JPS59109661A - Scene cast pc panel, slab concrete and method and apparatus for promoting curing concrete in cold region - 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 strength development of concrete is determined by calculating the curing temperature, and is generally cured at high temperature (50 to 70°C) using steam, etc.
It is said that it is good to do this. 'Therefore, in winter or in cold regions, care must be taken to ensure that the temperature does not drop below at least 0℃ until the hardening reaction of concrete is completed, and temporary frame supports for slabs and floor beams must be placed at temperatures of 5℃ or less. In some cases, it may be necessary to leave the temporary frame in place for a long period of 2 to 4 weeks or more.

Furthermore, Geno 1 heaters and heating wires are currently being used to prevent freezing.

However, the jet heaters and electric heating wires commonly used for on-site pouring are accompanied by rapid temperature rise and drying, and the temperature distribution becomes uneven, which has a negative effect on the strength development of concrete. It is not suitable for large concrete construction components such as PC plates, slab concrete, and concrete floor beams, which emphasize strong strength.

However, large-scale concrete construction components such as PC plates are highly required to be cast on site due to road conditions, transportation costs, etc., and therefore an appropriate curing and hardening accelerator for construction sites is required.

The present invention is in response to such a demand, and a curing chamber is temporarily constructed using a heat-resistant sheet, and the amount of steam discharged from a steam blow-off pipe installed therein is controlled by two or more temperature sensors. Two or more temperature valves each individually controlled by a temperature sensor are interposed in parallel between the temperature sensor and the steam blow-off pipe, and each set of the corresponding temperature sensor and temperature valve is connected to a certain set of temperature sensors and a temperature valve. The temperature valve is 30-50℃, and the other set of temperature sensors and temperature valves are 50℃.
By controlling the amount of steam blown out from the steam blowing pipe, the temperature range is divided between 20 and 70°C, such as 0 to 70°C.
After concrete is poured, it is kept at a temperature that does not freeze (around 20°C) for 2 to 3 hours as pre-curing, and then heated for 15 hours.
The temperature is raised at a rate of ~25°C/hour, and the temperature is increased from 50 to 70°C for 3 to 5 hours, followed by gradual cooling. The project aims to construct a temporary concrete tank, automatically control the steam curing temperature using a temperature sensor of 211M or higher, and pour concrete on-site in a one- to two-day cycle.

The present invention will be explained below with reference to illustrated embodiments.

Figure 1 is a piping diagram of the steam pipe 21, where 9 is a small boiler, 20 is a pressure gauge, 22 is a valve, 23 is I. Lehner, 24 is a pressure reducing valve, 25 is steam 1 to lamp, and 4 is a steam pipe. It is a curing chamber with a heat-resistant sheet 3 and 17F, and inside the curing chamber, steam blow-off etc. are piped, and two temperature sensors 7 and 8 are housed. - Between the secondary pressure a120 and the secondary pressure gauge 20, and between the secondary pressure gauge 20 and the steam blow-off pipe 6
There are bypasses 26 and 27, respectively, between the secondary pressure gauge 20 and the steam blow-off pipe 6, and the route is branched into a route passing through the temperature valve 0 and a route passing through the temperature valve 11. The opening and closing of the temperature valve 10 is automatically operated according to the instructions from the temperature sensor 7, and the opening and closing of the temperature valve 11 is automatically operated according to the instructions from the temperature sensor 8, and the operating temperature range of the temperature sensor 7 is 30 to 50 degrees Celsius. The operating temperature range of the temperature sensor 8 is 50~
It is set at 70°C. Further, a large number of thermocouples 28 of a multi-point thermometer 29 are arranged in the curing chamber 4, so that the temperature in the curing chamber 4 can be measured at any time.

FIG. 2 is a cross-sectional view of the PC plate curing chamber 4, in which the steel plate head 1 is supported by supports 12 and cloth foundations 13, and the curing chamber 4 is constructed by covering the copper plate head 1 with a heat-resistant sheet 3. be done.

In the figure, 18 is a temporary frame for hand-casting, 2 is a PC plate or poured concrete, and 6 is a movable steam Suita pipe, which is placed in parallel on the concrete building member 2 at a certain interval. A few books have been posted.

Such a heat-resistant sheet 3 is a fireproof sheet for construction use [...
Also, as the steam blow-off pipe 6, a water pipe is used with a large number of holes of about 2 mm in diameter.

FIG. 3 is a partial cross-sectional view of a curing chamber for concrete under a beam or concrete slab, and the steam blow-off pipe 6 is also set near the side of the floor beam that protrudes below the concrete building member 2, making it resistant to p :4> A small curing chamber 4 surrounded by sheets 3 is constructed.

After concrete is poured, the surface of concrete 1-2 is surrounded by a heat-resistant sheet 3 to create a curing chamber 4, and when the outside temperature is below 5°C, the concrete is not in a very favorable condition, so a temperature sensor 7 is installed. The temperature valve 1 (1) is opened and closed to pass steam into the curing chamber 4 so that the temperature is around 20 to 30°C, and then left for 2 to 3 hours. After that, the temperature valve 10 and the temperature are Open and close valve 11 and gradually heat to 50-70°C for about 2 hours at 15-b.
! Let it warm up, and when the set maximum temperature is reached, the temperature sensor IJ--8
6 in the curing chamber 4 by opening and closing the temperature valve 11 using a chisel.
11!1 degrees seems to be the maximum set temperature (50 to 70 degrees Celsius)
Steam is passed through Mosei Chamber 4 for about 3 to 5 hours, then slowly cooled.
If it is a PC version, remove the mold, and if it is a floor or beam, check its strength before removing the support.

As described above, according to the present invention, in the case of FIG. 2, the operation from pouring concrete to completion of high-temperature curing of the concrete building member 2 is completed in about 8 to 10 hours, and the steam control during that time is automatically operated. The concrete building members 2 that have been cured seven times and the temporary frame 18 are removed from the mold, relocated, stocked, etc., and work such as repeated pouring of concrete 19 is performed in parallel to complete the concrete construction at a speed of one cycle per day. Part 2 can be manufactured. In addition, the curing chamber 4 is constructed of a heat-resistant sheet 3 that is flexible and light and easy to carry, and the steam blow-off pipe 6, temperature sensor 7, temperature valve 10, small boiler 9, etc. are also lightweight, making it impossible for large vehicles to enter. Even in narrow spaces such as back alleys, these materials can be freely brought in and assembled into hardening accelerators to manufacture PC plates and accelerate the high-temperature curing of concrete.
There are advantages such as omitting transportation from the factory to the construction site, shortening the construction period, and reducing construction costs. Furthermore, since jet heaters and heating wires are not used, there is no drying of the concrete 1 and 2 or uneven distribution due to localized heating temperatures, and it is possible to obtain concrete building components 2 with excellent strength even if they are large. It will be done. Furthermore, the controllable range of the temperature valve is around 20°C, and the present invention uses this above 2 + 11i1, so
(Again) Effects such as being able to control the temperature of the curing chamber 4 within the range of 30 to 70°C, which is optimal for single curing, are produced.

[Brief explanation of drawings]

ff's Figure 1 is a layout diagram of the curing accelerator, Figure fA2 is a cross-sectional view of the curing chamber, and Figure 3 is a partial plan view of the curing chamber. 1. Steel plate head, 2. Concrete 1. Building shrine, 3. 1iiJ heat sheet, 4. Curing room, 6. Steam outlet pipe, 7.8. Temperature sensor, 9. Small size. Boiler patent applicant Daiwa House Industry Co., Ltd.

Claims (1)

[Scope of Claims] <1) A curing chamber is formed by surrounding the poured concrete surface, a steam blow-off pipe, and two or more temperature sensors with a heat-resistant sheet, and a small temperature sensor is installed through two or more temperature valves arranged in parallel. Connect the boiler and the air outlet, and check their temperature sensor or 2.
The temperature range (temperature range) from 0 to 70°C is shared and the temperature is sensed.
[The lil's temperature valve is repeatedly set, and the amount of steam blown out is controlled by the temperature sensor, and the temperature inside the curing chamber is kept at 1A (1A) for 2 to 3 hours after concrete is poured.
After that, the temperature was raised to 50-70°C at a rate of 15-25°C/hour, and the temperature was kept at a high temperature of 50-70°C for the next 3-5 hours for curing. , A method for accelerating the hardening of cast-in-place 20 plates, slab concrete, concrete, etc. in cold regions, which is characterized by slow cooling thereafter. (2) Cover the concrete pouring surface with a heat-resistant seal l- and use the sheet as a curing chamber, and install a seedling air blow-off pipe and a temperature sensor on 271 in the production chamber, and install two or more in parallel. A small boiler and a steam blow-off pipe are connected through a temperature valve placed in the curing chamber, and a temperature sensor controls the opening and closing of the temperature valve according to the temperature inside the curing chamber. Curing of slabs, slab concrete, concrete in cold regions, etc. (y-axis device).