JPS6344076A - Mold release timing detection method in case of placing of concrete - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial field for fil) The present invention measures the temperature of poured concrete, estimates its initial strength, and detects the time to remove the formwork during concrete pouring. This invention relates to a method for detecting demolding time.

(Conventional technology) In the variable cross-section slip 11 method and sliding method, in which concrete is poured by raising the formwork one after another, it is necessary to know when to remove the formwork in order to raise it up. Conventionally, a thermocouple is set in the formwork, the temperature of the poured concrete is measured in that state, the temperature is integrated to obtain the integrated temperature, and the estimation is based on the integrated temperature. Determine the compressive strength, compare the estimated compressive strength with the set compressive strength determined in advance by experiment and which is sufficient to express the initial strength, and when the estimated compressive strength exceeds the set compressive strength, it is considered as the time for demolding. This was detected and demolding was performed based on that information.

(Problem to be solved by the invention) However, in the case of such conventional methods, care must be taken not to cut the wires of the installed thermocouples when arranging reinforcing bars or pouring concrete. This has the disadvantage that reinforcing work and concrete pouring are time-consuming.Moreover, thermocouples cannot be reused because they are embedded in the concrete of the building structure, and thermocouples are used every time the formwork is raised. This had the drawback of requiring a pair to be set, which required a long construction period and increased construction costs.

The present invention has been made in view of the above circumstances, and an object of the present invention is to enable the temperature of poured concrete to be measured with less effort.

(Means for Solving the Problems) In order to achieve the above purpose, the method for detecting demolding time during concrete pouring of the present invention uses infrared rays emitted from concrete poured in a formwork. It is characterized in that the surface temperature is detected by an infrared radiation thermometer, the surface temperature based on the detected infrared rays is integrated by the calculation means to calculate the integrated temperature, and the demolding time is detected based on the calculated integrated temperature.

(Function) According to the method of the present invention, an infrared radiation thermometer is installed on the formwork of the concrete pouring part or the scaffolding for the formwork, and based on the infrared rays emitted from the poured concrete,
The surface temperature of the poured concrete is measured without contact, and the cumulative temperature is calculated from the measured surface temperature and curing time.
The estimated compressive strength is calculated from the cumulative temperature, and the demolding time is detected by determining whether the estimated compressive strength exceeds the set compressive strength mentioned above, and accordingly, the time for demolding is determined to ensure sufficient self-supporting strength for the poured concrete. It is possible to raise the formwork while holding it.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings. FIG. 1 is a schematic side view illustrating an embodiment of the method of the present invention, and FIG. 2 is a block diagram showing the configuration of an infrared radiation thermometer and its peripheral equipment.

Sensor parts 4 of three infrared radiation thermometers 3 were installed at predetermined intervals in the vertical direction on a raised scaffolding 2 that held the formwork 1, and concrete was poured into the formwork 1. Immediately after, infrared rays emitted from the surface of the poured concrete C are detected through holes 5 formed in the formwork 1 corresponding to the sensor parts 1, respectively, and the surface temperature based on the detected infrared rays is measured by the infrared rays. Measure with radiation thermometer 3.

Next, the temperature measured by the infrared radiation thermometer 3 is digitized by the hybrid recorder 6, and the temperature is digitized by the hybrid recorder 6.
7 and a memory 8, the microcomputer 9 as a calculation means integrates the surface temperature to calculate the integrated temperature (curing temperature x time), and calculates the estimated compressive strength based on the calculated integrated temperature. Further, the estimated compressive strength is compared with a set compressive strength that is sufficient to develop the initial strength, which has been determined in advance by experiment, and when the estimated compressive strength exceeds the set compressive strength, the estimated compressive strength is displayed on the display device 10. , activates a notification device 11 such as a buzzer or lamp to notify that it is time to demold the mold.

Reference numeral 12 in the figure is a support stay connected to the raised scaffolding 2 for installing the hybrid recorder 6 and the microcomputer 9.

Next, regarding the operation by the microcomputer 9,
This will be explained using the flowchart shown in FIG.

First, it is determined whether a sampling time T such as 3 minutes (this time may be set to an appropriate time such as 1 minute or 5 minutes depending on the situation, however, the unit time) has elapsed (Sl ).

When the sampling time T has elapsed, the process moves to step S2, where the surface temperature of the concrete C measured by the infrared radiation thermometers 3 is inputted via the hybrid recorder 6, and the three infrared radiation thermometers 3 are input. ... Calculate the average temperature of the measured surface temperature, and use the average temperature as the detected temperature T
' (Unit: °C).

Then, based on the sampling time T and the detected temperature T0, the integrated temperature T0 ・T is calculated, and the estimated sample compressive strength σT of concrete C is calculated using the following relational expression % formula %
(S3) Q where a and b are constants determined by preliminary experiments.

After that, the estimated compressive strength XI accumulated so far is read from the memory 8, and the sample compressive strength σ is added to the estimated compressive strength XI to calculate the estimated compressive strength X.S4
), the estimated compressive strength X is displayed on the display device IO (S
5).

Next, the estimated compressive strength 2 of true compressive strength for self-reliance
．． S6) If the estimated compressive strength X is smaller than the set compressive strength X, use the estimated compressive strength X as the integrated estimated compressive strength XI. After storing to memory 8 (S7)
, return to step S1.

When it is determined in step S6 that the estimated compressive strength X is larger than the set compressive strength X, step S8
The system then activates all alarms such as buzzers and lamps to notify the worker that it is time to demold the mold.

FIG. 4 is a schematic side view showing another embodiment of temperature measurement, in which an infrared radiation thermometer 3, a sensor part 1 of the infrared radiation thermometer 3, a hybrid recorder 6, and a microcomputer 9 are raised up onto a scaffold. Support stay 1 connected to 2
On the other hand, holes 13 are formed at predetermined locations in the formwork l so that infrared rays from the surface of the poured concrete C can pass therethrough. The field of view from the sensor part 4 is set to cover the entire surface of the formwork l, and the number of infrared rays q
The thermometer 3 is configured to input infrared rays as a temperature signal when it receives infrared rays from the holes 13 during scanning.

Thereby, the surface temperature of the poured concrete C can be detected by one infrared radiation thermometer 3 and its sensor part 4.

In the above embodiment, when the estimated compressive strength X exceeds the set compressive strength X, the notification device II is used to notify the user. It is possible to display a message indicating that it is time to demold the mold, or to have the operator make a judgment based on the numerical value of the estimated compressive strength displayed on the display device 10.
When it is time to remove the mold, a drive signal is output to a hydraulic jack (not shown) that drives and raises the raised scaffold 2, and the formwork l is automatically raised to the next concrete placement position. It would be better to configure it so that it increases.

Further, in the above embodiment, the estimated compressive strength 2x is calculated from the integrated temperature T0 ・T, and the demolding time is detected by comparing the estimated compressive strength X with the set compressive strength X. The set cumulative temperature that is sufficient to develop the initial strength for the self-supporting of the poured concrete C is determined in advance through experiments, and the set cumulative temperature (this value is, for example, about 40T0 ・T) and the cumulative Temperature T0
- The demolding time may be detected based on the fact that the integrated temperature T'-T exceeds the set integrated temperature by comparing T itself.

(Effects) As described above, according to the method of the present invention, the temperature of poured concrete is measured based on the infrared rays emitted from the poured concrete, so it can be measured without contacting the poured concrete, and construction can begin. Sometimes, once the infrared radiation thermometer is installed at a designated location, there is no need for subsequent wiring or repositioning.Also, since the wiring is not inside the concrete of the structure, there is no need to cut the wiring during reinforcing reinforcement or concrete construction. This makes it possible to perform reinforcement work and concrete work more efficiently without having to worry about this, making it possible to construct concrete structures in a shorter period of time and reducing construction costs.

Moreover, unlike conventional thermocouples, they are not embedded in the concrete structure, so they can be reused over a long period of time, making them economical.

[Brief explanation of drawings]

FIG. 1 is a schematic side view illustrating an embodiment of the method of the present invention;
FIG. 2 is a block diagram showing the configuration of an infrared radiation thermometer and its peripheral equipment, FIG. 3 is a flowchart explaining the operation of the calculating means, and FIG. 4 is a schematic diagram explaining another embodiment of temperature measurement. FIG. 1... Formwork, 3... Infrared radiation thermometer, 9... Microcomputer as calculation means.

Claims (1)

[Claims] (1) An infrared radiation thermometer detects the infrared rays emitted from the concrete placed in the formwork, and a calculation means calculates the cumulative temperature by integrating the surface temperature based on the detected infrared rays, and the calculated cumulative temperature A method for detecting demolding time during concrete pouring, characterized by detecting demolding time based on.