JP2017132164A - Control system for kneading temperature of concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control system for the kneading temperature of a shotcrete capable of accurately measuring a concrete temperature at optional time point in a mixer using a temperature measurement system in addition to measurement of temperature in various concrete materials, and capable of efficiently, economically controlling the kneading temperature by: measuring a concrete temperature at a construction site in consideration of temperature change involving time elapse after kneading completion; and setting the concrete temperature using the estimated equation of a kneading finish temperature obtained from the specific heat and mass or heat capacity of each material for setting the target range of the kneading temperature.SOLUTION: A control system for kneading temperature of concrete is characterized by: measuring the temperature of various materials of concrete; obtaining the heat capacity values of various materials for setting the target range of the concrete kneading temperature with reference to measured temperature of various materials ; setting a heating or cooling temperature for a kneading water and an aggregate using the equation estimating a kneading finish temperature from the heat capacity values; and controlling the concrete kneading temperature by heating or cooling the materials.SELECTED DRAWING: Figure 1

Description

The present invention relates to an on-site concrete production facility (on-site batcher plant) designed to keep the kneading temperature generated in an on-site construction batcher plant within a target temperature range, and a method for producing concrete using the production facility. In particular, the present invention relates to a concrete kneading temperature control system generated in a batcher plant constructed on-site.

  A so-called shotcrete is generally known as the concrete produced in a batcher plant constructed on site. The shotcrete is a main supporting member of a mountain tunnel by, for example, the NATM method.

  In addition, the spray construction using shotcrete requires a very short construction time due to the time restriction of the tunnel excavation process, and a mechanical function as a support member is required immediately after the construction.

  For this reason, shotcrete is made by special construction that uses compressed air, centrifugal force, etc., without using a formwork, and a quick setting agent is mixed immediately before spraying to obtain early strength. ing.

  In addition, shotcrete is highly temperature dependent, particularly when the concrete temperature is low, strength development is delayed. In order to cope with this, methods such as increasing the rate of addition of the quick-setting agent and increasing the kneading temperature by using hot water are taken.

  However, changing the rate of addition of the quick-setting agent affects strength development immediately after spraying, and therefore causes a large quality fluctuation.

  Therefore, in recent years, for the purpose of ensuring reliable strength development of shotcrete and reducing quality fluctuations, for example, the construction of a system that controls the mixing temperature of concrete and stabilizes the rate of addition of rapid setting agent is required. ing.

  Conventionally, from the relationship between the measured temperature of the storage area (receiving bin) before mixing of various materials, the temperature of various materials and the measured value of the temperature in the kneading section, and the measured value of the temperature at the completion of concrete production , Create a prediction formula for predicting the temperature at the time of completion of concrete production, and obtain the predicted temperature value at the time of completion of concrete production at the concrete production site obtained by the weather forecast information communication means, the temperature of various materials and the temperature in the kneading part An invention is known in which a predicted temperature at the time of completion of concrete production is calculated based on a prediction formula based on an actual measurement value, and whether or not the manufacturing is possible is determined based on the predicted temperature (Patent Document 1).

  Further, the surface water ratio of the aggregate to be input and the temperature of the aggregate after being cooled are measured, and the target cooling temperature is determined based on the measured surface water ratio data and temperature data and the target production speed of concrete. An invention is also known in which the amount of aggregate to be input and the amount and temperature of air to be blown are controlled so as to ensure the supply amount of the aggregate that has been cooled (Patent Document 2).

Furthermore, a temperature sensor is disposed in each material measuring tank of the ready-mixed concrete manufacturing plant, and the specific heat of the material to be used is input and stored in advance in the temperature management device. And when producing ready-mixed concrete, the invention also takes the measured value and temperature of each material weighed into a temperature management device and estimates the kneading temperature of ready-mixed concrete from these measured value, temperature and pre-stored specific heat Known (Patent Document 3).

JP 2011-140164 A JP-A-10-329129 Japanese Patent Laid-Open No. 08-127020

  However, as described above, the conventional invention is a method of measuring the kneading temperature indirectly from the temperature of each material and the environment temperature, and is not a method of directly measuring the concrete temperature. Therefore, the kneading temperature is measured by a person using an alcohol thermometer, which is a conventional method, and there is a problem that continuous kneading temperature cannot be measured.

Thus, the present invention was devised to address the above-mentioned conventional technical problems, and in addition to the measurement of various concrete material temperatures, the present invention is used in a concrete mixer using a newly invented temperature measurement system. It is possible to accurately measure the concrete temperature at any point in time, such as when it is being finished and when it is finished, and considering the temperature change over time after completion of the kneading, measure the concrete temperature at the construction site. , Use the estimation formula for the kneading temperature obtained from the specific heat and mass (or heat capacity) of each material to reach the target range (10-30 ° C) of the concrete kneading temperature, and heat the kneading water and aggregate Set the temperature or cooling temperature and control the mixing temperature efficiently and economically. It is an object to provide a control system.

An equation for measuring the temperature of various materials of concrete, obtaining the heat capacity value of the various materials to make the concrete mixing temperature target range with reference to the temperature of the measured material, and estimating the kneading temperature from the heat capacity value Set the mixing temperature of the mixing water and aggregate, or control the mixing temperature of the concrete by heating or cooling the material.
It is characterized by
Or
Measure the temperature of various materials of concrete, refer to the measured temperature of the various materials of concrete, find the heat capacity value of the various materials to make the concrete mixing temperature target range, and knead from the heat capacity value While using the equation to estimate the temperature, measure the concrete temperature at any time, such as during and after completion of the kneading in the concrete mixer,
Setting the mixing water, the heating temperature or the cooling temperature of the aggregate with reference to the concrete temperature during the kneading in the concrete mixer and at the time of completion of the kneading, and controlling the kneading temperature,
The target range of the concrete kneading temperature is in the range of 10 ° C to 30 ° C,
It is characterized by
Or
Obtain the mine temperature and concrete temperature at the construction site, set the target temperature of the concrete at the time of spraying, and modify the target temperature at the completion of concrete mixing in consideration of temperature changes during transportation and construction standby. Set the mixing or heating temperature or cooling temperature of the aggregate, and control the mixing temperature.
The target range of the concrete kneading temperature is in the range of 10 ° C to 30 ° C,
It is characterized by
Or
For the measurement of the temperature of various materials of the concrete, a continuous temperature measuring device is used, and the continuous temperature measuring device measures a concrete kneading temperature in a mixer of an on-site batcher plant, and the temperature. A shutter member for blocking between the meter and the inside of the mixer, a rocking device for rocking the shutter plate of the shutter member so as to be able to measure the concrete kneading temperature in the mixer, and opening the block;
An inhibitor removing member for removing a temperature measurement inhibitor generated during kneading in the mixer,
It is characterized by this.

  According to the present invention, the temperature of the concrete before spraying can be stabilized daily throughout the year, thereby suppressing the variation in the rate of addition of the quick setting agent. Can be reduced.

Also, in winter, the concrete temperature becomes low and the setting delay occurs, causing peeling and peeling. On the other hand, in the summer, if the concrete is too high, the setting is too early, causing problems such as not sticking to the spray surface. In addition, by controlling the concrete temperature to 10 to 30 ° C. at all times, construction troubles caused by the environmental temperature can be avoided. Furthermore, according to the kneading temperature, it is possible to set the kneading water, the heating temperature or the cooling temperature of the aggregate to achieve the target kneading temperature, and it is excellent that the utility cost can be reduced. There is an effect.

It is a system configuration diagram of the present invention. FIG. 2 is a configuration explanatory diagram of a kneading section (a mixer for controlling a kneading temperature with a continuous temperature measuring device) in the present invention. It is structure explanatory drawing of a continuous temperature measuring apparatus. It is a flow (1) explaining operation | movement of this invention. It is a flow (2) explaining operation | movement of this invention. It is a table | surface of the measurement physical quantity (variable) used for kneading temperature control.

  First, a schematic configuration of the present invention will be described with reference to a system configuration diagram shown in FIG.

  In FIG. 1, the code | symbol 1 shows an on-site batcher plant, the code | symbol 2 shows a raw control vehicle, and the code | symbol 3 shows the spray machine arrange | positioned in the tunnel mine 4. In FIG. And the sprayer 3 is equipped with the hopper 5 which receives the concrete from the ready-mixed vehicle 2, and the pressure feed pump 6 which sends the received concrete to the spraying part.

  Reference numeral 7 denotes a temperature management control device installed in or near the on-site batcher plant 1, and the temperature management control device 7 is provided with a management PC 8. The management PC 8 has a kneading temperature calculation processing unit 9 that performs calculation processing of the kneading temperature using each mathematical formula described below.

  Reference numeral 10 denotes a supply control unit for hot water or cooling water. The target temperature Ttf of the concrete at the time of spraying set by the kneading temperature calculation processing unit 9 is a predetermined temperature and a predetermined amount. Control is performed to send hot water or cooling water to the on-site batcher plant 1.

  Furthermore, the code | symbol 11 is a mixing | blending and measurement control part, It has the structure by which the mixing | blending and input amount of various concrete materials are controlled and supplied by this mixing | blending and measurement control part.

  Reference numeral 12 denotes a transmission / reception unit using a wireless LAN. For example, information on the temperature of various concrete materials detected by a temperature detector 13 provided near the supply port of various concrete materials is a transmission / reception unit such as the wireless LAN. 12 and can be received by the transmission / reception unit 12 of the management PC 8.

  The temperature information of the various concrete materials detected and transmitted is used for temperature control of hot water and cooling water in the hot water and cooling water supply control unit 10.

  Reference numeral 14 denotes a continuous temperature measuring device, which is measured by the continuous temperature measuring device 14 in the mixer in the on-site batcher plant 1 and temperature information at the time of primary kneading of the concrete before cement is added and cement input. The temperature information at the time of secondary kneading of concrete that has been kneaded later is transmitted to the management PC 8 via the transmission / reception unit 12.

  These pieces of temperature information are also used for temperature control of the hot water and the cooling water in the hot water and cooling water supply control unit 10, and are used for setting the target temperature Ttf of the concrete at the time of spraying.

  As can be seen from FIG. 1, the temperature Trf of the concrete supplied at the time of spraying supplied to the sprayer 3 can also be detected by the temperature detector 13 and the like, and information on the detected temperature Trf of the concrete at the time of spraying is also available. This information is transmitted to the management PC 8 via the transmission / reception unit 12, and this information is also used for temperature control of the hot water and the cooling water, and further used for setting the target temperature Ttf of the concrete at the time of spraying.

  The detailed configuration of the continuous temperature measuring device 14 will be described with reference to FIGS. As described above, the continuous temperature measuring device 14 is installed in the kneading section 16 in the on-site batcher plant 1. As shown in FIG. 2, the ready-mixed concrete is kneaded in the mixer 15 by a kneading member. During this kneading operation, the mixer 15 is filled with steam and dust.

  Reference numeral 21 denotes a suction member that sucks the steam and dust in the sealed mixer 15, and the steam and dust are sucked by the suction member 21.

  Reference numeral 17 denotes, for example, a radiation type thermometer using infrared rays. The infrared radiation energy is installed on the upper part of the sealed mixer 15 and emitted from the raw concrete surface in the mixer 15 toward the radiation type thermometer 17. When the infrared sensor detects (released from below to above), the temperature of the ready-mixed concrete being kneaded in a non-contact state can be measured.

  At the time of measurement, if steam or dust is filled above the ready-mixed concrete, the temperature cannot be measured. Therefore, at the time of temperature measurement, vapor and dust are sucked in immediately before the temperature measurement set in advance by the suction member 21, and measurement is performed after the inside of the mixer 15 is extremely clear. That is, the suction member 21 can reliably and accurately measure the temperature of the ready-mixed concrete that has been kneaded in the mixer 15, and can further make this kneading work environment a factory.

  Reference numeral 18 denotes a shutter member that shields or opens the infrared radiation opening and the inside of the mixer 15. As shown in FIG. 3, a shutter plate that shields the infrared radiation opening and the inside of the mixer 15. 19 and an air cylinder 20 that swings the shutter plate 19.

  The above-described configuration of the kneading unit 16 makes it possible to instantaneously and continuously measure the temperature of the ready-mixed concrete during the kneading in the mixer 15, and the temperature information of the ready-mixed concrete measured by the radial thermometer 17. Is sent to the management PC 8 instantaneously via the transmission / reception unit 12 as described above, thereby making it possible to achieve labor saving and unmanned control related to the work-up such as material weighing.

  Next, the operation of the present invention will be described based on the flow shown in FIG. FIG. 4 is a flow showing winter construction in a cold region, for example.

  First, at the start of concrete production, the setting of the target temperature Ttf of the concrete at the time of spraying is set. This setting is performed using the management PC 8 described above.

  This target temperature can be arbitrarily set within a range of approximately 10 ° C. to 20 ° C. Here, Ttf = 15 ° C. was set (step 100).

  Further, an error α (° C.) for temperature management is set. That is, for example, ± α = ± 2.0 ° C. is set. The temperature error is set in consideration of temperature measurement, material weighing error, construction conditions, etc. (step 100).

  When i = 1, measure the mine temperature at the first time, ie, Tit (1), and record the measured value when producing concrete for the i-th time, that is, the first spraying work. (Step 101). Note that this record may be sent to the management PC 8.

  Here, i represents the number of ready-mixed vehicles 2 that receive the supply of concrete from the on-site batcher plant 1, for example. The number of ready-mixed vehicles 2 varies depending on the length and size of the construction site such as the tunnel mine 4 where the spraying work is performed. For example, if the tunnel to be constructed is long, the concrete required for this will increase and the number of ready-mixed vehicles 2 will also increase.

Then, if the fresh concrete car 2 capacity 4m ^3, site Batcher first concrete plant 1, 4m ^3, will be produced as a first time (i-th). Incidentally, instead of once producing a concrete capacity 4m ^3, for example, it shall be produced for each batch of 0.5 m ³ or 1 m ^3. Therefore, when manufacturing every 0.5 m ^3, the concrete capacity 4m ³ is intended to be manufactured in 8 batches. Therefore, as will be described later, the number of batches is indicated by j.

  Next, a time from the completion of the i-th kneading to the start of spraying (hereinafter referred to as kneading time): tsc (i) (hr) is set (step 102). For example, the kneading time tsc (i) is set to 1.0 hr according to the site construction conditions. Such setting is also performed by the management PC 8.

  Next, the target temperature Tta (i) for the i-th kneading is calculated and set by the following equation (1) (step 103). This is also performed by the management PC 8.

(Equation 1)
Trf (i-1) = Tta (i) −0.15 × (Tta (i) −Tit (i-1)) × tsc (i) (1)

Tta (i) = (Trf (i-1) +0.15 ・ Tit (i-1) ・ tsc (i)) / 0.85
Here, Trf (i-1): Previous spraying concrete temperature However, when i = 1, the target temperature Ttf or the latest spraying concrete temperature is adopted.

  Next, the temperature of various concrete materials thrown in for the i-th time is measured and recorded (step 104). This is also performed by the management PC 8.

  Examples of various concrete materials include coarse aggregate: Tca, fine aggregate: Tfa, cement: Tcm, normal temperature water: Tnw, and hot water: Thw.

  Here, it should be noted that coarse aggregate and fine aggregate should not be heated to 65 ° C. or higher.

  Furthermore, the management PC 8 calculates the amount of hot water added to the i-th concrete (step 105).

  At the time of on-site blending, the amount of hot water added Whw is calculated by equation (2) so that the target kneading temperature Tta (i) is obtained.

ここに、
WcaおよびTca：粗骨材の質量(kg)および温度(℃）
WfaおよびTfa：細骨材の質量（kg)および温度（℃）
WcmおよびTcm：セメントと質量(kg)および温度(℃）
WnwおよびTnw：練混ぜに用いる水の質量(kg)および温度（℃）
WhwおよびThw：練混ぜに用いる温水の質量(kg)および温度(℃）
Cs：セメントおよび骨材の比熱の水の比熱に対する割合、一般には0.2と仮定してよい。
β：補正係数、通常はβ＝1.0とする。 (Equation 2)

here,
Wca and Tca: coarse aggregate mass (kg) and temperature (° C)
Wfa and Tfa: Fine aggregate mass (kg) and temperature (° C)
Wcm and Tcm: cement and mass (kg) and temperature (℃)
Wnw and Tnw: mass (kg) and temperature (° C) of water used for mixing
Whw and Thw: Mass (kg) and temperature (° C) of hot water used for mixing
Cs: Ratio of specific heat of cement and aggregate to specific heat of water, generally 0.2 can be assumed.
β: Correction coefficient, usually β = 1.0.

From the above equation (2), coarse aggregate: Wca, fine aggregate: Wfa, cement: Wcm, normal temperature water: Wnw, hot water: Whw are determined.
Here, Wtw is a unit water amount and is expressed by Wtw = Wnw + Whw.

  Further, based on the equation (2), the control PC 8 calculates the amount of each room temperature water and warm water based on the equation (2) so that the primary mixing temperature Tfm (i, j) is 40 ° C. or less. It is.

  As described above, when the jth batch: for example, j = 1, first, each concrete material of each kneading batch is weighed (step 106).

  Then, coarse aggregate, fine aggregate and water (room temperature water, warm water) excluding the weighed cement are added and primary mixing is performed (step 107).

  Next, the temperature Tfm (i, j) of the concrete in the mixer 15 at the completion of the primary mixing is measured and recorded by the above-described continuous temperature measuring device 14 (step 108).

  Then, it is measured whether the primary kneading temperature Tfm (i, j) is 40 ° C. or less (step 109).

  If the primary mixing temperature Tfm (i, j) is not 40 ° C. or lower (NO in step 109), the mixing material is discharged and discarded (step 110). This is because when water or aggregate is mixed with cement, it must be 40 ° C. or lower.

  Then, in order to reset the hot water addition amount, the hot water amount is redesigned based on the equation (2) (step 111). Then, the process from step 106 is repeated again.

  When the primary mixing temperature Tfm (i, j) is 40 ° C. or lower (YES in Step 109), the weighed cement is added and the secondary mixing is performed (Step 112).

  Next, the concrete temperature Tsm (i, j) in the mixer 15 at the completion of the secondary mixing is measured and recorded (step 113).

  Then, whether or not the temperature Tsm (i, j) at the time of the secondary mixing is within the control value is confirmed by the expression (3) (step 114).

(Equation 3)
Tta (i) −α ≦ Tsm (i, j) ≦ Tta (i) + α (3) Expression α: Management error

If the temperature Tsm (i, j) during the secondary kneading is within the control value (YES in step 114), it is further confirmed whether or not the continuous kneading is finished (step 115).
That is, it is confirmed whether j = M (M: total number of batches).

  If the temperature Tsm (i, j) at the time of the secondary mixing is not within the control value (NO in step 114), an error reduction for the mixed concrete temperature is implemented (step 116).

  For example, the hot water temperature and the hot water addition amount are adjusted, the storage temperature of the aggregate (coarse aggregate, fine aggregate) is adjusted, or the addition amount of each material at the time of kneading the next batch (j + 1) is adjusted. Thereafter, it is confirmed whether or not the continuous kneading is finished (step 115).

  If the continuous kneading has not ended (NO in step 115), j = j + 1 is set and the process from step 106 is repeated again.

  When the continuous kneading has been completed (YES in step 115), the average value of the i-th concrete kneading temperature Tra (i): the temperature at the completion of the secondary kneading of all M batches is calculated ( Step 117).

  Next, the concrete temperature Trf (i) at the time of the i-th spraying (in the mine) is measured and recorded (step 118).

  Then, whether or not the temperature Trf (i) at the time of spraying is within the control value is confirmed by equation (4) (step 119).

(Equation 4)
Ttf−α ≦ Trf (i) ≦ Ttf + α (4) Equation α: Management error

If the temperature Trf (i) at the time of spraying is within the control value (YES in step 119), it is further confirmed whether or not the spraying operation is completed (step 120).
That is, it is confirmed whether i = N (N: total number of spraying operations).

  If the temperature Trf (i) at the time of spraying is not within the control value (NO at step 119), the concrete target temperature Tta (i) at the time of mixing is corrected (step 121).

  Then, the reduction of the concrete temperature error is examined and implemented (step 122). For example, the hot water temperature and the amount of hot water added are adjusted or the storage temperature of the aggregate (coarse aggregate, fine aggregate) is adjusted. Thereafter, it is confirmed whether or not the spraying work is completed (step 120).

  If the spraying operation is not completed (NO in step 120), i = i + 1 is set and the process from step 101 is repeated again.

  If the spraying operation has been completed (YES in step 120), the concrete production ends.

  Next, a second embodiment of the present invention, that is, summer construction of shotcrete will be described based on the flow shown in FIG.

  At the start of concrete production, set the target temperature Ttf for concrete during spraying. Since the target temperature is summer construction, it can be arbitrarily set within a range of about 20 ° C to 30 ° C. Here, Ttf = 25 ° C. was set (step 200).

  Further, an error α (° C.) for temperature management is set. That is, for example, ± α = ± 2.0 ° C. is set. The temperature error is set in consideration of temperature measurement, material weighing error and construction conditions (step 200).

  When i = 1, at the time of manufacturing concrete for the i-th, that is, the first spraying operation, the mine temperature at the first time, ie, Tit (i), is measured, and the measured value is recorded. (Step 201).

  Here, i indicates the number of ready-mixed vehicles 2 that receive the supply of concrete from the on-site batcher plant 1, for example. The number of ready-mixed vehicles 2 varies depending on the size of a construction site such as a tunnel mine where spraying work is performed.

Then, if the fresh concrete car 2 capacity 4m ^3, site Batcher first concrete plant 1, 4m ^3, will be produced as a first time (i-th). Incidentally, instead of once producing a concrete capacity 4m ^3, for example, it shall be produced for each batch of 0.5 m ³ or 1 m ^3. Therefore, when manufacturing every 0.5 m ^3, the concrete capacity 4m ³ is intended to be manufactured in 8 batches. Therefore, as will be described later, the number of batches is indicated by j.

  Next, a time from completion of the i-th kneading to the start of spraying: tsc (i) (hr) is set (step 202). For example, the kneading time tsc (i) is set to 1.0 hr according to the site construction conditions.

  Next, the target temperature Tta (i) at the time of the i-th kneading is calculated by equation (4) and set (step 203).

(Equation 4)
Trf (i-1) = Tta (i) + 0.15 × (Tta (i) −Tit (i-1)) × tsc (i) (4)

Tta (i) = (Trf (i-1) −0.15 ・ Tit (i-1) ・ tsc (i)) / 0.85
Here, Trf (i-1): Previous spraying concrete temperature However, when i = 1, the target temperature Ttf or the latest spraying concrete temperature is adopted.

Next, the temperature of various concrete materials thrown in the i-th time is measured and recorded (step 204).
Examples of various concrete materials include coarse aggregate: Tca, fine aggregate: Tfa, cement: Tcm, normal temperature water: Tnw, and cooling water: Tcw.

Furthermore, the cooling water addition amount of the i-th concrete is calculated (step 205).
In the on-site blending, the cooling water addition amount Wcw is calculated by the equation (2) so that the target kneading temperature Tta (i) is obtained.

ここに、
WcaおよびTca：粗骨材の質量(kg)および温度(℃）
WfaおよびTfa：細骨材の質量（kg)および温度（℃）
WcmおよびTcm：セメントと質量(kg)および温度(℃）
WnwおよびTnw：練混ぜに用いる水の質量(kg)および温度（℃）
WcwおよびTcw：練混ぜに用いる冷却水の質量(kg)および温度(℃）
Cs：セメントおよび骨材の比熱の水の比熱に対する割合、一般には0.2と仮定してよい。
β：補正係数、通常はβ＝1.0とする。 (Equation 2)

here,
Wca and Tca: coarse aggregate mass (kg) and temperature (° C)
Wfa and Tfa: Fine aggregate mass (kg) and temperature (° C)
Wcm and Tcm: cement and mass (kg) and temperature (℃)
Wnw and Tnw: mass (kg) and temperature (° C) of water used for mixing
Wcw and Tcw: mass (kg) and temperature (° C) of cooling water used for mixing
Cs: Ratio of specific heat of cement and aggregate to specific heat of water, generally 0.2 can be assumed.
β: Correction coefficient, usually β = 1.0.

From the above equation (2), coarse aggregate: Wca, fine aggregate: Wfa, cement: Wcm, normal temperature water: Wnw, and cooling water: Wcw are determined.
Here, Wtw is a unit water amount and is expressed by Wtw = Wnw + Wcw.

  Furthermore, based on the above equation (2), the control PC 8 calculates the amount of each room temperature water and cooling water based on the above equation (2) so that the primary mixing temperature Tfm (i, j) is 40 ° C. or less. Done.

As described above, when the jth batch: for example, j = 1, first, each concrete material of each kneading batch is weighed (step 206).
Then, coarse aggregate, fine aggregate and water (room temperature water, cooling water) excluding the weighed cement are added and primary mixing is performed (step 207).

Next, the concrete temperature Tfm (i, j) in the mixer 15 at the completion of the primary mixing is measured and recorded (step 208).
Then, it is measured whether the primary mixing temperature Tfm (i, j) is 40 ° C. or less (step 209).

  If the primary mixing temperature Tfm (i, j) is not 40 ° C. or lower (NO in step 209), the mixing material is discharged and discarded (step 210). It should be noted here that as a management value in the summer, the mixing temperature of aggregate and water before cement is required to be 40 ° C. or lower.

  Then, in order to reset the cooling water addition amount, the cooling water amount is redesigned based on the equation (2) (step 211). Then, the process from step 206 is repeated again.

  If the primary mixing temperature Tfm (i, j) is 40 ° C. or lower (YES in step 209), the measured cement is charged and secondary mixing is performed (step 212).

  Next, the concrete temperature Tsm (i, j) in the mixer 15 when the secondary mixing is completed is measured and recorded using the continuous temperature measuring device 14 (step 213).

  Then, whether or not the temperature Tsm (i, j) at the time of the secondary mixing is within the control value is confirmed by the expression (3) (step 214).

(Equation 3)
Tta (i) −α ≦ Tsm (i, j) ≦ Tta (i) + α (3) Expression α: Management error

  If the temperature Tsm (i, j) during the secondary kneading is within the control value (YES in step 214), it is further confirmed whether or not the continuous kneading is finished (step 215). That is, it is confirmed whether j = M (M: total number of batches).

  If the temperature Tsm (i, j) at the time of the secondary mixing is not within the control value (NO in step 214), an error reduction for the mixed concrete temperature is implemented (step 216). For example, the cooling water temperature and the cooling water addition amount are adjusted, the storage temperature of the aggregate (coarse aggregate, fine aggregate) is adjusted, or the addition amount of each material at the time of kneading the next batch (j + 1) is adjusted. Thereafter, it is confirmed whether or not the continuous kneading is finished (step 215).

  If the continuous kneading has not ended (NO in step 215), j = j + 1 is set and the process from step 206 is repeated again.

  When the continuous kneading has been completed (YES in step 215), the average value of the i-th concrete kneading temperature Tra (i): the temperature at the completion of the secondary kneading of all M batches is calculated (step 217).

Next, the concrete temperature Trf (i) at the time of the i-th spraying (in the mine) is measured and recorded (step 218).
Then, whether or not the temperature Trf (i) at the time of spraying is within the control value is confirmed by equation (4) (step 219).

(Equation 4)
Ttf−α ≦ Trf (i) ≦ Ttf + α (4) Equation α: Management error

  If the temperature Trf (i) at the time of spraying is within the control value (YES in step 219), it is further confirmed whether or not the spraying operation is completed (step 220). That is, it is confirmed whether i = N (N: total number of spraying operations).

  If the temperature Trf (i) at the time of spraying is not within the control value (NO at step 219), the concrete target temperature Tta (i) at the time of mixing is corrected (step 221).

  Then, the reduction of the concrete temperature error is examined and implemented (step 222). For example, the cooling water temperature and the cooling water addition amount are adjusted or the storage temperature of the aggregate (coarse aggregate, fine aggregate) is adjusted. Thereafter, it is confirmed whether or not the spraying work is completed (step 220).

  If the spraying operation has not been completed (NO in step 220), i = i + 1 is set and the process from step 201 is repeated again.

  If the spraying operation has been completed (YES in step 220), the concrete production ends.

The list is shown in FIG. 6 in order to clarify the measured physical quantities (variables used in the text) used for kneading temperature control.

DESCRIPTION OF SYMBOLS 1 On-site batcher plant 2 Ready-mixed car 3 Spraying machine 4 Tunnel pit 5 Hopper 6 Pressure feed pump 7 Temperature management control device 8 Management PC
9 Kneading temperature calculation processing unit 10 Warm water / cooling water supply control unit 11 Blending, light weight control unit 12 Transmission / reception unit 13 Temperature detector 14 Continuous temperature measuring device 15 Mixer 16 Kneading unit 17 Radiation type thermometer 18 Shutter member 19 Shutter plate 20 Air cylinder 21 suction member

Claims (4)

An equation for measuring the temperature of various materials of concrete, obtaining the heat capacity value of the various materials to make the concrete mixing temperature target range with reference to the temperature of the measured material, and estimating the kneading temperature from the heat capacity value Set the mixing temperature of the mixing water and aggregate, or control the mixing temperature of the concrete by heating or cooling the material.
A system for controlling the temperature of kneading of shotcrete.
Measure the temperature of various materials of concrete, refer to the measured temperature of the various materials of concrete, find the heat capacity value of the various materials to make the concrete mixing temperature target range, and knead from the heat capacity value While using the equation to estimate the temperature, measure the concrete temperature at any time, such as during and after completion of the kneading in the concrete mixer,
Setting the mixing water, the heating temperature or the cooling temperature of the aggregate with reference to the concrete temperature during the kneading in the concrete mixer and at the time of completion of the kneading, and controlling the kneading temperature,
The target range of the concrete kneading temperature is in the range of 10 ° C to 30 ° C,
The system for controlling the temperature of kneading of shotcrete according to claim 1.
Obtain the mine temperature and concrete temperature at the construction site, set the target temperature of the concrete at the time of spraying, and modify the target temperature at the completion of concrete mixing in consideration of temperature changes during transportation and construction standby. Set the mixing or heating temperature or cooling temperature of the aggregate, and control the mixing temperature.
The target range of the concrete kneading temperature is in the range of 10 ° C to 30 ° C,
The control system of the kneading temperature of the shotcrete according to claim 1 or 2, characterized by the above-mentioned.
For the measurement of the temperature of various materials of the concrete, a continuous temperature measuring device is used, and the continuous temperature measuring device measures a concrete kneading temperature in a mixer of an on-site batcher plant, and the temperature. A shutter member for blocking between the meter and the inside of the mixer, a rocking device for rocking the shutter plate of the shutter member so as to be able to measure the concrete kneading temperature in the mixer, and opening the block;
An inhibitor removing member for removing a temperature measurement inhibitor generated during kneading in the mixer,
The control system for the kneading temperature of the shotcrete according to any one of claims 1 to 3.

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