JPS5879859A - Manufacture of concrete 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 The present invention relates to an improvement in the method of manufacturing concrete bodies, particularly concrete bodies containing at least hydraulic cement and calcium aluona minerals.

Concrete molded bodies are often used as building materials and civil engineering materials. One of the manufacturing methods is to manufacture cement concrete bodies using the rapid hardening properties of calcium aluminate minerals.) Calcium aluminate minerals A method of using an aqueous slurry for molding obtained by pre-mixing other admixtures in the form of powder and then adding water, if necessary, and adding a surfactant to the slurry. ,
A method of using a slurry for molding lightweight aerated concrete, which is a mixture of protein degradation products and aqueous bubbles of pine tar soap;
A method in which a rapidly hardening cement material and a hydraulic cement material are made into an aqueous slurry separately in advance, and then an aqueous slurry for molding obtained by mixing both slurries is used, and a method in which the above-mentioned IWj-like aqueous bubbles are mixed into this aqueous slurry. Depending on the method of using the obtained lightweight aqueous slurry for molding, a rapidly hardening concrete aqueous slurry is prepared by one of these methods. or a soluble salt thereof, a mixture thereof, or a mixture of the oxycarboxylic acid salt and one or more soluble inorganic carbonates to adjust the pot life of the slurry. The rapidly hardening aqueous slurry prepared using this slurry is poured into a predetermined mold, and after setting and hardening reaches a predetermined strength, it is removed from the mold and further processed. Products are manufactured by curing using either normal temperature and humid air curing, steam accelerated f19! curing, or high-position, high-pressure steam curing in an autoclave. In the case of the body, %lI!l is the same.

The main reason for using calcium aluminate minerals in rapid-hardening concrete is that the mineral's ability to accelerate setting and hardening can be used to quickly develop the strength of concrete necessary for demolding, allowing for early demolding. ◎As a result, even concrete products with complex shapes can be produced in large quantities using only a small number of formworks, which is economically advantageous. There is. and,
Calcium aluminate minerals, which are quick-hardening components, are generally suspended at a mixing ratio of 10 to 20 percent by weight of the total cement solids, including silica sand and lime, which are added as necessary. In the case of slurry preparation, the slurry is removed within 30 to 60 minutes. For example, in the case of a concrete product with a dry specific gravity of 0.5, slurry am
After 40 minutes, compressive strength of concrete required for demolding f 2
．． 5 kt/- or more, or blocker penetration resistance value 409
Expresses initial strength of a1 or higher. The mixing ratio of 1111 for the rapid hardening component is determined based on the time required for demolding, but if the amount added is small, the initial strength necessary for demolding concrete aggregates will be inversely proportional to this. Because of the delay, the quantification of concrete products decreases.

The biggest disadvantage of the rapid-hardening Funkrete composition system is that the calcium aluminate mineral used is an energy-intensive cement, so it is more expensive than other hydraulic cements. ! Therefore, it goes without saying that it is economically desirable to be able to quickly and smoothly develop initial strength with a small amount of calcium aluminate minerals. The purpose is to promote the initial strength development during setting and hardening of a concrete body having a hydraulic cement composition mixed with minerals, and to lower the mixing ratio of calcium aluminate minerals to be added.

The present invention provides a rapid hardening concrete slurry containing calcium aluminate minerals. In the case of simulation, if cement wastewater etc. obtained by washing the slurry adhering to the mixer area after preparing and sprinkling the hydraulic cement slurry is mixed into the concrete forming steel aqueous slurry as an additive, this operation will be performed as follows. It is based on the discovery that it is possible to simultaneously achieve the above two objectives by using a ring element (-).

Namely, according to the present invention, there is provided a method for producing a punctate body containing at least some hydraulic cement (F) and calcium aluminate minerals, comprising: (1) fresh cement water containing hydraulic cement F; eA1 Chain line slurry of the wastewater, 61 Dried mold powder of the slurry, - Sludge mixed with the mold powder and water, (Ma; Sludge mixed with hydraulic cement and water % - Hardening of hydraulic cement At least one additive selected from the group consisting of crushed body mold and - slurry obtained by mixing Zengji mold and water is added to the water-based slurry for concrete forming. A method for producing a cement body is provided: 4゜Cement fresh water as one of the additives in the present invention (2) refers to hydraulic cement that has been left in water for a long time, and does not contain the expeditious ingredients. Cement wastewater and molds are obtained by washing away slurry that adheres to Miki I-1 piping, storage tanks, etc. with a large amount of water when ordinary hydraulic cement slurry is prepared and then transferred to a storage tank or cast into a mold. Cement wastewater is obtained by collecting the slurry that re-overflows from the C2 formwork when it is poured into a frame with a large amount of water. It is also possible to use concentrated slurry obtained by concentrating wastewater, fine powder obtained by further drying the reduced slurry, slurry obtained by mixing the fine powder with water, and even slurry. The finely pulverized concrete body C2 obtained from the molding process and the slurry obtained by mixing the pulverized limestone mold and water are the same as the pulverized concrete body C2. In order to achieve dimensional accuracy of the bottom shape after hardening, the C2 surface mt is scraped off.It includes the resulting shaving male, and the crushing force of the generated chipped part 4 when transporting the JIE shape after curing. The crushed material is
It is preferable to use a ball mill, etc., or a wet wheel crushing method (Q, =) in conjunction with the use of a ball mill, etc., as there are shavings, fist-sized particles, and block-shaped particles with missing parts. Alternatively, the slurry can also be obtained during the production process of rapid hardening concrete.

For example, as a method for manufacturing rapid-hardening concrete slurry, a method is adopted in which hydraulic cement and rapid-hardening components are slurried in advance in separate mixers, and then mixed together (in the case of lightweight cellular concrete, water-based bubbles are further mixed at this stage). In this case, after the preparation of the slurry is completed and taken out, cement wastewater can be obtained in the process of cleaning the hydraulic cement slurry F@t mixer and the liquid pipe.

Water &! in the present invention! Materials include ordinary Portland cement, slag cement, silica cement,
It refers to fly ash cement, etc., but depending on the case, silica sand may be added to these cements.

It also includes cementitious materials with added lime, gypsum, etc.

In addition, the calcium aluminate minerals as rapid hardening components in the present invention are alumina cement), 3CaO+mu1sc
k = CJL O” A bC) a * * 2 C
&0' 7 AIA m C&O'2A1ρ3. or a solid solution of a halogen element in these, or a mixture of these, or a mixture of these minerals and 1*ii*m, or a simultaneous chemical storage of this mixture.0 Additives to cement wastewater, etc. The features of Slime Autumn II
Even if it is left in the presence of water, like water, it will no longer have hydraulic properties and will retain a slurry state. Surprisingly, when a small amount of ring addition is added to an aqueous slurry of concrete or hydraulic seven-mention nullary, it significantly accelerates the initial strength development of the rapidly hardening nullary and also increases the amount of the rapidly hardening component itself added to the aqueous slurry of concrete for forming. On the other hand, the initial acceleration effect of additives remains the same even if the additive has been used for 4 hours or more than 1 hour.

The method for preparing rapidly hardening cement slurry in the present invention is as follows:
Other than adding additives such as cement wastewater and rapidly hardening cement to an ink pot first, Katsura Rido's other mixing method can be adopted.
That is, a method in which a rapidly hardening cement slurry for molding is prepared in advance in a conventional manner and then the cement wastewater additives of the hydraulic cement are added at the end, or the above additives are added in advance in the process of preparing the aqueous slurry of the hydraulic cement. Either method of obtaining a quick-fixing concrete slurry by the usual method after 1 or adding superadditives at the same time as the hydraulic cement and the quick-hardening component to an aqueous atmosphere can be adopted. The rapid hardening concrete prepared by the method of the invention is
The initial strength development speed of the slurry after solidification is extremely fast, so the time required to start demolding the molded part can be significantly shortened, and the amount of rapidly hardening components added can also be reduced. The amount of additives added to the cement waste water stream is preferably 4 to 20% by weight based on the total amount of hydraulic cement, based on the solid content. However, the effect on the initial strength development of rapidly hardening concrete is poor;
This is because, if it exceeds this, although the initial strength development property is sufficient, the strength of the molded product after curing decreases.

When preparing a rapid hardening cement by blending the above-mentioned rapid hardening components into a hydraulic cement material, Ca (OH)! ICo
o. It is possible to increase the initial strength after solidification by adding additional forces to CaC and MgC as appropriate.If the additives are converted according to the present invention, the use of these is not necessarily necessary, and it is less complicated. The structure of the present invention described in detail above can also be applied to fixed aerated concrete using aqueous foam. For aqueous bubbles, the following agents are used: imitation foams commonly used as foaming agents, pine resin soap, sodium 9um or ammonium salts of arylsulfonate in alcohol, polyethylene diethylene alkylaryl sulfate salts, etc. Crystalline surfactants can be used, as well as water-soluble polymeric substances commonly used to improve bubble stability, various types of seven-leaf trout conductors, polyvinyl alcohol, etc. In case (: I!!
Expect. These foaming agents are added to water and forcedly stirred or pressurized! When air is blown, it becomes aqueous bubbles.

In order to prepare the aqueous slurry for molding in the present invention, it is necessary to prepare in advance additives that are more warped than the desired composition described above.Among the additives, cement wastewater, I! The amount of solids in the raw material can be determined by the methods usually adopted, such as drying a small amount of the additive to determine the amount of solids, or creating a calibration curve of the specific gravity of the additive and the solid content 1Nll11'' before adding it. The specific gravity of an object is measured using a method that determines the solid content concentration, but if it contains air bubbles for lightweight aerated concrete, these air bubbles are removed and measured.Solid content concentration of additives is 25 to 45 because of its good fluidity.
Weight is preferably -, but it is not limited to this.

The additive-containing concrete slurry obtained in this manner is poured into a mold, allowed to set and harden, is removed from the mold, and subjected to main curing to obtain a concrete product.

The present invention will be explained below using examples.

Incidentally, 100 parts by weight of hydraulic cement consisting of 7 parts by weight of Portland cement (1) and 67 parts by weight of finely divided silica sand were added to a construction mixer at a ratio of 2,000 parts by weight of water, and slowly stirred for 2 days and nights. Make a wastewater of hydrated hydraulic cement, leave it to stand, let the solid content settle, and remove the supernatant to obtain a noble slurry with a solid concentration of 35% by weight. Example 1 (Portland cement) 46.9 parts by weight, fine silica sand 3LS used as an additive in the following examples and comparative examples
A hydraulic cement slurry consisting of 1.8 parts by weight of slaked lime, 23.0 parts by weight of water, 1 part by weight of citric acid, and 6 parts by weight of the above additive 2B were added to the construction day, After equalization, 1! ! 128.6 tons of aqueous bubbles (high foam specific gravity 0.0!L) (foaming agent: "Glu 7 Ohm" manufactured by Sun Orient Chemical Co., Ltd.) consisting of 1 ml of white matter decomposing agent were mixed. Next, a rapidly hardening cement wastewater solution consisting of 10 parts by weight of Arunnacemen) and 7 parts by weight of water was mixed to prepare a rapidly hardening lightweight cement #II:2 cement free with a slurry specific gravity of 0.740. , A8TM C-40
3, the initial strength development of the slurry after solidification was measured, and the molded body cast in a 4X4X1M- lid frame was deassembled after hardening, and autoclaved at 180°C for 8 hours to achieve a constant weight of air drying. The dry ratio of this molded product is aOJ4, and the strength was measured using a universal side am at a crosshead of 0.5 cm/min.The results are shown in Figures 1 and 1I112. 0 based Example 2 Portland cement) 45.2 parts by weight, finely divided silica sand 30.
1 part by weight, 1.7 parts by weight of slaked lime, 514 parts by weight of fillers,
The same amount of aqueous bubbles as in Example 1 was introduced into a hydraulic cement slurry consisting of 11.7 parts by weight of water and 5 parts by weight of citric acid, and 5 parts by weight of Altna cement and 3.5 parts by weight of water. A rapidly hardening cement slurry was mixed to obtain a rapidly hardening lightweight cellular contour slurry.The same test as in Example 1 was carried out, and the results were
Shown in the table.

Example 3 50.21 parts of Poldrasitocemene, 33 parts of fine silica sand,
Except that it is a hydraulic cement slurry made of S parts by weight, 19 parts by weight of slaked lime, 12.6 parts by weight of additives, 33.4 parts by weight of water, and 32 parts by weight of citric acid powder.
A rapid hardening cement nutcer was obtained in the same manner as Ishikoji @ka. 6 A test was carried out in P11, and the results are shown in Figures 1 and 1.
1! -Comparison-11 52.8 parts by weight of Portland cement, 3s of finely divided silica sand,
2 parts by weight, 2.0 parts by weight of slaked lime, 41.6 parts by weight of water, and 0.28 parts by weight of sodium citrate.
A test similar to Example 1 was conducted in which a rapidly hardening cement slurry was obtained, and the results are shown in Section 1 and Table 1.

Comparative Example 2 Portland cement) 44.0 parts by weight, finely divided silica sand 29.0 parts by weight.
3 parts by weight, slaked lime 1.7 parts by weight, additives 57.1 parts by weight S
A rapidly hardening cement slurry was obtained in the same manner as in Example 1, except that a hydraulic cement slurry consisting of 8.0 parts by weight of water and 0.45 parts by weight of sodium citrate was used.

The same test as in Example 1 was conducted, and the results are shown in FIG. 1 and Table 1.

Table 1 Strength after autoclave curing Example 4 100 parts by weight of Portland cement, 67 parts by weight of finely divided silica sand! After mixing 2000 parts by weight of water with 100 parts by weight of IJffi hydraulic 7-mention to form an aqueous slurry, it was passed through F and the dried product was pulverized in a ball mill to obtain an additive. A rapid hardening cement slurry containing no aqueous air bubbles was prepared by using this additive as a cement base system with a completely uniform solid content ratio as in Example 2. Comparing initial strength development properties with a slurry without additives, the Puke I-value after 40 minutes of slurry preparation of the all-additive mixture showed 1.8 times the strength of the additive-free system. 30 parts by weight and l of the dry, finely ground additive shown in
70 parts by weight of hydraulic cement wastewater consisting of 41 parts by weight of Il type was mixed to form a hydraulic cement wastewater with a solid content of 33.4 parts by weight.
-, but the initial strength development after 30 minutes compared to that without additives
,.

fart 0, which showed 3.2 times the strength

[Brief explanation of the drawing]

gtll is a diagram showing the initial strength development rate of the concrete bodies prepared in the actual implementation of this work and in the comparative example as the elapsed time of the water-based Nutree tone sn for acid type versus Broctor penetration resistance value.

Claims (1)

[Claims] 1. A method for producing a concrete body containing at least hydraulic cement and calcium aluminate minerals. (1) Cement wastewater containing hydraulic cement, (
1) *Concentrated slurry of wastewater, 100 million) Dried fine powder of the slurry, 徊 Sludge mixed with the fine powder and water. (m) Sludge mixed with hydraulic cement and water, (vi
) Adding to the concrete aqueous slurry at least one additive selected from the group consisting of a finely pulverized product of a hardened hydraulic cement material, and a slurry obtained by mixing the finely pulverized product with water. A method for producing a concrete body characterized by: 2. The additive is added in an amount of 4.0 to 20 weight percent based on the hydraulic cement with a solid content of 3. Method of manufacturing the concrete body described. 3. A method for producing a concrete body according to claim 1 or 2, characterized by a pre-water distributing slurry and air bubbles for lightweight cellular concrete.