Claims] When manufacturing concrete products by vibrating compaction of concrete to which a formalin condensate cement water reducing agent of β-naphthalene sulfonate has been added, the concrete formwork is used in a concrete formwork with an oil concentration of 5 to 25% by weight in a gravimetric emulsion formwork. A method for manufacturing high-strength concrete products, which comprises applying a release agent, pouring concrete, and compacting it by vibration.