JPS623057A - Manufacture of cement set body - 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 <Industrial Application Field> The present invention relates to an ultra-rapid manufacturing method for a hardened cement body having a relatively small volume.

<Prior art> Conventionally, when manufacturing small-volume hardened cement bodies, such as formwork spacers used to secure reinforcing bars in reinforced concrete structures, or similar small-volume hardened cement bodies, Portland cement has been used as cement. When using a solvent, the setting time will be 2 hours or more. In addition, especially with improved quick hardening properties, for example,
When using something like Onoda Cement's product name ``Jet Cement,'' the setting time was adjusted to about one hour before various operations such as mixing, kneading, driving, and compaction were possible. .

That is, in the conventional technology, in a method of producing a compacted hardened cement body by adding water to raw materials for a hardened cement body, mixing and kneading the raw materials, and putting the mixture into a mold, the process of mixing, kneading,
In order to secure the time required for molding until compaction, a setting start time of around 1 hour is required, even if it is short.

Furthermore, a considerable amount of curing time is required in order to ship the hardened cement product as a product or to obtain standardized strength.

Even when using the above-mentioned "jet cement," which is said to have the highest hardening speed among those currently available, a compressive strength of about 50 degrees Celsius, which is suitable for handling such as shipping, is obtained, so the button is heated at 20 degrees Celsius. Even when cured, it takes several hours or more.

<Problems to be Solved by the Invention> As described above, in the conventional technology, manufacturing was carried out at individual sites through normal curing over several days, which required labor and time. Therefore, from the viewpoint of economy, it has been desired to implement a rapid curing method close to instant setting and to automate the manufacturing method.

The present invention is a rapidly hardening admixture made of calcium aluminate and gypsum that can solidify and harden a mixture of raw materials and kneading in a very short time without special curing such as high temperature curing or autoclave curing. The present invention focuses on the coagulation and hardening characteristics of two-mixtures using aggregate, cement, and a high-performance water reducing agent as main raw materials, and provides a method for producing a hardened cement body that is compatible with the characteristics.

Means for Solving the Problems〉 That is, the present invention uses a rapidly hardening admixture consisting of calcium aluminate and gypsum, aggregate, cement, and a high performance water reducing agent as the main raw materials, and reduces the raw material requirements per molded body. This is a method for producing a hardened cement product, which is characterized by mixing and kneading 21, immediately putting the entire amount into molds located close to each other, compacting, and demolding after hardening. As a hard admixture,
1 part by weight of calcium aluminate and stone "TO,"
This is a method for producing a hardened cement body using a rapidly hardening admixture consisting of 1 to 5 parts by weight.

The present invention will be explained in more detail below.

The main raw materials of the present invention are a rapidly hardening admixture consisting of calcium aluminate and gypsum, sand and other aggregates, cement, and a high performance water reducer. Therefore, it can exhibit rapid hardening, and in order to utilize this rapid hardening to mass produce and ship products rapidly, we invented forming methods such as mixing, cross-wiring, and compaction.
It can be removed from the mold in minutes, and has the strength to withstand immediate packaging.

By mixing and kneading the required amount for each molded object, mass production is possible with the maximum curing time of the material, and there is no problem in production.

Next, the rapidly hardening admixture used in the present invention will be explained.

The calcium aluminate according to the present invention is calcium haloaluminate in which calcium alumina-1 and other halogen elements are solidly dissolved, particularly preferably 12 CaO
e 7 Minerals made of A120s or 1lcao.7At, 0.0.・CaX
, are amorphous substances.

Further, as the gypsum, anhydrite is preferable because it provides high strength, but gypsum hemihydrate and gypsum dihydrate are also included. Furthermore, it is also possible to use sodium sulfate.

Calcium aluminate and plaster have a Blaine value of 2,000 to 10.00 oct! l/rs degrees are preferred.

The ratio of calcium aluminate to gypsum is 1 part by weight of calcium aluminate to 5 parts by weight of gypsum, preferably 1 part by 0.5 to 1.51°C. 0.
If it is less than 11 parts, the rapid setting will be excessive and the strength will also be reduced. Further, if the amount exceeds 5 parts by weight, the rapid setting property becomes low and the product expands over a long period of time, which is not preferable.

A setting retarder can be used in combination with the above-mentioned rapidly hardening admixture. As setting retarders, organic carboxylic acids or their salts such as gluconic acid and sodium citrate, and mixtures of these organic acids or their salts with carbonates such as sodium carbonate, potassium carbonate, magnesium carbonate, and calcium carbonate are used. can.

Any commonly used aggregate can be used. The amount of aggregate used is 1 to 5 parts by weight per 1 part by weight of cement.

Further, examples of the cement include Portland cement and mixed cement.

Furthermore, examples of high performance water reducing agents include β-naphthalenesulfonic acid type, melamine sulfone M type, and acid type. The amount of the high performance water reducing agent used is 0.1 to 5% by weight based on the total amount of the rapid hardening admixture and cement, preferably 0.
．． 5 to 1.5 weight ratio.

The amount of water used when mixing and cross-mixing the above raw materials is 30 to 60% by weight based on the total amount of the rapid hardening admixture and cement, but the smaller the amount is, the less time is required for demolding. This is preferable from the standpoint of increasing speed.

Although the Kirihara tray can be mixed and mixed using the usual method, it is necessary to quickly mix and knead the amount required for drawing one molded product and knead it in a short time. It is also possible to mix and knead in a mold from the standpoint of kneading in a short time.

Further, the method for shaping the kneaded raw materials is not particularly limited, but for example, a method of compacting each batch while applying vibration or a method of compacting by applying pressure is preferable.

Further, curing is not particularly limited, and the cement hardened body can be taken out from the mold as soon as it reaches demolding strength.

<Example> The present invention will be further explained below based on Examples.

Using the formulation in Example Table-1, mix with a mortar mixer,
The mixture was kneaded for seconds, and the entire amount was immediately poured into a spacer mold.

The mold was forcefully vibrated with a vibrator for 30 seconds and filled with mortar. The mold was demolded 2 minutes after the cross-crossing, and as shown in Table 2, sufficient strength was obtained.

Table-1 Materials used〉 Force: Amorphous 12Ca (17NtOs, aluminate fineness s, xoOi/r) Gypsum: Anhydrite, powder IE4,800crI/f
Set retarder: Sodium carbonate 50III 1%, sodium citrate 50% by weight mixture Aggregate Material: Himeyo natural sand 5-lower cement: Ordinary Portland cement, manufactured by Denki Kagaku Kogyo High performance water reducer: Denki Kagaku Kogyo ■Product name Denka FT-8
Table 2 shows the relationship between the main component of OJ, β-7talene sulfonate, the time required for the hardened cement to solidify after adding water, the age of the cement, and the compressive strength.

For comparison, Table 2 also shows the setting time and compressive strength when using early strength cement and jet cement. The quick-hardening cement was used in place of the quick-hardening components, gypsum, and cement in Table-1. Further, no setting retarder was added.

Table-2 Materials used〉 Early-strength cement: Denki Kagaku Kogyo ■Produced by Onoda Cement Comparative example Using the formulation shown in Table-1, 10 times the amount of raw material required per molded body and 1/4 The amount was mixed and kneaded.

Each mixture was injected into a mold to create a molded body.

As a result, when 10 times the amount was kneaded, curing started when 3 pieces were made, and in order to cast the entire amount, the curing time had to be increased 5 times as long, and the demolding time was extremely long, about 10 times as long. There is a drawback. This reduces productivity and is not practical.

Also, when mixed at 1/4 times the mixing ratio, it is possible to mix wires with a short curing time, but if this is done, a spliced part will be formed in the cured product, and the strength of the product will be significantly reduced.

<Effects of the Invention> As is clear from the above, according to the present invention, compared to conventional manufacturing methods, the raw material can be sufficiently poured and compacted, and
Products made of hardened cement, such as spacers for reinforced concrete structures or similar small-volume plates, can be easily handled in a few minutes (about a few tenths of the time compared to conventional methods), such as by demolding and packaging. , mass production of agglomerates and rapid commercialization has made it possible to supply products in large quantities and to make them more economical.

Patent applicant: Denki Kagaku Kogyo Co., Ltd. Ito Shin Nozawa - Department

Claims (1)

[Claims] 1) The main raw materials are a rapidly hardening admixture consisting of calcium aluminate and gypsum, aggregate, cement, and a high performance water reducer,
A method for producing a hardened cement body, which comprises mixing and kneading the required amount of raw materials for one molded body, immediately putting the entire amount into molds placed in close proximity, compacting, and demolding after hardening. 2) Curing according to claim 1, characterized in that the rapidly hardening admixture consisting of calcium aluminate and gypsum consists of 0.1 to 5 parts by weight of gypsum per 1 part by weight of calcium aluminate. How the body is manufactured.