JPS62103557A - Adiabatic temperature rise tester for concrete and mortar - Google Patents

Abstract

PURPOSE:To enable the testing for a rise in the adiabatic temperature at a better condition, by controlling a heat medium jacket temperature without time delay by a rate of change computing means and a heat medium control means. CONSTITUTION:Analog converters 26 and 27 converts the measured values of a sample thermometer 6a and heat medium jacket thermometer 16c into voltage. Based on the results of the measurements of the thermometers 6a, a rate of change computing unit 28 computes the rate of change in the center temperature of the sample 15. Moreover, a heat medium temperature controller 29 controls the heat medium temperature of water, silicon oil or the like so as to coincide with the center temperature of the sample 15 by regulating a thyristor S. The unit 29 controls the temperature of the heat medium by driving the thyristor S lest the rise in the heat medium should fall behind the rise in the center temperature of the sample 15 on the basis of the results of the computation of the unit 28. This can always keep the temperature in a test tank the same as the temperature of the sample. Thus, the sample is set thermally insulated, thereby enabling a testing for an adiabatic rise at a better condition.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an adiabatic temperature rise testing device for concrete and mortar, and in particular, a heating medium is used to increase the temperature of concrete or mortar as a sample stored in a test chamber. This invention relates to a device that controls the heat medium temperature so that the surface temperature of the jacket matches, keeps the sample in the test chamber in an adiabatic state, and measures the adiabatic temperature rise of the sample.

[Conventional technology]

Conventionally, it has been widely used as a test device for adiabatic temperature testing of concrete IJ and mortar in order to confirm the placement status of concrete or mortar at a construction site.

That is, the adiabatic temperature test is performed by forming concrete or the like in a test device using a mixture similar to the actual mixture at a construction site.

Generally, such an adiabatic temperature rise testing device for concrete or the like uses water or air as a heating medium and is provided with a fixed tank number for the heating medium. In other words, in the case of an air tank, the test tank is covered with a buffering material such as cork, styrofoam, or styrene, and in the case of an aquarium, the sample in the test tank is covered with a buffering material such as cork. The purpose is to control the temperature of the heat medium in the tank to follow the temperature rise due to the hydration reaction of cement, artificially create an adiabatic state, and measure the amount of adiabatic temperature rise in the concrete sample. be. As shown in Fig. 6, an example of an adiabatic temperature rise test device for concrete using air as a heating medium is used. A cylindrical buffer container 2 made of cork is installed in a stainless steel calorimeter box 1 serving as a container, and a concrete 3 as a sample is stored inside the buffer container 2 in a sealed test tank 8. has been done. A heater 4 is disposed, for example, on the side of the buffer container 2, and its operation is controlled by a temperature difference controller 9. In addition, inside the test tank 8-
A sample thermometer 6a for measuring the center temperature of the concrete 3 is inserted into the concrete 3 stored in the container, and an in-tank thermometer 6b for measuring the temperature in the tank is installed inside the calorimeter box 1. , the sample thermometer 6
a and the tank thermometer 6b are both connected to a temperature difference calculator T. This temperature difference calculator 7 calculates the temperature difference between the center temperature of the concrete 3 and the temperature inside the tank. Reference numeral 9 denotes a temperature difference regulator, which drives the thyristor S so as to make the temperature difference zero based on the calculation result of the temperature difference calculator T.

The thyristor S turns on and off the heater 4 based on a control signal from the temperature difference regulator 9 and adjusts the temperature inside the L tank. In this way, in this device, the heater 4 operates in a manner that follows changes in the temperature rise of the sample in the test chamber 8, and
The amount of adiabatic temperature rise of the sample is measured while the temperature inside the test tank 8 and the temperature inside the calorimeter box 1 are kept approximately the same.

[Problems with conventional technology]

By the way, in conventional adiabatic temperature rise test equipment, the difference between the center temperature of concrete and the temperature inside the tank is calculated, and the heater is driven to raise the temperature inside the tank so that the difference becomes zero. 4, there is a time lag between the temperature rise in the test chamber 8 and the temperature rise in the chamber, and there is a problem in that the temperature difference cannot be eliminated after all.

Therefore, an object of the present invention is to effectively form an adiabatic state by making the difference between the center temperature of a sample such as concrete and the surface temperature of the concrete zero.

[Means for solving problems]

The technical means of the present invention that solves the above problems is that the containment vessel is formed of a heat insulating material and a heat medium jacket provided inside the heat insulating material, and is also provided in close contact with the test tank and the heat medium jacket. , further comprising a rate-of-change calculation means for calculating a rate of change in the center temperature of the sample, and driving a heat-medium jacket control means for controlling the heat-medium jacket temperature based on the calculation result of the rate-of-change calculation means; The center temperature of the sample and the heat medium jacket temperature are matched.

[Embodiments of the invention]

The present invention will be described below based on embodiments shown in the accompanying drawings.

As shown in FIGS. 2A to 2D, the concrete and mortar adiabatic temperature rise test apparatus 2 according to this embodiment consists of a containment vessel 10 and a control section 11, and the containment vessel 10 is connected to a movable trolley 12. is installed on top. The containment vessel 10 is formed into a substantially rectangular parallelepiped, and consists of a heat insulating material 13 and a heat medium jacket 14 provided inside the heat insulating material 13.
A test tank 16 containing concrete 15 as a sample is placed closely adjacent to the test tank 4 . As shown in FIG. 2B, the test chamber 16 according to this embodiment has a cylindrical shape with a diameter of 600 mm and a height of 60011 EII. Further, the containment vessel 10 consisting of the heat insulating material 13 and the heat medium jacket 14 is formed so that the top surface portion 10d and the side surface portions 10e can be split into two in the width direction except for the bottom surface portion 10c. That is, the rear surface portion 10aK of the containment vessel 10 has hinge portions t7 and 18 attached at two places, and the hinge portions 17 and 18K are inserted with hinge irons 19, and the hinge portions 17 and 18K are inserted into the rear surface portion 10aK of the containment vessel 10. Two handles 20 and a locking device 21 are attached to the front part 10b. Therefore, the storage container 10 can be rotated in the left and right directions about the hinge iron 19 and can be divided into two parts.

(9) The concrete and mortar adiabatic temperature rise test device according to this embodiment uses water, silicone oil, etc. as a heat medium, and as shown in FIG. Water supply pipes 22, 22' and drain pipes 23, 23' extend thereto, and are attached to the heat medium jacket 14 provided in the containment vessel 10 via connection parts 22a, 22a', 23a, 23a', respectively. There is. The reference numeral 24 is a lift hook for lifting the containment vessel 10, and the reference numeral 25 is a lever used for lifting the containment vessel 10.

On the other hand, the control section 11 controls the temperature inside the containment vessel 10 and records the amount of temperature rise of the sample 15, and is configured as shown in FIG. 1, for example.

In FIG. 1, 26 and 27 are the sample thermometers 5 and 5, respectively.
a, an analog converter that converts the measured value of the heat medium jacket thermometer 60 into voltage; Reference numeral 28 denotes a rate of change calculation device that calculates the rate of change in the center temperature of the concrete 15, which is a sample, based on the measurement results of the sample thermometer 6a. 29 is Thyristor S? This is a heating medium temperature control device that controls the temperature of a heating medium such as water or silicone oil to match the center temperature of the concrete IJ-N5.

This heating medium temperature control device 29 includes the rate of change calculation device 28
Based on the calculation result (predicted center temperature change rate), the heating medium temperature rises inside the concrete 15.

The temperature of the heating medium is controlled by driving the thyristor S to keep up with the rise in heart temperature. 30 is a heating device that heats the heat medium in the heat medium jacket, 31 is a cooling device that cools the heat medium, and 32 is a cooling device! A driving device 33 that drives the IL 31 is a pump that circulates a heat medium. 34 is a recorder that records the center temperature of the concrete 15 as a sample and the temperature of the heat medium jacket 14. Note that 35 is a center temperature indicator that displays the center temperature of the concrete 15. Further, 36 is a changeover switch, and by switching to constant value operation, the heat medium jacket temperature is kept constant at a temperature preset by the heat medium temperature control device 29.

When performing an adiabatic temperature test using the adiabatic temperature rise test device 9 configured as described above, the containment vessel 10 is lifted onto the trolley 12 by pulling the lever 25fC and using the 7tons 1γ, and the lever 25 is fixed. 10 containment vessels will be maintained in a lifted state.

Next, the locking device 21 attached to the front part 10b of the containment vessel 10 is released, and the containment vessel 10 is opened using the handle 20.
Divide into two horizontally. Then, the test tank 16 containing the sample is installed in the heat medium jacket 14, and is closed with the containment vessel 10 and relinked with ecI.

Thereafter, the lever 25 is pushed down and the containment vessel 10 is lowered onto the trolley 12 for testing. In addition, when testing samples of different sizes, as shown in the second diagram, a heat transfer jacket 29 and a heat insulating material 30 are used to accommodate a separately prepared airtight container 28 of any size. This is done by replacing the test tank 31 with a new one.

Next, temperature control of the heat medium jacket 14 is performed as follows.

The center temperature of the conch IJ-N5 measured by the sample thermometer 6a is converted into voltage by the analog female converter 26, displayed on the center temperature display meter 35, and inputted to the rate of change calculation device 28.

On the other hand, heat medium jacket thermometer 6c'''jm 1ill
The determined temperature of the heat medium jacket 14 is determined by the analog transformer 2.
7 and is input to the heat medium temperature control device 29. The rate of change calculating device 28 calculates the rate of change of the center temperature of the conch IJ-) 15 and the difference between the center temperature and the heat medium jacket temperature, and sends the heat medium jacket temperature to the heat medium temperature control device 29 to determine whether the heat medium jacket temperature is the center temperature. Provide optimal settings to keep up with changes. Therefore, the heating medium temperature control device 29 performs a PID calculation (proportional + integral plus differential calculation) on the given set value and the heating medium jacket temperature, and continuously controls the heating device 3o using the thyristor SK. At this time, by circulating the heat medium at high speed using the pump 33, the temperature of the heat medium can be kept uniform. When the calorific value of the concrete 15 per unit time is large, the rate of change calculating device 28 predicts the rate of change of the center temperature of the concrete IJ-N5 and controls the heat medium jacket temperature.

Therefore, the center temperature of the concrete 15 and the temperature of the heat medium can be matched without causing any time lag in control.

Incidentally, at the time when the heat generation of Conc IJ-) 15 has ended, the center temperature change rate becomes zero, but in this case as well, the heating medium temperature is controlled to match the sample center temperature based on the center temperature change rate. Ru.

Examples of experiments conducted using the concrete and mortar adiabatic temperature rise test device according to the present invention are shown below.

For mortar with the mix shown in Figure 3 and concrete with the mix shown in Figure 4, the results of the adiabatic temperature rise using the device according to the present invention are compared with the results of the adiabatic temperature rise using the conventional device shown in Fig. Figure 5 shows the change in center temperature from the time of concrete pouring when a cubic concrete block is covered with styrofoam with a thickness of 2 ocrn. From FIG. 5, it is clear that the adiabatic temperature increase result obtained by this device accurately reproduces the change in the center temperature of the concrete block, which can be regarded as a substantially adiabatic type. In addition, the adiabatic temperature rise results obtained using conventional equipment are lower than the temperature at the center of the concrete block, making it difficult to call this an accurate adiabatic temperature rise test.

As described above, the apparatus according to this embodiment is provided in close contact with the heat medium jacket 14 provided inside the test tank and the heat insulating material, and the heat medium jacket 14 is connected to the rate of change calculation device 28 and the heat medium jacket 14. The temperature control device 29 always controls the temperature to be the same as the sample center temperature without any time delay. Therefore, the temperature within the test chamber can be increased without causing a time lag, and heat will not flow out from the sample within the test chamber. In addition, because the heating medium circulates at high speed, the surface of the heating medium jacket 14 is kept at a uniform temperature, and the temperature distribution inside the containment vessel does not become uneven as in the conventional case, making it possible to perform ideal adiabatic temperature rise tests. It can be carried out. On the other hand, since the containment vessel 10 is installed on the trolley 12 and is movable, the test tank 16 can be quickly installed.If the initial temperature of the sample is measured in advance, the temperature inside the containment vessel 10 can be adjusted to the temperature of the sample. It is possible to set the initial temperature. Furthermore, since the test chamber 16 is connected to the heat medium jacket 14 and is not in direct contact with the heat medium, it is less susceptible to the effects of stirring heat and can maintain a good heat insulation state. In addition, the containment vessel 10 is removably installed on the trolley 12, and can be replaced with a containment vessel that can accommodate a larger test tank, allowing you to store samples of various sizes. Since it is possible to conduct tests using this method, it is possible to faithfully reproduce the actual mix of concrete and the properties of concrete at construction sites.

〔Effect of the invention〕

The present invention provides a test chamber in close contact with a heat medium jacket provided inside the heat insulating material, and uses a change rate calculation means and a heat medium temperature control means to constantly control the temperature of the heat medium jacket at the center of the sample without any time delay. Since it is controlled to match the temperature, the temperature inside the test chamber is always maintained at the same temperature as the sample.

Therefore, the sample is placed in a completely adiabatic state, and an adiabatic temperature rise test can be performed under good conditions.

[Brief explanation of drawings]

Figure 1 is an overall configuration diagram showing a concrete and mortar adiabatic temperature rise test apparatus according to an embodiment of the present invention, and Figure 2 (A
) is a side view showing the concrete and mortar adiabatic temperature rise test device according to the present invention, FIG. 2 (B) is a partially cutaway top view of the same, FIG. 2 (C) is a front view of the same, and FIG. 2 CD) is a replacement. Figure 3 is a table showing the mix of mortar used in the experiment, Figure 4 is a table showing the mix of concrete IJ-t used in the experiment, and Figure 5 is a table showing the mix of mortar used in the experiment. FIG. 6 is an explanatory diagram showing a conventional air circulation type adiabatic temperature rise test device. 9... Concrete IJ-metal and mortar adiabatic temperature rise test device 10... Containment vessel iod... Upper plate 10e.
...Side plate 11...Control device 12...Dolly 13...Insulating material 14...Heating medium jacket 15...Sample 16...Test tank 24.
... Lift hook 28 ... Rate of change calculating device 29 ... Heating medium temperature control device Patent applicant Sumitomo Cement Co., Ltd. Figure 6 Procedural amendment (method) December 5, 1988

Claims (1)

[Claims] A sample made of concrete or mortar is stored in a test tank located inside the containment vessel, and the heating medium temperature is controlled so that the surface temperature of the test tank matches the temperature rise of the heat of hydration generated by the hydration reaction. In the concrete and mortar adiabatic temperature rise testing device which maintains the sample in the test tank in an adiabatic state and measures the adiabatic temperature change of the sample by The test chamber is formed by a heating medium jacket and is provided in close contact with the heating medium jacket, and a rate of change calculation means is provided for calculating the rate of change in the center temperature of the sample, and based on the calculation result of the rate of change calculation means. An adiabatic temperature rise testing device for concrete and mortar, characterized in that the center temperature of the sample and the heat medium jacket temperature are matched by driving a heat medium temperature control means that controls the heat medium jacket temperature.