JP2019098707A - Method for controlling curing time of concrete, control device and method for constructing concrete - Google Patents

Abstract

To provide a method for controlling the curing time of concrete capable of adjusting a leveling operable time, a control device, and a method for constructing concrete.SOLUTION: Provided is a method for controlling curing time of concrete comprising: prediction steps S1 to S3 where, based on water pouring time and conductivity reduction time or based on predicted temperature and water pouring time, leveling operable time of concrete is predicted; a determination step S4 where whether the predicted leveling operable time satisfies prescribed time conditions or not is determined; and an adjustment step S5 where, in the case it is determined that the same does not satisfy the prescribed time conditions, a curing accelerator for accelerating the curing of the concrete or a curing retarder for delaying the curing of the concrete is added to the concrete during construction or before the construction, and curing speed of the concrete is adjusted.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a control method of hardening time of concrete such as a concrete slab, a control device and a construction method of concrete.

  Conventionally, when constructing a concrete slab, after placing fresh concrete carried by a mixer from a plant on a formwork, an operation is carried out in which the whole is leveled to a predetermined height. (See, for example, Patent Document 1). The concrete hardens with the passage of time, and after it becomes hard enough for the operator to get on, treatment of bleeding water and ends etc. is carried out, and the surface is repeatedly pressed with a hand-held trowell or scissors.

  This repeated pressing operation is an operation necessary for smoothing and densifying the concrete surface, which greatly affects the quality of the slab. However, the pressing timing is determined by the hardness of the operator touching the concrete surface with a finger, the color of the appearance, the generation of bleeding water, and the like. Therefore, the finish quality such as the smoothness of the slab and the quality such as the fineness of the surface are likely to be influenced by the experience of the worker particularly in the environmental conditions where construction is difficult.

  In the concrete slab casting design plan, the number of workers, the number of workers, the number of working machines, etc. are determined in consideration of conditions such as air temperature, casting area and casting speed on the day of construction. This decision is left to the operator's empirical judgment, and the placement position of concrete is roughly determined by the placement speed. As for the timing of the subsequent pressing work, the operator judges the degree of hardening of the concrete on the day of the construction day by finger touch and visual observation, and proceeds according to the circumstances. Therefore, in the concrete design plan, the number of workers and the construction procedure according to the degree of hardening of the concrete are not planned. The press start time and end time depend on the construction of the construction day, and there are many vague parts as a construction plan.

  Furthermore, the construction of the concrete slab depends on the temperature conditions of the day. For example, in the hot summer season, the case where the temperature reaches 35 ° C. is not uncommon in recent years, and the hardening speed of concrete becomes faster than expected, and the number of workers and construction machines that have been arranged is insufficient. On the other hand, in the cold winter season, the hardening speed of concrete becomes slower, the waiting time of the workers becomes longer, and the work may be late at night. The field work depends on the hardening of the concrete, which may lead to the poor finish of the concrete slab and the deterioration of the working environment.

The finishing work of the concrete slab is carried out according to the degree of hardening of the concrete. As a method of grasping the degree of hardening of this concrete, there is a penetration resistance test (JIS A 1147: 2007) of JIS. This is a method of determining the penetration resistance value when a mortar obtained by removing coarse aggregate from concrete is used as a test body and a specified penetration needle is pierced vertically. According to this method, as shown in the measurement example of FIG. 1, the measurement results are plotted and the initial development time of the concrete (time until the penetration resistance value becomes 3.4 N / mm ² , for example), the termination time (penetration resistance) The slope A, the intercept B, and the approximate expression can be obtained from the value of, for example, 28.0 N / mm ² ) and the approximate curve of these plots. Workers wear a neta geta and have hardness slightly sinking their feet about 0.5 (N / mm ² ) of penetration resistance empirically, then ride on concrete and remove bleeding water etc. The preparation of the work is started, the pressing work is started from the first flight time, and the work is finished at the closing time.

  However, since this penetration resistance value is obtained by measuring in real time each time the hardening proceeds, it is impossible to predict the pressing timing (the time when the pressing operation can be started) in advance by this method. In addition, the test work is also time-consuming, and there are few cases where it is used for on-site construction management, and there is a problem that the penetration resistance test is mainly intended to acquire data.

  In order to solve these problems, the present applicant has proposed a prediction technique of the concrete workable period as shown in Patent Documents 2 and 3. Patent Document 2 is a technology that predicts the time when the concrete can be leveled on the basis of "water injection time" in which cement and water are mixed at the time of preparation of fresh concrete, and "conductivity decrease time" in which the conductivity of concrete decreases. is there. Patent Document 3 is a technology for predicting a time when a concrete can be leveled on the basis of "expected temperature" and "scheduled water injection time" in a construction time zone. According to these techniques, it is possible to easily grasp the pressing operation start time, the pressing operation end time, and the pressing operation possible time before the concrete surface leveling operation is started.

JP, 2015-203204, A Japanese Patent Application No. 2017-200254 (not yet published at this time) Japanese Patent Application No. 2017-200255 (not published at the moment)

  However, even if each time or time can be predicted before work by the techniques of Patent Documents 2 and 3 described above, if there is a problem with the time or time, there is a risk that work may be performed under adverse conditions. This will be described using a specific example.

  FIG. 2: is an example of the input-output screen of the estimation apparatus of said patent document 2. As shown in FIG. A screen as illustrated is displayed on a display unit such as a display of the prediction device. When two items of “water injection time” and “conductivity decrease time” of the input unit (INPUT) are input, “time when a person can get on”, “pressing start time”, “pressing operation” by an operation process of an operation unit (not shown) The work end time, the "time until the work start", and the "time available for pressing work" are calculated, and are instantaneously output and displayed in each column of the output unit (OUTPUT). Therefore, the user of this prediction device can easily grasp the above time and time through this input / output screen. In the example of the figure, the output result in the case where 9:00 is input to “water injection time” and 12:00 is input to “conductivity decrease time” is shown. In this case, the pressing operation end time is 16:21, and the pressing operation possible time is 1 hour and 37 minutes, and there is room for the operation.

  However, for example, in summer when the air temperature is high, as shown in FIG. 3, there are cases where the “water injection time” is 9:00 and the “conductivity decrease time” is 11:10. At this time, the pressing work start time is 12:05, and the pressing work end time is 12:37. The workable time is as short as 32 minutes, so if the construction area is large, work may not be in time.

  On the other hand, for example, in winter when the air temperature is low, as shown in FIG. 4, there are cases where the “water injection time” is 9:00 and the “conductivity decrease time” is 12:50. At this time, the press work start time is 20:56, the press work end time is 1:48, and the press work available time is 4 hours 51 minutes. The site manager as well as the workers will remain on site for a long time, which is extremely severe as a working environment.

  Therefore, there is a need for a technology that can control the hardening time of concrete so as not to cause any problem when it is found that there is a problem in performing the pressing operation at the predicted time or time. The

  This invention is made in view of the above, Comprising: It aims at providing the control method of the hardening time of a concrete which can adjust the leveling operation possible time, a control apparatus, and the construction method of concrete.

  In order to solve the problems described above and achieve the object, the method of controlling the hardening time of concrete according to the present invention is to perform the leveling operation before performing the leveling operation on the surface of the concrete under construction. A method of predicting a suitable leveling time and controlling the hardening time of concrete when the predicted leveling time does not satisfy a predetermined time condition for properly performing the leveling operation. , Based on the water injection time when mixing cement and water to make fresh concrete, and the conductivity decrease time obtained by measuring the conductivity of concrete under construction, or expected in the construction time zone Based on the temperature and the water injection time, a prediction step for predicting the leveling time of concrete leveling operation, and a determination as to whether or not the predicted leveling time period of the leveling condition satisfies a predetermined timewise condition Tep and a hardening accelerator for accelerating the hardening of the concrete when it is judged that the predetermined temporal conditions are not satisfied, or a hardening retarder for delaying the hardening of the concrete during or before the construction And adjusting the hardening rate of the concrete.

  In the control method of hardening time of another concrete according to the present invention, in the above-mentioned invention, the predicting step measures the conductivity of the concrete under construction and obtains the conductivity lowering time, and the obtained conductivity Apply the time of decrease to the relationship between the time from the time of water injection determined in advance to the time of conductivity decrease of concrete, and the inclination information of the approximate expression representing the relationship between the penetration resistance value obtained by the predetermined penetration resistance test and the elapsed time And determining the slope information corresponding to the determined conductivity lowering time, estimating the relationship between the penetration resistance value and the elapsed time corresponding to the determined slope information, and the relationship between the estimated penetration resistance value and the elapsed time And the step of predicting the leveling time of concrete leveling operation from the determined conductivity lowering time.

  In the control method of hardening time of another concrete according to the present invention, in the above-mentioned invention, the prediction step is predicted in the construction time zone, considering that the air temperature of the construction time zone and the temperature of the concrete are correlated. Is applied to the relationship between the temperature of concrete and the slope information of the approximate expression that represents the relationship between the penetration resistance value obtained by the predetermined penetration resistance test obtained in advance and the relationship between the temperature of concrete, and the gradient corresponding to the expected temperature The conductivity decrease time corresponding to the obtained inclination information is obtained by applying the step of obtaining information and the obtained inclination information to the relationship between the previously determined time of water injection and the time when the conductivity of the concrete decreases and the inclination information. Estimating the relationship between the penetration resistance value corresponding to the obtained inclination information and the elapsed time, and the relationship between the estimated penetration resistance value and the elapsed time If, from the estimated conductivity decreases time, characterized by comprising the step of predicting the leveling workable time of the concrete.

  Moreover, the control apparatus of the hardening time of the concrete according to the present invention predicts a time suitable for performing the leveling operation before performing the leveling operation on the surface of the concrete under construction. A device for controlling the hardening time of concrete when the predicted leveling possible time does not satisfy the predetermined timing conditions for properly performing the leveling operation, and cement and water are used to produce fresh concrete. The leveling of concrete based on the water injection time when mixing and the conductivity decrease time obtained by measuring the conductivity of concrete under construction, or based on the predicted air temperature and the water injection time expected in the construction time zone The prediction means for predicting the workable time, the judgment means for judging whether or not the predicted equalization workable time satisfies the predetermined temporal condition, and the judgment that the predetermined temporal condition is not satisfied In this case, a hardening accelerator for accelerating the hardening of the concrete or a hardening retarder for delaying the hardening of the concrete is added to the concrete during or before construction to adjust the hardening speed of the concrete. And means.

  Further, according to the control apparatus of the setting time of the other concrete according to the present invention, in the above-mentioned invention, the prediction means measures the conductivity of the concrete under construction to obtain the conductivity decrease time, and the obtained conductivity Apply the time of decrease to the relationship between the time from the time of water injection determined in advance to the time of conductivity decrease of concrete, and the inclination information of the approximate expression representing the relationship between the penetration resistance value obtained by the predetermined penetration resistance test and the elapsed time Then, means for obtaining inclination information corresponding to the determined conductivity lowering time, means for estimating the relationship between penetration resistance value and elapsed time corresponding to the determined inclination information, relationship between estimated penetration resistance value and elapsed time And means for predicting the leveling time of concrete leveling operation from the determined conductivity lowering time.

  Further, in the control apparatus of the setting time of the other concrete according to the present invention, in the above-mentioned invention, the prediction means is predicted in the construction time zone assuming that the air temperature of the construction time zone and the temperature of the concrete are correlated. Is applied to the relationship between the temperature of concrete and the slope information of the approximate expression that represents the relationship between the penetration resistance value obtained by the predetermined penetration resistance test obtained in advance and the relationship between the temperature of concrete, and the gradient corresponding to the expected temperature The conductivity decrease time corresponding to the obtained inclination information is obtained by applying the means for obtaining information and the obtained inclination information to the relationship between the previously-known time from water injection time to the conductivity decrease time of concrete and the inclination information. Means for estimating the relationship between the penetration resistance value corresponding to the obtained inclination information and the elapsed time, the relationship between the estimated penetration resistance value and the elapsed time, and the estimated From the rate reduction time, characterized in that comprising a means for predicting the leveling workable time of the concrete.

  Moreover, the construction method of concrete according to the present invention is a method of constructing concrete using the above-described control method of hardening time of concrete, and after adjusting the hardening speed based on the predicted leveling time. And performing the leveling operation on the surface of the concrete.

  According to the control method of the hardening time of concrete according to the present invention, before performing the leveling operation on the surface of the concrete under construction, it is possible to predict a suitable leveling operation possible time for performing the leveling operation, It is a method of controlling the curing time of concrete when the predicted leveling possible time does not satisfy the predetermined timing conditions for properly performing the leveling operation, and the cement and water are used to produce fresh concrete. The leveling of concrete based on the water injection time when mixing and the conductivity decrease time obtained by measuring the conductivity of concrete under construction, or based on the predicted air temperature and the water injection time expected in the construction time zone A prediction step of predicting a workable time, a judgment step of determining whether or not the predicted workable time satisfies a predetermined temporal condition, and a predetermined temporal condition If it is judged that a hardening accelerator for accelerating the hardening of concrete or a hardening retarder for delaying the hardening of concrete is added to the concrete during or before construction to adjust the hardening speed of concrete And, if the predicted available work time does not satisfy the predetermined time conditions for properly performing the equalization work, the hardening work is adjusted by adjusting the hardening speed of the concrete. It has the effect of being able to adjust the workable time so that it can be properly performed.

  Further, according to another control method of hardening time of concrete according to the present invention, the prediction step measures the conductivity of the concrete under construction to obtain the conductivity decrease time, and the determined conductivity decrease time Determined by applying to the relation between the time from the water injection time grasped in advance to the electric conductivity decrease time of concrete and the inclination information of the approximate expression expressing the relation between penetration resistance value and elapsed time obtained by the predetermined penetration resistance test The step of obtaining inclination information corresponding to the conductivity lowering time, the step of estimating the relationship between the penetration resistance value and the elapsed time corresponding to the determined inclination information, the relationship between the estimated penetration resistance value and the elapsed time, and Since the step of predicting the leveling time of concrete can be predicted from the conductivity decrease time, the conductivity decrease time is determined from the water pouring time of the concrete and the conductivity decrease time. By predicting the leveling possible time at the point in time, as a result, when the predetermined temporal conditions are not satisfied, a hardening accelerator or hardening retarder is added to the concrete under construction to adjust the hardening speed, The effect is that it is possible to adjust the time when the leveling operation is possible.

  Further, according to another control method of hardening time of concrete according to the present invention, the prediction step assumes that the air temperature in the construction time zone and the temperature of the concrete are in correlation, and the predicted air temperature expected in the construction time zone The inclination information corresponding to the expected air temperature is determined by applying the above to the relation between the inclination resistance value of the approximate expression representing the relation between the penetration resistance value obtained by the predetermined penetration resistance test and the elapsed time obtained beforehand and the temperature of the concrete. The conductivity decrease time corresponding to the obtained inclination information is estimated by applying the step and the calculated inclination information to the relationship between the previously determined water injection time to the conductivity decrease time of the concrete and the inclination information. The step, the step of estimating the relationship between the penetration resistance value corresponding to the obtained inclination information and the elapsed time, the relationship between the estimated penetration resistance value and the elapsed time, and the estimated conduction Since the step of predicting the leveling time of concrete can be predicted from the rate decrease time, the leveling work time can be predicted before the construction from the predicted air temperature and the water injection time predicted in the construction time zone, and the result When the prescribed temporal conditions are not satisfied, the level of workable period can be adjusted by adjusting the hardening rate by adding a hardening accelerator or hardening retarder to concrete during or before construction It plays an effect.

  In addition, according to the control device of the hardening time of concrete according to the present invention, it is possible to predict a time suitable for performing the leveling operation before performing the leveling operation on the surface of the concrete under construction. A device for controlling the hardening time of the concrete when the predicted possible work time does not satisfy the predetermined time condition for properly performing the work, and the cement and the cement for producing fresh concrete Based on the water injection time when mixing water and the conductivity decrease time obtained by measuring the conductivity of the concrete under construction, or based on the predicted air temperature and water injection time expected in the construction time zone, The prediction means for predicting the averaging work available time, the judging means for determining whether the predicted averaging work available time satisfies the predetermined temporal condition, and the predetermined temporal condition are not satisfied If it is determined, a hardening accelerator for accelerating the hardening of the concrete or a hardening retarder for delaying the hardening of the concrete is added to the concrete during or before construction to adjust the hardening speed of the concrete Since the adjustment means is provided, if the predicted available work time does not satisfy the predetermined time condition for performing the work properly, the speed of the concrete is properly adjusted by adjusting the hardening speed of the concrete. There is an effect that it is possible to adjust the available work time so as to

  Moreover, according to the control apparatus of the hardening time of the other concrete which concerns on this invention, a prediction means measures the conductivity of the concrete under construction, and a means to obtain | require the conductivity fall time, The conductivity fall time calculated | required Determined by applying to the relation between the time from the water injection time grasped in advance to the electric conductivity decrease time of concrete and the inclination information of the approximate expression expressing the relation between penetration resistance value and elapsed time obtained by the predetermined penetration resistance test The means for obtaining inclination information corresponding to the conductivity lowering time, the means for estimating the relationship between the penetration resistance value and the elapsed time corresponding to the obtained inclination information, the relationship between the estimated penetration resistance value and the elapsed time, and Since the method comprises means for predicting the leveling time of the concrete from the conductivity lowering time, the leveling operation is carried out at the time of the conductivity lowering time from the water pouring time of the concrete and the conductivity lowering time. It is possible to level the work period by predicting the possible time, and as a result, if the prescribed time conditions are not satisfied, the hardening accelerator or the hardening retarder is added to the concrete under construction to adjust the hardening speed. The effect is that you can adjust the

  Moreover, according to the control apparatus of the hardening time of the other concrete which concerns on this invention, the prediction means considers that the air temperature of a construction time zone and the temperature of a concrete have correlation, and is an expected air temperature forecasted in a construction time zone The inclination information corresponding to the expected air temperature is determined by applying the above to the relation between the inclination resistance value of the approximate expression representing the relation between the penetration resistance value obtained by the predetermined penetration resistance test and the elapsed time obtained beforehand and the temperature of the concrete. The conductivity decrease time corresponding to the obtained inclination information is estimated by applying the means and the calculated inclination information to the relationship between the previously determined water injection time to the conductivity decrease time of the concrete and the inclination information. Means, means for estimating the relationship between penetration resistance value and elapsed time corresponding to the obtained inclination information, relationship between estimated penetration resistance value and elapsed time, and estimated conductivity decrease time Since it consists of a means to predict the leveling possible time of concrete, the leveling possible time is estimated before the construction from the predicted air temperature and the water injection time which are expected in the construction time zone, and as a result, a predetermined time When the conditions are not satisfied, by adding a hardening accelerator or a hardening retarder to concrete during or before construction to adjust the hardening speed, it is possible to adjust the time when the leveling operation can be performed.

  Further, according to the method of constructing concrete according to the present invention, the method of constructing concrete using the method of controlling the hardening time of concrete described above is used, and the hardening speed is adjusted based on the predicted leveling time. Since the step of performing the leveling operation on the surface of the concrete later is provided, the leveling operation can be performed properly so that the predicted leveling workable time does not satisfy the predetermined temporal conditions. You can adjust the time. This produces an effect that it is possible to construct concrete of stable quality.

FIG. 1 is a view showing a measurement example of a penetration resistance test according to JIS. FIG. 2: is an input-output screen figure which shows an example of the prediction apparatus of the leveling operation possible time of concrete. FIG. 3 is a diagram showing an example of the case where the temperature in summer is high. FIG. 4 is a diagram showing an example of the case where the temperature in winter is low. FIG. 5 is a view showing the relationship between the temperature T of the concrete and the inclination A. As shown in FIG. FIG. 6 is a view showing an example of adjustment of the inclination A by the curing retarder and the curing accelerator. FIG. 7 is a flow chart showing an embodiment of the method of controlling the hardening time of concrete according to the present invention.

  Hereinafter, an embodiment of a control method of a hardening time of concrete, a control device and a construction method of concrete according to the present invention will be described in detail based on the drawings. The present invention is not limited by the embodiment.

[Control method of hardening time of concrete]
First, an embodiment of a method for controlling the hardening time of concrete according to the present invention will be described.

(Basic principle)
First, the basic principle of the present invention will be described.
Generally, the concrete in the setting process is subjected to the penetration resistance test described in, for example, JIS A 1147, and when the penetration resistance value is plotted at each elapsed time, a scatter diagram as shown in FIG. 1 is obtained. From these plots, the relationship between the penetration resistance value P and the elapsed time t can be represented by a logarithmic approximation formula t = A × Ln (P) + B. Here, A is inclination (inclination information) and B is an intercept.

  On the other hand, in the prediction technology of Patent Document 2 described above, the inclination A is obtained from the water injection time and the conductivity decrease time of concrete, and the time when a person can get on the basis of the obtained inclination A The time, the time until the start of work, and the time when the pressing work is possible (evening work available time) are predicted. Further, in the prediction technology of Patent Document 3 described above, the inclination A is obtained from the predicted air temperature in the construction time zone and the scheduled water injection time, and these times and times are predicted based on the calculated inclination A. As described above, in the prediction techniques of Patent Documents 2 and 3 described above, prediction based on the slope A is performed.

  FIG. 5 illustrates the relationship between the temperature T of the concrete and the slope A. As shown in this figure, it can be seen that the concrete temperature T has a high correlation with the slope A. Therefore, as shown in FIG. 6, when the temperature is low, the inclination A is small, and when the temperature is high, the inclination A is large, as shown in FIG. It should be adjusted to be By adjusting the slope A, each time and time predicted by the above-mentioned Patent Documents 2 and 3 are also adjusted according to the adjustment amount, so that the optimum operation in a temperature environment such as summer or winter It will be possible to secure time.

  For example, when each time and time are predicted using the above-mentioned Patent Document 2, when the temperature is low, the hardening accelerator is sprayed on the concrete surface at the time when the “conductivity decrease time” is measured. It is sufficient to accelerate the curing. On the other hand, when the temperature is high, the curing retarder may be dispersed on the surface of the concrete to delay the curing at the time when the "time of decrease in conductivity" is measured. At the early stage of hardening of concrete, for example, in the case of FIG. 3, since there are 55 minutes from the "conductivity decrease time" to the pressing start time, the hardening retarder is dispersed when the "conductivity decrease time" is measured. If this is done, the effect of the curing retarder will be added by the time 55 minutes have passed, and there will be room for later work.

  With regard to combinations of types and amounts of the hardening accelerator and the hardening retarder, the relationship between the temperature of the concrete and the inclination A as shown in FIG. 5 beforehand by experiments etc. The hardening accelerator as shown in FIG. And, a database such as the relationship with the adjustment amount of the inclination A by the dispersion of the curing retarder may be constructed, and it may be selected appropriately as needed.

(Specific control procedure)
Next, the specific procedure of the control method of the hardening time of the concrete which concerns on this Embodiment is demonstrated.

  In this embodiment, before performing the pressing operation (leveling operation) on the surface of concrete under construction, the leveling operation possible time suitable for performing the pressing operation is predicted and the predicted leveling operation possible time Is a method of controlling the hardening time of concrete when the predetermined temporal conditions for appropriately performing the pressing operation are not satisfied, and it comprises a prediction step, a determination step, and an adjustment step.

  The prediction step predicts the leveling possible time of concrete based on a predetermined parameter described later. As the prediction step, the prediction method described in Patent Document 2 or Patent Document 3 described above can be used.

  In the determination step, it is determined whether or not the predicted leveling possible time satisfies a predetermined temporal condition.

  In the adjustment step, when it is determined that the predetermined temporal conditions are not satisfied, a hardening accelerator for accelerating the hardening of the concrete, or a hardening retarder for delaying the hardening of the concrete during or before the construction. It is added to concrete to adjust the hardening rate of concrete.

  In the following, the case where the prediction method described in Patent Document 2 is used as the prediction step is described as Embodiment 1, and the case where the prediction method described in Patent Document 3 is used is described as Embodiment 2.

Embodiment 1
First, the first embodiment will be described. In the first embodiment, based on the “water injection time” and the “conductivity decrease time” of the concrete, the “pressing time to start concrete”, the end time, and the workable time are predicted in advance at “the conductivity decrease time”, If the time and time are unreasonable, it is the case to control the hardening time of the concrete.

The prediction principle of the first embodiment (see Patent Document 2) will be schematically described below.
When an electrode of a conductivity meter is placed on concrete and the conductivity is measured, the conductivity gradually increases, but starts decreasing at a certain time. The conductivity lowering time is related to the reaction of cement in concrete, and is known to coincide with the time at which a penetration resistance of 0.1 (N / mm ² ) is developed.

  On the other hand, it is known that the time t from the water injection time of concrete (the time when cement and water are mixed in the plant at the time of preparation of fresh concrete) to the electric conductivity decrease time has a high correlation with the slope A. The water injection time is always included as product information of the concrete carried to the site, so if the conductivity decrease time is known, the slope A can be obtained from the time t from the water injection time to the conductivity decrease time. Therefore, the slope A can be obtained by previously grasping the relationship between the time t from the water injection time to the conductivity decrease time and the slope A, and applying the time from the water injection time to the conductivity decrease time to this relationship. .

The obtained slope A is substituted into the approximate expression of FIG. 1 to determine the relationship between the penetration resistance value and the elapsed time. However, as described above, since the conductivity lowering time coincides with the time when the penetration resistance value becomes 0.1 (N / mm ² ), the relationship between the penetration resistance value and the elapsed time is set with this time as the origin (0 minute). Ask. Using this relationship, the elapsed time for the penetration resistance to reach 0.5 (N / mm ² ), the elapsed time for the penetration resistance for the first flight time to reach 3.4 (N / mm ² ), the penetration resistance for the termination time The elapsed time to reach 28.0 (N / mm ² ) is determined. The time at each penetration resistance value is calculated by adding the obtained elapsed time to the conductivity reduction time. In addition, since these times are obtained at the time when the conductivity lowering time is obtained, there is a sufficient time to start the work. As a result, it is possible to predict the following work time (time available for work) and time before construction.

  That is, it is possible to predict the work time such as the time when a person can get on the surface of the concrete slab, the start time of the press work, and the finish time of the press work. The time from the time when a person can get on to the time when the pressing work starts is the time when preparation can be made, such as removal of bleeding water and repairing of the concrete slab end. The time from the pressing operation start time to the pressing operation end time is the pressing operation possible time.

  In the first embodiment, each time and time is predicted using this prediction principle, and each predicted time and time does not satisfy predetermined temporal conditions for appropriately performing pressing work. Control cure time. This specific procedure will be described with reference to the flow chart of FIG.

  As shown in FIG. 7, first, in step S1, a concrete sample is collected, and a conductivity meter is installed on the collected concrete sample to start measurement of conductivity.

  Next, in step S2 (prediction step), each time and time described above are predicted from the water injection time and the conductivity decrease time. More specifically, the time from the water injection time to the conductivity decrease time is calculated, and the inclination A is calculated by applying the above relationship. The relationship between the penetration resistance value and the elapsed time is calculated using the slope A, and the time at each penetration resistance value is calculated by adding the elapsed time to the conductivity lowering time using this relationship. Thus, as in step S3, each time and time described above can be predicted before construction.

  According to this prediction method, it is possible to easily predict the pressing timing of the concrete slab before construction by measuring the conductivity decrease time of the concrete. As a result, it becomes possible to plan the number and arrangement of workers and construction machines suitable for construction, and it is possible to make use of it for construction preparation and construction management. For this reason, a concrete slab of stable quality can be constructed.

  Next, in step S4 (determination step), it is determined whether there is a problem in each predicted time or time. This determination is performed by determining whether each predicted time or time satisfies a predetermined predetermined temporal condition. As a result of the determination, if the predetermined temporal condition is satisfied, the process is ended (no problem at step S4), and if not satisfied, the process proceeds to step S5 (adjustment step) (problem "present at step S4). This determination can be performed immediately after the time when the conductivity decrease time is measured.

  For example, when the predicted pressing workable time is extremely short with respect to the construction area (for example, about 30 minutes or less), the work may not be in time. Therefore, for example, an extremely short time (for example, 40 minutes) with respect to the construction area is set in advance as a threshold of the temporal condition regarding the pressing workable time. If the predicted pressing workable time is 32 minutes as in the example of FIG. 3, it is determined that the temporal requirement is not satisfied because it is less than the threshold (40 minutes), for example, the predicted pressing work possible time 1 If it is time, it is determined that the temporal requirement is satisfied because it is more than the threshold (40 minutes).

  On the other hand, for example, when the predicted press start time and press end time are late in the night (for example, around 1:00 midnight), the operator and the site manager are restrained at the site until the late time. It may be a harsh working environment. Therefore, for example, a late time zone (20:00 to 5:00) at night is set in advance as a time zone of an adverse condition which does not satisfy the temporal condition regarding the pressing operation start time and the pressing operation end time. If the predicted press end time is 1:48 as in the example of FIG. 4, it is determined that the temporal requirement is not satisfied because of the time zone of bad condition (20:00 to 5:00), For example, when the predicted pressing end time is 19:50, it is determined that the temporal requirement is satisfied because it is not a time zone of adverse conditions.

  Next, in step S5 (adjustment step), a hardening accelerator for accelerating the hardening of the concrete or a hardening retarder for delaying the hardening of the concrete is sprayed on the concrete surface during construction to harden the concrete Adjust the speed. The application of the hardening accelerator accelerates the hardening speed of the concrete and shortens the hardening time. The application of a hardening retarder slows the hardening speed of the concrete and prolongs the hardening time.

  For example, in the case of FIG. 3, since there are 55 minutes from the conductivity lowering time to the pressing operation start time, if the curing delay agent is sprayed when the conductivity lowering time is measured, 55 minutes have elapsed Since the effect of the curing retarder is added, it is possible to afford later work.

  The degree of adjustment of the curing rate is determined depending on the types and application amounts of the curing accelerator and the curing retarder. With regard to the combination of the type and the application rate, the relationship between the temperature of the concrete and the inclination A as shown in FIG. 5 by experiment etc. in advance, and the adjustment of the inclination A by application of hardening accelerator and hardening retarder as shown in FIG. Build a database such as the relationship with quantity and make it possible to select it as needed.

  After the process of step S5, the process proceeds to step S2. However, the process may be ended when it is considered that the predetermined temporal requirement is satisfied. In the case where the process proceeds to step S2, the inclination A after the application is obtained using the relation with the adjustment amount of the inclination A by the application of the curing accelerator and the curing retarder, which is grasped in advance. Thereafter, in step S2, the relationship between penetration resistance value and elapsed time is calculated using this slope A, and each time and time is predicted by adding the elapsed time to the conductivity decrease time using this relationship. Steps S2 to S5 may be repeated until predetermined temporal conditions are satisfied.

  As described above, according to the first embodiment, when the conductivity lowering time is measured from the water pouring time of the concrete and the conductivity lowering time, the pressing start time, the pressing end time, and the pressing available time of the concrete are measured. If there is a problem in the time and time, it is possible to control the hardening time of the concrete so as not to overdo the pressing work by spraying the hardening accelerator and the hardening retarder on the concrete surface. As a result, the construction environment can be improved, and a concrete slab of stable quality can be constructed.

Second Embodiment
Next, the second embodiment will be described. In the second embodiment, based on the “expected temperature” and the “water injection time” of the construction time zone, the concrete pressing work start time, end time and workable time are predicted in advance, and the time and time are unreasonable. One case is to control the hardening time of the concrete.

The prediction principle of the second embodiment (see Patent Document 3) will be schematically described below.
As shown in FIG. 5, it can be seen that the concrete temperature T has a high correlation with the slope A. Therefore, if the predicted air temperature in the construction time zone (for example, the day of construction) is obtained, the slope A can be obtained from this figure on the premise that the temperature does not differ significantly from the temperature of the concrete.

On the other hand, when an electrode of a conductivity meter is placed on concrete and the conductivity is measured, the conductivity gradually increases, but starts to decrease at a certain time. The conductivity lowering time is related to the reaction of cement in concrete, and is known to coincide with the time at which a penetration resistance of 0.1 (N / mm ² ) is developed.

  On the other hand, it is known that the time t from the water pouring time of concrete to the conductivity decreasing time has a high correlation with the slope A. That is, if the inclination A is known, the time t from the water injection time to the conductivity decrease time can be obtained. Therefore, using the relationship as shown in FIG. 5, the slope A is obtained from the predicted temperature in the construction time zone, and "time t from water injection time to conductivity decrease time" corresponding to the obtained slope A is grasped in advance It is calculated from “the relationship between the slope A and the time t from the water injection time to the conductivity decrease time”. Then, the water injection time is set to a predetermined time, and the conductivity decrease time corresponding to the water injection time is obtained from “the time t from the water injection time to the conductivity decrease time”. As the water injection time, it is possible to use the water injection scheduled time before water injection, and the water injection time attached to the product information of concrete after water injection.

The relationship between the penetration resistance value and the elapsed time is determined by substituting the slope A obtained from the predicted air temperature into the approximate expression of FIG. However, as described above, the conductivity reduction time is obtained from the slope A and the water injection time. Since this conductivity decrease time coincides with the time when the penetration resistance value becomes 0.1 (N / mm ² ), the relationship between the penetration resistance value and the elapsed time is determined using this time as the origin (0 minute). Using this relationship, the elapsed time for the penetration resistance to reach 0.5 (N / mm ² ), the elapsed time for the penetration resistance for the first flight time to reach 3.4 (N / mm ² ), the penetration resistance for the termination time The elapsed time to reach 28.0 (N / mm ² ) is determined. The time at each penetration resistance value is calculated by adding the obtained elapsed time to the conductivity reduction time. In addition, since these times are calculated | required at the time (for example, time before a construction day) which set the estimation | forecast air temperature and the water injection time, it has sufficient time until it starts an operation | work. Thereby, it becomes possible to predict the work time and time mentioned above before construction.

  In the second embodiment, each time and time is predicted using this prediction principle, and each predicted time and time does not satisfy predetermined temporal conditions for appropriately performing pressing work. Control cure time. The specific procedure is substantially the same as that of the first embodiment (see FIG. 7) described above, but is as follows.

  First, the predicted air temperature during the construction period is acquired by weather forecast and the like, and the water injection time is set. Next, each time and time described above are predicted from the predicted air temperature and the water injection time (prediction step). More specifically, the slope A is obtained from the predicted temperature using the relationship as shown in FIG. Subsequently, the conductivity reduction time is determined from the slope A and the water injection time by using “the relationship between the inclination A and the time t from the water injection time to the conductivity reduction time”. The relationship between the penetration resistance value and the elapsed time is calculated using the slope A, and the time at each penetration resistance value is calculated by adding the elapsed time to the conductivity lowering time using this relationship. Thereby, the above-mentioned each time and time can be predicted before construction.

  According to this prediction method, the pressing timing of the concrete slab can be easily predicted before construction based on the predicted air temperature and the water injection time. As a result, it becomes possible to plan the number and arrangement of workers and construction machines suitable for construction, and it is possible to make use of it for construction preparation and construction management. For this reason, a concrete slab of stable quality can be constructed.

  Next, it is determined whether there is a problem in each predicted time or time (determination step). This determination is performed by determining whether each predicted time or time satisfies a predetermined predetermined temporal condition. As a result of the determination, if the predetermined temporal condition is satisfied, the process is ended, and if not, the process proceeds to the adjustment step. The threshold value of the temporal condition used for the determination and the processing content of the adjustment step are the same as those in the first embodiment described above.

  In addition, said determination item can be determined immediately after the time of setting both an estimated air temperature and the water injection time. Therefore, for example, when both of the predicted temperature and the water injection time are set before the construction date, it is possible to determine whether the temporal condition is satisfied before the construction date. As a result of the judgment, if it is expected that the temporal conditions will not be satisfied, the hardening rate of the concrete after being cast can be obtained by adding the hardening accelerator or the hardening retarder to the concrete before putting in advance. You may adjust. Alternatively, instead of doing so, a hardening accelerator or hardening retarder may be sprayed on the concrete surface after placement to adjust the hardening speed.

  As described above, according to the second embodiment, when the water injection time and the predicted air temperature are set from the water injection time and the predicted air temperature of concrete, the press start time, the press end time, and the press work available time of concrete are predicted. If there is a problem with the time and time, add a hardening accelerator or hardening retarder to the pre-construction concrete in advance, or disperse it on the concrete surface during construction, so that the pressing work is not excessive The hardening time of concrete can be controlled. As a result, the construction environment can be improved, and a concrete slab of stable quality can be constructed.

[Control device of hardening time of concrete]
Next, an embodiment of the control device for the hardening time of concrete according to the present invention will be described.

  The control apparatus of the hardening time of concrete concerning this embodiment embodies the control method of the hardening time of concrete mentioned above as an apparatus, and is provided with a prediction means, a judgment means, and an adjustment means. Here, an embodiment of the method for controlling the hardening time of concrete according to the above-mentioned first embodiment will be described as an example.

  The prediction means corresponds to the above-mentioned prediction step, and can be constituted by, for example, an input unit, an output unit, an operation unit, and a display unit. The prediction means can be configured by, for example, a computer having a CPU, hardware such as a memory or a display, or software such as a computer program running on the hardware. The display unit of this prediction means can be configured by, for example, an input / output screen as shown in FIG. In this screen, an input unit (INPUT) and an output unit (OUTPUT) are arranged.

  The input section (INPUT) consists of a field for entering "water injection time" for mixing cement and water at the time of preparation of fresh concrete, and a field for entering "conductivity reduction time" for decreasing the conductivity of concrete. . The input values for each column are used in the arithmetic processing of the arithmetic unit.

  The output unit (OUTPUT) is a final output item, a column for outputting "(water injection-decrease) time" (time from water injection time to conductivity decrease time) and "slope A", which are intermediate output items. It consists of columns for outputting "time when a person can ride", "time for starting pressing operation", "time for ending pressing operation", "time until operation start", and "time available for pressing operation". The calculated value calculated by the arithmetic processing of the arithmetic unit is output to each column.

  When two items of “water injection time” and “conductivity decrease time” of the input unit are input, the time from the water injection time to the conductivity decrease time is calculated and the inclination A is calculated by the calculation processing of the calculation unit Ru. Then, from these calculated values, the “time when a person can ride”, “pressing start time”, “pressing end time”, “time until work start”, and “pressing possible time” are calculated. These calculated values are instantaneously output and displayed in each column of the output unit. Therefore, the user of this prediction apparatus can easily grasp the above-mentioned work time and time through this input / output screen. In the example of the figure, the output result in the case of entering 9:00 as the water injection time and 12:00 as the conductivity decrease time is shown.

  The determination means corresponds to the above-described determination step, and can be configured by, for example, a computer having a CPU, hardware such as a memory, or software such as a computer program operating on the hardware. The determination means determines whether or not a predetermined temporal condition is satisfied based on, for example, a threshold of the temporal condition stored in a memory or the like.

  The adjusting means corresponds to the above-mentioned adjusting step, and can be constituted by, for example, a spraying device for spraying a curing accelerator or a curing retarder. This adjustment means scatters a hardening accelerator and a hardening retarder on a concrete surface, for example with a spraying device, when not satisfying predetermined temporal conditions.

  According to the present embodiment, each time and time is predicted, and if there is a problem with the time and time, it is not possible to press the work by spreading the hardening accelerator and the hardening retarder on the concrete surface under construction The hardening time of the concrete can be controlled so as not to As a result, the construction environment can be improved, and a concrete slab of stable quality can be constructed.

[Concrete construction method]
Next, a concrete slab construction method according to an embodiment of the present invention will be described with reference to the case where a concrete slab is constructed using the above-described first embodiment.

  First, fresh concrete is cast on a formwork to construct a concrete slab. During this construction, the conductivity lowering time is measured by the prediction step of the above-mentioned control method of the hardening time of concrete, “time when people can get on”, “pressing start time”, “pressing end time”, “starting work” Estimate the time until ", and the" time for pressing operation ". Next, using the determination step, it is determined whether each predicted time and time satisfies the predetermined temporal condition. As a result, when the predetermined temporal condition is not satisfied, the processing of the adjustment step is advanced. That is, a hardening accelerator and a hardening retarder are sprayed on the concrete surface under construction, and the hardening speed of concrete is adjusted. Thereafter, the inclination A is updated according to the type and amount of the curing accelerator and the curing retarder, and each time and time are predicted again by the prediction step. When it is determined in the determination step that the predetermined temporal condition is satisfied, the pressing operation is performed on the concrete surface based on each time and time at that time.

  More specifically, when "the time when a person can get on", a worker gets on the hardened concrete slab and performs operations such as treatment of bleeding water and an end. This work is planned to be completed within the "time to work start". After that, when the “pressing start time” is reached, the surface is repeatedly pressed with a hand-held trowell or a hook. This work is performed in a planned manner so as to finish within the “pressing work possible time”, and the work is finished at the “pressing work end time”.

  As described above, according to the present embodiment, when each predicted time or time does not satisfy a predetermined temporal condition, each time or time can be adjusted so that the pressing operation can be appropriately performed. This makes it possible to construct a concrete slab of stable quality.

  As described above, according to the control method of the hardening time of concrete according to the present invention, the leveling operation suitable for performing the leveling operation before performing the leveling operation on the surface of the concrete under construction can be performed This is a method of predicting the time and controlling the hardening time of the concrete when the predicted available work time does not satisfy the prescribed time condition for properly performing the balancing work, and a fresh concrete is produced. Based on the water injection time when mixing cement and water, and the conductivity decrease time obtained by measuring the conductivity of the concrete under construction, or based on the predicted air temperature and water injection time expected in the construction time zone A prediction step of predicting the leveling time of the concrete, a determining step of determining whether or not the predicted leveling time of the concrete satisfies a predetermined timing condition, and A hardening accelerator for accelerating the hardening of the concrete or a hardening retarder for delaying the hardening of the concrete is added to the concrete during construction or before construction if it is determined that the preliminary conditions are not satisfied. Since the adjustment step of adjusting the hardening rate of the concrete is provided, the hardening rate of the concrete is adjusted when the predicted available work time does not satisfy the predetermined time conditions for properly performing the equalization work. Thus, it is possible to adjust the time when the leveling operation can be performed so that the leveling operation can be properly performed.

  Further, according to another control method of hardening time of concrete according to the present invention, the prediction step measures the conductivity of the concrete under construction to obtain the conductivity decrease time, and the determined conductivity decrease time Determined by applying to the relation between the time from the water injection time grasped in advance to the electric conductivity decrease time of concrete and the inclination information of the approximate expression expressing the relation between penetration resistance value and elapsed time obtained by the predetermined penetration resistance test The step of obtaining inclination information corresponding to the conductivity lowering time, the step of estimating the relationship between the penetration resistance value and the elapsed time corresponding to the determined inclination information, the relationship between the estimated penetration resistance value and the elapsed time, and Since the step of predicting the leveling time of concrete can be predicted from the conductivity decrease time, the conductivity decrease time is determined from the water pouring time of the concrete and the conductivity decrease time. By predicting the leveling possible time at the point in time, as a result, when the predetermined temporal conditions are not satisfied, a hardening accelerator or hardening retarder is added to the concrete under construction to adjust the hardening speed, It is possible to adjust the time available for leveling.

  Further, according to another control method of hardening time of concrete according to the present invention, the prediction step assumes that the air temperature in the construction time zone and the temperature of the concrete are in correlation, and the predicted air temperature expected in the construction time zone The inclination information corresponding to the expected air temperature is determined by applying the above to the relation between the inclination resistance value of the approximate expression representing the relation between the penetration resistance value obtained by the predetermined penetration resistance test and the elapsed time obtained beforehand and the temperature of the concrete. The conductivity decrease time corresponding to the obtained inclination information is estimated by applying the step and the calculated inclination information to the relationship between the previously determined water injection time to the conductivity decrease time of the concrete and the inclination information. The step, the step of estimating the relationship between the penetration resistance value corresponding to the obtained inclination information and the elapsed time, the relationship between the estimated penetration resistance value and the elapsed time, and the estimated conduction Since the step of predicting the leveling time of concrete can be predicted from the rate decrease time, the leveling work time can be predicted before the construction from the predicted air temperature and the water injection time predicted in the construction time zone, and the result When the prescribed temporal conditions are not satisfied, the level of workable period can be adjusted by adjusting the hardening rate by adding a hardening accelerator or hardening retarder to concrete during or before construction .

  In addition, according to the control device of the hardening time of concrete according to the present invention, it is possible to predict a time suitable for performing the leveling operation before performing the leveling operation on the surface of the concrete under construction. A device for controlling the hardening time of the concrete when the predicted possible work time does not satisfy the predetermined time condition for properly performing the work, and the cement and the cement for producing fresh concrete Based on the water injection time when mixing water and the conductivity decrease time obtained by measuring the conductivity of the concrete under construction, or based on the predicted air temperature and water injection time expected in the construction time zone, The prediction means for predicting the averaging work available time, the judging means for determining whether the predicted averaging work available time satisfies the predetermined temporal condition, and the predetermined temporal condition are not satisfied If it is determined, a hardening accelerator for accelerating the hardening of the concrete or a hardening retarder for delaying the hardening of the concrete is added to the concrete during or before construction to adjust the hardening speed of the concrete Since the adjustment means is provided, if the predicted available work time does not satisfy the predetermined time condition for performing the work properly, the speed of the concrete is properly adjusted by adjusting the hardening speed of the concrete. It is possible to adjust the time when the leveling operation can be performed.

  Moreover, according to the control apparatus of the hardening time of the other concrete which concerns on this invention, a prediction means measures the conductivity of the concrete under construction, and a means to obtain | require the conductivity fall time, The conductivity fall time calculated | required Determined by applying to the relation between the time from the water injection time grasped in advance to the electric conductivity decrease time of concrete and the inclination information of the approximate expression expressing the relation between penetration resistance value and elapsed time obtained by the predetermined penetration resistance test The means for obtaining inclination information corresponding to the conductivity lowering time, the means for estimating the relationship between the penetration resistance value and the elapsed time corresponding to the obtained inclination information, the relationship between the estimated penetration resistance value and the elapsed time, and Since the method comprises means for predicting the leveling time of the concrete from the conductivity lowering time, the leveling operation is carried out at the time of the conductivity lowering time from the water pouring time of the concrete and the conductivity lowering time. It is possible to level the work period by predicting the possible time, and as a result, if the prescribed time conditions are not satisfied, the hardening accelerator or the hardening retarder is added to the concrete under construction to adjust the hardening speed. Can be adjusted.

  Moreover, according to the control apparatus of the hardening time of the other concrete which concerns on this invention, the prediction means considers that the air temperature of a construction time zone and the temperature of a concrete have correlation, and is an expected air temperature forecasted in a construction time zone The inclination information corresponding to the expected air temperature is determined by applying the above to the relation between the inclination resistance value of the approximate expression representing the relation between the penetration resistance value obtained by the predetermined penetration resistance test and the elapsed time obtained beforehand and the temperature of the concrete. The conductivity decrease time corresponding to the obtained inclination information is estimated by applying the means and the calculated inclination information to the relationship between the previously determined water injection time to the conductivity decrease time of the concrete and the inclination information. Means, means for estimating the relationship between penetration resistance value and elapsed time corresponding to the obtained inclination information, relationship between estimated penetration resistance value and elapsed time, and estimated conductivity decrease time Since it consists of a means to predict the leveling possible time of concrete, the leveling possible time is estimated before the construction from the predicted air temperature and the water injection time which are expected in the construction time zone, and as a result, a predetermined time When the conditions are not satisfied, the hardening work can be adjusted by adjusting the hardening rate by adding a hardening accelerator or a hardening retarder to the concrete during or before construction.

  Further, according to the method of constructing concrete according to the present invention, the method of constructing concrete using the method of controlling the hardening time of concrete described above is used, and the hardening speed is adjusted based on the predicted leveling time. Since the step of performing the leveling operation on the surface of the concrete later is provided, the leveling operation can be performed properly so that the predicted leveling workable time does not satisfy the predetermined temporal conditions. You can adjust the time. This makes it possible to construct concrete of stable quality.

  As mentioned above, the control method of the hardening time of concrete concerning the present invention, a control device, and the construction method of concrete are useful for construction of a concrete slab. It is suitable for adjusting the available work time when the predetermined time conditions for performing properly are not satisfied.

Claims (7)

Before performing the leveling operation on the surface of concrete under construction, forecasting a suitable leveling operation possible time for performing the leveling operation and performing the predicted leveling operation time appropriately perform the leveling operation A method of controlling the hardening time of concrete when the predetermined temporal conditions are not satisfied.
Based on the water injection time when mixing cement and water to make fresh concrete, and the conductivity decrease time obtained by measuring the conductivity of the concrete under construction, or the predicted air temperature expected in the construction time zone Forecasting step to predict the leveling time of concrete leveling operation based on the water injection time and
A determination step of determining whether or not the predicted leveling possible time condition satisfies a predetermined temporal condition;
A hardening accelerator for accelerating the hardening of the concrete or a hardening retarder for delaying the hardening of the concrete is added to the concrete during or before construction if it is judged that the predetermined temporal conditions are not satisfied. And adjusting the hardening speed of the concrete. The prediction step is
Measuring the conductivity of the concrete under construction and determining the conductivity decrease time,
The calculated conductivity decrease time, the time from the water injection time grasped in advance to the conductivity decrease time of concrete, and the inclination information of the approximate expression representing the relationship between the penetration resistance value obtained by the predetermined penetration resistance test and the elapsed time Determining inclination information corresponding to the determined conductivity lowering time by applying to a relationship;
Estimating a relationship between penetration resistance value and elapsed time corresponding to the obtained inclination information;
The concrete hardening time according to claim 1, characterized by comprising the step of predicting the leveling time of the concrete from the relationship between the estimated penetration resistance value and the elapsed time and the conductivity lowering time determined. Control method. The prediction step is
Assuming that the air temperature in the construction time zone and the temperature of the concrete are correlated, the predicted air temperature predicted in the construction time zone is the relationship between the penetration resistance value obtained by a predetermined penetration resistance test grasped beforehand and the elapsed time Obtaining inclination information corresponding to the predicted air temperature by applying the relation between the inclination information of the approximate expression to be expressed and the temperature of the concrete;
Estimating the conductivity decrease time corresponding to the obtained tilt information by applying the obtained tilt information to the relationship between the time from the water injection time grasped in advance to the conductivity decrease time of concrete and the tilt information;
Estimating a relationship between penetration resistance value and elapsed time corresponding to the obtained inclination information;
The concrete hardening time according to claim 1, characterized by comprising the step of predicting the leveling time of the concrete from the relationship between the estimated penetration resistance value and the elapsed time and the estimated conductivity decrease time. Control method. Before performing the leveling operation on the surface of concrete under construction, forecasting a suitable leveling operation possible time for performing the leveling operation and performing the predicted leveling operation time appropriately perform the leveling operation A device for controlling the hardening time of concrete when the predetermined temporal condition is not satisfied,
Based on the water injection time when mixing cement and water to make fresh concrete, and the conductivity decrease time obtained by measuring the conductivity of the concrete under construction, or the predicted air temperature expected in the construction time zone Forecasting means for predicting the leveling time of concrete leveling work based on the water pouring time and
A determination unit that determines whether or not the predicted averaging work enablement condition satisfies a predetermined temporal condition;
A hardening accelerator for accelerating the hardening of the concrete or a hardening retarder for delaying the hardening of the concrete is added to the concrete during or before construction if it is judged that the predetermined temporal conditions are not satisfied. And an adjusting means for adjusting the hardening speed of the concrete. The prediction means is
A means for measuring the conductivity of the concrete under construction to determine the time of conductivity decrease;
The calculated conductivity decrease time, the time from the water injection time grasped in advance to the conductivity decrease time of concrete, and the inclination information of the approximate expression representing the relationship between the penetration resistance value obtained by the predetermined penetration resistance test and the elapsed time A means for determining inclination information corresponding to the determined conductivity lowering time by applying to a relation;
A means for estimating the relationship between penetration resistance value and elapsed time corresponding to the obtained inclination information;
The hardening time of the concrete according to claim 4, characterized by comprising: a means for predicting the leveling time of the concrete from the relationship between the penetration resistance value and the elapsed time which has been estimated, and the conductivity lowering time which has been obtained. Control device. The prediction means is
Assuming that the air temperature in the construction time zone and the temperature of the concrete are correlated, the predicted air temperature predicted in the construction time zone is the relationship between the penetration resistance value obtained by a predetermined penetration resistance test grasped beforehand and the elapsed time A means for obtaining inclination information corresponding to the predicted air temperature by applying the relation between the inclination information of the approximate expression to be expressed and the temperature of the concrete;
A means for estimating the conductivity decrease time corresponding to the obtained tilt information by applying the obtained tilt information to the relationship between the time from the water injection time grasped in advance to the conductivity decrease time of concrete and the tilt information;
A means for estimating the relationship between penetration resistance value and elapsed time corresponding to the obtained inclination information;
The hardening time of concrete according to claim 4, characterized in that it comprises means for predicting the leveling possible time of concrete from the relationship between the estimated penetration resistance value and the elapsed time and the estimated conductivity decrease time. Control device. It is a method of constructing concrete using the control method of hardening time of concrete according to any one of claims 1 to 3,
And D. performing a leveling operation on the surface of the concrete after adjusting the hardening rate based on the predicted leveling time.

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