Method and device for predicting timing of concrete construction, and method for constructing concrete

Abstract

To provide a method for predicting concrete construction timing, a prediction device, and a concrete construction method that can easily predict construction timing.SOLUTION: There provided steps of determining intercept information corresponding to measured initial temperature, estimating elapsed time from the determined intercept information and time of water pouring until a predetermined penetration resistance value is reached, measuring temperature of the concrete at time obtained by adding time obtained by subtracting predetermined subtraction time from the estimated elapsed time to the time of water pouring to the concrete, obtaining slope information corresponding to the measured temperature of the concrete, and determining an approximate equation representing the relationship between the penetration resistance and the elapsed time by using the obtained slope information and the intercept information to predict construction timing of the pushing operation.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a method and device for predicting the timing of concrete construction for, for example, a concrete slab, and a method for constructing concrete. [Background technology]

[0002] Conventionally, concrete slabs are constructed in the following order: pouring → leveling → topping → pressing. More specifically, concrete is delivered from the plant in a mixer (agitator truck) and poured onto a formwork, and the entire structure is leveled to a set height. The concrete hardens over time, and once it is hard enough for workers to stand on it, bleeding water is added and the edges are treated, and the surface is repeatedly pressed down with a trowel.

[0003] The work from the lining to the pressing is necessary for smoothing and densifying the concrete surface, and has a large impact on the quality of the slab. This pressing work is judged by experienced workers based on their senses, such as the hardness of the concrete surface when they touch it, the color it appears to be, and the amount of bleeding water that occurs. Due to the recent shortage of workers, this method of construction based on sense is becoming unfeasible, and there is a risk that this will lead to a decline in the construction quality of concrete slabs. In particular, there has been a demand for mechanization of construction in recent years to make up for the labor shortage in the construction industry, and as the weight and power of machines become greater compared to manual work, management of the timing of construction has become extremely important.

[0004] Known conventional methods for grasping the hardening state of concrete include the methods described in Patent Documents 1 and 2. The method in Patent Document 1 uses mortar obtained by removing coarse aggregate from a concrete sample as a test specimen, and, based on data from a JIS penetration resistance test (JIS A 1147:2007) that determines the penetration resistance value when a specified penetration needle is inserted vertically, records the relationship between time and conductivity obtained from a conductivity meter (or a resistance meter) installed in the test specimen, and calculates the coefficient A of the concrete hardening speed from the time of the inflection point of the waveform and the time of pouring water into the concrete, thereby calculating the time at which the concrete will have a subsequent penetration resistance value. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-73898 A [Patent Document 2] JP 2019-73962 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the conventional method of Patent Document 1 requires waiting for the timing when the conductivity changes, and in order to avoid overlooking it, the measurer must be restrained until the change is identified, or the measurement must be automated. In addition, the relationship between the conductivity of concrete and the degree of hardening tends to be difficult for concrete workers and construction sites to imagine and to work on. In addition, the method of managing the construction timing while measuring the penetration resistance value at the actual construction site is reliable, but requires the work of removing the coarse aggregate, the work of cleaning the tools used, and the work of measuring the penetration resistance value every hour. For this reason, a method that can easily predict the construction timing of concrete without much effort has been required.

[0007] The present invention has been made in consideration of the above, and aims to provide a method and device for predicting the timing of concrete construction, and a concrete construction method, which make it possible to easily predict the timing of construction. [Means for solving the problem]

[0008] In order to solve the above problems and achieve the object, the method for predicting the timing of concrete construction according to the present invention is a method for predicting a construction timing suitable for performing a pressing operation before performing a pressing operation on the surface of concrete being constructed, and includes the steps of acquiring a concrete water pouring time, measuring an initial temperature of the concrete, applying the measured initial temperature to a relationship between intercept information of an approximation equation expressing a relationship between a penetration resistance value obtained by a predetermined penetration resistance test and elapsed time that is previously understood, and the initial temperature of the concrete, thereby obtaining intercept information corresponding to the measured initial temperature, applying the obtained intercept information to an approximation equation expressing the relationship between the penetration resistance value and elapsed time, thereby obtaining an elapsed time until the predetermined penetration resistance value is reached, and adding the obtained elapsed time to the concrete water pouring time, thereby estimating an elapsed time from the water pouring time until the predetermined penetration resistance value is reached, and measuring the temperature of the concrete at a time obtained by adding the time obtained by subtracting a predetermined subtraction time from the elapsed time measured, to the time of pouring water into the concrete; obtaining slope information corresponding to the measured concrete temperature by applying the measured concrete temperature to slope information of an approximation equation expressing the relationship between a penetration resistance value obtained by a predetermined penetration resistance test known in advance and the elapsed time, and the concrete temperature at the time when the predetermined subtraction time is subtracted from the elapsed time until the predetermined penetration resistance value is reached; determining an approximation equation expressing the relationship between the penetration resistance value and the elapsed time using the obtained slope information and intercept information, obtaining the elapsed time by applying a penetration resistance value corresponding to the execution timing of the holding down work to the determined approximation equation, and predicting the time obtained by adding the obtained elapsed time to the time of pouring water into the concrete as the execution timing of the holding down work.

[0009] In addition, another method for predicting the timing of concrete construction according to the present invention is the above-mentioned invention, in which the predetermined penetration resistance value is 1 (N / mm 2 ) and the predetermined subtraction time is 60 minutes.

[0010] The concrete construction timing prediction device according to the present invention is a device for predicting a construction timing suitable for carrying out a pressing operation before carrying out a pressing operation on the surface of concrete being constructed, and includes a means for acquiring a concrete water pouring time, a means for measuring an initial temperature of the concrete, a means for applying the measured initial temperature to intercept information of an approximation equation expressing the relationship between a penetration resistance value obtained by a predetermined penetration resistance test that is previously grasped and elapsed time, and the relationship between the initial temperature of the concrete, to obtain intercept information corresponding to the measured initial temperature, a means for applying the obtained intercept information to an approximation equation expressing the relationship between the penetration resistance value and elapsed time, to obtain the elapsed time until the predetermined penetration resistance value is reached by applying the obtained intercept information to the approximation equation expressing the relationship between the penetration resistance value and elapsed time, and a means for estimating the elapsed time from the water pouring time until the predetermined penetration resistance value is reached by adding the obtained elapsed time to the water pouring time of the concrete, and a means for calculating the predetermined penetration resistance value from the estimated elapsed time. the measured concrete temperature is calculated based on the slope information of an approximation equation that expresses the relationship between a penetration resistance value obtained by a predetermined penetration resistance test and the elapsed time, and the concrete temperature at the time when the predetermined subtraction time is subtracted from the elapsed time until the predetermined penetration resistance value is reached, thereby obtaining slope information corresponding to the measured concrete temperature; and means for determining an approximation equation that expresses the relationship between the penetration resistance value and the elapsed time using the obtained slope information and intercept information, obtaining the elapsed time by applying a penetration resistance value that corresponds to the timing of the pressing work to the determined approximation equation, and predicting the time obtained by adding the obtained elapsed time to the concrete water pouring time as the timing of the pressing work.

[0011] In addition, the present invention provides a method for predicting the timing of concrete construction, in which the predetermined penetration resistance is 1 (N / mm 2 ) and the predetermined subtraction time is 60 minutes.

[0012] In addition, the concrete construction method of the present invention is characterized by having a step of predicting the construction timing using the above-mentioned method for predicting the timing of concrete construction, a step of pouring concrete, and a step of performing pressing work on the surface of the concrete based on the predicted construction timing. Effect of the Invention

[0013] According to the method for predicting the timing of concrete construction of the present invention, there is provided a method for predicting the timing suitable for carrying out a pressing operation before carrying out a pressing operation on the surface of concrete being constructed, the method including the steps of acquiring a concrete water pouring time, measuring an initial temperature of the concrete, applying the measured initial temperature to intercept information of an approximation equation expressing the relationship between a penetration resistance value obtained by a predetermined penetration resistance test and elapsed time that is previously known, and the relationship between the initial temperature of the concrete, thereby obtaining intercept information corresponding to the measured initial temperature, applying the obtained intercept information to an approximation equation expressing the relationship between the penetration resistance value and elapsed time, thereby obtaining the elapsed time until the predetermined penetration resistance value is reached, and adding the obtained elapsed time to the water pouring time of the concrete, thereby estimating the elapsed time from the water pouring time until the predetermined penetration resistance value is reached, and adding the time obtained by subtracting a predetermined subtraction time from the estimated elapsed time to the water pouring time of the concrete. the step of applying the measured concrete temperature to the relationship between the slope information of an approximation equation expressing the relationship between a penetration resistance value obtained by a predetermined penetration resistance test and the elapsed time, and the temperature of the concrete at the time when a predetermined subtraction time is subtracted from the elapsed time until the predetermined penetration resistance value is reached, thereby obtaining slope information corresponding to the measured concrete temperature; the step of determining an approximation equation expressing the relationship between the penetration resistance value and the elapsed time using the obtained slope information and intercept information, obtaining the elapsed time by applying a penetration resistance value corresponding to the execution timing of the holding down work to the determined approximation equation, and predicting the time obtained by adding the obtained elapsed time to the concrete water pouring time as the execution timing of the holding down work, thereby achieving the effect of easily predicting the execution timing of the concrete holding down work by measuring the concrete water pouring time, initial temperature, and the concrete temperature at the predetermined time.

[0014] According to another method for predicting the timing of concrete construction according to the present invention, the predetermined penetration resistance is 1 (N / mm 2) and the predetermined subtraction time is 60 minutes, it is possible to easily and accurately determine an approximation formula expressing the relationship between the penetration resistance value and the elapsed time.

[0015] Further, according to the concrete construction timing prediction device of the present invention, there is provided a device for predicting a construction timing suitable for carrying out a pressing operation before carrying out a pressing operation on the surface of concrete being constructed, comprising: a means for acquiring a concrete water pouring time; a means for measuring an initial temperature of the concrete; a means for applying the measured initial temperature to intercept information of an approximation equation expressing the relationship between a penetration resistance value obtained by a predetermined penetration resistance test and elapsed time that is previously understood, and the relationship between the initial temperature of the concrete, thereby obtaining intercept information corresponding to the measured initial temperature; a means for applying the obtained intercept information to an approximation equation expressing the relationship between the penetration resistance value and elapsed time, thereby obtaining the elapsed time until the predetermined penetration resistance value is reached, and adding the obtained elapsed time to the concrete water pouring time; and a means for estimating the elapsed time from the water pouring time until the predetermined penetration resistance value is reached by subtracting a predetermined subtraction time from the estimated elapsed time, and adding the time obtained by subtracting a predetermined subtraction time from the estimated elapsed time to the concrete water pouring time. the measured concrete temperature at a certain time; a means for applying the measured concrete temperature to the relationship between the slope information of an approximation equation expressing the relationship between a penetration resistance value obtained by a predetermined penetration resistance test and the elapsed time, and the concrete temperature at the time when a predetermined subtraction time is subtracted from the elapsed time until the predetermined penetration resistance value is reached, thereby obtaining slope information corresponding to the measured concrete temperature; and a means for determining an approximation equation expressing the relationship between the penetration resistance value and the elapsed time using the obtained slope information and intercept information, obtaining the elapsed time by applying a penetration resistance value corresponding to the execution timing of the holding down work to the determined approximation equation, and predicting the time obtained by adding the obtained elapsed time to the concrete water pouring time as the execution timing of the holding down work. Thus, by measuring the concrete water pouring time, initial temperature, and the concrete temperature at a predetermined time, it is possible to easily predict the execution timing of the subsequent holding down work.

[0016] In addition, according to another concrete construction timing prediction device of the present invention, the predetermined penetration resistance value is 1 (N / mm 2 ) and the predetermined subtraction time is 60 minutes, it is possible to easily and accurately determine an approximation formula expressing the relationship between the penetration resistance value and the elapsed time.

[0017] Furthermore, the concrete construction method according to the present invention includes a step of predicting the timing of construction using the above-mentioned method for predicting the timing of concrete construction, a step of pouring concrete, and a step of carrying out a pressing operation on the surface of the concrete based on the predicted timing of construction, so that the pressing operation on the surface of the concrete can be carried out appropriately based on the predicted timing of construction before construction, thereby achieving the effect of being able to construct concrete of stable quality. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram showing an example of the relationship between elapsed time and penetration resistance value, where (1) is the relationship between elapsed time and penetration resistance value, and (2) is the case where (1) is converted into a logarithmic value. [Diagram 2] FIG. 2 is a diagram showing an example of the relationship with the initial concrete temperature, where (1) is the relationship between the initial concrete temperature and the slope A, and (2) is the relationship between the initial concrete temperature and the intercept B. [Diagram 3] Figure 3(1) shows the breakdown of the elapsed time calculated from intercept B at a penetration resistance value of 1 (N / mm2) for all test samples, and Figure 3(2) shows the relationship between the work content and the penetration resistance value. [Figure 4] FIG. 4 is a diagram showing an example of the relationship between the predicted concrete temperature and the slope A when the penetration resistance value is 1 (N / mm 2 ). [Diagram 5] FIG. 5 is a flow chart showing an embodiment of the method for predicting the timing of concrete construction according to the present invention. [Figure 6] FIG. 6 is a screen diagram showing an embodiment of a concrete construction timing prediction device according to the present invention. [Figure 7] FIG. 7 is a screen diagram showing an embodiment of a concrete construction timing prediction device according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, embodiments of the method and device for predicting timing of concrete construction and the method for concrete construction according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to these embodiments.

[0020] [Method of predicting timing of concrete construction] First, an embodiment of a method for predicting timing of concrete construction according to the present invention will be described.

[0021] (Basic principle) First, the basic principle of the present invention will be described. Figure 1 (1) shows an example of the measurement results of the penetration resistance value versus the elapsed time after concrete pouring in summer, intermediate season (spring), and winter. R in the figure is the correlation coefficient. According to this figure, it can be seen that there is a high correlation between the two, and that concrete hardens in a short time in summer and takes a long time to harden in winter. For this waveform, if the X-axis and Y-axis are converted to logarithmic values ​​and the X-axis and Y-axis are swapped for easier understanding, it becomes Figure 1 (2). As shown in this figure, the penetration resistance value (X-axis) and elapsed time (Y-axis) can be expressed by a linear function formula as shown below, and if the slope A (slope information) and intercept B (intercept information) are obtained, the elapsed time can be calculated from the penetration resistance value.

[0022] Logarithm of elapsed time = A × (logarithm of penetration resistance) + B Formula (1)

[0023] As shown in the figure, the greater the slope A, the greater the logarithm of the elapsed time, and therefore the slower the concrete hardening rate. In other words, A tends to be smaller in the hot summer months and larger in the cold winter months. Also, as shown in Figure 1 (2), intercept B is the value where the logarithm of the penetration resistance value is 0.0 (zero), which corresponds to a penetration resistance value of 1 (N / mm 2 )

[0024] Figure 2 shows the relationship between the initial concrete temperature, obtained by taking samples from an agitator truck (concrete mixer) and actually measuring the penetration resistance, and the slope A and intercept B. The concrete used varies in construction time, measurement location, shipping plant, etc., but the type of concrete is general slab concrete, excluding special mixes. The initial concrete temperature in this figure is the temperature of the concrete taken from the agitator truck when it arrives at the casting site.

[0025] According to this figure, the correlation between the initial concrete temperature (X-axis) and the slope A (Y-axis) is not very good, but the correlation between the initial concrete temperature (X-axis) and the intercept B (Y-axis) is good. As mentioned above, the intercept B is the point where the logarithm of the penetration resistance is 0.0, that is, the penetration resistance is 1 (N / mm 2 ), by applying it to the above formula (1), the logarithm of the elapsed time can be calculated regardless of the slope A, and the elapsed time can be obtained by finding the exponential value of this value. In other words, by measuring the initial temperature of the concrete, the penetration resistance value 1 (N / mm 2 The time elapsed until the concrete was poured into the agitator can be calculated by adding the calculated time to the time of pouring water into the concrete, which is written on the mill sheet of the agitator vehicle, etc., to obtain the penetration resistance value 1 (N / mm 2 ) can be calculated. Note that for intercept B, the correlation is calculated using a logarithmic regression curve, but there is almost no difference in the correlation coefficient when using a linear regression curve. Therefore, either can be selected, but at this point it is acceptable to use a logarithmic regression curve, and then later, when more data is collected and the correlation with the linear regression curve improves, it can be changed to that at that point.

[0026] The penetration resistance is measured when the concrete is still soft (for example, when the measurement value can be obtained, 0.01 to 0.1 (N / mm 2 ) there is variability in the measured values, so the slope A tends not to be stable. In addition, the temperature of concrete is affected by the surrounding air temperature and solar radiation, and in summer and intermediate seasons the temperature gradually rises over time. On the other hand, in winter the temperature of concrete can gradually drop from the beginning. Therefore, it is desirable to determine the slope A at a point when as much data as possible has been obtained.

[0027] Figure 3(1) shows the penetration resistance values ​​1 (N / mm 2 The shortest time was 129 minutes, and the longest was 545 minutes. For example, as shown in Figure 3 (2), the start of the pressing work was when the penetration resistance value was 0.5 (N / mm 2 ), the work timing needs to be predicted before that time. On the other hand, if the time is predicted too early, the accuracy may be poor. Therefore, in the present invention, the penetration resistance value 1 (N / mm 2 ) is predicted using the following methods (1) to (4).

[0028] (1) Penetration resistance value 1 (N / mm 2 ) is subtracted a predetermined subtraction time (for example, 60 minutes) from the elapsed time. (2) Calculate the difference between the actual measured concrete temperature and the initial concrete temperature at the elapsed time in (1). (3) Since the temperature calculated in (2) has changed over the elapsed time in (1), the percentage of temperature change is calculated. (4) Using the rate of temperature change obtained in (3), the penetration resistance value 1 (N / mm 2 ) to calculate the predicted concrete temperature.

[0029] Figure 4 shows the penetration resistance value 1 (N / mm 2) shows the relationship between the predicted concrete temperature and the slope A. Comparing this figure with the relationship between the slope A and the initial concrete temperature shown in Figure 2 (1), it can be seen that the correlation is greatly improved. Penetration resistance value 1 (N / mm 2 ), the concrete temperature measurements taken after subtracting 60 minutes from the elapsed time show that the two points in the 20°C range indicated by the arrows are further from the approximation line than the other measurements, but this is because the data is from an intermediate period, and the temperature did not rise much after the time when the actual measurements were predicted, and rose much more than expected. This is due to weather changes at the time of measurement. Especially during periods with large fluctuations in temperature, such as intermediate periods, the penetration resistance value of 1 (N / mm 2 ) and the final concrete temperature. Therefore, in the current calculation of the slope A, the penetration resistance value 1 (N / mm 2 It is desirable to adopt the relationship shown in Figure 4, which is the concrete temperature measurement value obtained by subtracting 60 minutes from the elapsed time of the concrete temperature measurement. In addition, since there is a large fluctuation in temperature during periods when the range of fluctuation in temperature is large, it is desirable to have a shorter subtraction time, such as 30 or 20 minutes, rather than 60 minutes.

[0030] (Specific prediction steps) Next, a procedure for predicting the pressing timing during construction of a concrete slab using the prediction method according to this embodiment will be described.

[0031] As shown in FIG. 5, first, the initial temperature of concrete is measured from an agitator vehicle that has arrived at a pouring site, and the time of pouring water into the concrete is recorded by referring to the mill sheet of the agitator vehicle or the like (step S1).

[0032] Next, calculate the intercept B from the relationship in Figure 2 (2), and substitute the calculated intercept B into the above formula (1) to obtain the logarithm of the elapsed time. Then, add the exponential value of this value to the concrete pouring time to obtain the penetration resistance value 1 (N / mm 2 ) is calculated (step S2).

[0033] Next, the calculated penetration resistance value 1 (N / mm 2 The time is calculated by subtracting 60 minutes from the elapsed time of the above steps, and the concrete temperature at that time is measured (step S3).

[0034] Next, the slope A is calculated from the relationship in FIG. 4 (step S4).

[0035] Next, the start time of each holding work as shown in Fig. 3(2) is calculated, and the timing of holding down the concrete slab construction is managed (step S5). This makes it possible to predict the time and duration of each work (construction timing) before construction.

[0036] In this way, according to the prediction method of this embodiment, the timing for holding down the concrete slab can be easily predicted before construction by simply measuring the temperature of the concrete. Therefore, the time when construction preparation and holding down work can be performed can be easily understood. It is known from experience by workers and construction managers that concrete hardens quickly in hot summer months and slowly in cold winter months, and the advantage of using temperature to manage construction timing is that it is easy for anyone to imagine.

[0037] In addition, since the pressing timing can be known in advance, it is possible to utilize this information for preparation of workers and construction machinery and construction management. This allows for the construction of concrete slabs of consistent quality. In addition, by clarifying the end time of work, unnecessary work can be eliminated, leading to time savings.

[0038] The concrete targeted in the present invention is not limited to any particular type, so long as it is used for ordinary slabs, excluding special cases.

[0039] [Concrete construction timing prediction device] Next, an embodiment of the concrete construction timing prediction device according to the present invention will be described.

[0040] The concrete construction timing prediction device according to this embodiment is an embodiment of the above-mentioned method for predicting concrete construction timing as a device, and is composed of, for example, an input unit, an output unit, a calculation unit, a display unit, and a temperature measurement unit. The input unit, output unit, calculation unit, and display unit can be configured using hardware such as a computer having a CPU, a memory, and a display, and software such as a computer program that runs on this hardware. The temperature measurement unit can be configured by a thermometer that measures the temperature of concrete, or the like.

[0041] 6 is an example of an input / output screen of the concrete construction timing prediction device according to the present embodiment. A screen like this is displayed on a display unit such as a display.

[0042] The input section is an input cell consisting of four items on the left side of the screen. The cells are cell (1) for inputting the "water pouring time" of the concrete from the mill sheet, cell (2) for inputting the "measurement time" of the initial temperature of the concrete from the site, cell (3) for inputting the "initial temperature of the concrete," and cell (4) for inputting the penetration resistance value1 (N / mm 2 ) is used to input the "concrete temperature" 60 minutes before the time of the measurement. The input data for each cell is used for calculation processing in the calculation section. The data to be input is the four pieces of data listed above, and the other items are automatically calculated in the output section described below, and the slope A and intercept B can be obtained.

[0043] The output section is an output cell consisting of multiple items on the right side of the screen. Each cell is "Intercept B", "Penetration resistance value 1 (N / mm 2 ) and "Penetration resistance value 1 (N / mm 2 ) 60 minutes before, "Penetration resistance value 1 (N / mm 2 ) and "gradient A". Each cell outputs a calculated value calculated by the calculation unit.

[0044] The operation of the above configuration will be described. When the three items of "water pouring time", "measurement time" and "concrete initial temperature" are input to the input section, the calculation section performs calculation processing to calculate "intercept B" and to obtain "penetration resistance value 1 (N / mm 2 ) and "Penetration resistance value 1 (N / mm 2 ) to the time 60 minutes ago. These calculated values ​​are instantly output and displayed in each cell of the output section. After that, the penetration resistance value 1 (N / mm 2 ) and input the measured value into the "Concrete Temperature" field in the input section. The calculation section will process the data to obtain the "Penetration Resistance Value 1 (N / mm 2 ) and "predicted concrete temperature" and "slope A" are calculated. These calculated values ​​are instantly displayed in each cell of the output section. Note that the example in the figure shows a case where the water pouring time was 8:00, the measurement time was 9:31, the initial concrete temperature was 15.0°C, and the concrete temperature was 29.2°C, and the intercept B = 5.82 and slope A = 0.10 were calculated.

[0045] FIG. 7 is an example of a screen in which the construction timing for each task is calculated using the slope A and intercept B calculated in FIG. 6. When the slope A and intercept B are calculated, the calculation unit automatically calculates the start time for each task as shown in FIG. 7. Therefore, the user of this prediction device can easily understand the time of each task through this screen. In this example, the initial concrete temperature is measured at 9:31, and the concrete temperature at that time is measured at 12:37, and the time after 13:14 when people can stand on the concrete is calculated. The work ends at 14:43, which makes it less likely that problems such as peeling, cracking, and uneven coloring due to excessive pressing will occur, and the elimination of subsequent tasks also leads to time savings.

[0046] In this way, the prediction device of this embodiment can easily predict the timing of holding down a concrete slab before construction by simply measuring the temperature of the concrete. Also, since only four items of data need to be entered, the work is easy and anyone can easily obtain the time of the holding down timing.

[0047] [Concrete construction method] Next, an embodiment of the concrete construction method according to the present invention will be described taking as an example the case of constructing a concrete slab.

[0048] First, before constructing the concrete slab, the construction timing is predicted using the above-mentioned method for predicting the timing of concrete construction. This makes it possible to grasp the construction timing of each holding work before construction. As a result, construction timing information such as that shown in Figure 7 is obtained.

[0049] Next, fresh concrete is poured onto the formwork to construct the concrete slab. Then, referring to Figure 7, the construction timing is checked, and when it is time for people to stand on it (13:14), workers stand on the hardening concrete slab and carry out tasks such as bleeding water and processing the edges. This work is planned to be completed by the start time of the disk and top-heavy work (14:01). After that, the disk and top-heavy work is carried out, and when it is time to start the first trowel (14:21), the trowel is used to repeatedly press down the surface. After that, when it is time to start the second trowel (14:43), the trowel is used to finish the surface.

[0050] In this way, according to the present embodiment, it is possible to appropriately perform the pressing work on the surface of the concrete slab based on the construction timing predicted before construction, thereby enabling the construction of a concrete slab of consistent quality.

[0051] As described above, the method for predicting the timing of concrete construction according to the present invention is a method for predicting the timing suitable for carrying out a pressing operation before carrying out a pressing operation on the surface of concrete being constructed, and includes the steps of acquiring a concrete pouring time, measuring an initial temperature of the concrete, applying the measured initial temperature to intercept information of an approximation equation expressing the relationship between a penetration resistance value obtained by a predetermined penetration resistance test and elapsed time that is previously known, and the relationship between the initial temperature of the concrete, thereby obtaining intercept information corresponding to the measured initial temperature, applying the obtained intercept information to the approximation equation expressing the relationship between the penetration resistance value and elapsed time, thereby obtaining the elapsed time until the predetermined penetration resistance value is reached, and adding the obtained elapsed time to the water pouring time of the concrete, thereby estimating the elapsed time from the water pouring time until the predetermined penetration resistance value is reached, and calculating the time obtained by subtracting a predetermined subtraction time from the estimated elapsed time as the water pouring time of the concrete. a step of measuring the temperature of the concrete at a time obtained by adding the measured temperature of the concrete to the slope information of an approximation equation expressing the relationship between a penetration resistance value obtained by a predetermined penetration resistance test and the elapsed time, and the temperature of the concrete at the time when a predetermined subtraction time is subtracted from the elapsed time until the predetermined penetration resistance value is reached, thereby obtaining slope information corresponding to the measured temperature of the concrete; and a step of determining an approximation equation expressing the relationship between the penetration resistance value and the elapsed time using the obtained slope information and intercept information, obtaining the elapsed time by applying a penetration resistance value corresponding to the execution timing of the pressing work to the determined approximation equation, and predicting the time obtained by adding the obtained elapsed time to the concrete water pouring time as the execution timing of the pressing work. Therefore, by measuring the concrete water pouring time, initial temperature, and the concrete temperature at a predetermined time, it is possible to easily predict the execution timing of the subsequent pressing work.

[0052] According to another method for predicting the timing of concrete construction according to the present invention, the predetermined penetration resistance is 1 (N / mm 2) and the predetermined subtraction time is 60 minutes, so that an approximation formula expressing the relationship between the penetration resistance value and the elapsed time can be easily and accurately determined.

[0053] Furthermore, according to the concrete construction timing prediction device of the present invention, there is provided a device for predicting a construction timing suitable for carrying out a pressing operation before carrying out a pressing operation on the surface of concrete being constructed, comprising: means for acquiring a concrete water pouring time; means for measuring an initial temperature of the concrete; means for applying the measured initial temperature to the relationship between intercept information of an approximation equation expressing the relationship between a penetration resistance value obtained by a predetermined penetration resistance test and elapsed time that is previously understood, and the initial temperature of the concrete, to obtain intercept information corresponding to the measured initial temperature; means for obtaining the elapsed time until the predetermined penetration resistance value is reached by applying the obtained intercept information to the approximation equation expressing the relationship between the penetration resistance value and elapsed time, and adding the obtained elapsed time to the concrete water pouring time; and means for estimating the elapsed time from the water pouring time until the predetermined penetration resistance value is reached by subtracting a predetermined subtraction time from the estimated elapsed time, and adding the time obtained by subtracting the predetermined subtraction time to the concrete water pouring time. The concrete temperature measuring apparatus includes: a means for measuring the temperature of the concrete at the obtained time; a means for applying the measured concrete temperature to the relationship between the slope information of an approximation equation that expresses the relationship between a penetration resistance value obtained by a predetermined penetration resistance test that has been previously determined and the elapsed time, and the temperature of the concrete at the time when a predetermined subtraction time is subtracted from the elapsed time until the predetermined penetration resistance value is reached, thereby obtaining slope information corresponding to the measured concrete temperature; and a means for determining an approximation equation that expresses the relationship between the penetration resistance value and the elapsed time using the obtained slope information and intercept information, obtaining the elapsed time by applying a penetration resistance value that corresponds to the timing of the holding down work to the determined approximation equation, and predicting the time obtained by adding the obtained elapsed time to the concrete water pouring time as the timing of the holding down work, thereby making it possible to easily predict the timing of the subsequent holding down work by measuring the concrete water pouring time, initial temperature, and the concrete temperature at the predetermined time.

[0054] In addition, according to another concrete construction timing prediction device of the present invention, the predetermined penetration resistance value is 1 (N / mm 2 ) and the predetermined subtraction time is 60 minutes, so that an approximation formula expressing the relationship between the penetration resistance value and the elapsed time can be easily and accurately determined.

[0055] Furthermore, the concrete construction method according to the present invention includes the steps of predicting the timing of construction using the above-mentioned method for predicting the timing of concrete construction, pouring concrete, and carrying out pressing work on the surface of the concrete based on the predicted timing of construction, so that pressing work on the surface of the concrete can be carried out appropriately based on the predicted timing of construction before construction, thereby enabling concrete of stable quality to be constructed. [Industrial Applicability]

[0056] INDUSTRIAL APPLICABILITY As described above, the concrete construction timing prediction method, prediction device, and concrete construction method of the present invention are useful for the construction of concrete slabs, and are particularly suitable for predicting the construction timing of concrete slab holding down work.

Claims

1. A method for predicting a suitable construction timing for carrying out a pressing operation before carrying out a pressing operation on a surface of concrete being constructed, comprising: Obtaining a concrete pouring time; measuring the initial temperature of the concrete; A step of applying the measured initial temperature to a relationship between intercept information of a linear function that represents a relationship between a logarithm of a penetration resistance value obtained by a predetermined penetration resistance test and a logarithm of an elapsed time, and an initial temperature of concrete, thereby obtaining intercept information corresponding to the measured initial temperature; A step of applying the obtained intercept information to a linear function that expresses the relationship between the logarithm of the penetration resistance value and the logarithm of the elapsed time to obtain the elapsed time until the predetermined penetration resistance value is reached, and adding the obtained elapsed time to the time of pouring water into the concrete to estimate the elapsed time from the time of pouring water to the time of reaching the predetermined penetration resistance value; measuring the temperature of the concrete at a time obtained by adding a time obtained by subtracting a predetermined subtraction time from the estimated elapsed time to a time of pouring water into the concrete; A step of applying the measured concrete temperature to a relationship between slope information of a linear function that represents a relationship between a logarithm of a penetration resistance value obtained by a predetermined penetration resistance test and a logarithm of an elapsed time, and a concrete temperature at a time when a predetermined subtraction time is subtracted from the elapsed time until the predetermined penetration resistance value is reached, thereby obtaining slope information corresponding to the measured concrete temperature; a step of determining a linear function that expresses the relationship between the logarithm of the penetration resistance value and the logarithm of the elapsed time using the obtained slope information and intercept information, determining the elapsed time by applying the penetration resistance value corresponding to the timing of the holding down work to the determined linear function, and predicting the time obtained by adding the determined elapsed time to the time of pouring water into the concrete as the timing of the holding down work.

2. The predetermined penetration resistance is 1 (N / mm ２ 2. The method for predicting timing of concrete construction according to claim 1, wherein the predetermined subtraction time is 60 minutes.

3. A device for predicting a suitable construction timing for carrying out a pressing operation before carrying out a pressing operation on a surface of concrete being constructed, comprising: A means for acquiring a concrete pouring time; a means for measuring the initial temperature of the concrete; A means for applying the measured initial temperature to the relationship between intercept information of a linear function that represents the relationship between the logarithm of the penetration resistance value obtained by a predetermined penetration resistance test and the logarithm of the elapsed time, and the initial temperature of concrete, thereby obtaining intercept information corresponding to the measured initial temperature; a means for applying the obtained intercept information to a linear function that expresses the relationship between the logarithm of the penetration resistance value and the logarithm of the elapsed time, thereby obtaining the elapsed time until a predetermined penetration resistance value is reached, and adding the obtained elapsed time to the time of pouring water into the concrete, thereby estimating the elapsed time from the time of pouring water until the predetermined penetration resistance value is reached; A means for measuring the temperature of concrete at a time obtained by adding a time obtained by subtracting a predetermined subtraction time from the estimated elapsed time to a time of pouring water into the concrete; a means for applying the measured concrete temperature to a relationship between slope information of a linear function that represents a relationship between a logarithm of a penetration resistance value obtained by a predetermined penetration resistance test and a logarithm of an elapsed time, and a concrete temperature at a time when a predetermined subtraction time is subtracted from the elapsed time until the predetermined penetration resistance value is reached, thereby obtaining slope information corresponding to the measured concrete temperature; a means for determining a linear function that expresses the relationship between the logarithm of the penetration resistance value and the logarithm of the elapsed time using the obtained slope information and intercept information, determining the elapsed time by applying the penetration resistance value corresponding to the timing of the holding down work to the determined linear function, and predicting the time obtained by adding the determined elapsed time to the time of pouring water into the concrete as the timing of the holding down work.

4. The predetermined penetration resistance is 1 (N / mm ２ 4. The apparatus for predicting timing of concrete construction according to claim 3, wherein the predetermined subtraction time is 60 minutes.

5. 3. A method for constructing concrete, comprising the steps of: predicting construction timing using the method for predicting the timing of concrete construction according to claim 1 or 2; pouring concrete; and performing pressing work on the surface of the concrete based on the predicted construction timing.

Images