Method and apparatus for predicting construction timing of concrete compositions, and method for constructing concrete compositions

Abstract

To provide a method for predicting the construction timing of concrete compositions that can conveniently and efficiently predict the appropriate construction timing for leveling the surface of the concrete composition.SOLUTION: The method for predicting the appropriate construction timing for leveling the surface of a concrete composition, includes calculating the predicted elapsed time until the concrete composition reaches a predetermined penetration resistance value from the time water is added to the concrete composition, using a relationship formula that shows the relationship between the concrete composition mixing temperature, the ambient temperature during placement of the concrete composition, and the predetermined penetration resistance value of the concrete composition.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a method and apparatus for predicting the timing of application of a concrete composition, and a method for applying a concrete composition. [Background technology]

[0002] Precast concrete slabs are used as concrete slabs for expressways, bridges, etc. Precast concrete slabs are arranged with gaps between them, and are joined together by pouring filler concrete into the gaps and constructing slab joints. A composition containing fine aggregate and coarse aggregate has been proposed as filler concrete for connecting a pair of precast concrete slabs facing each other across such a gap (see Patent Document 1).

[0003] In addition, deck joints often have a slope. When constructing a deck joint with a slope, a restraining tool (a formwork restrainer) is required to prevent the concrete composition from flowing out of the formwork after being poured into the formwork.

[0004] Air bubbles may form in the concrete composition after it is poured, and large bubbles may appear on the top surface. Also, if the construction site has a slope, the concrete composition may become uneven within the formwork, causing settling at the top of the slope. For this reason, finishing (leveling) work must be carried out after the clamping devices are removed. Leveling work must be carried out when the concrete composition has hardened to a degree that it will not flow out of the formwork, but is not too hard, so the timing of removing the clamping devices is important.

[0005] The timing for removing the clamping tool generally requires a skilled worker to judge the timing based on their sense and experience, such as the hardness of the concrete composition when touched, its apparent color, and the occurrence of bleeding water. In recent years, a shortage of skilled workers has made this approach to construction unviable, potentially leading to a decline in the quality of concrete construction. Furthermore, the hardening of a concrete composition is also affected by environmental conditions such as curing temperature. During high temperatures, the concrete composition hardens quickly, which can lead to delayed removal of the clamping tool, resulting in excessive hardness and making leveling difficult. Conversely, during low temperatures, the concrete composition hardens slowly, resulting in premature removal of the clamping tool, which can cause problems such as peeling of the concrete composition's surface. Thus, while managing the timing for removing the clamping tool is extremely important in the construction of concrete compositions, there is a problem in that it is difficult to determine the timing.

[0006] One method for checking the hardening state of concrete compositions is the JIS penetration resistance test (JIS A 1147:2019). This involves sieving mortar from concrete through a 4.75mm mesh sieve as a test specimen, and determining the penetration resistance value when a specified penetration needle is inserted vertically. According to this method, the measurement results are plotted and the hardening state of concrete is calculated based on the initial time (when the penetration resistance value is 3.5N / mm 2 Time until the penetration resistance reaches 28.0 N / mm 2 The slope A, intercept B, and approximate equation can be determined from the approximate curve of these plots. This method requires placing a sample formwork at the construction site, curing the concrete composition to be used at the construction site in the sample formwork, and conducting a penetration resistance test at predetermined intervals (for example, every 30 minutes to 1 hour) to observe the progress. However, this observation can take more than 10 hours, which is very time-consuming. Furthermore, the penetration resistance value appropriate for leveling work varies depending on the composition of the concrete composition, so ultimately, as mentioned above, an experienced worker must determine the appropriate timing for leveling work.

[0007] Therefore, there is a need for a prediction method and a prediction device that can easily and efficiently predict the appropriate construction timing for leveling the surface of a concrete composition in order to remove the holding tool and perform leveling work. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2022-79221 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention aims to solve the above-mentioned problems of the prior art and to achieve the following object: That is, the present invention aims to provide a method and a prediction device for predicting the timing of application of a concrete composition, which can simply and efficiently predict the timing appropriate for leveling the surface of a concrete composition, and a simple and efficient method for applying a concrete composition. [Means for solving the problem]

[0010] A method for predicting the timing of application of a concrete composition (hereinafter, sometimes abbreviated as "prediction method") as a means for solving the above-mentioned problem is a method for predicting the appropriate timing of application for leveling the surface of a concrete composition, and is characterized in that it includes calculating a predicted elapsed time from the time water is poured into the concrete composition until the concrete composition reaches the predetermined penetration resistance value, using a relational equation that shows the relationship between the mixed temperature of the concrete composition, the ambient temperature at the time of pouring the concrete composition, and a predetermined penetration resistance value of the concrete composition. [Effects of the Invention]

[0011] According to the present invention, it is possible to solve the above-mentioned problems in the prior art, achieve the above-mentioned object, and provide a method and device for predicting the timing of application of a concrete composition, which can simply and efficiently predict the appropriate application timing for leveling the surface of a concrete composition, as well as a simple and efficient method for application of a concrete composition. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a flowchart showing one embodiment of the method of predicting the timing of application of a concrete composition according to the present invention. [Figure 2] FIG. 2 is a diagram showing one embodiment of an input / output screen of the device for predicting the timing of application of a concrete composition according to the present invention. [Figure 3] 3 is a graph showing the relationship between the average penetration resistance value (N / mm2) and the time (h) elapsed from the time of water pouring in Test Example 2-2. The vertical axis represents the average penetration resistance value (N / mm2), and the horizontal axis represents the time (h) elapsed from the time of water pouring. [Figure 4] Fig. 4 is a graph showing the relationship between the average penetration resistance value (N / mm2) and the time (h) elapsed from the time of pouring water under conditions 1 to 8, which were obtained by changing the combination of the mixing temperature and curing temperature of the concrete composition in Test Example 3. The vertical axis represents the average penetration resistance value (N / mm2), and the horizontal axis represents the time (h) elapsed from the time of pouring water. [Figure 5] Figure 5 is a diagram illustrating "tangent line a" passing through the point on the graph where the average penetration resistance value is 1.0 N / mm2, "tangent line b" passing through the point where the elapsed time from the time of water pouring is 0 hours and passing through the point where the average penetration resistance value is 0 N / mm2 (i.e., the origin), and "intersection X" between tangent line a and tangent line b, based on a graph that extracts only condition 2 (curing at 22°C-20°C) from Figure 4. The vertical axis represents the average penetration resistance value (N / mm2), and the horizontal axis represents the elapsed time (h) from the time of water pouring. [Figure 6]Figure 6 is a graph in which the relationship between the ratio [ambient temperature / as-mixed temperature] for conditions 1 to 8, which varied the combination of the as-mixed temperature and curing temperature of the concrete composition in Test Example 3, and the time (h) elapsed from the time of pouring water indicated by the intersection point X for each of conditions 1 to 8 is plotted, and an approximate curve is drawn. The vertical axis represents the ratio [ambient temperature / as-mixed temperature], and the horizontal axis represents the time (h) elapsed from the time of pouring water indicated by the intersection point X. Relational formula (1-4) can be derived from this approximate curve. [Figure 7] Figure 7 is a graph in which the relationship between the average penetration resistance value corresponding to the elapsed time (h) from the time of water pouring in Figure 4 and the ratio [elapsed time from the time of water pouring / elapsed time from the time of water pouring indicated by intersection X] is plotted and an approximate curve is drawn. The vertical axis represents the average penetration resistance value (N / mm2), and the horizontal axis represents the ratio [elapsed time from the time of water pouring / elapsed time from the time of water pouring indicated by intersection X]. This approximate curve derives the relational expression (2-3). DETAILED DESCRIPTION OF THE INVENTION

[0013] The method and device for predicting the timing of application of a concrete composition, and the method for application of a concrete composition of the present invention will be described in detail below. Note that the present invention is not limited to the embodiments shown below, and can be modified within the scope of what a person skilled in the art can conceive, such as other embodiments, additions, modifications, or deletions. Any embodiment is within the scope of the present invention as long as it exhibits the functions and effects of the present invention.

[0014] (Method for predicting timing of concrete composition construction) The method for predicting the application timing of a concrete composition of the present invention is a method for predicting the appropriate application timing for leveling the surface of a concrete composition, and includes calculating a predicted elapsed time from the time water is poured into the concrete composition until the concrete composition reaches the predetermined penetration resistance value, using a relational equation that shows the relationship between the mixed temperature of the concrete composition, the ambient temperature at the time of pouring the concrete composition, and a predetermined penetration resistance value of the concrete composition, and further includes other steps as necessary.

[0015] The relational expression includes step 1 (S1): a step of determining the pouring time when water is added to the raw materials of the concrete composition; step 2 (S2): a step of measuring the penetration resistance of the concrete composition corresponding to a plurality of combinations of the as-mixed temperature when the concrete composition is mixed and the ambient temperature when the mixed concrete composition is poured into a form; step 3 (S3): a step of determining a relationship I between the penetration resistance and the elapsed time from the pouring of water; step 4 (S4): a step of determining, based on the relationship I, a tangent a passing through a predetermined point of the penetration resistance appropriate for leveling the surface of the concrete composition for each of a plurality of combinations of the as-mixed temperature and the ambient temperature; step 5 (S5): a step of determining, based on the relationship I, a tangent b passing through the origin at which the elapsed time from the pouring of water is 0 hours for each of a plurality of combinations of the as-mixed temperature and the ambient temperature; step 6 (S6): a step of determining the tangent a and the It is preferable that the calculation is performed by the following steps: determining an intersection X with the tangent line b for each of a plurality of combinations of the as-mixed temperature and the ambient temperature; step 7 (S7): determining a ratio [ambient temperature / as-mixed temperature] obtained by dividing the ambient temperature by the as-mixed temperature for each of the plurality of combinations of the as-mixed temperature and the ambient temperature in step 2; step 8 (S8): determining a relationship II between the time elapsed from the time of water-pouring indicated by the intersection X and the ratio [ambient temperature / as-mixed temperature]; step 9 (S9): determining a ratio [time elapsed from the time of water-pouring / time elapsed from the time of water-pouring indicated by the intersection X] obtained by dividing the time elapsed from the time of water-pouring based on the relationship I by the time elapsed from the time of water-pouring indicated by the intersection X; and step 10 (S10): determining a relationship III between the ratio [time elapsed from the time of water-pouring / time elapsed from the time of water-pouring indicated by the intersection X] and the penetration resistance value corresponding to the time elapsed from the time of water-pouring based on the relationship I.

[0016] Further, the calculation of the predicted elapsed time is carried out by step 11 (S11): calculating a predicted elapsed time from the time of pouring water until the penetration resistance value appropriate for leveling the surface of the concrete composition is reached, based on the penetration resistance value appropriate for leveling the surface of the concrete composition from the relationship III and the elapsed time from the time of pouring water indicated by the intersection X derived from the relationship II.

[0017] It is also preferable that the prediction method further includes step 12 (S12): adding the predicted elapsed time from the time of pouring water calculated in step 11 until the penetration resistance value appropriate for leveling the surface of the concrete composition is reached to the actual time recorded at the time of pouring water in step 1, and determining the time to start the leveling work.

[0018] Furthermore, the prediction method may further include, before step 4 (S4), step 13 (S13): determining a range of penetration resistance values ​​appropriate for leveling the surface of the concrete composition.

[0019] A flowchart showing one embodiment of the method for predicting the timing of application of a concrete composition of the present invention is shown in Figure 1. Hereinafter, the method for predicting the timing of application of a concrete composition of the present invention will be described with reference to Figure 1.

[0020] <Process 1 (S1)> The step 1 (S1) is a step of determining the water pouring time for adding water to the raw materials of the concrete composition. Hereinafter, the step 1 (S1) may be referred to as a "water pouring time determining step."

[0021] The water-pouring time determination step (S1) determines the "reference time (0 hours)" of the time elapsed from the next step onwards. Therefore, the "elapsed time" in the next step onwards means the time elapsed from this "water-pouring time".

[0022] In the present invention, the term "at the time of pouring water" means the time when the water is added to the raw materials of the concrete composition.

[0023] In the water pouring time determination step (S1), the actual time (T hours, t minutes) when the water is added to the raw materials of the concrete composition may be recorded together with the "reference time (0 hours)." This allows the start time of the leveling work to be determined in step 12 (S12).

[0024] <<Concrete Composition>> The concrete composition is not particularly limited and can be appropriately selected from raw materials for known concrete compositions. It preferably contains aggregates such as fine aggregate and coarse aggregate, and water, and may further contain other components as necessary.

[0025] -aggregate- The aggregate is not particularly limited as long as it can be used in a concrete composition and can be appropriately selected depending on the purpose, and examples thereof include natural aggregate, semi-artificial aggregate, lightweight aggregate, etc. These may be used alone or in combination of two or more.

[0026] Examples of the natural aggregate include river sand, river gravel, sea sand, sea gravel, mountain sand, mountain gravel, etc. These may be used alone or in combination of two or more.

[0027] Examples of the semi-artificial aggregate include crushed sand, crushed stone, etc. These may be used alone or in combination of two or more.

[0028] Examples of the lightweight aggregate include slag aggregate, artificial aggregate, etc. These may be used alone or in combination of two or more.

[0029] The aggregate is divided into fine aggregate and coarse aggregate depending on its particle size. In the present invention, "fine aggregate" means aggregate that passes entirely through a 10 mm mesh sieve and 85% by mass or more of which passes through a 5 mm mesh sieve, as defined in JIS A 0203:2014 (concrete terminology). In addition, in the present invention, "coarse aggregate" means aggregate of which 85% by mass or more is retained on a 5 mm mesh sieve, as defined in JIS A 0203:2014 (concrete terminology).

[0030] -Fine aggregate- The fine aggregate is not particularly limited, and can be appropriately selected from the examples of aggregates given above depending on the target mechanical strength of the hardened concrete composition.

[0031] Specific examples of the fine aggregate include crushed stone and crushed sand as specified in JIS A 5005:2020 (Crushed stone and crushed sand for concrete); ferronickel slag such as those conforming to FNS1.2A or FNS5A as specified in JIS A 5011-2:2016 (Slag aggregate for concrete - Part 2); copper slag as specified in JIS A 5011-3:2016 (Slag aggregate for concrete - Part 3); and electric furnace oxidizing slag such as those conforming to EFS1.2 N or H as specified in JIS A 5011-4:2016 (Slag aggregate for concrete - Part 4). Since these are all by-product-derived materials, using them as ingredients in concrete compositions can contribute to reducing the burden on the global environment.

[0032] Among these, the fine aggregate preferably contains a slag-based fine aggregate, and more preferably contains ferronickel slag. The fine aggregate containing ferronickel slag may be partly or entirely ferronickel slag, but it is preferable that the entire fine aggregate is ferronickel slag.

[0033] The ferronickel slag is obtained by slowly cooling molten slag, which is a by-product of smelting ferronickel, or by quenching it with water or air, and then adjusting the particle size to be used as fine aggregate for concrete. This slag has a significant effect of suppressing autogenous shrinkage, and can reduce the possibility of cracks occurring in concrete.

[0034] The water absorption rate of the fine aggregate is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1.50% or more, more preferably 2.0% or more. There is also no particular upper limit to the water absorption rate of the fine aggregate. The water absorption rate of the fine aggregate can be calculated by the following formula (A-1). Water absorption rate of fine aggregate (%) = water absorption amount of fine aggregate / bone dry mass of fine aggregate × 100 Formula (A-1) In the formula (A-1), the "water absorption amount of fine aggregate" indicates the mass of water when the surface of the fine aggregate is in a dry state (surface-dry state) and the voids inside the fine aggregate are saturated with water, and the "bone-dry mass of fine aggregate" indicates the mass of the fine aggregate in a bone-dry state.

[0035] The bone dry density of the fine aggregate is not particularly limited and can be appropriately selected depending on the purpose. 3 More than 2.7g / cm is preferable. 3 The above is more preferable. There is no particular limitation on the upper limit of the bone dry density of the fine aggregate. The bone dry density of the fine aggregate can be calculated by the following formula (A-2). Bone-dry density of fine aggregate (g / cm 3 ) = Mass of fine aggregate in bone dry state [g] / Volume of fine aggregate in bone dry state [cm 3 ] ... Formula (A-2)

[0036] The content of the fine aggregate in the concrete composition is not particularly limited and can be selected appropriately depending on the purpose, but a mortar fine aggregate volume ratio of 22% to 41% is preferable in terms of ensuring good fluidity. In the present invention, the "mortar fine aggregate volume ratio" is a value obtained by dividing the volume of fine aggregate by the total volume of water, binder, and fine aggregate, and is expressed by the following formula. Mortar fine aggregate volume ratio = fine aggregate volume / (total volume of water, binder, and fine aggregate)

[0037] -Coarse aggregate- The coarse aggregate is not particularly limited, and can be appropriately selected from the examples of aggregates given above depending on the target mechanical strength of the hardened product of the concrete composition.

[0038] Specific examples of the coarse aggregate include coarse aggregate conforming to crushed stone 2015, crushed stone 2013, crushed stone 2010, crushed stone 1505, crushed stone 1305 of JIS A 5005:2020 (crushed stone and crushed sand for concrete) or No. 5 or 6 of JIS A 5001:2008 (crushed stone for roads), natural coarse aggregates such as crushed hard sandstone, crushed andesite, crushed basalt, and crushed quartz schist; coarse aggregate conforming to ferronickel slag aggregate (a by-product of ferronickel production) of JIS A 5011-2:2016 (slag aggregate for concrete - Part 2), and artificial coarse aggregates derived from by-products such as artificial corundum and sintered bauxite.

[0039] The surface dry density of the coarse aggregate is not particularly limited and can be appropriately selected depending on the purpose. 3 The above is preferable. There is no particular limitation on the upper limit of the surface dry density of the coarse aggregate. The surface dry density of the coarse aggregate can be calculated by the following formula (A-3). Surface dry density of coarse aggregate (g / cm 3 ) = Mass of coarse aggregate in surface-dry state [g] / Volume of coarse aggregate in surface-dry state [cm 3 ] ... Formula (A-3)

[0040] The content of the coarse aggregate in the concrete composition is not particularly limited and can be appropriately selected depending on the purpose. 3 is preferred. In the present invention, the term "unit coarse aggregate absolute volume (L / m)" is used. 3 )" refers to the hardened concrete composition of 1 m 3 This means the volume (L) of the coarse aggregate required to produce the concrete.

[0041] -water- The water is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include pure water, tap water, well water, mineral water, hot spring water, spring water, fresh water, etc., as well as waters obtained by subjecting these to various treatments, etc. These may be used alone or in combination of two or more types. The treatments to be applied to the water include, for example, purification, heating, sterilization, filtration, ion exchange, adjustment of osmotic pressure, etc. Therefore, the water also includes purified water, hot water, ion-exchanged water, etc.

[0042] The content of the water in the concrete composition is not particularly limited and can be appropriately selected depending on the purpose. 3 ~175kg / m 3 is preferred. In the present invention, the unit water content (kg / m 3 )" refers to the hardened concrete composition of 1 m 3 This refers to the mass (kg) of water required to produce the product.

[0043] -Other ingredients- The other components of the concrete composition are not particularly limited as long as they are used in concrete compositions and can be appropriately selected depending on the purpose, and examples thereof include binders, fibers, chemical admixtures, gypsum, expansive agents, shrinkage-reducing agents, synthetic resin powders, synthetic resin fibers, polymers, monomers, oligomers, limestone fine powder, fluidizing agents, setting accelerators, setting retarders, etc. These may be used alone or in combination of two or more.

[0044] --Binding material-- The binder is not particularly limited as long as it can be used as a binder for concrete compositions, and can be appropriately selected depending on the purpose, and examples thereof include cement, siliceous fine powder, etc. These may be used alone or in combination of two or more.

[0045] ---cement--- The cement is not particularly limited and can be appropriately selected depending on the purpose. Examples include Portland cement (normal, moderate heat, low heat, early strength, ultra-early strength, sulfate-resistant, etc.), mixed cements such as blast furnace cement, fly ash cement, and silica cement; ultra-rapid hardening cements such as alumina cement and jet cement; and Irwin cement. These may be used alone or in combination of two or more. Of these, moderate heat Portland cement is preferred.

[0046] The density of the cement is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 2.5 g / cm 3 More than 3.5g / cm is preferable. 3 The above is more preferable. There is no particular upper limit to the density of the cement.

[0047] The content of the cement in the concrete composition is not particularly limited and can be selected appropriately depending on the purpose, but it is preferably 55% by volume relative to the total powder in the concrete composition (the total volume of cement and siliceous fine powder).

[0048] ---Silica fine powder--- The siliceous fine powder is not particularly limited and can be appropriately selected depending on the purpose. Examples include silica fume, which is a by-product in the production of metallic silicon or ferrosilicon; siliceous fine powder, which is a by-product in the production of silica glass, etc.; amorphous siliceous fine powder synthesized from silicon or silicon dioxide; and fly ash, which has been classified or pulverized to a particle size of 1 μm or less and has enhanced pozzolanic activity. These may be used alone or in combination of two or more. Among these, the siliceous fine powder preferably includes fly ash and silica fume, and has an SiO content of 85% by mass or more and a specific surface area by BET method of 15 m, which conforms to the quality standard of JIS A 6207:2016 (Silica fume for concrete). 2It is more preferable that the concrete composition contains silica fume at a concentration of 1 / 2 g or more. Since these materials are by-products, using them as ingredients in concrete compositions can contribute to reducing the burden on the global environment.

[0049] The density of the siliceous fine powder is not particularly limited and can be appropriately selected depending on the purpose. 3 The above is preferable. There is no particular upper limit to the density of the siliceous fine powder.

[0050] The content of the siliceous fine powder in the concrete composition is not particularly limited and can be selected appropriately depending on the purpose, but a volume ratio of 45% relative to the total powder in the concrete composition (total volume of cement and siliceous fine powder) is preferred.

[0051] --fiber-- The fibers are not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include metal fibers, carbon fibers, glass fibers, and vinylon fibers. These may be used alone or in combination of two or more. Among these, metal fibers are preferred, and steel fibers are more preferred.

[0052] The diameter and length of the fibers are not particularly limited and can be appropriately selected depending on the purpose, but short fibers with a diameter of 0.1 mm to 1 mm and a length of 10 mm to 70 mm are preferred.

[0053] The volume ratio of the fibers in the concrete composition is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.1% by volume to 1.5% by volume relative to the total volume of the concrete composition.

[0054] --Chemical admixtures-- The chemical admixture is not particularly limited and can be appropriately selected depending on the purpose. Examples include polycarboxylic acid-based high-performance water-reducing agents and polyoxyalkylene alkyl ether-based antifoaming agents. These may be used alone or in combination of two or more. Among these, polycarboxylic acid-based high-performance water-reducing agents with a high water-reducing rate are preferred. The chemical admixture may be in powder form or liquid form.

[0055] The content of the chemical admixture in the concrete composition can be adjusted appropriately depending on the intended fluidity of the concrete composition, but is preferably 0.5% by mass or more and 4.0% by mass or less relative to the total mass of the hydraulic binder consisting of the fine aggregate, the coarse aggregate, the cement, the siliceous fine powder, etc.

[0056] The content of the antifoaming agent in the concrete composition can be adjusted appropriately depending on the target air content of the concrete composition, etc., but is preferably 0.01 mass % or more and 0.5 mass % or less based on the total mass of the hydraulic binder consisting of the fine aggregate, the coarse aggregate, the cement, the siliceous fine powder, etc.

[0057] --plaster-- The gypsum can be derived from a by-product, and examples thereof include flue gas desulfurization gypsum dihydrate, which is a by-product of flue gas desulfurization at thermal power plants, etc., hydrofluoric anhydrous gypsum, which is a by-product of hydrofluoric acid production, phosphogypsum, which is a by-product of phosphoric acid production, and titanium gypsum, which is a by-product of titanium oxide production. These may be used alone or in combination of two or more. Using a material derived from a by-product as the gypsum is preferable in that it can contribute to reducing the burden on the global environment.

[0058] The form of the gypsum is not particularly limited as long as it does not contain excessive amounts of components harmful to the concrete composition, such as chloride ions and sodium ions, and may be gypsum anhydride or gypsum dihydrate.

[0059] The method for preparing the concrete composition is not particularly limited, and any known preparation method can be used. For example, a method in which powder components such as pre-fine aggregate, the coarse aggregate, and the other components are placed in a container, and then water is added and the mixture is kneaded can be used.

[0060] The method for kneading the concrete composition is not particularly limited as long as the materials for the concrete composition are mixed uniformly, and the concrete composition may be kneaded manually or using a known device such as a mixer.

[0061] <Process 2 (S2)> The step 2 (S2) is a step of measuring the penetration resistance of the concrete composition corresponding to a plurality of combinations of the mixed temperature when the concrete composition is mixed and the ambient temperature when the mixed concrete composition is poured into a formwork. Hereinafter, the step (S2) may be referred to as a "penetration resistance measurement step."

[0062] In the present invention, the term "at the time of completion of mixing" refers to the point at which mixing of the concrete composition is completed. Completion of mixing of the concrete composition means that the slump flow value of the concrete composition is within the range of 675 mm ± 50 mm. The slump flow value is measured by mixing the concrete composition with a known mixing means such as a mixer, and conducting a test in accordance with JIS A 1150:2020 (Test method for slump flow of concrete) at the time when the concrete composition is discharged from the mixing means.

[0063] The mixing temperature is not particularly limited and can be selected appropriately depending on the temperature (ambient temperature) at the construction site, but is preferably 5°C to 40°C, more preferably 15°C to 40°C, even more preferably 15°C to 36°C, even more preferably 15°C to 35°C, and particularly preferably 19°C to 35°C.

[0064] The mixed temperature may be set and determined in advance by a user of the prediction method, or may be determined at the construction site from the temperature measured after mixing the concrete composition.

[0065] The method for measuring the kneaded temperature is not particularly limited, and it can be measured using a known thermometer. The thermometer may be attached to the container used in the water-pouring time determining step (S1).

[0066] In the present invention, the "ambient temperature" refers to the ambient temperature when the mixed concrete composition is poured into a formwork, and preferably refers to the ambient temperature when the mixed concrete composition is poured into a formwork and a pressing operation is performed on the surface of the concrete composition using a pressing tool. In the present invention, the terms "ambient temperature" and "curing temperature" have the same meaning.

[0067] The ambient temperature is not particularly limited and can be appropriately selected depending on the season, climate, etc., but is preferably 5°C to 45°C, and more preferably 5°C to 35°C. The method for measuring the atmospheric temperature is not particularly limited, and the temperature can be measured using a known thermometer.

[0068] The ambient temperature is preferably determined based on the air temperature measured at the construction site during construction, but may also be determined based on the predicted air temperature based on a weather forecast or the like when planning construction.

[0069] The hardening rate of the concrete composition is affected by temperature conditions. These temperature conditions include the mixing temperature of the concrete composition and the ambient temperature. Therefore, in order to accommodate various mixing conditions depending on the composition of the concrete composition and various ambient temperatures depending on the location, season, climate, etc., when pouring, data on the penetration resistance of the concrete composition corresponding to multiple combinations of the mixing temperature and the ambient temperature can be obtained, thereby enabling more accurate prediction of the construction timing. Therefore, in the penetration resistance measurement step (S2), it is necessary to measure the penetration resistance of the concrete composition corresponding to each of multiple combinations of the mixing temperature and the ambient temperature.

[0070] In the present invention, the penetration resistance value is measured by a predetermined penetration resistance test. That is, the penetration resistance value in the present invention is a penetration resistance value per unit area (N / mm ) measured in accordance with JIS A 1147:2019 (Concrete Setting Time Test Method) by using a known penetration resistance tester (for example, a digital Proctor penetration resistance tester S-221 manufactured by Nishinippon Testing Instruments Co., Ltd.) and pressing the tip of a penetration needle to a depth of 25 mm from the surface of the concrete composition for 10 seconds. 2 ) means

[0071] In order to more accurately predict the timing of construction, it is preferable to measure the penetration resistance at a plurality of arbitrarily selected points on the surface of the concrete composition for one combination of the as-mixed temperature and the ambient temperature by the penetration resistance test, calculate the average of the penetration resistance values ​​at the plurality of points, and use this "average penetration resistance value" as the penetration resistance value in the penetration resistance value measurement step (S2). The number of arbitrarily selected points when calculating the average penetration resistance value is not particularly limited as long as it is two or more, and is preferably three or more.

[0072] When a pressing operation using a pressing tool is performed on the surface of the concrete composition, the pressing tool must be removed before measuring the penetration resistance value. Therefore, the formwork may be prepared as a sample formwork separate from the formwork at the construction site, and the penetration resistance value may be measured experimentally using the sample formwork.

[0073] Since the concrete composition is uniformly mixed in the water pouring time determining step (S1), the concrete composition hardens uniformly as a whole. Therefore, in the prediction method, the size of the sample formwork is not particularly limited and may be different in size from the formwork at the construction site, for example, a rectangular formwork with an inner diameter of 15 cm in height, 15 cm in width, and 53 cm in length.

[0074] <Process 3 (S3)> The step (S3) is a step of determining the relationship I between the penetration resistance value and the elapsed time from the time of pouring water. Specifically, this is a step of determining the relationship I between the penetration resistance value of the concrete composition corresponding to a plurality of combinations of the as-mixed temperature and the ambient temperature and the elapsed time from the time of pouring water. Hereinafter, the step (S3) may be referred to as the "relationship I determination step."

[0075] The penetration resistance values ​​of the concrete composition corresponding to a plurality of combinations of the as-mixed temperature and the ambient temperature are obtained in the penetration resistance value measuring step (S2).

[0076] Specifically, the relationship I can be determined by plotting the penetration resistance of the concrete composition corresponding to a given combination of the as-mixed temperature and the ambient temperature on the vertical axis and the time elapsed since the pouring of water for the concrete composition corresponding to the given combination of the as-mixed temperature and the ambient temperature on the horizontal axis. In this case, the penetration resistance is measured over time from the pouring of water for one combination of the as-mixed temperature and the ambient temperature and plotted.

[0077] <Process 4 (S4)> Step 4 (S4) is a step of determining, for each of a plurality of combinations of the as-mixed temperature and the ambient temperature, a tangent a that passes through a predetermined point of penetration resistance appropriate for leveling the surface of the concrete composition, based on the relationship I. Hereinafter, step 4 (S4) may be referred to as the "tangent a determination step."

[0078] The tangent line a passes through a predetermined point of the penetration resistance value appropriate for leveling the surface of the concrete composition, and therefore, in the graph in the relationship I determination step (S3), it is a linear function that has an intersection with the horizontal axis indicating the elapsed time from the time of pouring water (i.e., in the graph in the relationship I determination step (S3), it does not have an intersection with the vertical axis indicating the penetration resistance value). The penetration resistance value appropriate for leveling the surface of the concrete composition has a certain range, as described in the penetration resistance value range determination step (S13) described later, and therefore the slope of the tangent line a changes depending on the desired penetration resistance value.

[0079] <Process 5 (S5)> Step 5 (S5) is a step of determining, for each of a plurality of combinations of the mixing temperature and the ambient temperature, a tangent line b that passes through the origin at which the elapsed time from the water pouring time is 0 hours, based on the relationship I. Hereinafter, step 5 (S5) may be referred to as a "tangent line b determination step."

[0080] The tangent line b is a linear function that passes through the point where the elapsed time from the time of water injection is 0 hours, and in the graph in the relationship I determining step (S3), the penetration resistance value is 0 N / mm 2 It is a linear function that passes through the point (i.e., the origin). As described in the penetration resistance measurement step (S2), the penetration resistance value of the concrete composition varies depending on the combination of the mixing temperature and the ambient temperature, and therefore the slope of the tangent line b varies depending on the combination of the mixing temperature and the ambient temperature.

[0081] <Process 6 (S6)> The step 6 (S6) is a step of determining an intersection X between the tangent line a and the tangent line b for each of a plurality of combinations of the mixing temperature and the ambient temperature. Hereinafter, the step 6 (S6) may be referred to as an "intersection X determination step."

[0082] The tangent line a determined in the tangent line a determining step (S4) and the tangent line b determined in the tangent line b determining step (S5) have different slopes and therefore have an intersection point X. In the intersection X determination step (S6), an intersection X between the tangent a determined in the tangent a determination step (S4) and the tangent b determined in the tangent b determination step (S5) is determined for each combination of the kneading temperature and the atmosphere temperature, thereby obtaining the intersection X for a plurality of conditions of the combination of the kneading temperature and the atmosphere temperature.

[0083] <Process (S7)> The step 7 (S7) is a step of determining a ratio [ambient temperature / as-kneaded temperature] obtained by dividing each of the ambient temperatures by the as-kneaded temperatures for a plurality of combinations of the as-kneaded temperatures and the ambient temperatures in the penetration resistance value measuring step (S2). Hereinafter, the step 7 (S7) may be referred to as a "ratio [ambient temperature / as-kneaded temperature] determining step."

[0084] The "ambient temperature" and "as-kneaded temperature" in the ratio [ambient temperature / as-kneaded temperature] are temperatures obtained in the penetration resistance value measuring step (S2).

[0085] <Step 8 (S8)> Step 8 (S8) is a step of determining the relationship II between the time elapsed from the time of water pouring indicated by the intersection X and the ratio [ambient temperature / mixed temperature]. Hereinafter, step 8 (S8) may be referred to as the "relationship II determination step."

[0086] The intersection X is obtained in the intersection X determination step (S6), and the time elapsed from the time of water pouring corresponding to the intersection X is derived from the relationship I determined in the relationship I determination step (S3). Specifically, the time elapsed from the time of water pouring corresponding to the intersection X is obtained from the graph in the relationship I determination step (S3).

[0087] The ratio [ambient temperature / as-kneaded temperature] is obtained by the ratio [ambient temperature / as-kneaded temperature] determination step (S7).

[0088] Specifically, the relationship II is a linear function that can be determined by plotting a graph in which the vertical axis represents the ratio [ambient temperature / mixed temperature] and the horizontal axis represents the time elapsed since the water was poured, which corresponds to the intersection point X. The slope and intercept of this linear function change depending on the composition of the concrete composition, etc.

[0089] <Step 9 (S9)> Step 9 (S9) is a step of determining the ratio [time elapsed since water pouring / time elapsed since water pouring indicated by intersection X] obtained by dividing the time elapsed since water pouring based on the relationship I by the time elapsed since water pouring indicated by intersection X. Hereinafter, step 9 (S9) may be referred to as a "ratio [time elapsed since water pouring / time elapsed since water pouring corresponding to intersection X] determination step."

[0090] For the "time elapsed from the time of water pouring" in the ratio [time elapsed from the time of water pouring / time elapsed from the time of water pouring corresponding to intersection X], a numerical value is substituted for each plot in the graph in the relationship I determination step (S3) for a predetermined combination of the as-mixed temperature and the ambient temperature (for example, a combination of as-mixed temperature: 22°C and ambient temperature: 20°C), and for the "time elapsed from the time of water pouring corresponding to intersection X" in the ratio [time elapsed from the time of water pouring / time elapsed from the time of water pouring corresponding to intersection X], the time elapsed from the time of water pouring corresponding to intersection X in the graph in the relationship I determination step (S3) for the predetermined combination of the as-mixed temperature and the ambient temperature (for example, a combination of as-mixed temperature: 22°C and ambient temperature: 20°C) is substituted. When the as-mixed temperature and the ambient temperature are a different predetermined combination (for example, a combination of as-mixed temperature: 27°C and ambient temperature: 20°C), the "time elapsed from the time of water-pouring" in the ratio [time elapsed from the time of water-pouring / time elapsed from the time of water-pouring corresponding to intersection X] is substituted with a numerical value for each plot in the graph in the relationship I determination step (S3) in the different predetermined combination of the as-mixed temperature and the ambient temperature (for example, a combination of as-mixed temperature: 27°C and ambient temperature: 20°C), and the "time elapsed from the time of water-pouring corresponding to intersection X" in the ratio [time elapsed from the time of water-pouring / time elapsed from the time of water-pouring corresponding to intersection X] is substituted with the time elapsed from the time of water-pouring corresponding to intersection X in the graph in the relationship I determination step (S3). In this way, from among the multiple times of time that have elapsed since the water was poured, those that correspond to a predetermined combination of the kneaded temperature and the ambient temperature are combined to calculate the ratio [time that has elapsed since the water was poured / time that has elapsed since the water was poured corresponding to the intersection point X].

[0091] Therefore, in the ratio [time elapsed since pouring water / time elapsed since pouring water corresponding to intersection X] determination step (S9), multiple numerical values ​​of the ratio [time elapsed since pouring water / time elapsed since pouring water corresponding to intersection X] are obtained depending on the number of plots on the graph in the relationship I determination step (S3) and the number of predetermined combinations of the kneaded temperature and the ambient temperature.

[0092] <Process 10 (S10)> Step 10 (S10) is a step of determining a relationship III between the ratio [time elapsed since pouring water / time elapsed since pouring water indicated by intersection X] and the penetration resistance value corresponding to the time elapsed since pouring water, based on the relationship I. Hereinafter, step 10 (S10) may be referred to as a "relationship III determination step."

[0093] The ratio [time elapsed since pouring water / time elapsed since pouring water corresponding to intersection X] is determined in the ratio [time elapsed since pouring water / time elapsed since pouring water corresponding to intersection X] determination step (S10).

[0094] The penetration resistance value is the penetration resistance value corresponding to the time elapsed since the water was poured, based on the relationship I. Specifically, the penetration resistance value is the penetration resistance value obtained in the relationship I determination step (S4) corresponding to the "time elapsed since the water was poured" used in calculating the ratio [time elapsed since the water was poured / time elapsed since the water was poured corresponding to the intersection X] in the ratio [time elapsed since the water was poured / time elapsed since the water was poured corresponding to the intersection X] determination step (S9).

[0095] Specifically, the relationship III is a function that can be determined by creating a graph in which the vertical axis represents the penetration resistance value appropriate for leveling the surface of the concrete composition, preferably the average penetration resistance value appropriate for leveling the surface of the concrete composition, and the horizontal axis represents the ratio [time elapsed since pouring water / time elapsed since pouring water corresponding to intersection point X].

[0096] <Step 11 (S11)> Calculating the predicted elapsed time from the time of pouring water into the concrete composition until the concrete composition reaches the predetermined penetration resistance value can be specifically performed by the step 11 (S11). That is, the step 11 (S11) is a step of calculating the predicted elapsed time from the time of pouring water until the concrete composition reaches the penetration resistance value appropriate for leveling the surface of the concrete composition, based on the penetration resistance value appropriate for leveling the surface of the concrete composition from the relationship III and the elapsed time from the time of pouring water indicated by the intersection X derived from the relationship II. Hereinafter, the step 11 (S11) may be referred to as the "predicted elapsed time calculation step."

[0097] The penetration resistance value appropriate for leveling the surface of the concrete composition can be appropriately selected from the range of penetration resistance values ​​determined in the penetration resistance value range determination step (S13) described below.

[0098] The time elapsed from the time of water pouring corresponding to the intersection X derived from the relationship II is derived from the relationship I determined in the relationship I determination step (S3), as described in the relationship II determination step (S8). Specifically, the time elapsed from the time of water pouring corresponding to the intersection X is found from the graph in the relationship I determination step (S3).

[0099] The relationship III is determined by the relationship III determination step (S10).

[0100] Specifically, the elapsed time from the time of pouring water until the penetration resistance value appropriate for leveling the surface of the concrete composition is reached can be predicted by substituting the penetration resistance value appropriate for leveling the surface of the concrete composition and the elapsed time from the time of pouring water corresponding to the intersection point X into the relationship III.

[0101] <Step 12 (S12)> Step 12 (S12) is a step of determining the leveling work start time by adding the predicted elapsed time from the time of pouring water predicted in step 11 until the concrete composition reaches the penetration resistance value appropriate for leveling the surface of the concrete composition to the actual time recorded at the time of pouring water in step 1. Hereinafter, step 12 (S12) may be referred to as the "leveling work start time determination step."

[0102] In particular, if the actual time (T hours, t minutes) when the water is added to the raw materials of the concrete composition is recorded in the water pouring time determination step (S1), it is preferable to include the leveling work start time determination step (S12) in order to determine the leveling work start time.

[0103] <Step 13 (S13)> The step (S13) is a step of determining a range of penetration resistance values ​​appropriate for leveling the surface of the concrete composition. Hereinafter, step 13 (S13) may be referred to as a "penetration resistance range determination step."

[0104] The step (S13) of determining the range of the penetration resistance value is preferably performed before the step (S4) of determining the tangent line a, and more preferably after the step (S1) of determining the time of water pouring.

[0105] Specifically, the range of penetration resistance suitable for leveling the surface of the concrete composition is determined as follows. First, the penetration resistance value of the concrete composition is measured at a plurality of successively changed elapsed times from the water-pouring time determined in the water-pouring time determining step (S1). Next, the following evaluations (i) and (ii) will be carried out by the expert evaluator. Evaluation (i) An expert evaluator observes the flow state of the concrete composition when the holding tool is removed from the concrete composition at each elapsed time. (ii) An expert assessor actually performs leveling of the surface of the concrete composition at each elapsed time. Finally, when the concrete composition satisfies the two conditions that the concrete composition is in a non-fluid state in the evaluation (i) and the surface of the concrete composition can be leveled in the evaluation (ii), the range of the penetration resistance value of the concrete composition is determined as the range of the penetration resistance value appropriate for leveling the surface of the concrete composition.

[0106] In the penetration resistance range determination step (S13), it is sufficient to determine the range of penetration resistance of the concrete composition when the following two conditions are satisfied: the concrete composition is in a non-fluid state in the evaluation (i), and the surface of the concrete composition can be leveled in the evaluation (ii). There are no particular restrictions on the temperature at which the concrete composition is mixed and the ambient temperature at which it is poured when the evaluation is performed.

[0107] Hereinafter, one embodiment of the prediction method when a concrete composition containing fine aggregate, coarse aggregate, and water is used as the concrete composition will be specifically described with reference to the drawings, but the present invention is not limited thereto.

[0108] First, in the water-pouring time determination step (S1), the time when water is added to the fine aggregate and coarse aggregate, which are raw materials for the concrete composition, is determined as the "water-pouring time" (reference time, 0 hours), and preferably the actual time when water is added (T hours, t minutes) is recorded. At this time, multiple samples of the concrete composition are prepared so as to have multiple as-mixed temperatures.

[0109] Next, in the penetration resistance measurement step (S2), samples of multiple concrete compositions having various as-mixed temperatures are poured into a formwork at multiple ambient temperatures to prepare multiple poured samples combining as-mixed temperatures and ambient temperatures. The penetration resistance of each of the multiple poured samples is measured in accordance with JIS A 1147:2019 (Test method for concrete setting time) after continuously changing the elapsed time from pouring water. At this time, the penetration resistance of each poured sample is measured at three randomly selected points, and the average penetration resistance of the three points is calculated.

[0110] Next, in the step (S13) of determining the range of penetration resistance values, a concrete composition containing fine aggregate, coarse aggregate, and water of the same composition as the concrete composition in the step (S1) of determining the time of pouring water is separately prepared, and the time elapsed since pouring water into the fine aggregate and coarse aggregate is continuously changed, and the average penetration resistance value of the concrete composition is measured at each of the elapsed times. Furthermore, the evaluations (i) and (ii) are performed by an expert evaluator, and the range of the average penetration resistance value of the concrete composition is determined as the range of the average penetration resistance value appropriate for leveling the surface of the concrete composition when the two conditions that the concrete composition is in a non-fluid state in the evaluation (i) and the surface of the concrete composition can be leveled in the evaluation (ii) are satisfied.

[0111] The range of the average penetration resistance value suitable for leveling the surface of the concrete composition is not particularly limited, but in the case of a concrete composition containing the fine aggregate, the coarse aggregate, and the water, it is 0.25 N / mm 2 ~1N / mm 2 is preferable, and 0.25N / mm 2 is more preferred.

[0112] Next, in the relationship I determination step (S3), the relationship I between the average penetration resistance value of the concrete composition and the elapsed time from the time of pouring water corresponding to each of a plurality of combinations of the as-mixed temperature and the ambient temperature is determined. An example of a graph showing the relationship I is shown in Fig. 4. Fig. 4 shows the average penetration resistance (N / mm 2 ) on the vertical axis and the elapsed time (h) from the time of water injection on the horizontal axis.

[0113] Next, in the tangent line a determining step (S4), a tangent line a passing through a predetermined point of the average penetration resistance value appropriate for leveling the surface of the concrete composition is determined for each of a plurality of combinations of the as-mixed temperature and the ambient temperature based on the relationship I. Also, in the tangent line b determining step (S5), a tangent line a passing through the point where the elapsed time from the water pouring time is 0 hours and the average penetration resistance value is 0 N / mm is determined based on the relationship I. 2 A tangent line b passing through the point (origin) is determined for each of a plurality of combinations of the as-mixed temperature and the atmosphere temperature. In an intersection X determination step (S6), an intersection X between the tangent line a and the tangent line b is determined for each of a plurality of combinations of the as-mixed temperature and the atmosphere temperature.

[0114] The tangent line a, the tangent line b, and the intersection point X will be described with reference to FIG. FIG. 5 is a graph excerpted from the graph of FIG. 4 when the mixing temperature is 22° C. and the ambient temperature is 20° C. (condition 2). The "tangent line a" is a linear function that passes through a predetermined point of the average penetration resistance value appropriate for leveling the surface of the concrete composition and has an intersection with the horizontal axis indicating the elapsed time from the time of pouring water. Here, the predetermined point of the average penetration resistance value appropriate for leveling the surface of the concrete composition is 1.0 N / mm 2 We have adopted the following. "Tangent line b" passes through the point where the elapsed time from the time of water injection is 0 hours and the average penetration resistance is 0 N / mm 2 It is a linear function that passes through the point (origin).

[0115] By drawing the "tangent line a" and the "tangent line b" in this way, their "intersection point X" is generated. In this embodiment, this operation is performed for each combination of the mixing temperature and the atmosphere temperature shown in FIG. Furthermore, from the graph in Figure 5, the "intersection point X" indicates the "time elapsed (h) from the time of water injection."

[0116] Next, in the ratio [ambient temperature / as-kneaded temperature] determination step (S7), the ratio [ambient temperature / as-kneaded temperature] is determined. In this embodiment, the ratio [ambient temperature / as-kneaded temperature] is determined from the combination of the as-kneaded temperature and the ambient temperature shown in FIG.

[0117] Next, in the relationship II determination step (S8), a relationship II between the time elapsed since pouring water corresponding to the intersection X and the ratio [ambient temperature / as-kneaded temperature] is determined. An example of a graph representing relationship II in this embodiment is shown in FIG. 6. FIG. 6 is a graph in which the ratio [ambient temperature / as-kneaded temperature] is plotted on the vertical axis and the time elapsed (h) since pouring water indicated by the intersection X is plotted on the horizontal axis, and an approximate curve is drawn. In this embodiment, relationship II is preferably a linear function represented by the following relationship (1-1), more preferably a linear function represented by the following relationship (1-2), even more preferably a linear function represented by the following relationship (1-3), and particularly preferably a linear function represented by the following relationship (1-4). The time elapsed from the time of water injection indicated by intersection point X (h) = {(ambient temperature (°C) / kneaded temperature (°C)) - 6.1} / -0.3 ··· Relational formula (1-1) The time elapsed from the time of water injection indicated by intersection point X (h) = {(ambient temperature (℃) / kneaded temperature (℃)) - 6.08} / -0.33 ··· Relational formula (1-2) The time elapsed from the time of water injection indicated by intersection point X (h) = {(ambient temperature (℃) / kneaded temperature (℃)) - 6.081} / -0.331 ··· Relational formula (1-3) The time elapsed from the time of water injection indicated by intersection point X (h) = {(ambient temperature (℃) / kneaded temperature (℃)) - 6.0811} / -0.3307 ··· Equation (1-4)

[0118] Next, in a ratio [time elapsed since pouring water / time elapsed since pouring water corresponding to intersection X] determination step (S9), the ratio [time elapsed since pouring water / time elapsed since pouring water corresponding to intersection X] is determined. For example, in Figure 5, which shows the case in Figure 4 where the mixing temperature is 22°C and the ambient temperature is 20°C (condition 2), the "time elapsed since pouring water corresponding to intersection X" is 14.5 hours.

[0119] Next, in the relationship III determination step (S10), a relationship III is determined between the ratio [time elapsed since pouring water / time elapsed since pouring water corresponding to intersection X] and the average penetration resistance value corresponding to the time elapsed since pouring water, based on the relationship I.

[0120] An example of a graph showing Relationship III in this embodiment is shown in Figure 7. Figure 7 is a graph in which the average penetration resistance value is plotted on the vertical axis and the ratio [time elapsed since pouring water / time elapsed since pouring water corresponding to intersection point X] is plotted on the horizontal axis, and an approximate curve is drawn. In this embodiment, Relationship III is preferably a function expressed by the following Relationship (2-1), more preferably a function expressed by the following Relationship (2-2), and even more preferably a function expressed by the following Relationship (2-3). Estimated elapsed time from water injection (h) = [-0.7 × EXP (- average penetration resistance value (N / mm 2 ) / 0.03)-0.3×EXP(-Average penetration resistance value (N / mm 2 ) / 0.6)+1] × elapsed time (h) from the time of water injection indicated by intersection X ··· Relational formula (2-1) Estimated elapsed time from water injection (h) = [-0.69 × EXP (-average penetration resistance value (N / mm 2 ) / 0.034)-0.3×EXP(-Average penetration resistance value (N / mm 2 ) / 0.62)+1.1] × elapsed time (h) from the time of water injection indicated by intersection X ··· Relational formula (2-2) Estimated elapsed time from water injection (h) = [-0.687 × EXP (-average penetration resistance value (N / mm 2 ) / 0.0343)-0.295×EXP(-Average penetration resistance value (N / mm2 ) / 0.623)+1.080] × elapsed time (h) from the time of water injection indicated by intersection X ··· Relational formula (2-3)

[0121] Next, in the predicted elapsed time calculation step (S11), a predicted elapsed time from the time of pouring water until the concrete composition reaches an average penetration resistance value suitable for leveling the surface is calculated. In the predicted elapsed time calculation step (S11), a predetermined average penetration resistance value (N / mm) that can level the concrete composition is added to the function expressed by the relational expression (2-1), the function expressed by the relational expression (2-2), or the function expressed by the relational expression (2-3). 2 ) and the elapsed time (h) from the time of pouring water indicated by the intersection point X obtained by the relational expression (1-1), the relational expression (1-2), the relational expression (1-3), or the relational expression (1-4), it is possible to calculate the predicted elapsed time (h) from the time of pouring water until a predetermined average penetration resistance value is reached.

[0122] Preferably, in a further leveling work start time calculation step (S12), the leveling work start time is calculated by adding the predicted elapsed time (h) from the time of pouring water predicted in step (S11) until the concrete composition reaches an average penetration resistance value appropriate for leveling the surface of the concrete composition to the actual time (T hours t minutes) recorded at the time of pouring water in step (S1). Specifically, the leveling work start time can be calculated based on the following relational expression (3). Leveling work start time [Z hours z minutes] = actual time (T hours t minutes) recorded in the water pouring time determination step (S1) + predicted elapsed time (Y hours) from the time of water pouring until the average penetration resistance value appropriate for leveling the surface of the concrete composition is reached. Equation (3) In the relational formula (3), T, t, Z, and z represent any natural number or 0, and Y represents any natural number, a decimal number, or 0.

[0123] As a specific example, if the actual time recorded in the water injection time determination process (S1) is "8:00" and the predicted elapsed time is "13.78 hours" (i.e., 13 hours and 47 minutes), the predicted time for starting the leveling work will be "21:47."

[0124] In addition, the prediction method is the same as the above, in which the average penetration resistance value of the relational expression (2-1), the relational expression (2-2), or the relational expression (2-3) is added to the average penetration resistance value of the initial time of 3.5 N / mm 2 The average penetration resistance value of the final time is calculated by substituting the average penetration resistance value of 28.0 N / mm 2 It can also be used to predict the completion time by substituting

[0125] As described above, in the prediction method of the present invention, based on the relationship II, the "time elapsed from the time of water injection (h) indicated by intersection X" is calculated by substituting the "mixing temperature (°C)" and the "ambient temperature (°C)" into preferably the relationship formula (1-1), the relationship formula (1-2), the relationship formula (1-3), or the relationship formula (1-4). Next, based on the relationship III, preferably, the desired "average penetration resistance value (N / mm 2 )" and "the elapsed time (h) from the time of pouring water indicated by intersection X" are substituted, and the "predicted elapsed time (h)" from the time of pouring water until the average penetration resistance value appropriate for leveling the surface of the concrete composition is reached is calculated. This "predicted elapsed time (h)" is defined as the time elapsed from the time of pouring water until the concrete composition reaches an average penetration resistance value suitable for leveling the concrete composition.

[0126] Therefore, according to the prediction method of the present invention, by adjusting the temperature of the concrete composition after mixing according to the ambient temperature (air temperature) at the construction site, it is possible to predict the appropriate timing for removing the pressure tool and performing the leveling work after placing the pressure tool on the surface of the concrete composition without having to perform periodic penetration resistance tests. Furthermore, it is possible to determine the time to pour water into the powder components of the raw materials of the concrete composition according to the desired timing for performing the leveling work.

[0127] The prediction method of the present invention can be suitably applied to any construction site where a concrete composition is used, but in view of the composition of the concrete composition, it is particularly preferably used as a method for predicting the construction timing at a construction site for the joint of a pair of precast concrete decks facing each other with a gap between them.

[0128] Furthermore, the prediction method of the present invention is a method for predicting the appropriate timing for leveling work, i.e., the timing for removing the clamps, and therefore can be suitably applied even when the joints of the precast concrete deck have a slope.

[0129] (Device for predicting timing of concrete composition construction) The device for predicting the timing of application of a concrete composition of the present invention (hereinafter sometimes abbreviated as "the prediction device") is a device for predicting the appropriate timing of application for leveling the surface of a concrete composition, and includes: a means for calculating a relational equation showing the relationship between the mixed temperature of the concrete composition, the ambient temperature at the time of pouring the concrete composition, and a predetermined penetration resistance value of the concrete composition; and a means for calculating a predicted elapsed time from the time water is poured into the concrete composition until the concrete composition reaches the predetermined penetration resistance value, and may further include other means such as various input means, various display means, and control means, as necessary.

[0130] The means for calculating the relational expression is a prediction device for predicting an appropriate application timing for leveling the surface of a concrete composition, and includes a means for inputting the water pouring time when water is added to the raw materials of the concrete composition (hereinafter, this may be referred to as a "water pouring time input means"), a means for inputting penetration resistance values ​​of the concrete composition corresponding to a plurality of combinations of the mixed temperature when the concrete composition is mixed and the ambient temperature when the mixed concrete composition is poured into a form (hereinafter, this may be referred to as a "penetration resistance value input means"), and A means for determining a relationship I with the time elapsed since pouring water (hereinafter, sometimes referred to as a "relationship I determining means"), a means for determining, based on the relationship I, a tangent a passing through a predetermined point of the penetration resistance value appropriate for leveling the surface of the concrete composition for each of a plurality of combinations of the as-mixed temperature and the ambient temperature (hereinafter, sometimes referred to as a "tangent a determining means"), and a means for determining, based on the relationship I, a tangent b passing through the origin at which the time elapsed since pouring water is 0 hours for each of a plurality of combinations of the as-mixed temperature and the ambient temperature (hereinafter, sometimes referred to as a "tangent b determining means"). a means for determining an intersection X between the tangent line a and the tangent line b for each of a plurality of combinations of the as-mixed temperature and the ambient temperature (hereinafter, sometimes referred to as an "intersection X determining means"); a means for determining a ratio [ambient temperature / as-mixed temperature] obtained by dividing the ambient temperature by the as-mixed temperature for each of a plurality of combinations of the as-mixed temperature and the ambient temperature (hereinafter, sometimes referred to as a "ratio [ambient temperature / as-mixed temperature] determining means"); and a means for determining a relationship II between the time elapsed from the time of pouring water corresponding to the intersection X and the ratio [ambient temperature / as-mixed temperature]. means for determining a ratio [time elapsed from water pouring / time elapsed from water pouring indicated by intersection X] obtained by dividing the time elapsed from water pouring based on the relationship I by the time elapsed from water pouring indicated by the intersection X (hereinafter, this may be referred to as a "ratio [time elapsed from water pouring / time elapsed from water pouring corresponding to intersection X] determination means"); means for determining a relationship II between the ratio [time elapsed from water pouring / time elapsed from water pouring indicated by intersection X] and the penetration resistance value corresponding to the time elapsed from water pouring based on the relationship I (hereinafter,It is preferable to have a relationship III determining means.

[0131] Furthermore, it is preferable that the means for calculating the predicted elapsed time from the time of pouring water into the concrete composition until the concrete composition reaches the predetermined penetration resistance value is means for calculating, from the time of pouring water into the concrete composition, the predicted elapsed time until the concrete composition reaches the penetration resistance value appropriate for leveling the surface of the concrete composition, based on the penetration resistance value appropriate for leveling the surface of the concrete composition from the time of pouring water and the elapsed time from the time of pouring water indicated by the intersection X derived from the time of pouring water (hereinafter, this may be referred to as the "predicted elapsed time calculation means").

[0132] In addition, it is preferable that the prediction device further has a means for determining the start time of the leveling work by adding the predicted elapsed time from the time of water pouring calculated by the means for calculating the predicted elapsed time (predicted elapsed time calculation means) until the penetration resistance value appropriate for leveling the surface of the concrete composition is reached to the time of water pouring input by the means for inputting the time of water pouring (water pouring time input means).

[0133] In addition, it is preferable that the prediction device further has a means for determining a range of penetration resistance values ​​appropriate for leveling the surface of the concrete composition (hereinafter, sometimes referred to as a "penetration resistance value range determination means").

[0134] The apparatus for predicting the timing of application of a concrete composition of the present invention is suitably used in the method for predicting the timing of application of a concrete composition of the present invention. Therefore, the apparatus for predicting the timing of application of a concrete composition of the present invention is preferably an apparatus that embodies the method for predicting the timing of application of a concrete composition of the present invention.

[0135] <Input method when pouring water> The water pouring time input means is a means for inputting the time when water is poured into the raw materials of the concrete composition.

[0136] The water pouring time input means is executed at the time when the water is added to the raw materials of the concrete composition in the water pouring time determination step (S1), thereby inputting the "reference time (0 hours)" of the elapsed time after the penetration resistance value measurement step (S2) to the prediction device.

[0137] The information input by the water-pouring input means is transmitted to the relationship I determining means, the tangent line b determining means, the relationship II determining means, the ratio [elapsed time from the time of water-pouring / elapsed time from the time of water-pouring corresponding to the intersection point X] determining means, the relationship III determining means, the predicted elapsed time calculating means, the various input means, the various display means, etc.

[0138] <Means for inputting penetration resistance value> The penetration resistance value input means is a means for inputting penetration resistance values ​​of the concrete composition corresponding to a plurality of combinations of the as-mixed temperature when the concrete composition is mixed and the ambient temperature when the mixed concrete composition is poured into a formwork. The penetration resistance value input means suitably executes the penetration resistance value input step (S2).

[0139] The penetration resistance value input means is not particularly limited as long as it is a means that can input the penetration resistance value of the concrete composition measured in accordance with JIS A 1147:2019 (Test method for setting time of concrete).

[0140] The penetration resistance value input means may also function as a "penetration resistance value measuring unit" that measures the penetration resistance value of the concrete composition in accordance with JIS A 1147:2019 (Concrete setting time test method). The penetration resistance value measuring unit may be, for example, a known penetration resistance tester (for example, a digital Proctor penetration resistance tester S-221 manufactured by Nishinippon Testing Instruments Co., Ltd.).

[0141] The penetration resistance value input means may also function as a "penetration resistance value transmission unit" for transmitting information on the penetration resistance value measured by the penetration resistance value measurement unit to the relationship I determination means, the tangent a determination means, the relationship III determination means, the predicted elapsed time calculation means, etc.

[0142] The penetration resistance value input means may also include a mixing temperature measuring unit that measures the mixing temperature of the concrete composition when it is mixed, and an ambient temperature measuring unit that measures the ambient temperature when the mixed concrete composition is poured into a formwork.

[0143] <<Mixing temperature measurement unit>> The kneading temperature measuring unit may be a thermometer or the like.

[0144] The mixing temperature measuring unit is not particularly limited as long as it can measure the mixing temperature of the concrete composition, and may be installed in conjunction with a mixing tank in which the concrete composition is mixed, or may be installed to sample and measure a portion of the mixed concrete composition.

[0145] The information on the kneading temperature measured by the kneading temperature measuring unit is transmitted to the relationship I determining means, the tangent a determining means, the tangent b determining means, the intersection X determining means, the ratio [ambient temperature / kneading temperature] determining means, the relationship II determining means, etc.

[0146] The kneading temperature measuring unit may also function as an "as-kneaded temperature input unit" for inputting measured information. The kneading temperature measuring unit may also function as an "as-kneaded temperature transmitting unit" for transmitting information on the as-kneaded temperature measured by the as-kneaded temperature measuring unit to the relationship I determining means, the tangent a determining means, the tangent b determining means, the intersection X determining means, the ratio [ambient temperature / as-kneaded temperature] determining means, the relationship II determining means, etc.

[0147] <<Atmospheric temperature measurement section>> The ambient temperature measuring unit is not particularly limited as long as it can measure the ambient temperature when the concrete composition is poured, preferably when the pressing operation is performed, and examples thereof include a thermometer.

[0148] Information on the ambient temperature measured by the ambient temperature measuring unit is transmitted to the relationship I determining means, the tangent a determining means, the tangent b determining means, the intersection X determining means, the ratio [ambient temperature / as-kneaded temperature] determining means, the relationship II determining means, etc.

[0149] The atmosphere temperature measuring unit may also function as an "atmosphere temperature input unit" for inputting measured information. The atmosphere temperature measuring unit may also function as an "atmosphere temperature transmitting unit" for transmitting information on the as-mixed temperature measured by the atmosphere temperature measuring unit to the relationship I determining means, the tangent a determining means, the tangent b determining means, the intersection X determining means, the ratio [atmosphere temperature / as-mixed temperature] determining means, the relationship II determining means, etc.

[0150] <Means for determining relationship> The relationship I determining means is a means for determining the relationship I between the penetration resistance value and the time elapsed since the water was poured. The relationship I determining means suitably executes the relationship I determining step (S3).

[0151] The information on the relationship I determined by the relationship I determining means is transmitted to the tangent a determining means, the tangent b determining means, the relationship II determining means, the ratio [elapsed time from the time of water pouring / elapsed time from the time of water pouring corresponding to the intersection point X] determining means, etc.

[0152] The relationship I determining means may also function as a "relationship I input means" for inputting information about the determined relationship I. The relationship I determining means may also function as a "relationship I transmission means" for transmitting information about the determined relationship I to the tangent line a determining means, the tangent line b determining means, the relationship II determining means, the ratio [time elapsed since the time of water pouring / time elapsed since the time of water pouring corresponding to intersection point X] determining means, etc.

[0153] <Means for determining tangent a> The tangent line a determining means is means for determining, for each of a plurality of combinations of the as-mixed temperature and the ambient temperature, a tangent line a passing through a predetermined point of the penetration resistance value appropriate for leveling the surface of the concrete composition, based on the relationship I. The tangent line a determining means suitably executes the tangent line a determining step (S4).

[0154] Information about the tangent a determined by the tangent a determining means is transmitted to the intersection X determining means and the like.

[0155] The tangent a determining means may also function as a "tangent a determination input means" for inputting information on the determined tangent a. The tangent a determining means may also function as a "tangent a determination transmission means" for transmitting information on the determined tangent a to the intersection point X determining means or the like.

[0156] <Means for determining tangent b> The tangent line b determining means is means for determining, for each of a plurality of combinations of the mixing temperature and the ambient temperature, a tangent line b that passes through the origin at which the elapsed time from the time of pouring water is 0 hours, based on the relationship I. The tangent line b determining means suitably executes the tangent line b determining step (S5).

[0157] Information about the tangent b determined by the tangent b determining means is transmitted to the intersection X determining means and the like.

[0158] The tangent b determination means may also function as a "tangent b determination input means" for inputting information on the determined tangent b. The tangent b determination means may also function as a "tangent b determination transmission means" for transmitting information on the determined tangent b to the intersection point X determination means or the like.

[0159] <Intersection X determination method> The intersection X determining means is means for determining an intersection X between the tangent line a and the tangent line b for each of a plurality of combinations of the mixing temperature and the ambient temperature. The intersection X determining means preferably executes the intersection X determining step (S6).

[0160] Information on the intersection X determined by the intersection X determining means is transmitted to the relationship II determining means, the ratio [elapsed time from the time of water pouring / elapsed time from the time of water pouring corresponding to the intersection X] determining means, the relationship III determining means, the predicted elapsed time calculating means, etc.

[0161] The intersection X determination means may also function as an "intersection X determination input means" for inputting information on the determined intersection X. The intersection X determination means may also function as an "intersection X determination transmission means" for transmitting information on the determined intersection X to the relationship II determination means, the ratio [elapsed time from the time of water pouring / elapsed time from the time of water pouring corresponding to intersection X] determination means, the relationship III determination means, the predicted elapsed time calculation means, etc.

[0162] <Means for determining the ratio [ambient temperature / mixing temperature]> The ratio [ambient temperature / as-kneaded temperature] determining means is a means for determining a ratio [ambient temperature / as-kneaded temperature] obtained by dividing the ambient temperature by the as-kneaded temperature for each of a plurality of combinations of the as-kneaded temperature and the ambient temperature. The ratio [ambient temperature / as-kneaded temperature] determining means suitably executes the ratio [ambient temperature / as-kneaded temperature] determining step (S7).

[0163] Information on the ratio [ambient temperature / as-kneaded temperature] determined by the ratio [ambient temperature / as-kneaded temperature] determining means is transmitted to relationship II determining means.

[0164] The ratio [ambient temperature / as-kneaded temperature] determining means may also function as a "ratio [ambient temperature / as-kneaded temperature] input means" for inputting information on the determined ratio [ambient temperature / as-kneaded temperature]. It may also function as a "ratio [ambient temperature / as-kneaded temperature] transmitting means" for transmitting information on the ratio [ambient temperature / as-kneaded temperature] determined by the ratio [ambient temperature / as-kneaded temperature] determining means to the relationship II determining means.

[0165] <Means for determining relationship II> The relationship II determining means is a means for determining the relationship II between the time elapsed since the water pouring corresponding to the intersection X and the ratio [ambient temperature / mixed temperature]. The relationship II determining means suitably executes the relationship II determining step (S8).

[0166] The information on the relationship II determined by the relationship II determining means is transmitted to the predicted elapsed time calculating means.

[0167] The relationship II determination means may also function as a "relationship II input means" for inputting information on the determined relationship II, and may also function as a "relationship II transmission means" for transmitting the information on the relationship II determined by the relationship II determination means to the predicted elapsed time calculation means.

[0168] <Means for determining the ratio [time elapsed since water injection / time elapsed since water injection corresponding to intersection point X]> The ratio [time elapsed since pouring water / time elapsed since pouring water corresponding to intersection X] determining means determines the ratio [time elapsed since pouring water / time elapsed since pouring water indicated by intersection X] obtained by dividing the time elapsed since pouring water based on the relationship I by the time elapsed since pouring water indicated by intersection X. The ratio [time elapsed since pouring water / time elapsed since pouring water corresponding to intersection X] determining means preferably executes the ratio [time elapsed since pouring water / time elapsed since pouring water corresponding to intersection X] determining step (S9).

[0169] The information of the ratio [time elapsed since water pouring / time elapsed since water pouring corresponding to intersection X] determined by the ratio [time elapsed since water pouring / time elapsed since water pouring corresponding to intersection X] determining means is transmitted to the relationship III determining means.

[0170] The ratio [time elapsed since water-pouring / time elapsed since water-pouring corresponding to intersection X] determining means may also function as a "ratio [time elapsed since water-pouring / time elapsed since water-pouring corresponding to intersection X] input means" for inputting information on the determined ratio [time elapsed since water-pouring / time elapsed since water-pouring corresponding to intersection X]. It may also function as a "ratio [time elapsed since water-pouring / time elapsed since water-pouring corresponding to intersection X] transmission means" for transmitting information on the ratio [time elapsed since water-pouring / time elapsed since water-pouring corresponding to intersection X] determined by the ratio [time elapsed since water-pouring / time elapsed since water-pouring corresponding to intersection X] determining means to the relationship III determining means.

[0171] <Means for determining relationship III> The relationship III determining means is means for determining a relationship III between the ratio [time elapsed since pouring water / time elapsed since pouring water indicated by intersection X] and the penetration resistance value corresponding to the time elapsed since pouring water, based on the relationship I. The relationship III determining means suitably executes the relationship III determining step (S10).

[0172] Information on the relationship III determined by the relationship III determining means is transmitted to the predicted elapsed time calculating means.

[0173] The relationship III determination means may also function as a "relationship III input means" for inputting information on the determined relationship III, and may also function as a "relationship III transmission means" for transmitting the information on the relationship III determined by the relationship III determination means to the predicted elapsed time calculation means.

[0174] <Means for calculating predicted elapsed time> The predicted elapsed time calculation means is a means for calculating a predicted elapsed time from the time of pouring water into the concrete composition until the concrete composition reaches the predetermined penetration resistance value, and is preferably a means for calculating a predicted elapsed time from the time of pouring water until the concrete composition reaches the penetration resistance value appropriate for leveling the surface of the concrete composition based on the penetration resistance value appropriate for leveling the surface of the concrete composition from the time of pouring water and the elapsed time from the time of pouring water indicated by the intersection X derived from the time of pouring water. The predicted elapsed time calculation means suitably executes the predicted elapsed time calculation step (S11).

[0175] Information on the predicted elapsed time from the time of water injection calculated by the predicted elapsed time calculation means is preferably transmitted to a leveling work start time calculation means.

[0176] The predicted elapsed time calculation means may also function as a "predicted elapsed time input means" for inputting information on the calculated predicted elapsed time from the time of water pouring, and may also function as a "predicted elapsed time transmission means from the time of water pouring" for transmitting information on the predicted elapsed time from the time of water pouring calculated by the predicted elapsed time calculation means to the leveling work start time calculation means.

[0177] <Means for calculating the start time of smoothing work> It is preferable that the prediction device further includes a smoothing work start time calculation means in addition to the above means, in that the smoothing work start time can be calculated.

[0178] The leveling work start time calculation means is means for determining the leveling work start time by adding the predicted elapsed time from the time of water pouring calculated by the means for calculating predicted elapsed time (predicted elapsed time calculation means) until the penetration resistance value appropriate for leveling the surface of the concrete composition is reached to the time of water pouring input by the means for inputting water pouring time (water pouring time determination means). The leveling work start time calculation means suitably executes the leveling work start time calculation step (S12).

[0179] <Means for determining the range of penetration resistance values> In addition to the above-mentioned means, the prediction device preferably further includes a means for determining a range of penetration resistance values.

[0180] The penetration resistance range determination means is a means for determining a range of penetration resistance values ​​appropriate for leveling the surface of the concrete composition. The penetration resistance range determination means preferably executes the penetration resistance range determination step (S13).

[0181] The penetration resistance value range determination means may input the numerical value determined in the penetration resistance value range determination step (S13), or may input a known desired penetration resistance value range of a known concrete composition.

[0182] The penetration resistance range determining means may have a function of measuring the penetration resistance of the concrete composition to determine the penetration resistance range. In this case, the measurement may be performed by the penetration resistance measuring unit, or a separate device may have the same function as the penetration resistance measuring unit.

[0183] Information on the range of the penetration resistance value determined by the penetration resistance value range determining means is transmitted to the tangent line a determining means, the predicted elapsed time calculating means, and the like.

[0184] The penetration resistance value range determination means may also function as a "penetration resistance value range input unit" for inputting information on the determined penetration resistance value range. The penetration resistance value range determination means may also function as a "penetration resistance value range transmission unit" for transmitting information on the penetration resistance value range determined by the penetration resistance value range determination means to the tangent line a determination means, the predicted elapsed time calculation means, etc.

[0185] <Display means> Examples of the display means include a water pouring time display means, a kneading temperature display means, an ambient temperature display means, a penetration resistance value display means, a ratio [ambient temperature / kneading temperature] display means, a time elapsed since the time of water pouring corresponding to intersection X display means, a predicted time elapsed since the time of water pouring display means, and a leveling work start time display means.

[0186] The various display means are means for displaying information input by the various input means as numerical values. Specifically, the water-pouring time display means is a means for displaying the water-pouring time or the water-pouring time. The kneading temperature display means is a means for displaying the kneading temperature. The ambient temperature display means is a means for displaying the ambient temperature. The penetration resistance value display means is a means for displaying the penetration resistance value. The ratio [ambient temperature / as-kneaded temperature] display means is a means for displaying the ratio [ambient temperature / as-kneaded temperature]. The means for displaying the elapsed time from the time of pouring water corresponding to the intersection X is means for displaying the time of pouring water corresponding to the intersection X. The estimated elapsed time display means is means for displaying the estimated elapsed time from the time of water pouring. The leveling work start time display means is a means for displaying the leveling work start time.

[0187] <Control means> The control means is a means for controlling the various means, and examples thereof include hardware such as a computer having a CPU, a memory, a display, and software such as a computer program that runs on the hardware.

[0188] Below, the input / output screen as a display means of the device for predicting the timing of application of a concrete composition of the present invention will be described in detail using drawings, but the input / output screen of the device for predicting the timing of application of a concrete composition of the present invention is not limited to this.

[0189] FIG. 2 is a diagram showing an embodiment of an input / output screen showing an embodiment of the device for predicting the timing of application of a concrete composition according to the present invention. As an input / output screen of the prediction device, for example, a screen as shown in the figure is displayed on a display. On this screen, an input section (INPUT) and an output section (OUTPUT) are arranged.

[0190] The input section (INPUT) comprises a field for inputting the "water pouring time" when the raw materials of the concrete composition (for example, fine aggregate, coarse aggregate, and other powder components) are mixed with water when preparing the concrete composition, a field for inputting the "mixing temperature" of the concrete composition, a field for inputting the "ambient temperature" during curing of the concrete composition, and a field for inputting the "penetration resistance value" of the concrete composition. The input values ​​in each field are used for calculation processing in the various determination means.

[0191] The output section (OUTPUT) comprises a column for outputting the intermediate output items "ratio [ambient temperature / mixed temperature]" and "time elapsed since water pouring corresponding to intersection X", and a column for outputting the final output item "predicted time elapsed since water pouring", preferably "leveling work start time". Calculated values ​​calculated by the calculation processes in the various determination means are output in each column.

[0192] When two items, "Kneaded temperature" and "Atmosphere temperature", are input in the input section, the ratio [Atmosphere temperature / Kneaded temperature] is calculated by the ratio [Atmosphere temperature / Kneaded temperature] determining means, and the calculated value is displayed. Furthermore, when the "Water pouring time" and "Penetration resistance value" are input in the input section, the "Elapsed time from water pouring corresponding to intersection X" and the "Predicted elapsed time from water pouring" are calculated by calculation processing in the relationship II determining means, and the calculated values ​​are displayed. More preferably, the "Leveling work start time" is calculated by calculation processing in the leveling work start time calculating means, and the calculated value is displayed. These calculated values ​​are instantly output and displayed in each column of the output section. Therefore, the user of this prediction device can easily grasp the above work time and work duration through this input / output screen. In the embodiment of FIG. 2, "22°C" is input for "Kneaded temperature", "20°C" is input for "Atmosphere temperature", and "0.25N / mm 2 " and the output result when "8:00" is entered for the water injection time.

[0193] The prediction device for the timing of concrete composition construction similarly adds the average penetration resistance value of the initial time of "3.5 N / mm 2 " to display the first train time, or the average penetration resistance value of the final time "28.0 N / mm 2 " may be substituted to display the end time.

[0194] (Concrete composition application method) The method for applying the concrete composition of the present invention is a method that uses the method for predicting the timing of application of the concrete composition of the present invention, and includes a step of predicting the timing of application, a mixing step, a pouring step, and a leveling step, and may further include other steps as necessary.

[0195] <Construction timing prediction process> The construction timing predicting step is a step of predicting the construction timing of a concrete composition using the method of the present invention for predicting the construction timing of a concrete composition. Therefore, before the concrete composition is applied, the time to start the leveling work is predicted using the above-mentioned method for predicting the timing of application of the concrete composition.

[0196] <Kneading process> The mixing step is a step of mixing the concrete composition. The mixing step can be carried out using a mixing method that is normally used for concrete compositions, and is preferably carried out at a mixing temperature that is described as the mixing temperature in the method for predicting the timing of application of a concrete composition of the present invention.

[0197] <Pouring process> The casting step is a step of casting the mixed concrete composition into a formwork. The casting step in the method for applying the concrete composition of the present invention can be performed using a casting method that is normally used for concrete compositions, but it is preferable to perform the casting step using a method similar to the method described in the penetration resistance value measurement step (S2) in the method for predicting the timing of application of the concrete composition of the present invention.

[0198] As the concrete composition in the method for applying a concrete composition of the present invention, a known concrete composition can be used, but it is preferable to use one having the same composition as the concrete composition in the method for predicting the timing of application of a concrete composition of the present invention.

[0199] <Smoothing process> The leveling work step is a step of carrying out work to level the surface of the concrete composition based on the predicted construction timing.

[0200] The method for leveling the surface of the concrete composition is not particularly limited and can be appropriately selected depending on the size of the construction site, etc., and may be done manually using a trowel or using a known machine.

[0201] <Pressing process> In addition to the above steps, the method for applying a concrete composition preferably further includes a pressing step in which a pressing tool is used to press the surface of the concrete composition poured in the pouring step. The pressing step allows the mixed concrete composition to harden without flowing out of the formwork.

[0202] The pressing device is not particularly limited in shape and size, as long as it can cover the entire surface of the concrete composition (the top surface of the concrete composition near the top of the formwork) after the concrete composition has been poured into the formwork and poured, and can be selected appropriately depending on the purpose.

[0203] The method for applying the concrete composition of the present invention can be suitably applied to any construction site as long as the concrete composition is used at that site. However, in view of the composition of the concrete composition, it is particularly preferably used as an application method at a construction site for the joint of a pair of precast concrete decks facing each other with a gap between them.

[0204] Furthermore, since the method for applying the concrete composition of the present invention is carried out based on the method for predicting the timing of applying the concrete composition of the present invention, the timing for removing the clamping device can be appropriately determined, and the method can be suitably applied even when the joints of the precast concrete deck have a slope. The gradient is not particularly limited and can be selected appropriately depending on the construction site, but is preferably 0.5% to 5%, and more preferably 0.5% to 2.0%. The gradient of the construction site can be measured, for example, using a level survey or a gradiometer. [Example]

[0205] The present invention will be specifically explained below with reference to preparation examples and test examples, but the present invention is not limited to these preparation examples and test examples.

[0206] (Preparation Example 1: Preparation of Concrete Composition 1) Fine aggregate (ferronickel slag fine aggregate, water absorption rate 2.70%, air-dried state, bone-dry density 2.83 g / cm 3 , manufactured by Pacific Metals Co., Ltd.) and coarse aggregate (surface dry density 2.63 g / cm 3 , Kanuma hard sandstone crushed stone 1305), water (tap water, Nagareyama City, Chiba Prefecture), and cement (moderate heat Portland cement, density 3.21 g / cm 3 , manufactured by Taiheiyo Cement Corporation) and fly ash (density 2.39 g / cm 3 , Shikoku Electric Power Business Co., Ltd.) and silica fume (EFACO, density 2.26 g / cm 3 , produced in Egypt) and short fiber (steel fiber, diameter 0.2 mm x length 15 mm, tensile strength 2,000 N / mm2 Above, density 7.85g / cm 3 ) and the above were mixed in the amounts shown in Table 1 below to prepare a concrete composition. The time when water was added) was defined as "water pouring time." The "mixing temperature" of this concrete composition was adjusted to 22°C.

[0207] [Table 1] In Table 1, the "water-powder volume ratio [w / p]" indicates the ratio of the volume of water (w) to the total volume of cement, fly ash, and silica fume (p). In addition, the "mortar fine aggregate volume ratio [%]" showed the value expressed by the following formula. Mortar fine aggregate volume ratio [%] = fine aggregate volume / (total volume of water, binder, and fine aggregate) In addition, the "fine aggregate ratio [%]" showed the value expressed by the following formula. Fine aggregate ratio [%] = volume of fine aggregate / (total volume of fine and coarse aggregate)

[0208] (Preparation Example 2: Preparation of Concrete Composition 2) Concrete composition 2 was prepared in the same manner as in Preparation Example 1, except that the mixing temperature in preparation of concrete composition 1 in Preparation Example 1 was changed from 22°C to 27°C.

[0209] (Preparation Example 3: Preparation of Concrete Composition 3) Concrete composition 3 was prepared in the same manner as in Preparation Example 1, except that in the preparation of concrete composition 1 in Preparation Example 1, the mixing temperature was changed from 22°C to 36°C.

[0210] (Preparation Example 4: Preparation of Concrete Composition 4) Concrete composition 4 was prepared in the same manner as in Preparation Example 1, except that in the preparation of concrete composition 1 in Preparation Example 1, the mixing temperature was changed from 22°C to 19°C.

[0211] (Test example 1: Test to confirm the necessity of a clamp) Concrete composition 1 obtained in Preparation Example 1 was poured into a sample formwork (height 15 cm, width 15 cm, length 53 cm). Thereafter, at an ambient temperature of 10°C, the gradient of the bottom of the formwork was changed to 0%, 0.5%, 1.0%, 1.5%, and 2.0%, and the flow state of the concrete composition was visually observed by an expert evaluator.

[0212] As a result, it was confirmed that the concrete composition obtained in Preparation Example 1 has high fluidity and flows even at a gradient of 1.0%. Therefore, it was found that in places with a gradient, a clamp (a clamping tool) is necessary for the formwork.

[0213] (Test Example 2-1: Clamp Removal Time Verification Test 1) Concrete composition 3 obtained in Preparation Example 3 was poured into a sample formwork (15 cm high, 15 cm wide, and 53 cm long). The surface of the poured concrete composition was pressed down with a presser. After that, the presser was removed 6 hours, 9 hours, 12 hours, and 12.5 hours after the time of pouring water (i.e., 0 hours) in an atmosphere of 20°C (curing temperature), and the condition of the concrete composition was visually observed by an expert evaluator. After the visual observation, a finishing aid (Mastercure® 106, manufactured by Pozzolith Solutions, Inc.) was applied to the surface of the concrete composition at a rate of 100 mL / m. 2 ~150 mL / m 2 The concrete composition was sprayed to a degree and the surface was leveled using a trowel. An expert evaluator then checked the condition of the concrete composition when the surface was leveled using a trowel. The results are shown in Table 2 below.

[0214] [Table 2]

[0215] The results in Table 2 show that the time period during which the concrete composition obtained in Preparation Example 3 can be suitably leveled is within the range of 9 to 12 hours after pouring water during the preparation of the concrete composition.

[0216] (Test Example 2-2: Clamp Removal Time Verification Test 2) Next, the average penetration resistance of the concrete composition during the time required to level the concrete composition confirmed in Test Example 2-1 was confirmed by the following method.

[0217] Concrete composition 3 obtained in Preparation Example 3 was poured into a sample formwork (height 15 cm, width 15 cm, length 53 cm). The surface of the poured concrete composition was then covered with a pressure tool. In an atmosphere of 20°C (curing temperature), the pressure tool was removed every hour from the time of pouring water (i.e., 0 hour) until 3 hours later (3 hours after pouring water), and then every 15 minutes until 1 hour later (4 hours after pouring water). In accordance with JIS A 1147:2019 (Test method for setting time of concrete), a penetration resistance tester (digital Proctor penetration resistance tester S-221, manufactured by Nishinippon Testing Instruments Co., Ltd.) was used to measure the penetration resistance per unit area (N / mm) when the tip of a penetration needle was pressed to a depth of 25 mm from the surface of the sample concrete composition for 10 seconds. 2 The penetration resistance value was measured in the same manner at three randomly selected points on the surface of the concrete composition sample, and the three penetration resistance values ​​(N / mm 2 The average value of the average penetration resistance (N / mm 2 The results are shown in Figure 3.

[0218] From the results of Test Example 2-1 and Test Example 2-2, the average penetration resistance value during the time when the concrete composition could be leveled confirmed in Test Example 2-1 is as shown in Figure 3. The average penetration resistance value suitable for leveling the concrete composition is 0.25 N / mm 2 ~1.00N / mm 2 It was found that... The average penetration resistance of the concrete composition was 3.5 N / mm 2 The time elapsed from the time of pouring water until the concrete reached the initial state (initial time of the concrete composition) was 14 hours, and the average penetration resistance was 28.0 N / mm 2 The time elapsed from the time of pouring water until the concrete composition reached the set point (final setting time of the concrete composition) was 16 hours.

[0219] (Test example 3: Finishing time confirmation test) Concrete compositions 1 to 4 obtained in Preparation Examples 1 to 4 were poured into a sample formwork (height 15 cm, width 15 cm, length 53 cm), and the surface of the poured concrete composition was pressed with a presser, and then cured under the combinations of "as-mixed temperature" and "ambient temperature (curing temperature)" shown in Conditions 1 to 8 in Table 3 below. In addition, the ratios [ambient temperature / as-mixed temperature] obtained by dividing the as-mixed temperature under Conditions 1 to 8 by the ambient temperature were calculated.

[0220] [Table 3]

[0221] Under each condition, concrete compositions 1 to 4 in Preparation Examples 1 to 4 were tested every 30 minutes from the time of pouring water (i.e., 0 hours) using a penetration resistance tester (digital Proctor penetration resistance tester S-221, manufactured by Nishinippon Testing Instruments Co., Ltd.) in accordance with JIS A 1147:2019 (Test method for concrete setting time). The tip of the penetration needle was pressed into a depth of 25 mm from the surface of the concrete composition sample for 10 seconds, and the penetration resistance per unit area (N / mm 2 The penetration resistance value was measured in the same manner at three randomly selected points on the surface of the concrete composition sample, and the three penetration resistance values ​​(N / mm 2 ) The average value was calculated.

[0222] Figure 4 shows the time (h) elapsed from the time of water injection and the average penetration resistance (N / mm 2 ) is shown in the graph. From the graph in Figure 4, the average penetration resistance value of the graph for each condition was 1.0 N / mm 2 The tangent line a passing through the point where the elapsed time from the water injection on the graph is 0 hours and the average penetration resistance is 0.0N / mm 2 A tangent line a passing through the point indicated by tangent line a and tangent line b was drawn, and the time elapsed from the time of water injection indicated by the intersection point X of tangent line a and tangent line b was calculated.

[0223] The tangent line a, the tangent line b, and the intersection point X will be described with reference to specific examples in FIG. Figure 5 is a graph showing only condition 2 in Figure 4. The tangent line a indicates the average penetration resistance of the graph is 1.0 N / mm 2 The tangent line b is the line that passes through the point where the elapsed time from the time of water injection is 0 hours and the average penetration resistance is 0.0 N / mm 2 In the case of condition 2, the time elapsed from the time of water injection indicated by the intersection point X was 12.8 hours.

[0224] Figure 6 shows a graph showing the relationship between the time (h) elapsed from the time of water injection indicated by the intersection point X of conditions 1 to 8 thus obtained and the ratio [ambient temperature / mixed temperature] of conditions 1 to 8 shown in Table 3. From the linear function shown in Figure 6, the following relational expression (1-4) was established. In the graph of Figure 6, the coefficient of determination R 2 was 0.9152. The time elapsed from the time of water injection indicated by intersection point X (h) = {(ambient temperature (℃) / kneaded temperature (℃)) - 6.0811} / -0.3307 ··· Equation (1-4)

[0225] Next, for each condition in Figure 4, the time p (h) elapsed since pouring water corresponding to each plot was divided by the time (h) elapsed since pouring water indicated by the intersection X for each condition to calculate the ratio [time p elapsed since pouring water / time elapsed since pouring water indicated by the intersection X]. Additionally, for each condition in Figure 4, each average penetration resistance value q corresponding to the time p (h) elapsed since pouring water was calculated. The relationship between the ratio [time p elapsed since pouring water / time elapsed since pouring water indicated by the intersection X] and the average penetration resistance value q was then plotted, and these plots and their approximation curves are shown in Figure 7. The quadratic function indicated by the approximation curve in Figure 7 established the following relational expression (2-3): Estimated elapsed time from water injection (h) = {-0.687 × EXP (-average penetration resistance value (N / mm 2 ) / 0.0343)-0.295×EXP(-average penetration resistance value / 0.623)+1.080}×time elapsed from the time of water injection indicated by intersection X (h) ··· Equation (2-3)

[0226] From the above, by substituting a predetermined average penetration resistance value that can level the concrete composition into the above relational expression (2-3), it was possible to calculate the predicted elapsed time from the time water is poured into the concrete composition (0 hours) until the predetermined average penetration resistance value is reached.

[0227] The present invention includes, for example, the following aspects. <1> A method for predicting an appropriate construction timing for leveling the surface of a concrete composition, comprising: The method for predicting the timing of construction of a concrete composition comprises calculating a predicted elapsed time from the time water is poured into the concrete composition until the concrete composition reaches the predetermined penetration resistance value, using a relational equation that shows the relationship between the mixed temperature of the concrete composition, the ambient temperature at the time of pouring the concrete composition, and the predetermined penetration resistance value of the concrete composition. <2> Step 1: determining the water pouring time for adding water to the raw materials of the concrete composition; Step 2: measuring the penetration resistance of the concrete composition corresponding to a plurality of combinations of the mixed temperature of the concrete composition when mixed and the ambient temperature when the mixed concrete composition is poured into a formwork; Step 3: determining the relationship I between the penetration resistance value and the elapsed time from the time of water injection; Step 4: determining, based on the relationship I, a tangent line a passing through a predetermined point of a penetration resistance value appropriate for leveling the surface of the concrete composition for each of a plurality of combinations of the as-mixed temperature and the ambient temperature; Step 5: Based on the relationship I, a tangent line b passing through the origin at which the elapsed time from the time of water pouring is 0 hours is determined for each of a plurality of combinations of the kneaded temperature and the atmospheric temperature; Step 6: determining an intersection X between the tangent line a and the tangent line b for each of a plurality of combinations of the mixing temperature and the ambient temperature; Step 7: A step of determining the ratio [ambient temperature / as-mixed temperature] obtained by dividing the ambient temperature by the as-mixed temperature for each of a plurality of combinations of the as-mixed temperature and the ambient temperature in step 2; Step 8: A step of determining the relationship II between the time elapsed from the time of water injection indicated by the intersection point X and the ratio [ambient temperature / mixed temperature]; Step 9: A step of determining the ratio [time elapsed since water pouring / time elapsed since water pouring indicated by the intersection point X] obtained by dividing the time elapsed since water pouring based on the relationship I by the time elapsed since water pouring indicated by the intersection point X; Step 10: The ratio [time elapsed since pouring water / time elapsed since pouring water indicated by the intersection X] and the step of determining the relationship III between the penetration resistance value corresponding to the time elapsed since pouring water based on the relationship I; The above is calculated by <1> 2. A method for predicting the timing of application of the concrete composition described in claim 1. <3> Calculating the predicted elapsed time Step 11: A step of calculating a predicted elapsed time from the time of pouring water until the penetration resistance value appropriate for leveling the surface of the concrete composition is reached, based on the penetration resistance value appropriate for leveling the surface of the concrete composition from the relationship III and the elapsed time from the time of pouring water indicated by the intersection point X derived from the relationship II. <2> 2. A method for predicting the timing of application of the concrete composition described in claim 1. <4> Step 12: The method further includes a step of adding the predicted elapsed time from the time of pouring water calculated in step 11 until the penetration resistance value appropriate for leveling the surface of the concrete composition is reached to the actual time recorded at the time of pouring water in step 1, and determining a time to start the leveling work. <3> 2. A method for predicting the timing of application of the concrete composition described in claim 1. <5> Step 13: determining a range of penetration resistance values ​​suitable for leveling the surface of the concrete composition, <2> from <4> 1. A method for predicting the timing of application of a concrete composition according to any one of claims 1 to 8. <6> The range of penetration resistance suitable for leveling the surface of the concrete composition is 0.25 N / mm 2 ~1.00N / mm2 The above <2> from <5> 1. A method for predicting the timing of application of a concrete composition according to any one of claims 1 to 8. <7> The mixing temperature range is 5°C to 40°C. <1> from <6> 1. A method for predicting the timing of application of a concrete composition according to any one of claims 1 to 8. <8> The ambient temperature range is 5°C to 45°C. <1> from <7> 1. A method for predicting the timing of application of a concrete composition according to any one of claims 1 to 8. <9> The concrete composition comprises fine aggregate, coarse aggregate, and water. <1> from <8> 1. A method for predicting the timing of application of a concrete composition according to any one of claims 1 to 8. <10> A prediction device for the appropriate construction timing for leveling the surface of a concrete composition, A means for calculating a relational expression showing the relationship between the mixed temperature of the concrete composition, the ambient temperature at the time of pouring the concrete composition, and a predetermined penetration resistance value of the concrete composition; a means for calculating a predicted elapsed time from the time water is poured into the concrete composition until the concrete composition reaches the predetermined penetration resistance value; The present invention relates to a prediction device for predicting the timing of application of a concrete composition, the device comprising: <11> The means for calculating the relational expression is A means for inputting the time of adding water to the raw materials of the concrete composition; A means for inputting penetration resistance values ​​of the concrete composition corresponding to a plurality of combinations of the mixing temperature of the concrete composition when it is mixed and the ambient temperature when the mixed concrete composition is poured into a formwork; A means for determining a relationship I between the penetration resistance value and the elapsed time from the time of water injection; A means for determining, based on the relationship I, a tangent line a passing through a predetermined point of the penetration resistance value appropriate for leveling the surface of the concrete composition for each of a plurality of combinations of the mixing temperature and the ambient temperature; A means for determining a tangent line b passing through the origin at which the elapsed time from the time of pouring water is 0 hours based on the relationship I, for each of a plurality of combinations of the kneading temperature and the ambient temperature; A means for determining an intersection X between the tangent line a and the tangent line b for each of a plurality of combinations of the mixing temperature and the ambient temperature; A means for determining a ratio [ambient temperature / as-mixed temperature] obtained by dividing the ambient temperature by the as-mixed temperature for each of a plurality of combinations of the as-mixed temperature and the ambient temperature; A means for determining the relationship II between the time elapsed since the water pouring corresponding to the intersection X and the ratio [ambient temperature / mixed temperature]; A means for determining a ratio [time elapsed since water pouring / time elapsed since water pouring indicated by intersection point X] obtained by dividing the time elapsed since water pouring based on relationship I by the time elapsed since water pouring indicated by intersection point X; A means for determining a relationship III between the ratio [time elapsed since pouring water / time elapsed since pouring water indicated by the intersection X] and the penetration resistance value corresponding to the time elapsed since pouring water based on the relationship I; The aforementioned <10> 1 is a prediction device for predicting the timing of application of the concrete composition described in <12> The means for calculating the predicted elapsed time a means for calculating a predicted elapsed time from the time of pouring water until the penetration resistance value appropriate for leveling the surface of the concrete composition is reached, based on the penetration resistance value appropriate for leveling the surface of the concrete composition from the relationship III and the elapsed time from the time of pouring water indicated by the intersection point X derived from the relationship II; <11> 1 is a prediction device for predicting the timing of application of the concrete composition described in <13> The method further comprises a means for adding the predicted elapsed time from the time of pouring water calculated by the means for calculating the predicted elapsed time until the penetration resistance value appropriate for leveling the surface of the concrete composition is reached to the time of pouring water input by the means for inputting the time of pouring water, and determining a time to start the leveling work. <11> from <12> 1. A prediction device for predicting the timing of application of a concrete composition according to any one of the preceding claims. <14> The method further comprises determining a range of penetration resistance values ​​suitable for leveling the surface of the concrete composition. <11> from <13> 1. A prediction device for predicting the timing of application of a concrete composition according to any one of the preceding claims. <15> The aforementioned <1> from <9> A step of predicting the timing of application of a concrete composition using the method for predicting the timing of application of a concrete composition according to any one of the above items; mixing the concrete composition; Pouring the mixed concrete composition into a formwork; A step of leveling the surface of the concrete composition based on the predicted construction timing; A method for applying a concrete composition comprising the steps of: <16> The above-mentioned is used for constructing a joint between a pair of precast concrete slabs facing each other with a gap therebetween. <15> 2. A method for applying the concrete composition according to claim 1. <17> The joints of the precast concrete slab have a slope. <16> 2. A method for applying the concrete composition according to claim 1. <18> The gradient is 0.5% to 5%. <17> 2. A method for applying the concrete composition according to claim 1.

[0228] The aforementioned <1> from <9> A method for predicting the timing of construction of a concrete composition according to any one of the preceding claims. <10> from <14> A prediction device for predicting the timing of construction of a concrete composition according to any one of the preceding claims, and <15> from <18> The method for applying a concrete composition according to any one of the above items can solve the above-mentioned problems in the prior art and achieve the object of the present invention.

Claims

1. A method for predicting an appropriate construction timing for leveling the surface of a concrete composition, comprising: A method for predicting the timing of construction of a concrete composition, comprising: calculating a predicted elapsed time from the time water is poured into the concrete composition until the concrete composition reaches the predetermined penetration resistance value, using a relational equation that shows the relationship between the mixed temperature of the concrete composition, the ambient temperature at the time of pouring the concrete composition, and the predetermined penetration resistance value of the concrete composition.

2. The relation is: Step 1: determining the water pouring time for adding water to the raw materials of the concrete composition; Step 2: measuring the penetration resistance of the concrete composition corresponding to a plurality of combinations of the mixing temperature of the concrete composition when mixed and the ambient temperature when the mixed concrete composition is poured into a formwork; Step 3: determining the relationship I between the penetration resistance value and the elapsed time from the time of water injection; Step 4: determining, based on the relationship I, a tangent line a passing through a predetermined point of a penetration resistance value appropriate for leveling the surface of the concrete composition for each of a plurality of combinations of the mixing temperature and the ambient temperature; Step 5: Based on the relationship I, a tangent line b passing through the origin at which the elapsed time from the time of water pouring is 0 hours is determined for each of a plurality of combinations of the kneading temperature and the atmospheric temperature; Step 6: determining an intersection X between the tangent line a and the tangent line b for each of a plurality of combinations of the mixing temperature and the ambient temperature; Step 7: A step of determining a ratio [ambient temperature / as-mixed temperature] obtained by dividing the ambient temperature by the as-mixed temperature for each of a plurality of combinations of the as-mixed temperature and the ambient temperature in step 2; Step 8: A step of determining the relationship II between the time elapsed from the time of water pouring indicated by the intersection point X and the ratio [ambient temperature / kneaded temperature]; Step 9: A step of determining a ratio [time elapsed since water pouring / time elapsed since water pouring indicated by the intersection point X] obtained by dividing the time elapsed since water pouring based on the relationship I by the time elapsed since water pouring indicated by the intersection point X; Step 10: The ratio [time elapsed since pouring water / time elapsed since pouring water indicated by the intersection X] and the penetration resistance value corresponding to the time elapsed since pouring water based on the relationship I, and a step of determining a relationship III; The method for predicting the timing of application of a concrete composition according to claim 1, wherein the method is calculated by the following formula:

3. Calculating the predicted elapsed time Step 11: A step of calculating a predicted elapsed time from the time of pouring water until the concrete composition reaches a penetration resistance value appropriate for leveling the surface of the concrete composition, based on the penetration resistance value appropriate for leveling the surface of the concrete composition from the time of pouring water indicated by the intersection point X derived from the time of pouring water, from the time of pouring water.

4. Step 12: The method for predicting the timing of application of a concrete composition according to claim 3, further comprising a step of adding the predicted elapsed time from the time of pouring water calculated in step 11 until the penetration resistance value appropriate for leveling the surface of the concrete composition is reached to the actual time recorded at the time of pouring water in step 1, thereby determining a start time for leveling work.

5. Step 13: The method for predicting the timing of application of a concrete composition according to claim 2, further comprising the step of determining a range of penetration resistance values ​​appropriate for leveling the surface of the concrete composition.

6. The range of penetration resistance suitable for leveling the surface of the concrete composition is 0.25 N / mm ２ ~1.00N / mm ２ The method for predicting the timing of application of a concrete composition according to claim 2,

7. The method for predicting the timing of application of a concrete composition according to claim 1, wherein the mixed temperature ranges from 5°C to 40°C.

8. The method for predicting the timing of application of a concrete composition according to claim 1, wherein the ambient temperature range is 5°C to 45°C.

9. The method for predicting the timing of construction of a concrete composition according to claim 1 , wherein the concrete composition comprises fine aggregate, coarse aggregate, and water.

10. A prediction device for the appropriate construction timing for leveling the surface of a concrete composition, A means for calculating a relational expression showing the relationship between the mixed temperature of the concrete composition, the ambient temperature at the time of pouring the concrete composition, and a predetermined penetration resistance value of the concrete composition; a means for calculating a predicted elapsed time from the time water is poured into the concrete composition until the concrete composition reaches the predetermined penetration resistance value; A device for predicting the timing of application of a concrete composition, comprising:

11. The means for calculating the relational expression is A means for inputting the time of adding water to the raw materials of the concrete composition; A means for inputting penetration resistance values ​​of the concrete composition corresponding to a plurality of combinations of the mixing temperature of the concrete composition when it is mixed and the ambient temperature when the mixed concrete composition is poured into a formwork; A means for determining a relationship I between the penetration resistance value and the elapsed time from the time of pouring water; The concrete composition is then subjected to a series of mixing steps to obtain a concrete surface with a predetermined temperature and a predetermined value of the penetration resistance. A means for determining a tangent line b passing through the origin at which the elapsed time from the time of water pouring is 0 hours based on the relationship I, for each of a plurality of combinations of the kneading temperature and the atmospheric temperature; a means for determining an intersection X between the tangent line a and the tangent line b for each of a plurality of combinations of the mixing temperature and the ambient temperature; A means for determining a ratio [ambient temperature / as-mixed temperature] obtained by dividing the ambient temperature by the as-mixed temperature for each of a plurality of combinations of the as-mixed temperature and the ambient temperature; A means for determining the relationship II between the time elapsed since the water pouring corresponding to the intersection X and the ratio [ambient temperature / mixed temperature]; a means for determining a ratio (elapsed time from water pouring / elapsed time from water pouring indicated by the intersection point X) obtained by dividing the elapsed time from water pouring based on the relationship I by the elapsed time from water pouring indicated by the intersection point X; A means for determining a relationship III between the ratio [time elapsed since pouring water / time elapsed since pouring water indicated by the intersection X] and the penetration resistance value corresponding to the time elapsed since pouring water based on the relationship I; The apparatus for predicting timing of application of a concrete composition according to claim 10, comprising:

12. The means for calculating the predicted elapsed time 12. The apparatus for predicting the timing of application of a concrete composition according to claim 11, wherein the apparatus is means for calculating a predicted elapsed time from the time of pouring water until the concrete composition reaches a penetration resistance value appropriate for leveling the surface of the concrete composition, based on the penetration resistance value appropriate for leveling the surface of the concrete composition from the time of pouring water indicated by the intersection point X derived from the time of pouring water.

13. 12. The apparatus for predicting the timing of application of a concrete composition according to claim 11, further comprising a means for determining a start time of leveling work by adding a predicted elapsed time from the time of water pouring calculated by the means for calculating the predicted elapsed time until the penetration resistance value appropriate for leveling the surface of the concrete composition is reached to the time of water pouring input by the means for inputting the time of water pouring.

14. The apparatus for predicting the timing of application of a concrete composition according to claim 11, further comprising means for determining a range of penetration resistance values ​​appropriate for leveling the surface of the concrete composition.

15. A step of predicting the timing of application of a concrete composition using the method for predicting the timing of application of a concrete composition according to claim 1; mixing the concrete composition; Pouring the mixed concrete composition into a formwork; A step of leveling the surface of the concrete composition based on the predicted construction timing; A method for applying a concrete composition comprising:

16. A method for applying the concrete composition according to claim 15, wherein the concrete composition is used for applying a joint between a pair of precast concrete slabs facing each other with a gap therebetween.

17. 17. The method of applying a concrete composition according to claim 16, wherein the joints of the precast concrete slab have a slope.

18. 18. The method of claim 17, wherein the slope is between 0.5% and 5%.

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