JP2000329719A - Testing apparatus for adiabatic temperature rise of concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a testing apparatus, for the adiabatic temperature rise of concrete, in which a cause affecting the test accuracy of an adiabatic rise test is eliminated, in which a change with the passage of time in an adiabatic property is eliminated and by which a test assuming a concrete placing operation in a large volume so as to reveal the secondary peak of a temperature rise can be executed with good accuracy. SOLUTION: This testing apparatus for the adiabatic temperature rise of concrete is constituted in such a way that a sample container 12 which comprises a freely detachable lid 12b, in which a space used to house a concrete sample 11 so as to be freely taken in and out is installed and in which a heater 33 used to heat the outer face of the container including the lid 12b is installed integrally is provided, that a vacuum container 13 which houses the sample container 12 and which decompresses the space used to house the sample container 12 to a vacuum state so as to be maintained is provided, that a decompression device 2 which decompresses the vacuum container 13 to a prescribed vacuum is provided and that a temperature control device 3 which measures the central temperature and the peripheral temperature of the concrete sample inside the sample container 13 and which adjusts electric power to be supplied to the heater 33 on the basis of the measured temperatures is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete adiabatic temperature rise test apparatus for obtaining heat generation characteristics of mass concrete in the field of civil engineering and construction.

[0002]

2. Description of the Related Art In mass concrete structures, it is important to prevent temperature cracks caused by heat of hydration of cement from the viewpoints of usability and durability. Therefore, it is important to predict the occurrence of temperature cracks when constructing a structure, and to take effective measures such as selecting appropriate materials and construction methods.

[0003] Accordingly, the amount of increase in the adiabatic temperature of concrete is input as the heat generation characteristic, and the temperature is measured by FEM or the like.
The thermal stress is analyzed by the P method and FEM, etc., and the thermal crack index (temperature crack index Icr (t) = ft (t)
/ Σt (t)) and a technique for examining the probability of occurrence of temperature cracks has been established.

In the temperature analysis, a method of measuring the heat of hydration of the cement paste by a melting heat method or a conduction type microcalorimeter as a heat generation characteristic of concrete is considered. Since the heat is measured, it is difficult to apply the measured value directly to the temperature analysis of mass concrete. As described above, in the thermal stress analysis of mass concrete, it is indispensable to accurately determine the adiabatic temperature rise of concrete as a heat generation characteristic.

At present, typical adiabatic temperature rise test devices used in Japan can be roughly classified into an air circulation type and a water circulation type with respect to devices for maintaining an adiabatic state. , The size of the test specimen, the presence or absence of a heat insulating material around the test specimen, the method of controlling the heat insulation state, the physical quantity for detecting the temperature, and the like, each have many practical differences. ("Quality Evaluation Test Method Research Committee Report"
Japan Concrete Institute, December 1998)

As mentioned in this report, the inventors of the present invention have also developed several heat medium jacket type adiabatic temperature rise test apparatuses for improving the accuracy of this type of test (see, for example, Japanese Patent Application Laid-Open No. H11-157556). Japanese Patent Publication No. 8-7170, Japanese Patent Publication No. 7-48066, Japanese Patent Publication No. 6-41927, and Japanese Patent Publication No. 6-50292.

[0007] In such various adiabatic temperature rise test devices, several factors have been pointed out as factors that influence the accuracy of the adiabatic temperature rise test, as follows. (1) Unless special control is performed so that there is no temperature difference between the center of the specimen and the surface, accuracy may decrease depending on the heat capacity of the heat insulating material. In this case, it is necessary to perform precise temperature measurement on the test body and perform accurate temperature control based on the measured data. (2) Similarly, it is conceivable that the heat capacity of the specimen container containing concrete may affect the test accuracy. As a countermeasure, ultimately, it is desired that there is no test container in the adiabatic temperature rise test apparatus for concrete. (3) In a long-term test, it is ideal that the ambient temperature of the specimen does not have any instantaneous disturbance due to external disturbance. However, in general, a heat insulating layer made of a heat insulating material is provided around the heat medium including the test piece. However, due to deterioration of the heat insulating material over time, the heat insulating state of the heat insulating layer is reduced, and the influence of disturbance is apparent. It becomes to become.

In addition to these, in the high-belite low-heat cement recently JIS-based, the heat generation rate of the cement itself is low, so that the period during which the rise in the adiabatic temperature of the concrete converges tends to be long. Alternatively, depending on the type of concrete, there has been a case where the amount of increase in the adiabatic temperature of concrete cannot be converged during the measurement period conventionally performed. On the other hand, in the case of concrete to be poured into dams and large bridges, on the construction side, the part to be poured is divided into layers, and concrete with low heat generation is hardened in order from the bottom and piled up. Therefore, the lower layer becomes adiabatic after several layers are stacked, and after a relatively long time has passed, the temperature rise due to the hydration reaction is surfaced, and a secondary peak of the temperature rise appears.

For this reason, in an adiabatic temperature rise test assuming a large-capacity concrete casting such as a dam or a large bridge, it is necessary to accurately evaluate the behavior of the thermal expansion and contraction during hardening of the test specimen. The adiabatic temperature rise test must be performed and evaluated stably until the next peak appears.

[Problems] Due to the problems of the materials of cement and concrete, and the problems of the construction of mass concrete such as dams, in the adiabatic temperature rise test, a long-term stable test condition is maintained. However, the conventional adiabatic temperature rise test equipment had little requirement for such a long-term test, so it was not considered until the long-term test. There was a problem of being affected.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior art, and a technical problem specifically set to solve the problem is an adiabatic temperature rise test. It is an object of the present invention to provide a concrete adiabatic temperature rise test apparatus capable of stably and accurately measuring for a long period of time by eliminating a factor affecting test accuracy and a temporal change of heat insulating property.

[0012]

According to the present invention, there is provided a concrete heat insulation temperature rise test apparatus according to the present invention, which is a concretely constructed means for effectively solving the above-mentioned problems. A sample container having a detachable lid, a space for accommodating a concrete sample in a removable manner, a heater integrally heating a container outer surface including the lid, and a sample container for accommodating the sample container. A vacuum container for holding the space containing the container under reduced pressure and maintaining the vacuum container, a decompression device for reducing the pressure of the vacuum container to a predetermined degree of vacuum, and measuring the central temperature and the peripheral temperature of the concrete sample in the sample container and A temperature control device for adjusting power supplied to the heater based on the measured temperature.

According to a second aspect of the present invention, there is provided a concrete adiabatic temperature rise test apparatus, wherein the sample container is formed to have a shape which is uniformly expanded toward the lid, and a thin film made of synthetic resin is provided in the sample container. It is characterized by containing a concrete sample through a material.

According to a third aspect of the present invention, there is provided a concrete adiabatic temperature rise test apparatus, wherein the heater is formed in a panel shape by arranging a linear sheath type heater in a plane, and is integrally attached to an outer surface of the sample container. It is characterized by the following.

[0015] Further, a concrete heat insulating temperature rise test apparatus according to claim 4 is characterized in that a heat insulating material is provided on the outer surface side of the vacuum vessel.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below. However, this embodiment is specifically described for better understanding of the gist of the invention, and does not limit the content of the invention unless otherwise specified.

[Structure] As shown in FIG. 1, a concrete heat insulation temperature rise test apparatus according to this embodiment includes a heat insulation apparatus 1 for accommodating a test body and maintaining a heat insulation state, and a vacuum for the heat insulation apparatus 1. And a temperature control device for controlling the temperature of the test sample housed in the heat insulating device 1 so as to eliminate the temperature difference between the central portion and the peripheral portion. 3

The heat insulating apparatus 1 includes a concrete container 11 formed as a slurry and a concrete container 11 formed in such a manner that the concrete sample 11 can be discharged after curing, and the concrete container 11 is accommodated therein. And a vacuum container 13 for maintaining a space in which the accommodated sample container 12 is held in a vacuum state.

The pressure reducing device 2 is provided with an oil diffusion pump 21 for reducing the pressure inside the vacuum vessel 13 to create a vacuum state, and an oil rotary vacuum pump 22 used as an auxiliary pump of the oil diffusion pump 21.

The temperature control device 3 is provided on the side of the heat insulating device 1 to measure the temperatures of the central portion and the peripheral portion of the concrete sample 11 respectively. The central temperature sensors 31 (31a, 31b, 3)
1c) and the ambient temperature sensor 32 (32a, 32b, 3)
2c), and a heater 33 (33a, 33b, 33) which is adhered and fixed to the surface of the sample container 12 and is heated or kept warm so that the peripheral temperature of the concrete sample 11 follows the central temperature.
c), the center temperature sensor 31 and the peripheral temperature sensor 32
The heater 33 (33a, 33b,
33c) is provided with a control unit 34 for controlling the heating state and managing the temperature so as to eliminate the temperature difference between the central part and the peripheral part of the concrete sample 11.

As shown in FIG. 2, the sample container 12 comprises a bucket-shaped sample container main body 12a having an open top and a lid 12b for closing the opening of the sample container main body 12a. Means that a single-plate wall is formed, a heater 33 is directly fixed to the outer wall surface of the wall, and a temperature sensor 32 for measuring the wall surface temperature is attached to an appropriate position. The temperature can be controlled so that a temperature difference does not occur between the central part and the peripheral part.

The shape of the sample container main body 12a is a bottomed cylindrical shape having a height substantially equal to or larger than the inner diameter, and the minimum inner diameter is three times the maximum size of the coarse aggregate contained in the concrete sample 11. Above. Then, in order to take out the hardened concrete, a draft is formed on the opening side so that the diameter increases.

Also, between the concrete sample 11 and the sample container main body 12a, a sheet, bag or bucket container made of synthetic resin such as vinyl, polyvinylidene chloride, polyethylene or polyester is used for preventing or peeling concrete. Thin film material 50 (for example, FIG.
(See Reference) to make it easier to remove the hardened concrete. As the thin film material 50, a bag of thermoplastic saturated polyester is preferably used in terms of availability. Also,
In this case, the film thickness is preferably about 40 to 50 μm.

At the open end of the sample container body 12a and the outer peripheral end of the lid 12b, flanges 12c and 12d projecting outward in the radial direction are provided, and a plurality of bolt holes 12e,. , 12f, ..., 12
, 12g, and nuts 12h,..., 12h are screwed into the bolts 12g,..., 12g, and tightened by bolts to make the lid 12b detachable. Allow the opening to be sealed.

The O-ring 12i is fitted into the O-ring groove 12j formed in the lid 12b in the seal between the sample container main body 12a and the lid 12b, so that the tightening pressure of the bolt at the time of sealing is obtained. Seal with.

As shown in FIG. 3, the center temperature sensors 31a and 31a for measuring the sample temperature are provided at the center and at a plurality of positions moved outward from the center.
A short pipe 12k forming a sensor insertion hole through which b and 31c can be inserted is welded, and the internal temperature of the sample can be measured at a plurality of locations through this pipe 12k. The pipe 12k is provided with a female screw at the upper end so that the center temperature sensors 31a, 31b, 31c can be detachably and replaceably attached.

Center temperature sensors 31a, 31b, 31c
As shown in FIG. 4, a sensor pipe 41 internally provided with a thermosensitive element such as a resistance thermometer, a rubber ring 42 fitted on the upper end of the sensor pipe 41, and a pipe 12k at one end.
A ring-shaped screw part 43 serving as an insertion guide for a sensor pipe 41 in which a male screw is cut into the upper end and a female screw is cut in the other end, and a rubber ring 42 is externally fitted, and the ring-shaped screw part And a bolt 44 having an external thread to be screwed to the screw 43 and having a sensor pipe insertion hole.

For this attachment, a ring-shaped screw part 43 is used.
Is screwed into the upper end of the pipe 12k, a sensor pipe 41 with a rubber ring 42 externally fitted thereto is inserted into the pipe 12k via a ring-shaped screw part 43, and a bolt 44 is externally fitted to the sensor pipe 41 to form a ring. The bolt 44 is screwed into the female screw of the ring-shaped threaded component 43 and tightened, and the rubber ring 42 is pressed by the tip of the bolt 44 on the side where the male thread is cut. This is performed by compressing the rubber ring 42 and fixing the sensor pipe 41 to the inner surface of the female screw engraving side.

As shown in FIGS. 3 and 5, the heater 33 closely adhered to the surfaces of the sample container body 12a and the lid 12b is constituted by a peripheral heater 33a, a bottom heater 33b and a lid heater 33c. Heating or keeping the temperature of the peripheral surface and the bottom surface of the main body 12a and the lid 12b uniform.

The heater 33a for the peripheral surface is adapted to
The linear sheath-type heaters, which are arranged in the region equally divided into three in the circumferential direction of a, are arranged side by side with no gap in the plane and divided into heaters 33a-1, 33a-2, and 33a-3 formed in a panel shape.
The bottom heater 33b and the lid heater 33c are formed in a panel shape by arranging linear sheath type heaters arranged on the bottom surface of the sample container main body 12a and the upper surface of the lid 12b without any gaps in a plane.

The three divided heaters 33a-1, 33a-
, 3a-3 have a plurality of terminals 33d,..., 3 each having a wiring terminal portion and a mechanical coupling portion.
3d is connected to facilitate connection of power supply wiring and to make heater attachment to the peripheral surface uniform. The bottom heater 33b and the lid heater 33c are provided with terminals 33e and 33f as wiring terminal portions, respectively, to facilitate connection of power supply wiring.

The sample container body 12a and the lid 12b are attached to the heater fixing portions of the sample container body 12a and the lid 12b, respectively.
The measurement end of the ambient temperature sensor 32 (32a, 32b, 32c) is arranged and sandwiched between the outer surface of the heater and the gap between the adjacent sheathed heaters provided with the heaters 33 (33a, 33b, 33c). .

To attach the heater 33 (33a, 33b, 33c) and the peripheral temperature sensor 32 (32a, 32b, 32c) to the outer surfaces of the sample container body 12a and the lid 12b, the heater 33 (33a, 33b, 33c) and the peripheral A metal holding member (not shown) made of a stainless steel plate or the like from outside the temperature sensor 32 (32a, 32b, 32c)
Is welded to the sample container main body 12a and the lid 12b, for example, by applying a pressing force toward the outer surfaces of the sample container main body 12a and the lid 12b to be pressed and fixed.

As shown in FIG. 2, the vacuum container 13 has a vacuum container main body 13a having an opening at an upper portion so as to allow the concrete sample 11 to be taken in and out, and a vacuum container main body 13a.
.., 13c that support the sample container 12 housed in the vacuum vessel main body 13a from the bottom side.

The outer surfaces of the vacuum vessel body 13a and the lid 13b are covered with heat insulating materials 13d and 13e made of foam, respectively, and the outer surfaces are protected by covering them with thin metal plates 13f and 13g. The support member 13c is formed of a material having poor thermal conductivity and having a strength that does not break the concrete sample 11 in and out of the sample container 12 accommodated in the vacuum container 13. As a material used for the support member 13c, for example, polytetrafluoroethylene, which is well-known as Teflon, is suitable.

At the inner peripheral ends of the opening end of the vacuum vessel main body 13a and the edge of the lid 13b, inner flanges 13h and 13i which are in contact with each other are provided to form a joint portion. An O-ring groove is engraved on the mating surface side, and an O-ring 13j is fitted therein so that the vacuum vessel 13 can be sealed when the lid 13b is closed.

A pipe connection portion 13k is formed by welding a pipe or duct material for exhaust to a side peripheral surface of the vacuum vessel body 13a, and a shutoff valve 131 is provided at a tip end thereof.
3l, a vacuum port 14 having the same diameter as the pipe connection portion 13k is provided at the connection end opposite to the vacuum vessel side so that the pipe on the pressure reducing device 2 side can be connected. Opening enables the evacuation and decompression of the inside of the vacuum vessel, and closing of the shut-off valve 131 makes it possible to seal the inside of the decompressed vacuum vessel.

As shown in FIG. 1, a pipe 21a is connected to the pressure reducing device 2 from a vacuum port 14 provided in a vacuum tank body 13a to an oil diffusion pump 21.
A cut-off valve 21b on the oil diffusion pump inlet side is provided at the end of the oil diffusion pump 21a, and a pipe 22a is connected between the exhaust port of the oil diffusion pump 21 and the oil rotary vacuum pump 22. A shutoff valve 22b on the outlet side of the oil diffusion pump is provided at a position close to the oil diffusion pump side, and branches off from a position upstream of the shutoff valve 21b of the pipe 21a to join a position downstream of the shutoff valve 22b of the pipe 22a. A pipe 23 is provided, and a shutoff valve 23 for changing a flow path is provided at an intermediate position of the pipe 23.
a, and a branch valve is provided in the middle of the pipe 22a, and a shutoff valve 23b is provided to open one of the pipes to the atmosphere. The shutoff valve 21b is adjusted to a degree of vacuum according to the characteristics of the oil diffusion pump 21 and the oil rotary vacuum pump 22. By opening and closing each of the shut-off valves 22b and 23a, the pressure can be appropriately reduced, and the atmospheric pressure can be restored by opening the shut-off valve 23b as necessary.

Center temperature sensor 3 in temperature control device 3
1 (31a, 31b, 31c) and ambient temperature sensor 3
2 (32a, 32b, 32c) to the control section 34 are connected to the vacuum vessel main body 13 from the sensors 31 and 32 attached to the sample vessel 12 housed in the vacuum vessel.
is connected to a control unit 34 outside the heat insulating device 1 through a through-hole 13m provided in a.

In the control section 34, as shown in FIG. 6, the output signals from the respective central temperature sensors 31a, 31b, 31c are inputted to an average temperature calculator 34a to obtain an average temperature, and the obtained average temperature is calculated. The temperature is recorded on the temperature recorder 34b, and the temperature controllers 34d for the peripheral surface, the bottom surface, and the lid (three divided heaters 33a-
1, 33a-2, and 33a-3 corresponding to the temperature controllers 34d-1, 34d-2, and 34d-3, respectively), 34e, and 34f. Each of the peripheral temperature sensors 32a, 32b, 32 provided on the peripheral surface, the bottom surface, and the lid.
c from the temperature controllers 34d (34d-1, 34d-2, 34d) for the peripheral surface, the bottom surface, and the lid, respectively.
-3), 34e, and 34f, and obtains an operation amount of the PID control having the average temperature as a target value based on each ambient temperature and the average temperature, and outputs a control signal corresponding to the obtained operation amount for the peripheral surface. And power controllers 34g for bottom and lid (power controllers 34g-1, 34g-2, 34g- corresponding to temperature controllers 34d-1, 34d-2, 34d-3, respectively).
3, the same applies hereinafter), 34h and 34i. Each power regulator 34g (34g-1, 34g-2, 34g-3),
At 34h and 34i, the amount of power supplied to the corresponding heaters 33a, 33b, and 33c is adjusted by the input control signals to control the peripheral temperature to follow the central temperature.

[Preparation work] In conducting the test, the lid 13b of the vacuum vessel 13 was removed, and the vacuum vessel body 1
3a, the lid 12b of the sample container 12 is removed, and the sample container main body 12a, which is still contained in the vacuum container main body 13a, is made of a 40 μm thick thermoplastic saturated polyester for preventing concrete adhesion and peeling. The thin film material 50 formed in the bag is put, and a predetermined amount of concrete slurry is poured into the thin film material 50.

Then, as shown in FIGS. 7A and 7B, a positioning jig 52 for the embedding screw 51 is arranged at the upper end of the sample container main body 12a, and is drilled in the positioning jig 52. Screw 5 having a cork stopper 53 attached to the upper end thereof in accordance with the plurality of positioning holes 52a for the screw.
1 is buried substantially vertically for the required number.

Then, the positioning jig 52 is removed,
A lid 12b is attached to the sample container main body 12a, and as shown in FIG. 2, a bolt 44 and a rubber are inserted through a ring-shaped screw part 43 screwed to an upper end of a pipe 12k forming a sensor insertion hole provided in the lid 12b. The sensor pipe 41 with the ring 42 fitted therein is inserted into the concrete slurry, and when the tip of the sensor pipe 41 reaches a predetermined position, a bolt 44 is screwed into the ring-shaped threaded component 43 and tightened, so that a rubber ring is formed. 42 is compressed to fix the sensor pipe 41, and necessary wiring and connection are performed so that the center temperature can be measured.

After the preparation work related to the sample container 12 is completed, the lid 13b is attached to the vacuum container main body 13a and hermetically closed. Then, of the wires that are outside the vacuum vessel 13 and are not connected to the control unit 34, the wires are connected so that necessary measurement values can be obtained.

Thereafter, the shutoff valve 131 and the shutoff valve 23a
Is opened, and it is confirmed that the shutoff valves 21b and 22b are closed, and the oil rotary vacuum pump 22 is operated to depressurize the inside of the vacuum container 13. The oil diffusion pump 21 is operated after the inside of the vacuum container 13 has reached a predetermined vacuum degree, and the shutoff valve 2 has been turned on when the function of the oil diffusion pump 21 has reached a predetermined range.
3a is closed, the shut-off valve 22b is opened, and the shut-off valve 21
b, the interior of the vacuum vessel 13 is further depressurized, and after confirming that a predetermined degree of vacuum (for example, 10 ^-12 torr) has been reached, the shutoff valve 21b and the shutoff valve 131 are closed, and the shutoff valve 22b is further closed. Close and stop the oil diffusion pump 21 and the oil rotary vacuum pump 22.

After the oil diffusion pump 21 and the oil rotary vacuum pump 22 are stopped, the progress of hardening of the concrete sample 11 is measured, and the degree of vacuum inside the vacuum vessel 13 is monitored. In the case where is observed, the pressure reduction procedure is repeated to maintain the degree of vacuum, and a highly accurate temperature control is performed while maintaining a stable test state for a predetermined test period.

[Removal work] After a predetermined period has passed and the concrete sample 11 has hardened and the test is completed, the shut-off valve 2
After confirming that 1b and the shutoff valve 22b are closed, the shutoff valve 23b, the shutoff valve 23a and the shutoff valve 13l are opened in order, and the pressure inside the vacuum vessel 13 is returned to the atmospheric pressure.

After the inside of the vacuum vessel 13 returns to the atmospheric pressure, the lid 13b is removed from the vacuum vessel body 13a, the sensor pipe 41 is subsequently removed from the lid 12b of the sample vessel 12, and the cover 12b is removed from the sample vessel body 12a. hand,
The hardened concrete sample 11 can be taken out.

The cork stopper 53 is removed from the embedding screw 51 to which the cork stopper 53 is attached, and as shown in FIG. Into a state in which the concrete sample 11 can be lifted.

Then, the wire 55a of the lifting metal 55
The hook 55b provided at the lower end of the hook is engaged with the ring portion 54a of the suspension bolt 54, and the ring portion 55c of the lifting bracket 55 is engaged with a hook (not shown) of a lifting device such as a chain block or a crane. Lift by operating the lifting device.

When the wire 55a of the lifting metal 55 is stretched, the hardened concrete sample 11 is easily lifted away from the sample container main body 12a by the thin film material 50, and is lifted to the outside of the vacuum container main body 13a. It is moved, transferred to a transfer device (not shown), and transferred to a disposal place.

[Test Results] Thus, the sample container 1
In the case where the concrete sample 11 accommodated in 2 is placed in a state where the heat insulation state is maintained for a long period of time, the concrete sample of 6 months of age is used at each set temperature of 20 ° C., 45 ° C. and 70 ° C. The adiabatic retention capacity of the test device performed was verified.
FIG. 9 shows the result. From this result, the temperature error in the adiabatic state was less than 1/1000 ° C per day.

This was compared with the data of the method of verifying the heat insulation retention capacity performed in the same manner using a conventional heat insulation temperature rise test apparatus (for the heat insulation temperature rise test apparatus, the Japan Concrete Institute, Concrete Quality Evaluation Test). Compared with the results of the Symposium on Methodology, P15-20, 1998.12.4), the test results are as shown in FIG.
The temperature error of the adiabatic state is 2/1000 or 3/100 per day. Therefore, in the adiabatic temperature rise test apparatus according to the present embodiment, the temperature error in the adiabatic state is reduced to 以下 or less as compared with the conventional adiabatic temperature rise test apparatus.

[Operation and Effect] As described above, in the adiabatic temperature rise test apparatus according to the embodiment, the heater 33 (33a,
33b, 33c) is placed in the vacuum vessel 1
3 and provided with a vacuum layer between the sample container 12 and the vacuum container 13, the environmental conditions of the concrete sample 11 are less affected by atmospheric temperature and other disturbance elements, and the secular change to the heat insulating state And accuracy in long-term measurement can be increased.

Also, the concrete sample 11 and the sample container 1
2 is completely in close contact with the concrete sample 11, the air layer around the concrete sample can be completely eliminated from the sample container 12, and the heater 3 is attached to the concrete sample 11.
3 (33a, 33b, 33c), heat can be applied directly, the response is good, the temperature can be finely controlled, and it can be closer to the ideal heat insulation state, and more accurate heat insulation can be achieved. It becomes possible to measure the amount of temperature rise.

Further, the sample container 12 can be reused, and the expensive sample container is not disposable after the test, thereby reducing the test cost.

In addition, as a result of carrying out an examination of the heat insulation retention ability according to the “concrete heat insulation temperature rise test method (draft)” proposed by the Japan Concrete Institute,
It was confirmed that a constant heat-insulating holding capacity was maintained over a long period of time.

[Alternative Embodiment] Although such an embodiment has been specifically described in order to facilitate understanding of the gist of the present invention, it is not intended to limit the content of the present invention. The mode is not limited, and may be changed as appropriate. Several alternative embodiments in this sense that are consistent with the spirit of the invention are described below.

For example, although the case where three center temperature sensors 31 are shown, the number may be smaller or larger than this, and there is no particular limitation as long as the measurement accuracy of the test can be maintained. In addition, although the case where the peripheral heater 33a of the heater 33 is divided into three is shown, the number of divisions is not limited, and the optimal number of divisions may be set from the viewpoint of actual work such as power supply and wiring. , And need not be divided.

Although the heat insulating materials 13d and 13e of the vacuum vessel 13 are formed of a foam material, they are not particularly limited as long as they have a heat insulating effect capable of preventing heat from entering from outside. A combination of a vacuum or a laminated material of a film that reflects radiant heat and a vacuum may be used.

[0061]

As described above, according to the present invention, the concrete adiabatic temperature rise test apparatus according to the first aspect has a detachable lid, a space for accommodating the concrete sample in and out, and the lid is included. A sample container integrally provided with a heater for heating the outer surface of the container, a vacuum container for accommodating the sample container and holding the space accommodating the sample container in a vacuum state and maintaining the vacuum container at a predetermined degree of vacuum. By providing a decompression device for reducing pressure and a temperature control device for measuring the central temperature and the peripheral temperature of the concrete sample in the sample container and adjusting the power supplied to the heater based on the measured temperature, the concrete sample and The heater is completely in contact with the concrete sample, so that it can maintain heat insulation without creating an air layer around the concrete sample, and the sample container is placed in a vacuum space. The effect of environmental disturbance elements can be reduced by this, eliminating the factors that affect the test accuracy and the time-dependent change of the heat insulation, and the heat insulation temperature rise test of concrete with a long convergence period of the heat insulation temperature rise for a long time It can be executed with high accuracy and can measure the adiabatic temperature rise accurately for a long time. Further, since the expensive sample container can be reused, the cost for the test can be reduced.

Further, in the concrete adiabatic temperature rise test apparatus according to claim 2, the sample container is formed to have a shape which is uniformly expanded toward the lid, and a thin film made of synthetic resin is provided in the sample container. By containing the concrete sample through the material, the thin film material prevents the adhesion between the concrete sample and the inner surface of the sample container, and the solidified concrete sample can be easily extracted from the sample container, and the sample container is disposable The cost can be reduced because the expensive sample container can be reused without having to do so.

Further, in the concrete adiabatic temperature rise test apparatus according to the third aspect, the heater is formed in a panel shape by arranging linear sheath type heaters in a plane, and is integrally attached to the outer surface of the sample container. As a result, the heating or heat retention by the heater is generally uniform, the response to the influence or fluctuation of disturbance is good, and the entire sample is prevented from generating a temperature difference between the center and the periphery of a large concrete sample. The temperature can be made uniform and a good heat insulation state can be maintained.

In addition, in the concrete heat insulation temperature rise test apparatus according to the fourth aspect, by providing a heat insulating material on the outer surface side of the vacuum vessel, it is possible to minimize the influence of fluctuations in the atmospheric temperature and to maintain the heat insulation state. Can be easily maintained.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram schematically showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a sample container and a vacuum container in the embodiment.

FIG. 3 is a configuration diagram showing a lid of a sample container in the embodiment, (A) is a plan view, and (B) is a longitudinal sectional view.

FIG. 4 is a configuration diagram showing a fixture for a center temperature measurement sensor according to the embodiment; FIG.
(B) is a rubber ring, (C) is a mounting screw, (D) is a longitudinal sectional view showing an assembled state of these.

5A and 5B are configuration diagrams showing a sample container main body according to the embodiment; FIG. 5A is a plan view, FIG. 5B is a partial cross-sectional side view, and FIG.

FIG. 6 is a block diagram showing a measurement / control system of a control unit according to the embodiment.

FIGS. 7A and 7B are explanatory views showing an embedding state of an embedding screw in the embodiment, in which FIG. 7A is a plan view and FIG.

FIG. 8 is an explanatory view showing a lifting state of the concrete sample in the embodiment, (A) is a plan view before lifting, and (B) is a vertical sectional explanatory view at the time of lifting.

FIG. 9 is a graph showing a test result of an adiabatic holding ability in the test apparatus of the embodiment.

FIG. 10 is a graph showing a test result of a heat insulating holding ability in a conventional test apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulation device 2 Decompression device 3 Temperature control device 11 Concrete sample 12 Sample container 12a Sample container main body 12b Cover 12c, 12d Flange 12k Pipe (sensor insertion hole) 13 Vacuum container 13a Vacuum container main body 13b Cover 13c Support member 13d, 13e Heat insulating material 13h, 13i Inner flange 13k Piping connection 13l Shut-off valve 13m Through hole 14 Vacuum outlet 21 Oil diffusion pump 21a, 22a, 23 Piping 21b, 22b, 23a, 23b Shut-off valve 22 Oil rotary vacuum pump 31 Central temperature sensor 32 Ambient temperature Sensor 33 Heater 33a (For peripheral surface) Heater 33b (For bottom surface) Heater 33c (For lid) Heater 34 Control unit 34a Average temperature calculator 34b Temperature recorder 34c Average temperature transmitter 34d (For peripheral surface) Temperature controller 34e ( For bottom) temperature controller 3 4f (for lid) temperature controller 34g (for peripheral surface) power regulator 34h (for bottom surface) power regulator 34i (for lid) power regulator

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Yuichi Otabe 585 Tomicho, Funabashi-shi, Chiba Sumitomo Osaka Cement Co., Ltd. 2G040 AB12 BA02 BA05 BA22 BA25 BA29 CA02 CB03 CB14 DA02 DA13 DA14 DA15 EB05 FA01 GB01 GC01 GC07

Claims (4)

[Claims] 1. A test container for adiabatic temperature rise test of concrete, comprising a detachable lid, a space for accommodating a concrete sample in and out, and a heater integrally heating a container outer surface including the lid. A vacuum container that accommodates the sample container and maintains the space accommodating the sample container in a vacuum state, a decompression device that decompresses the vacuum container to a predetermined vacuum degree, and a center of a concrete sample in the sample container. A temperature control device for measuring a temperature and an ambient temperature and for adjusting electric power supplied to the heater based on the measured temperatures. 2. The method according to claim 1, wherein the sample container is formed in such a shape that its diameter is uniformly increased toward the lid, and a concrete sample is accommodated in the sample container via a thin film made of synthetic resin. The concrete heat insulation temperature rise test device according to claim 1. 3. The concrete as set forth in claim 1, wherein said heater is formed in a panel shape by arranging a linear sheath type heater in a plane, and is closely attached to an outer surface of said sample container. Adiabatic temperature rise test equipment. 4. The apparatus according to claim 1, wherein a heat insulating material is provided on an outer surface side of said vacuum vessel.