JPS61134206A - Manufacture of glazed cement 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] [Industrial Application Field] The present invention relates to a glazed cement product in which a glaze is applied to the surface of a cement molded body, and then fired and hardened by hydration.
The present invention relates to a method of manufacturing a glazed cement product whose concrete strength is improved using reinforcing bars or PC steel wires.

[Conventional technology]

Conventionally, when manufacturing this type of glazed cement product, first the cement mixture is poured into the formwork, and at the same time, tensicon is added to the PC steel wire and then it is buried or reinforcing bars are inserted. Then, in this state, it is cured in air for a predetermined period of time to harden it, and after hardening, the PC steel wire is cut. After that, the surface of such a cement molded body is glazed and fired at a predetermined temperature to be hydrated and hardened to produce a product.

[Problems to be solved by the present invention]

However, in the conventional manufacturing method, PCSW wire or reinforcing bars are charged before the firing process.

Therefore, the expansion coefficient of the cement and the expansion coefficient of the reinforcing bar or the PC steel wire during firing are different, and thermal stress is generated between the two. That is, the thermal expansion coefficients of the cement and the PC steel wire are different, and cranks occur in the cement due to the difference in the thermal expansion coefficients during firing. For this reason, it is not possible to increase the strength of the cement molded body itself, but rather there is a problem that the strength is decreased and that the cement molded body warps.

[Means for solving problems]

In view of the above-mentioned drawbacks of the conventional manufacturing method, the present invention improves and eliminates the above drawbacks.
To provide a method for manufacturing glazed cement products that does not generate thermal stress between the cement and the W wire, thereby preventing cement from cranking during firing and increasing the mechanical strength of the product. It is.

The gist of the present invention is to pour a cement mixture into a mold, cure it in air for a predetermined period of time, remove it from the mold, glaze it and fire it, and then place the cement molded product in water. After hydration hardening by immersion or steam curing, etc., insert reinforcing bars or PC steel wires into through-holes that have been drilled in advance or after hydration hardening in the cement compact after firing or hydration hardening. , a glazed cement characterized in that a filler such as cement mortar is injected into the gap between the through hole and the reinforcing bar or the PC1L wire and hardened, and the cement molded body after hydration and hardening is reinforced with the reinforcing bar or the PCSil wire or the like. It is the manufacturing method of the product.

The manufacturing method of the present invention will be explained in more detail below based on embodiments shown in the drawings.

〔Example〕

First, for example, the following materials are kneaded in the following proportions,
Use as a cement mixture.

Ordinary Boltrad cement; 23 parts by weight expanded shale; 26 parts by weight perlite powder; 9 parts by weight high performance water reducer; 0.1 part by weight water
712 parts by weight Next, the cement mixture thus kneaded was poured into the formwork 1 shown in FIGS.
Take time to heal. A sheath 2 is held in advance in the form l.This sheath 2 is used during the post tensioning process, which is carried out in a later process, to form a cement molded body 3 and p as shown in FIG.
This is to prevent the CG wire (tension material) 6 from adhering. The curing method and time are not particularly limited, and it is sufficient that the cement molded body 3 retains its shape sufficiently and is hardened to the extent that breakage is unlikely to occur when moving on to the next step. The formwork 1 is dismantled, and the cement molded body 3 taken out is heated and dried at a temperature of 200°C for 2 hours. After drying, the surface of the cement molded body 3 is glazed and fired in a roller hearth kiln, etc. The firing conditions were 850°C.

It is 300 minutes. The size of the roller hearth kiln used in this example is 80c11. The height from the roller is 20 cm and the length is 30 m.

After firing, the cement molded body 3 is immersed in water for 10 minutes,
Absorb enough moisture. This immersion in water is for quick replenishment of water and may be omitted.Next, the cement molded body 3 is charged into a curing chamber and heated at 60°C and 100% R.
Steam curing is performed for 3 days using fl for hydration hardening. Naturally, this hydration curing may be carried out by any suitable method such as water immersion, normal steam curing, or water sprinkling curing.The temperature and time of the steam curing may vary depending on equipment costs, curing costs, product performance, etc. It is determined from the viewpoint of

'In this way, the glazed cement products 4 obtained by glazing and firing are hydrated and hardened after firing, which makes them more durable than ordinary cement products (non-fired molded products hydrated and hardened). This greatly increases mechanical strength. This is a known technique. If necessary, preliminary hydration hardening such as immersion in water may be performed between the demolding process and the drying process. In comparison, it is possible to further increase the mechanical strength of the glazed cement product 4.

The present invention aims to further increase the strength of this glazed cement product 4. Therefore, in this embodiment, first, the prestressed PC steel wire 6 is inserted into the sheath hole (through hole) 5 during casting. Then, in this state, a filler 7 such as ordinary Portland cement mortar, quick-hardening cement mortar, early-strengthening cement mortar, etc. is filled between the PC steel wire 6 and the inner surface of the sheath 2, and after the filler 7 hardens, the PCG wire 6 is being cut. Thereby, it is possible to apply prestress to the glazed cement product 4, and it is possible to increase the tensile strength and bending strength.

Therefore, it is possible to obtain a glazed cement product 4 with excellent strength.

By the way, the sheath 2 is usually formed by connecting thin steel plates of about 0.2 to 0.3 mm in a helical shape to form a cylinder, but it is also possible to use a pipe made of thin steel plates instead of this. good,
When using a pipe, apply oil or silicone-based mold release agent to the circumferential surface of the pipe, pull out the pipe after molding, and bury the PCLL wire 6 into the remaining through hole in the same manner as described above. Ordinary reinforcing bars may be used in addition to the PCJl wire. Even in this case, it is possible to further improve the mechanical strength of the glazed cement product 4.

In addition, in the above embodiment, the sheath hole 5
A space (through hole) for the insertion of the wire 6 or reinforcing bar is formed, and a drilling machine is used to insert the cement mixture into the cement molding material 3 after pouring it into the formwork 1, or into the cement molding material 3 after hydration hardening. It may also be provided by drilling.

Furthermore, it is obvious that the composition of the cement kneaded product (the materials used and their mixing ratios) is not limited to the above-mentioned examples.

〔Effect of the invention〕

As explained above, according to the present invention, glazed cement products can be manufactured without generating thermal stress between reinforcing bars or PC steel wires and cement, and there is no generation of black or the like on the products. It is possible to further improve the mechanical strength of cement products. Therefore, it can be used under severe conditions and can be used in a wide range of applications.

[Brief explanation of drawings]

The drawings all show one embodiment of the present invention, and Fig. 1 is a perspective view of the formwork, Fig. 2 is a vertical cross-sectional view of the cement mixture poured into the formwork, and Fig. 3 is a perspective view of the cement mixture. A perspective view of the molded body, and FIG. 4 is a perspective view of the glazed cement product. 1... Formwork 3... Cement molded body 5.
...Through hole 6...PC steel wire 4...Glazed cement product patent applicant National Housing Industry Co., Ltd.
Ina Seito Co., Ltd. Attorney Patent Attorney Toshihiko Uchida Procedural Amendment Letter February 7, 1986

Claims (1)

[Claims] 1. Pour the cement mixture into a mold, cure it in the air for a specified period of time, remove it from the mold, glaze it, and fire it.
After that, the cement molded body is hydrated and hardened by immersion in water or steam curing, etc., and after firing or hydration hardening, the cement molded body is drilled in advance or penetrated after hydration hardening. Insert a reinforcing bar or a PC steel wire into the hole, inject a filler such as cement mortar into the gap between the through hole and the reinforcing bar or the PC steel wire, and harden the cement molded body after hydration hardening. A method for manufacturing a glazed cement product characterized by reinforcing it with wire, etc.