JPS60180944A - Manufacture of cement cured 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 (Technical Field) The present invention relates to a method for producing a hardened cement body used as a building material.

(Background technology) In general, in order to increase the strength of cement concrete products, the mixing ratio of cement and water is lowered, and an abrasive agent such as a water reducer is added to give fluidity, and then the concrete is poured into a concrete truck. is being carried out smoothly.

However, when considering this dry method, the use of water reducing agents and the like is limited. For this purpose, it is conceivable to perform molding by increasing the press pressure, but since the particles are large, it is difficult to increase the filling interval, and therefore high strength cannot be achieved. However, when considering the productivity and efficiency of industrial secondary products, the dry method becomes essential.

(Objective of the Invention) The present invention was proposed to improve the above-mentioned points, and in the production method of hardened cement, dry method 1 such as roll extrusion force type, self-propelled extrusion force type, press method etc. The aim is to manufacture a high-strength hardened body using cement, and aim to increase the strength by adjusting the particle size of the cement, and also to secure the starting time by adjusting the basicity of the cement mixture. The target is

(Disclosure of the Invention) ゛The present invention employs the dry method 1 in the production method of a cement hardened body, and in order to increase the degree of filling (that is, reduce the voids in the hardened body) and to manufacture a hardened body with strong cylinder strength. To,
This is achieved by limiting the particle size and accumulation of cement used.

In other words, according to the present invention, 40 parts by weight or less of cement having a Blaine value of 6000 cf/i/7 or more is added to 100 parts by weight of cement having a normal particle size, that is, a Blaine value of 2500 to 500 a/l/l. The purpose of the invention is to provide a method for producing a hardened cement product, which is characterized in that the water used in this case is not more than 9% by weight of cement, and is molded and hardened. be.

Next, the non-invention will be explained in detail. It should be noted that the embodiments are merely illustrative, and it goes without saying that various changes and improvements can be made without departing from the spirit of the present invention.

Ordinary cement has a particle size distribution as shown in FIG. In Figure 1, the horizontal axis is the particle size, and the vertical axis is the component. Curve IvA is ordinary cement, curve B has a pre-L value of 6300 ffl/f, and curve C has a Blaine value of 9000.
The particle size distribution of cr/f is shown.

In such conditions, the cement has phantom to 40% voids. Therefore, by embedding particles between them, the voids are reduced and the strength is improved. However, simply embedding a filler does not have a bonding force, so even if the mw degree is improved, a large strength cannot be expected.

Therefore, 100 parts by weight of continuous cement with a Blaine value of 2,500 to 30,001f was mixed with various types of fine cement, amount added, and water mixing ratio, and the pressure vs.
After molding at ~150 Ks+/2, it was cured at 60°C for one week to make it into a product, dried at 60°C for 24 hours, and its characteristic values, bulk density and bending strength (Kf/1f) were measured.The results are as follows. This is shown in Table 1. The bending strength was determined using a 4 cm x 16 cIn sample with a thickness of 1.5 cIn, a span of 10 cm, and a head speed of 0.5.
The results of the test are shown in m/min. Also, in Table 1, the * mark in the fine cement column of Comparative Example 2 indicates that CaC0ak was used. Further, as the fine cement, one manufactured by Onoda Cement was used.

From the above results, the Blaine value is 60 as a fine cement.
00 d/f or more, more preferably Blaine value 900
0d/7 Cementora is used, the amount added is 4 OZ or less, preferably 15 to 30 oz., and the water used is f 30 It %, preferably 0 to 25 pieces, is added, mixed, molded, and cured to reduce voids and increase strength.

The cement used is Portland cement.

Any hydraulic cement such as blast furnace cement may be used.

Now, when a product is manufactured by mixing fine cement with normal cement in this way, the startup time, that is, the time until the reaction starts when cement and water are distributed, may be shortened. be. If this starting time is too short, there is a risk that work efficiency will be deteriorated.

In order to eliminate this drawback in the present invention, the basicity of the fine cement to be added is fully adjusted to ensure the starting time of at least 1 hour or more, thereby improving workability.
Moreover, a hardened cement body with still high strength is produced.

The basicity in this case is determined by the components (each %) in the fine cement: CaO + MgO + Altos tow.

Table 2 shows Portland cement (Brain value 3200
, average particle size 22μ, basicity 3.2) Fine cements with different basicities were added to 100 car weight parts and mixed,
After molding with press pressure 100 Kμ wood, 1 at 60℃
After curing for a week, it was commercialized.

Table 2 The products in Table 2 above were subjected to the same tests as those in Table 1 to determine the bending strength. The results are shown in Table 3.

The basicity in Table 3 has a close relationship with the Blaine value of fine cement, and this relationship is preferable for F chain acids, which are indicated by the beveled edges in FIG. This reduces the starting time (approximately 1
time) can be secured.

(Effects of the Invention) As described above, the present invention reduces the bulk density and improves the strength by mixing fine cement with ordinary cement, and also adjusts the basicity of the fine cement to be added. This has the effect of securing starting time.

[Brief explanation of the drawing]

Figure 1 shows the relationship between cement particle size and components, and Figure 2 shows the relationship between the Blaine value and basicity of the fine cement to be added. Patent Applicant: Matsushita Electric Works Co., Ltd. No. 1 Fig. 1 If L diameter (μ), Fig. 2 Name of the invention 1. Process for producing hardened cement 3. Relationship with the amended case Patent applicant name (583) Matsushita Electric Works Co., Ltd. 4, Agent 160 Address 7-5-10 Nishi-Shinjuku, Shinjuku-ku, Tokyo No. 2 Mizota Building, 7th floor, 6, Contents of amendment 1, Specification page 2, line 7 [However, this dry method 1 method is corrected as J to ``However, dry method 1 method is corrected as J. In the 4th line, "vertical axis is component" [time axis is weight%]
Correct it with J.

Claims (2)

[Claims] (1) Normal particle size, that is, Blaine value is 2500 to 35
00 Shima Now's Semen) For 100i volume, the Blaine value is 6000 di/? A method for producing a hardened cement body, which comprises adding and mixing not more than 40 parts by weight of the above cement, and in this case adding water in an amount of not more than 30 quintillion i% to the cement, and then molding and hardening. (2) The 3A method of hardened cement according to claim 1, item H, which is characterized in that the basicity is maintained according to the Blaine value of the cement to be cooled compared to cement of normal particle size.