JPH0222437Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] This invention prevents the concrete poured on site for buildings and civil engineering structures from freezing and deteriorating in cold weather, promotes the hardening reaction, and produces high-quality concrete. This invention relates to panels for concrete mold frames that have a so-called heat retention curing function, which is a measure to maintain the concrete above a certain temperature limit.

[Prior art and problems]

The following methods are generally known as conventional heat retention methods.

As shown in Figure 1a, the surface of cast-in-place concrete 1 and the periphery of mold frame 2 are shielded with a heat-retaining sheet 3 made of heat-insulating material to provide thermal insulation and prevent a drop in temperature. Here, 4 is a support frame for the seat 3.

As shown in FIG. 1b, a support frame 4 is framed and covered with a heat-retaining sheet 3, a heating light bulb 5 is provided on the support frame 4, and cast-in-place concrete 1
An electric heating sheet 6 is provided on the surface of the cast-in-place concrete 1 to actively heat it, and a heat-retaining sheet 3 provides thermal insulation, thereby dealing with cases where the temperature drops significantly.

This is a modified example as shown in Fig. 1c, in which a temporary building for heat insulation 7 is used to cover the cast-in-place concrete 1 and the mold frame 2, and a burner 8 is used as a heat source for heating to enhance heat retention and heating effects.

However, with these conventional heat retention measures, various effective methods are used for exposed surfaces such as the top of the concrete, but when the concrete surface is covered with molded panels such as the sides and bottom, The insulation effect is uncertain in the areas covered by the concrete, and there is a risk that the concrete will freeze if the temperature drops lower than expected.
In addition, with this heat insulation equipment, material wear and tear is large due to repeated relocation, and costs such as material costs and labor costs are high. The temporary building 7 in the case of . and . . . easily obtains a heat retaining effect due to insulation, but costs such as assembly costs for the temporary building are higher than in the case of .

Next, with conventional mold frame heating equipment, heating is performed indirectly from the outer periphery of the mold frame panel in both cases, so losses due to air convection and reflection from the mold frame panel, heat flow resistance of the mold frame panel, etc. Due to this, the effectiveness of insulation equipment is low and the heat utilization rate is poor.
Or, because the heat sources are dispersed in points, it is difficult to uniformly control the surface temperature of the concrete to the planned value due to the effects of air convection, wind, and variations in heat flow resistance, and in severe cases. There is a risk of localized freezing and overheating. And heat sources such as burners, stoves, etc. pollute the air in the work space.

Another method is to heat the concrete directly by placing electrodes on it and passing electricity through it, which has the highest thermal efficiency, but the current distribution changes complicatedly depending on the shape of the concrete, and the temperature coefficient of resistance changes greatly. Since the current is shunted by reinforcing bars, tie rods, metal frame panels, etc., it is difficult to control the current distribution and heat generation distribution. There is also a risk of electrical leakage and electric shock.

[Purpose of invention]

This idea was devised in view of the above-mentioned circumstances, and its purpose was to have a simple structure, reduce material costs, labor costs for assembling the mold, etc., and to keep costs low. To provide a molded frame panel having a heat-retaining curing part with a reliable curing effect.

[Structure of the idea]

This idea is a mold panel that can be connected to form a concrete mold frame for on-site pouring.
A space is formed inside the face plate of the panel to serve as a heat dissipation chamber, and a plate-shaped electric heating element is incorporated inside this heat dissipation chamber to serve as a heat retention curing section. The present invention is characterized in that a temperature control device capable of controlling the heat generation temperature of the electric heating element is provided.

〔Example〕

This invention will be explained below with reference to illustrated embodiments.

A plurality of formwork panels 10 that are connected together to form a formwork for cast-in-place concrete form a space 13 inside a face plate 9 of the panel to form a heat radiation chamber 11, and a space part 13 is formed inside the face plate 9 of the panel to form a heat radiation chamber 11. A plate-shaped electric heating element 15 is incorporated, and a thermal insulation plate 1 made of a high heat transfer resistance material is installed on the opposite side of the electric heating element 15 from the face plate 9.
2 is provided as a heat retention curing section 2.

Note that the electric heating element 15 is protected by a heat-resistant, water-resistant, and electrically insulating coating 14;
The coating 14 is not required when using a heat generating resistance wire which itself has a sufficient protective coating. Further, power consumption for the electric heating element 15 is supplied from a power supply wiring outside the mold frame panel through a plug 17 attached to the crosspiece 18.

When insulating and curing cast-in-place concrete 1 using the mold panel 10 having such a configuration, electric power is supplied from the plug 17 to the electric heating element 15 in the mold frame formed by the mold panel 10 to generate heat.

The heat output of the electric heating element 15 at this time is made to be the same as the maximum loss amount of the internal heat of the cast-in-place concrete 1 (heat held before pouring and hardening heat) flowing out to the outside surface of the form panel 10. . This maximum loss is the concrete heat retention curing set temperature (Ts,
For example, when the wind speed on the outside of the panel 10 is at the set maximum value at a temperature difference between the set minimum temperature (To, min) on the outside of the mold frame panel 10 and the temperature difference between It is quantity.

As a result, the heat loss flowing through the panel 10 is compensated by the heating element 15. Concrete is usually set at a curing temperature (Ts) before pouring.
Concrete forming surface 1
0a Maintain the temperature at or above the time of pouring.

Therefore, the internal temperature of the concrete cannot be lower than the concrete surface, that is, the forming surface 10a, so that it can be maintained above the curing set temperature.

Furthermore, if the curing heat of the concrete increases and its internal temperature rises above the curing set temperature, the heat flowing out through the formwork panel 10 will increase, suppressing the excessive rise in concrete temperature, and ensuring proper curing. Can maintain temperature range.

Panel outside air temperature is the minimum outside air temperature set (To, min)
If the temperature of the concrete forming surface 10a increases, or if the curing heat of the concrete is large and there is a risk of exceeding the allowable heat retention curing temperature (Ts, max), monitor the concrete temperature and adjust the temperature of the heating element 15. The power supply is controlled to open and close manually or automatically to maintain the heat retention temperature within the permissible temperature range.

The heat insulating plate 12 provided on the electric heating element 15 increases the heat flow resistance of the mold panel 10, and can suppress heat loss between the concrete and the electric heating element 15. Therefore, the heat output of the electric heating element 15 can be reduced, resulting in an energy saving effect.

In addition, the panel 10 includes a temperature control device 16 (such as a thermal relay) in the heat radiation chamber 12 to detect the temperature in the heat radiation chamber, and adjusts the power consumption of the heating element 15 to keep the temperature of the concrete forming surface 10a constant. Even when the air temperature (To) on the outside surface of the mold frame panel 10 fluctuates significantly above the set minimum outside air temperature (To, min), it has a function of maintaining the heat retention curing temperature close to the set value.

In particular, the outside air temperature (To) has increased significantly and the concrete temperature has therefore decreased to the allowable curing temperature (Ts, max).
It is possible to prevent the danger of overheating.

In this way, an appropriate curing temperature can be maintained even if there is a large change in the outside temperature, and when the temperature of the concrete forming surface 10a rises, the power consumption of the heating element 15 can be limited, resulting in energy saving effects.

Next, another embodiment of the frame panel 10 of this invention will be described in which heat insulating plates 12 are provided on both sides of the electric heating element 15 in the heat radiation chamber 11 as shown in FIG.

The heat generated by the electric heating element 15 of the above-mentioned embodiment is
In contrast to the heating of the face plate (concrete forming surface 10a) of the mold frame panel 10 and the concrete, in this embodiment, both sides of the heating element 15 are covered with thermal insulation plates 12, so that the generated heat is It mainly heats the inside of the heat radiation chamber 11.

In this way, the heat dissipation chamber 11 can be used with less power consumption.
A wall surface having a high temperature inside can be formed, and the internal heat of the concrete 1 is suppressed from flowing out of the form panel 10. Therefore, the concrete 1 is self-heated by the curing heat and can maintain the necessary heat retention curing temperature.

As described above, this embodiment has a particularly high energy saving effect.

Further, in this embodiment, the crosspiece 18 is directly fixed to the face plate 9, and the external force applied to the crosspiece 18 during assembly is not applied to the heat radiation chamber 11, so it is safe.

In addition, for applications where large temperature differences may occur on the concrete forming surface 10a covered by one large panel such as for dam construction, the electric heating element may be divided into multiple parts as shown in the example in Fig. 4. By installing a temperature control device and controlling it independently, it is possible to maintain heat retention at a uniform temperature.

[Effect of idea]

This invention has the above configuration and has the following effects.

It has a simple structure, consisting of a plurality of mold frame panels connected together to form a mold frame, a heat radiating chamber provided inside the panel, and a heat retention curing section consisting of an electric heating element built into the heat radiating chamber. Assembly and maintenance are easy and costs are low. In addition, the electric heating element enables reliable curing of cast-in-place concrete.

If the electric heating element is covered with a heat insulating material, the heat insulating effect is high, so the inside of the heat dissipation chamber can be maintained at a predetermined temperature with less electric power, and the power supply to the electric heating element can be further saved, resulting in lower costs.

By detecting the temperature of the concrete forming surface in the heat dissipation chamber and controlling the temperature of the electric heating element, the temperature of cast-in-place concrete can be adjusted appropriately even in places where the outside temperature changes rapidly, and optimal heat retention and curing can be performed.

Since an electric heating element is used as a heating source, there is no contamination of the air in the work space, and there is no danger during curing work.

Main components such as electric heating elements and temperature control devices are housed and protected within a robust heat dissipation chamber. Therefore, it is less likely to be damaged and has a long lifespan.

[Brief explanation of the drawing]

Figures 1 a, b, and c are cross-sectional views showing heat retention and curing of conventional concrete mold frames, Figure 2 is a perspective view of mold frame panels that form the concrete mold frame of this invention, and Figure 3 is Figure 2. FIG. 4 is a cross-sectional view showing another embodiment of the mold frame panel. 1... Concrete, 2... Mold frame, 3... Heat retention sheet, 4... Support frame, 5... Light bulb, 6... Electric heating sheet,
7... Temporary building, 8... Burner, 9... Face plate, 10...
Mold frame panel, 10a...formation surface, 11...heat radiation chamber,
12... Heat insulation plate, 13... Space part, 14... Coating, 1
5... Electric heating element, 16... Temperature control device, 17... Connection portion, 18... Crosspiece, 19... Power cord, 20... Socket, 21... Cover, 22... Lead wire.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A mold frame panel that is connected in plurality to form a concrete mold frame for on-site casting, and a space is formed inside the face plate of the panel to form a heat radiating chamber, and this heat radiating chamber A plate-shaped electric heating element is incorporated inside the mold to serve as a heat retention curing section, and a temperature control device is provided in the heat radiation chamber that can control the heat generation temperature of the electric heating element according to the temperature of the concrete forming surface of the mold panel. Panels for cast-in-place concrete type frames. (2) Claim No. 1 for utility model registration, which is characterized in that the face plate side surface of the electric heating element is covered with a thermally insulating material.
Panels for cast-in-place concrete type frames as described in Section 1. (3) The cast-in-place concrete type frame panel according to claim 1, which is characterized in that the surface of the electric heating element opposite to the face plate is covered with a heat insulating material.