JP6126854B2 - Method and apparatus for managing concrete strength of concrete structures - Google Patents

Description

The present invention relates to a concrete strength management method for a concrete structure, in particular, a concrete structure having a design standard strength Fc = 200 N / mm ² class, and a management apparatus used for the management method.

Conventionally, as a concrete strength management method for a high-strength or ultra-high-strength concrete structure, for example, up to about a high-strength concrete having a design standard strength Fc = 150 N / mm ² class, it can be used as it is in the outside air without being subjected to high temperature / steam curing. In order to perform curing, it is necessary to obtain in advance strength correction values for structural concrete and cylindrical specimens by experiments.

  Moreover, the curing which simulates the temperature history of a concrete structure by a method such as simple thermal insulation of the specimen has been proposed (see Patent Documents 1 and 2), but the difference in strength between the core and the cylindrical specimen is experimentally examined. It is necessary to ask for.

Furthermore, in order to promote the strength development of ultra-high-strength concrete, steam-cured precast members have been put into practical use, but in the case of ultra-high-strength concrete with Fc = 200 N / mm ² class, it has not been realized on-site. .

JP 2004-294141 A JP 2006-118996 A

  As described above, in the conventional concrete strength management method for a concrete structure, in order to perform the concrete strength management in the ultra-high strength concrete with the cylindrical specimen, it is necessary to calculate a correction value by an experiment. In addition, it is a method that cannot be said to be strength management according to the substance because it takes time and effort to make it precast and put it to practical use. The concrete strength management method and management apparatus for a concrete structure according to the present invention have been proposed in order to solve such problems.

The gist of the concrete strength management device for a concrete structure according to the present invention to solve the above-mentioned problems and achieve the object is a device for managing the concrete strength in the concrete structure, which is placed at the construction site. A mold that surrounds the actual component of the structure to be formed, a heat insulating material that surrounds the mold and a part of the actual component that protrudes from the mold, and a temperature control provided in the mold A heating device that is used for heating curing from the time when the temperature at the temperature management position of the actual constituent member is “outside air temperature + 15 ° C. or higher” connected to the device, and the temperature in the mold is detected A temperature sensor that is partly embedded in the temperature management position in the actual component in the mold and is connected to the control device; and
A control device connected to the heating device and the temperature sensor to manage the temperature history of the actual component;
A mold that surrounds the simulated member, a heat insulating material that surrounds the mold for the simulated member, a heating device that is attached to the mold for the simulated member and connected to the control device, and the simulated member A temperature sensor connected to the control device and partially embedded in the simulation member to detect the temperature of the simulation member. It is to cure.

The gist for solving the above-mentioned problems of the concrete strength management method for a concrete structure according to the present invention is to form the concrete strength management device, and concrete having a concrete temperature of 83 ° C. and a boundary value of 80 ° C. or more. It is managed by the control device so as to stop the heating curing after continuing the member temperature for 72 hours or more , and the simulated member is cured by the control device according to the temperature history of the actual component member, and the simulated member is the same as the actual component member. It is to develop concrete strength under curing conditions.

  According to the concrete strength management method and management apparatus for a concrete structure of the present invention, the temperature history of the actual component member is directly given to the simulated member for concrete strength management, so that the concrete strength between the actual structure member and the simulated member is Will be equal. This eliminates the trouble of correction by the intensity correction value. In addition, since the core strength is directly tested, the reliability of securing the strength is improved. By using a panel heater as the heating device, an excellent effect is achieved that high temperature curing is possible and field driving is possible.

It is a perspective view which shows a mode that the actual structural member 2 is cured in the concrete strength management apparatus 1 of the concrete structure which concerns on this invention. In the concrete strength pipe device 1 of the concrete structure of the present invention, a sectional view (A) at a position indicated by a section 1 in FIG. 1, a sectional view (B) at a position indicated by a section 2, and a position indicated by a section 3. It is sectional drawing (C). It is a perspective view which shows a mode that the simulation member 8 is cured in the concrete strength pipe apparatus 1 of the concrete structure of the same invention. FIG. 4 is a cross-sectional view (A) of the position shown by cross-section 1 in FIG. 3 and a position shown by cross-section 3 in the concrete strength pipe device 1 of the concrete structure of the present invention, and a cross-sectional view (B) of the same position shown by cross-section 2. . It is a whole block diagram of the concrete strength pipe apparatus 1 of the concrete structure of the same invention. It is a flowchart which shows the procedure of the heat curing in the concrete strength management method of the concrete structure. It is explanatory drawing (A) which shows the relationship between curing temperature and core intensity | strength, and explanatory drawing (B) which shows the relationship between age and compressive strength. It is explanatory drawing which shows the relationship of the core strength of the simulation member 8 and the pillar which is the actual structural member 2. FIG.

  As shown in FIG. 5, the concrete strength management method and its management apparatus for a concrete structure according to the present invention directly gives the temperature history of the actual component (column) 2 to the simulation member 8.

A concrete strength management device 1 for a concrete structure according to the present invention is a device for managing the concrete strength in a concrete structure, and is formed by placing concrete at a construction site as shown in FIGS. For example, the mold 3 surrounding the actual component 2 of the column, and the column main reinforcement 2a that is part of the actual component 2 protruding from the mold 3 and the mold 3 are surrounded. Insulating materials 4, 4 a, a heating device 5 attached to the outer surface of the mold 3 and connected to the control device 6 for temperature management, and a temperature in the mold 3 are detected. Therefore, a temperature sensor 7 that is partly embedded in the temperature management position in the actual component 2 in the mold 3 and is connected to the control device 6, the heating device 5, and the temperature sensor 7 Connected to the actual component 2 There is a control device 6 which manages the temperature history.

  Further, as shown in FIGS. 3 and 5, the mold 3 surrounding the concrete simulation member 8, the heat insulating materials 4, 4 a surrounding the mold 3 for the simulation member 8, and the simulation member 8. And a heating device 5 that is attached to the mold 3 and connected to the control device 6, and a part of the simulation member 8 is embedded in the simulation member 8 in order to detect the temperature of the simulation member 8. And a temperature sensor 7 connected to the control device 6.

  Each said structural member is demonstrated. First, the curing device on the actual component 2 side shown in FIG. 1 and the left side in FIG. 5 will be described. The actual structural member of the concrete structure is the pillar 2. This is because the concrete structure is suitable and easy to handle as a target capable of high temperature steam curing. The pillar 2, which is an actual constituent member, is a pillar member in a state where the beam form frame and the slab form frame are not installed at the column beam joint.

  The mold 3 is a steel mold. The steel mold 3 covers the entire column 2 of the concrete structure (excluding the upper part). Panel heaters 5 are installed as heating devices for heat curing on the four surfaces in the vicinity of the column bases of the steel mold 3 (in the drawing, the outer heat insulating material 4 is omitted from a part of the lower part thereof. Shown).

  The panel heater 5 can control ON / OFF of a power source by, for example, a thermostat. The panel heater 5 is electrically connected to the control device 6. A heat insulating material (thickness t = 150 mm) 4 made of expanded polystyrene foam is installed on the outer surface of the steel mold 3. However, since the panel heater 5 is affixed in the vicinity of the column base, as shown in FIG. 2C, the thickness is adjusted from above the panel heater 5 to install the heat insulating material 4. .

  As shown in FIG. 2 (A), the heat insulating material 4 is also installed at the top of the column after completion of driving the column concrete into the steel mold 3. As shown in FIG. 1, the column main reinforcement 2a penetrates the heat insulating material 4 at the column top end. Appropriate heat insulating materials are individually wound around all the pillar main bars 2a protruding from the upper part of the pillar 2.

  Moreover, as shown in FIG. 1 and FIG. 2 (A), it covers with the heat insulation sheet | seat 4a so that the said column main reinforcement 2a may be wrapped. As shown in FIG. 1, the opening of the heat insulating sheet 4 a that covers the steel mold 3 is sealed with a string or the like.

  In this way, as shown in FIGS. 2A to 2C, the entire pillar 2 as an actual constituent member is covered with the heat insulating material 4, the heat insulating sheet 4 a, and the like, and then heated as shown in FIG. 6. Take care. In such curing, for example, when the expected average temperature at the time of placing concrete is 27 ° C. or lower, the inside of the heat insulating sheet 4a is heated by the heater 5a as shown in FIG.

  As shown in FIG. 1 and FIG. 2 (C), the heat curing by the panel heater 5 installed on the four surfaces in the vicinity of the column base is such that the temperature in the concrete temperature management position by the temperature sensor 7 is within the steel mold 3. It starts from the time when it becomes “outside air temperature + 15 ° C. or higher” with the setting reaction of the concrete placed in As shown in FIGS. 1 and 2C, the temperature control position in the concrete by the temperature sensor 7 is a point having a depth of +50 mm from the bottom end level of the column and 50 mm from the column surface in both the X and Y directions.

  The panel heater 5 is controlled via the control device 6 by a thermostat that turns on / off the power at the temperature control position in the concrete by the temperature sensor 7 with a “concrete temperature of 83 ° C.” as a boundary value. The concrete member temperature of 80 ° C. or higher is continued for 72 hours or longer.

  After the concrete member temperature of 80 ° C. or higher is continued for 72 hours or longer, the heat curing is stopped. After that, heat insulation curing is continued and it is confirmed that the concrete member temperature gradually decreases. It is preferable to prepare a generator (not shown) in case of a power failure.

  Next, the curing device on the simulated member 8 side shown on the right side in FIG. 5 will be described. As shown in FIG. 3 and FIGS. 4A and 4B, the entire simulated member 8 which is a column having the same cross-sectional size as that of the column 2 and a height of about 1 m is surrounded by the component mold 3. To do. The upper and lower surfaces of the simulation member 8 are covered with a heat insulating material 4. As a heating device, a panel heater 5 is attached to the outer surface of the steel mold 3 in two sheets on one side as shown in the figure.

  On the simulated member 8 side, the temperature management position by the temperature sensor 7 is a point having a height of 500 mm and a depth of 50 mm in both the X and Y directions from the column surface, and one end of the temperature sensor 7 is embedded therein. Then, a signal line is wired from the other end and connected to the control device 6, and the concrete temperature of the simulated member 8 is transmitted to the control device 6.

  The heat insulating sheet 4a is covered on the outside of the steel mold 3 so as to wrap the whole. Then, the simulation member 8 is heated and cured according to the temperature history of the actual component 2 by the control device 6.

  In this way, the concrete strength management device 1 according to the present invention is formed, the simulated member 8 is cured by the control device 6 according to the temperature history of the actual component 2, and the simulated member 8 is the same as the actual component 2. The concrete strength is expressed under curing conditions.

  Therefore, the temperature histories of the actual component 2 and the simulated member 8 are the same, the concrete strength is equal, and no strength correction is required. This shows the correlation between the core strengths as shown in FIGS. 7 to 8, and when the curing temperature is secured, the core expression strength is secured. The strength indicated by the 28-day strength by the core heat curing / thermal insulation curing is substantially constant in the subsequent course. In addition, the core strengths of the heated 1 m pillar and the full-size pillar are almost the same, indicating a high correlation.

Therefore, by checking the concrete strength of the simulation member 8 with a strength tester, the concrete strength of the concrete structure having the design standard strength Fc = 200 N / mm ² class can be immediately determined.

  The technical idea in the concrete strength management method and the management apparatus for the concrete structure according to the present invention is not limited to the concrete strength management method, and tests a part of a large object as an object as a test specimen. It can be applied to test methods such as durability.

1 Concrete strength management device for concrete structures,
2 actual components, 2a column main reinforcement,
3 Steel formwork,
4 heat insulation material, 4a heat insulation sheet,
5 Panel heater, 5a heater,
6 Control device,
7 Temperature sensor,
8 Simulated member.

Claims (2)

A device for managing concrete strength in a concrete structure,
A formwork that surrounds the actual structural member of the structure formed by placing the concrete at the construction site;
A heat insulating material surrounding the mold and a part of the actual constituent member protruding from the mold;
A heating device used for heating curing from the time when the temperature at the temperature management position of the actual component member is “outside air temperature + 15 ° C. or higher”, which is provided in the mold and connected to a control device for temperature management;
In order to detect the temperature in the mold, a temperature sensor that is partially embedded in the temperature management position in the actual constituent member in the mold and is connected to a control device;
A control device connected to the heating device and the temperature sensor to manage the temperature history of the actual component;
A mold that surrounds the simulated member;
A heat insulating material surrounding the mold for the simulated member;
A heating device which is attached to the mold for the simulated member and connected to the control device;
In order to detect the temperature of the simulation member, a part of the simulation member is embedded and a temperature sensor connected to the control device,
Curing the simulated member by the control device according to the temperature history of the actual component;
A concrete strength management device for a concrete structure. The concrete strength management device according to claim 1 is formed, and the concrete temperature of 80 ° C or higher is continued for 72 hours or more with a concrete temperature of 83 ° C as a boundary value, and then managed by the control device so as to stop heating curing.
Curing the simulated member by the control device according to the temperature history of the actual component, and making the simulated member have the same curing conditions as the actual component to develop concrete strength,
A concrete strength management method for a concrete structure characterized by the following.

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