• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
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    • 专利摘要:
    A method for predicting the maturity of af concrete during the curing process is disclosed. The method comprises the following steps:- predicting at least one future temperature within the concrete;- performing at least one temperature measurement, preferably a realtime temperature measurement of the concrete;- determining the energy production within the concrete.
    公开号:DK201700443A1
    申请号:DKP201700443
    申请日:2017-08-15
    公开日:2019-01-04
    发明作者:Ejersbo Petersen Tobias
    申请人:Sensohive Technologies Aps；
    IPC主号:
    专利说明:

    Method and System for Prediction of Concrete Maturity
    Field of invention
    The present invention relates to a method and a system for prediction of concrete maturity. The present invention more particularly relates to a method and a system for predicting early-stage strength and maturity in concrete.
    Prior art
    Temperature and maturity monitoring of concrete is an important issue because concrete constructions are used in various construction areas.
    Curing is the hydration process that occurs after the concrete has been placed, allowing calcium-silicate hydrate to form. Concrete curing requires time in order to gain strength and harden fully. In the following 15 the term setting is also used for curing.
    Optimum curing concrete leads to increased strength, whereas improper curing can cause scaling, reduced strength, poor abrasion resistance and cracking. Setting of cement is an exothermic process and the tem20 perature is a key parameter that has significant impact on the process, since the process time is important for coordination of the entire production time in production situations e.g. in a production facility. Accordingly, it is important to carry out temperature and/or maturity measurements on a continuous basis in order to monitor the curing pro25 cess.
    Moreover, in concrete element production facility, optimum coordination of the different production lines is required to save time. Accordingly, it is desirable to be able to predict concrete maturity so that the prepara30 tion of the next project on a production line can be carried out in good time. Basically, time and money can be saved by being able to predict concrete maturity.
    DK 2017 00443 A1
    The strength of concrete according to its class of strength is defined as the strength achieved after 28 days curing in a curing frame at 20oC. The temperature, however, typically varies as function of time and is 5 not kept at 20oC at the entire time-period. The chemical reactions occurring during setting of cement depends on the temperature and the relationship between the reaction time and temperature, confer the below-mentioned formula:
    ω_ , . , . The velocity at the actual temperature
    The relative velocity =-------------------------------------The velocity at 20o C
    The generated heat can be expressed as function of the maturity of the concrete. The maturity M is given by:
    n (2) M = Σ Hθ) -&t,, i=l where At{ is the length of the interval i;
    θ is the mean temperature in the time interval i, and
    H θ) is the velocity function defined by the following equation:
    (3)
    E(θ). ( 1 + 1 Ί'
    R (293 273 + θ) where R is the gas constant 8.314 J/mol oK;
    E(θ) is the activation energy for the concrete mixture.
    (4) E(θ) = 33.500 J / mol, for θ> 20oC (5) E(θ) = 33.500 J / mol +1470 (20 - θ), for θ< 20o C,
    Graphically, this can be expressed in the graph below:
    DK 2017 00443 A1
    Temperature influence on setting
    The duration of the setting depends on the concrete temperature. The relationship between the duration of the setting and the concrete temperature is shown in the following graph.
    Duration [days] Temperature influence on duration of the setting period
    The heat development Q is expressed as energy per kg cement and is determined by the following equations:
    Δβ„ = AQacc,n+AQtrans,n
    DK 2017 00443 A1 (7) Q = ΣXQ, n=1 where:
    AQacc,n is the change of accumulated energy in the concrete during the interval Atn;
    AQtrans,n is the change of transmitted energy from the concrete to the surroundings during the time interval Atn;
    θη and θη+1 is the concrete temperature at the beginning and end of the time interval Atn;
    C is the content of cement per m3 concrete measured in kg/m3;
    pc is the density of concrete measured in kg/m3;
    Cc is the specific heat of the concrete;
    fc n and fc n+1 is the output from box wall transducer at the beginning and end of the time interval;
    mc is the weight of the concrete sample (measured in kg);
    at is a calibration factor, and
    Atn is the time interval = tn+1-tn
    Prediction of the early-stage (e.g. the first 18 hours) strength of concrete is essential for the manufacturing of structural parts. Economic 20 and safe scheduling of such operations as form removal and reshoring and application of post-tensioning, and rapid delivery of products all are required to be based upon a good prediction of the strength development of the concrete in use. When manufacturing structural parts knowledge of the early-stage strength of concrete is of special im25 portance. Accelerated curing is used to achieve high early age strength in concrete. Accelerated curing techniques are particularly useful in the prefabrication industry, wherein high early age strength enables a fast removal of the formwork (e.g. within 24 hours). Hereby it is possible to
    DK 2017 00443 A1 reduce the cycle time and save costs. Accelerated curing can be achieved by using active heating e.g. by means of a heating source such as warm water, steam or electric heating. A curing cycle typically involves a preheating stage (delay period) in the range between 2 to 5 5 hours, in which the temperature is increased until a predefined maximum temperature (e.g. within the range 50-82 °C) has been achieved. Hereafter the maximum temperature is maintained, where after a cooling period is provided. Preferably, the entire cycle should not exceed 18 hours. Early-stage strength and maturity prediction of concrete may be 10 used to utilise the staff and production capacity in a more optimum manner in manufacturing of structural parts.
    One of the challenges is that environmental (e.g. ventilation and heat exchange with surrounding structures) heavily influences the curing 15 time. If a concrete production line comprises a supporting table that is heated, the concrete being poured into a frame supported by the supporting table will receive a high initial temperature. On the other hand, if the gates in a production hall are opened, the air temperature may suddenly drop and an increased airflow may introduce a cooling of the 20 concrete. All these factors are, at present, not taken into account. Accordingly, average curing times suitable under standard conditions are applied for lack of anything better. Unfortunately, this strategy sometimes leads to production of constructions with improper curing, which may cause scaling, reduced strength, poor abrasion resistance and 25 cracking. These constructions are typically thrown away as waste. On the other hand, in many situations, the actual curing time is shorter than the estimated curing time. Accordingly, a lot of free capacity in production facilities are used because most production facilities use the principle: better safe than sorry” meaning that safety-time is added to 30 the estimated curing time in order to be safe”.
    Thus, there is a need for a method and a system for prediction of conDK 2017 00443 A1 crete maturity.
    It is an object of the invention to provide a method and a system for prediction of concrete maturity.
    Summary of the invention
    The object of the present invention can be achieved by a method as defined in claim 1 and a system as defined in claim 7. Preferred embodiments are defined in the dependent subclaims, explained in the follow10 ing description and illustrated in the accompanying drawings.
    The method according to the invention is a method for predicting the maturity of concrete during the curing process, wherein the method comprises the following steps:
    - predicting at least one future temperature within the concrete;
    - performing at least one temperature measurement, preferably a realtime temperature measurement of the concrete;
    - determining the energy production within the concrete;
    Hereby, it is possible to provide a method for prediction of concrete maturity. The method can be used to predict strength, production time and maturity target reached temperature. Accordingly, by applying the method according to the invention it is possible to save time (using free capacity at productions lines) and to avoid errors made by applying too short curing periods. It is also possible to alert the risk for exceeding a predefined maximum allowable temperature limit before the temperature is exceeded. The method according to the invention makes it possible to detect that a too high temperature will be achieved if the heating process is continued. Accordingly, it is possible to turn off an exter- nal heating source and/or activate a cooling unit in order to regulate the temperature and avoid that that the temperature exceeds the maximum allowable temperature limit.
    DK 2017 00443 A1
    The method can be used to predict the future maturity of the concrete during the curing process and the remaining production time. By displaying this piece of information e.g. in a large production facility, it is 5 possible to enable and initiate new productions (e.g. starting up production on a production line, in which the strength of the construction is so enough that the construction may be removed) much faster than today. Moreover, errors can be eliminated because measurements are carried out to make sure that the curing process has reached a predefined ac10 ceptable level.
    The step of predicting at least one future temperature within the concrete is preferably carried out by using information about the relationship between temperature and heat generation in concrete.
    The step of performing at least one temperature measurement, preferably a real-time temperature measurement of the concrete, is preferably carried out by using one or more temperature sensors.
    In a preferred embodiment according to the invention the method is applied for prediction of maturity of the concrete during the early-stage curing process.
    In one embodiment according to the invention, the at least one temper25 ature measurement, is carried out by using one or more temperature sensors comprising one or more thermocouples embedded into the concrete.
    The step of determining the energy production within the concrete is 30 preferably carried out by applying information about the temperature of the concrete.
    DK 2017 00443 A1
    It may be an advantage that the method comprises the step of determining one or more environmental parameters. The one or more environmental parameters may be measured by using one or more sensors.
    The one or more environmental parameters may be one or more of the following:
    - the temperature of a supporting structure (e.g. a table supporting a concrete construction;
    - the environmental humidity;
    - ventilation measurement(s) such as airflow (velocity) and/or temperature that may influence the temperature of the concrete.
    It may be advantageous that the determination of the energy production within the concrete is performed by using the flowing formula:
    Q =^Q acc, n + AQ trans, n = (θη+ -«η ) · Cc P + at ' Pc f c, n + f c, n+1 m^c 2 •At where:
    AQacc,n is the change of accumulated energy in the concrete during the interval Atn;
    &Qtrars,n is the change of transmitted energy from the concrete to the surroundings during the time interval Atn;
    θη and θη+1 is the concrete temperature at the beginning and end of the time interval Atn;
    C is the content of cement per m3 concrete measured in kg/m3;
    pc is the density of concrete measured in kg/m3;
    Cc is the specific heat of the concrete;
    fc n and fc n+1 is the output from box wall transducer at beginning and
    DK 2017 00443 A1 end of the time interval;
    mc is the weight of the concrete sample (measured in kg);
    at is a calibration factor, and
    Atn is the time interval = tn+1-tn
    The heat development Q within the concrete can be calculated by using
    N-1 the following formula: Q = ΣAQn, n=1
    It may be beneficial that the environmental parameters are saved to form historical data.
    The environmental parameters may be stored in any suitable storage unit, e.g. on a server being accessible via the Internet.
    It may be an advantage that the environmental parameters include:
    - one or more environmental temperatures and/or
    - one of more air circulation measurements and/or
    - one or more humidity measurements.
    These parameters are easy to measure by using one or more sensors.
    Moreover, these parameters influence the concrete and thereby the heat generation of the concrete.
    It may be advantageous that at least some of the historical data are used for predicting at least one future temperature within the concrete. Hereby, it is possible to perform a better and more accurate prediction. The system according to the invention is a system for predicting the maturity of the concrete during the curing process, wherein the system
    DK 2017 00443 A1 comprises:
    - a predicting unit configured to predict at least one future temperature within the concrete;
    - at least one temperature sensor configured to perform temperature measurements, preferably real-time temperature measurements of the concrete;
    - an energy production estimator configured to estimate the energy production within the concrete.
    Hereby, it is possible to provide a system for prediction of concrete maturity. The method can be used to predict strength, production time and maturity target reached temperature. Accordingly, by applying the system according to the invention it is possible to save time (using free capacity at productions lines) and to avoid errors made by applying too short curing periods.
    The predicting unit may be formed as a processing unit e.g. being part of a computer or another electrical device configured to carry out the required calculations. In one embodiment according to the invention, the system comprises a web-based predicting unit that may be provided in a server accessible via the Internet.
    The predicting unit is configured to predict at least one future temperature within the concrete.
    The system comprises at least one temperature sensor configured to perform temperature measurements, preferably real-time temperature measurements of the concrete. The temperature sensor may be any suitable type of temperature sensor capable of detecting the tempera30 ture of the concrete.
    In one embodiment according to the invention, the at least one temper
    DK 2017 00443 A1 ature measurement, is carried out by using one or more temperature sensors comprising one or more thermocouples embedded into the concrete.
    The system comprises an energy production estimator configured to estimate the energy production within the concrete. The energy production estimator may be formed as a processing unit e.g. being part of a computer or another electrical device configured to carry out the required calculations. In one embodiment according to the invention, the 10 system comprises a web-based energy production estimator that may be provided in a server accessible via the Internet.
    It may be advantageous that the system comprises:
    - one or more environmental parameter determination units configured to determination one or more environmental parameters influencing the temperature of the concrete;
    Hereby, it is possible to take one or more environmental parameters influencing the temperature of the concrete into account in future pre20 dictions. Accordingly, the method according to the invention may gradually be improved as time goes by.
    The one or more environmental parameter determination units may be configured to determine (e.g. measure) one or more of the following:
    - the temperature of a supporting structure such as a table;
    - environmental humidity;
    - and/or ventilation measurement(s) such as airflow (velocity) and temperature) influencing the temperature of the concrete.
    It may be beneficial that the system is configured to store one or more environment parameters to form historical data.
    DK 2017 00443 A1
    Hereby, the environmental parameters forming historical data can be used to improve the accuracy of the system
    It may be an advantage that the system is configured to predict at least one future temperature within the concrete on the basis of the historical data.
    It may be preferred that real-time temperature measurements of the concrete are carried out on a continuous basis.
    It may be advantageous that real-time temperature measurements of the concrete are carried out on a continuous basis by using temperature sensors and a thermocouple electrically connected to said sensors.
    It may be an advantage that the temperature measurements are carried out by using a voltage sensor configured to measure the electric potential difference between two dissimilar conductors of the thermocouple cable.
    Description of the Drawings
    The invention will become more fully understood from the detailed description given herein below. The accompanying drawings are given by way of illustration only, and thus, they are not limitative of the present invention. In the accompanying drawings:
    Fig. 1A shows a schematic view of the setting time of concrete constructions produced on six production lines;
    Fig. 1B shows a cross-sectional view of a concrete construction being made by means of a casting frame in a production facility, in which the concrete emits heat to air above the concrete;
    Fig. 1C shows a cross-sectional view of the concrete construction
    DK 2017 00443 A1 shown in Fig. 1B, in a situation, in which the concrete receives heat from the air above the concrete;
    Fig. 2A shows a graph depicting measurement values from a calorimetric test, in which temperature is shown as function of 5 time;
    Fig. 2B shows a curve for a standard curing process and an accelerated curing process;
    Fig. 3A shows an example of, how the method according to the invention can be used to adjust the environmental influ10 ence to predict the temperature development and hereafter the maturity and corresponding strength of the concrete;
    Fig. 3B shows another example of, how the method according to the invention can be used to adjust the environmental influence to predict the temperature development and here15 after the maturity and corresponding strength of the conFig. 4
    Fig. 5 crete;
    shows a flowchart illustrating the steps carried out to predict the maturity of concrete according to one embodiment of the method of the invention;
    shows an example of, how the method according to the invention can be used to adjust the environmental influence to predict the temperature development and hereafter the maturity and corresponding strength of the concrete;
    Fig. 6A shows a cross-sectional view of a casting frame and two mounting devices according to the invention each attached to a rod, and
    Fig. 6B shows the casting frame shown in Fig. 6A while concrete has been poured into the casting frame.
    Detailed description of the invention
    Referring now in detail to the drawings for the purpose of illustrating preferred embodiments of the present invention, Fig. 1A illustrates a
    DK 2017 00443 A1 schematic view of the curing time Tc (setting time) of concrete constructions produced on six production lines Li, L2, L3, L4, L5, Le arranged in a production facility to produce the same construction.
    The curing time TC of the production lines Li, L2, L3, L4, L5, Le is indicated by boxes filled with dots. The estimated (safe) curing time E is indicated on the curing time axis. It can be seen, that the curing time of the first production line Li is shorter than the estimated (safe) curing time E. Accordingly, there is a capacity available” CAi. This means that 10 the construction process of the first production line Li could have been terminated and a new production process could have been initiated. Accordingly, time could have been saved.
    The curing time of the second production line L2 is even shorter than 15 the curing time of the first production line Li and therefore also shorter than the estimated curing time E. Therefore, there is a capacity available” CA2 and the construction process of the production line L2 may have been terminated in order to initiate a new production process.
    The curing time of the third production line L3 is longer than the estimated curing time E. Therefore, a construction process is actually terminated before the construction has received the required maturity and strength. Accordingly, the construction cannot be used and will therefore be waste.
    The curing time of the fourth production line L4 is shorter than the curing time of the first production lines Li and L2 as well as the estimated curing time E. Thus, there is a capacity available” CA3 and the construction process of the production line L4 could have been terminated 30 in order to use the production line L4 and initiate a new production process.
    DK 2017 00443 A1
    The curing time of the fifth production line L5 corresponds to the estimated curing time E.
    The curing time of the sixth production line Lß is shorter than the esti5 mated curing time E. Accordingly, there is a capacity available” CA4 and the construction process of the production line Le may have been terminated in order to initiate a new production process.
    Fig. 1A illustrates that even when constructing the same construction, 10 environmental influences makes it very difficult to estimate the curing time. Even though an additional safety-time is added to the estimated curing time E errors occur. Furthermore, a lot of time is wasted.
    Fig. 1B illustrates a cross-sectional view of a concrete construction be15 ing made by means of a casting frame 38 in a production facility, in which the concrete 36 emits heat 8 to the surrounding air above the foil 28 covering the top side of the concrete 36. The casting frame 38 is part of a support unit 4 shaped as a table with legs and an integrated heating unit 24 comprising electrical heating wires supplied with power 20 from an electrical connection (socket) 12 connected to a power supply by means of an electric plug 14. Alternatively, heating tubes may be arranged and configured to circulate a heating fluid (e.g. water) inside the casting frame 38.
    The heating unit 24 generates heat 6 that is transferred to the concrete in order to initiate or speed op the curing process. A system 50 according to the invention is applied to monitor the concrete construction process on a continuous basis. The system 50 comprises two sensors 26, 26' arranged to monitor the temperature inside the concrete 36.
    Each sensor 26, 26' measures the temperature of the concrete 36. The first sensor 26' measures the temperature of the concrete 36 by means of a cable 20 comprising a thermocouple embedded in the concrete 36.
    DK 2017 00443 A1
    The other sensor 26 is embedded in the concrete and measures the temperature of the concrete 36 and sends a wireless signal to a receiving unit. The cable 20 and the sensor 26 are attached to an elongated body (a rebar) 10 embedded in the concrete 36.
    The system 50 comprises a humidity sensor 16 arranged to measure the humidity of the surrounding air. The system 50 also comprises an airflow (velocity) sensor 22 arranged and configured to measure the flow of the circulating air 18 surrounding the top portion of the concrete 10 36.
    The sensors 16, 22, 26, 26' are arranged and configured to transmit the collected data wirelessly to an external device such as a server 44 via the Internet 42. The sensors 16, 22, 26, 26' may be configured to 15 communicate directly with an external device such as a smartphone 46.
    The smartphone 46 may communicate wirelessly with the Internet 42 and/or an Internet-based server 44.
    Fig. 1C illustrates a cross-sectional view of the concrete construction 20 shown in Fig. 1B, in a situation, which the concrete 36 receives heat 9 from the air above the concrete 36.
    Fig. 2A illustrates a graph depicting measurement values from a calorimetric test (e.g. a Quasi-adiabatic test), in which temperature 34 is 25 shown as function of time 32.
    A Quasi-adiabatic test makes it possible to estimate the heat being released due to the hydration of cement contained in the concrete specimen. The test incorporates all possible interactions between concrete 30 components, including the effects of admixtures.
    The calorimeter used for carrying out the test is typically a double
    DK 2017 00443 A1 walled caisson filled with an insulating material (e.g. polyurethane foam). The external wall may be made of polyvinyl chloride (PVC) and the internal wall may be of fiberglass-reinforced polyester.
    The test is conducted on the concrete compound in order to be able to perform temperature predictions using the test results. The test determines the produced energy from the exotherm process in the concrete as a function of the maturity in of the concrete. The test may be conducted in accordance with standards such as the NT BUILD 388 standard or the DS 423.37 e.g. a Quasi-adiabatic calorimetry test.
    The method according to the invention applies the information about, how energy development in the concrete occurs as function of time and the method applies real-time measurements in the concrete as well as the environment. This information makes it possible to isolate the environmental factor from the structures surrounding the concrete and assess the influence this will have on the future development (curing process).
    The duration of the first time interval (ti to t2) equals the duration Är2 of the second time interval (t2 to t3) and the duration At3of the third time interval (t3 to t4). The time intervals Atr, At2, At3 may e.g. be 60-1200 seconds, such as 120-900 seconds, preferably 300-900 seconds such as 450-800 second. In one test scenario, the time intervals Atx, At2, Är3are 600 seconds.
    Example 1
    In one example, the following values may be recorded:
    Atr, At2, At3 = 600 seconds;
    ΔΕι = 320 Joule, ΔΕ2 = 540 Joule, ΔΕ3 = 920 Joule;
    = 25°C, θ2 = 27°C, 03 = 30°C, Θ, = 38°C;
    DK 2017 00443 A1
    The quasi-adiabatic test identifies the amount of generated energy within the concrete in a 100% isolated environment. This reveals the relationship between the energy development and maturity of the con5 crete in a 100% isolated environment.
    Fig. 2B illustrates a curve 56 for a standard curing process as well as a curve 54 for an accelerated curing process, in which the strength 52 is plotted as function of time 32. The curing process is typically considered 10 to be accomplished after 28 days. The initial inclination of the curve 56 for the standard curing process is lower than the initial inclination of the curve 54 for the accelerated curing process. Accordingly, application of the accelerated curing process enables a much faster removal of construction produced e.g. in a production concrete panel factory.
    Fig. 3A illustrates a graph depicting measurement values during a concrete curing process, in which temperature 34 is shown as function of time 32. Four first measurement points B1, B2, B3, B4 are plotted in the graph. The theoretical point (calculated assuming 100% insulation) A1 is 20 plotted next to these points. A fifth measurement point B5 is plotted in the graph below the theoretical point A1. The difference between the fifth measurement point B5 and the theoretical point A1 is caused by environmental influence X. When using the method according to the invention, temperature measurements of the concrete are carried out 25 (preferably in real-time). Accordingly, it is possible to calculate the maturity of the concrete and match that with the energy development in the concrete. This enables determination of the amount of energy developed in the concrete, which energy can be correlated with the actual temperature development.
    Fig. 3B illustrates an example of, how the method according to the invention can be used to adjust the environmental influence to predict the
    DK 2017 00443 A1 temperature development and hereafter the maturity and corresponding strength of the concrete. The graph comprises the same points as the graph shown in Fig, 3A, however a projected point Z1 is added. The projected point Z1 is estimated by using the method according to the in5 vention applying the steps shown in the flowchart shown in Fig. 4. It can be seen, that the projected point Z1 is below the theoretical point A2 (assuming 100% insulation). The difference between the projected point Z1 and the theoretical point A2 is caused by environmental influence X. The environmental temperature C is shown in Fig. 3B.
    In one embodiment according to the invention, the method comprises the step of collecting environmental influence data. Hereby, it is possible to apply the data to improve the prediction precession of the method.
    In one embodiment according to the invention, the temperature of a support unit (e.g. a table) can be measured and collected (and preferably stored in a data storage). This temperature influences the curing process and may therefore be used to perform optimized future predic20 tions.
    In one embodiment according to the invention, the humidity of the surrounding air is measured and stored in a data storage. The specific heat capacity of humid air is greater than dry air and humid air will take 25 more energy to heat by a given amount. Accordingly, the humidity of the surrounding air influences the curing process and may therefore be used to perform optimized future predictions.
    In one embodiment according to the invention, the velocity of an airflow 30 adjacent to the concrete and/or the frame, into which the concrete is poured, is measured and stored in a data storage. The velocity of an airflow adjacent to the concrete and/or the frame influences the curing
    DK 2017 00443 A1 process. Accordingly, the velocity of an airflow adjacent to the concrete and/or the frame may therefore be used to perform optimized future predictions.
    In a preferred embodiment according to the invention, the temperature C of the surroundings is measured and stored in a data storage on a continuous basis. The temperature of the surroundings influences the curing process and therefore, it may be advantageous to apply the temperature of the surroundings to perform optimized future predic10 tions.
    Fig. 4 illustrates a flowchart illustrating the steps carried out to predict the maturity of concrete according to one embodiment of the method of the invention. Step I, is a step of calculating the maturity of the con15 crete. Step I, is carried out on the basis of an estimated temperature (carried out in Step four IV). Initially, when no temperature is estimated (in Step four IV), measured temperature values are applied. The temperatures are preferably measured by means of temperature sensors embedded in the concrete.
    Step II represents the step of projecting the internal energy generated inside the concrete. This can be applied by using the previously mentioned equation (6):
    (6) Q =^Q acc, n + AQ trans, n = («,+1 ) · Cc ~ + at · pc fc, n + fc .— •At mc C 2 t
    Step III represents the step of applying environmental influencing factors. This step may include applying information about the temperature of a support unit (e.g. a table), the humidity of the surrounding, the 30 velocity of an airflow adjacent to the concrete and/or the frame, the
    DK 2017 00443 A1 temperature of the surroundings.
    Step IV represents the step of estimating concrete temperature. This is effected by using historic data collected, preferably in the production 5 facility and even better in the actual production line within the production facility.
    Performing an analysis on the historical data enables the method according to the invention to take into account the influences (e.g. the 10 temperature of a support unit (e.g. a table) and/or the humidity of the surrounding and/or the velocity of an airflow adjacent to the concrete and/or the frame and/or the temperature of the surroundings) of the environment in which the concrete is manufactured. Accordingly, the historical data can be used to improve the prediction of the future tem15 perature development.
    The process for estimating the next data point is illustrated by the flowchart: The current maturity is calculated in Step I, the energy development is determined in Step II, the environment is accounted in 20 Step III. Step III makes it possible to derive at the next temperature point in Step IV.
    The process steps illustrated in Fig. 4 can now be repeated. Hereby, it is possible to estimate the remaining temperature development as illus25 trated in Fig. 5.
    Each repetition may factor in the new maturity and the corresponding energy development in the concrete. The environmental influence is adjusted according to surrounding parameters such as temperature, 30 humidity and air circulation.
    Fig. 5 illustrates an example of, how the method according to the inven
    DK 2017 00443 A1 tion can be used to adjust the environmental influence to predict the temperature development and hereafter the maturity and corresponding strength of the concrete.
    The graph depicts concrete temperature as function of time. The first portion of the graph corresponds to the graph shown in Fig. 3B. Further points have been added. These points are: A3, A4, A5, Ae, A7, Z2, Z3, Z4, Z5 and Z6 corresponding to the remaining curing period.
    Once the temperature development is predicted, the maturity of the concrete is predicted by using the steps shown in Fig. 4. The corresponding strength of the concrete can also be determined. In this manner, the method according to the invention, enables one to derive at the estimated time of completion for an element.
    In a preferred embodiment according to the invention, for each new data point measured by sensors, a recalculate the entire method is carried out to improve accuracy and improve the data model for estimating the environmental influence.
    Fig. 6A illustrates a cross-sectional view of a casting frame 38 and two mounting devices 2 configured to be used to attach thermocouples to rebar 10. Fig. 6B illustrates the casting frame 38 shown in Fig. 6A while concrete 36 has been poured into the casting frame 38. Concrete 36 is 25 poured into the casting frame 38 by means of a concrete nozzle 40.
    The sensors 26 may be configured to communicate wirelessly with an external device such as a server 44 via the Internet 42. The sensors 26 may be configured to communicate directly wirelessly with an external 30 device such as a smartphone 46. The smartphone 46 may communicate wirelessly with the Internet 42 and/or an Internet-based server 44.
    DK 2017 00443 A1
    In one embodiment according to the invention, the sensor 26' may be integrated in the mounting device 2 or detachably attached to the mounting device 2. Hereby, the server 26' may be attached to a rebar 10 by means of a mounting device 2' according to the invention. In such a solution, wireless communication may be provided between the sensor 26' and an external device such as a server 44 via the Internet 42. The sensors 26' may also be configured to communicate directly and wirelessly with an external device such a smartphone 46.
    The rebar 10 is part of a rebar cage (steel mesh). Each mounting device 2 is attached to a cable 20 that is plugged into a sensor 26. The sensors may be configured to perform real-time temperature and maturity monitoring of the concrete 36. The temperature may be detected by means of a cable 20 comprising a thermocouple having two dissimilar conductors forming electrical junctions at differing temperatures which are capable of producing a temperature-dependent voltage.
    DK 2017 00443 A1
    List of reference numerals
    2, 2'
    6
    14
    24
    26, 26'
    34
    44
    54, 56
    X
    Tc
    E
    Mounting device
    Support unit (table with integrated heating unit)
    Heat from the support unit
    Heat from the concrete to the surrounding
    Heat from the surroundings to the concrete
    Elongated body
    Electrical connection (socket)
    Electric plug
    Humidity sensor
    Circulating air
    Cable
    Airflow sensor
    Heating unit
    Sensor
    Foil
    Missing curing time
    Time
    Temperature
    Concrete
    Frame
    Concrete nozzle
    Internet
    Server
    External device
    System
    Strength
    Curve
    Longitudinal axis
    Curing time
    Prior art estimated curing time
    DK 2017 00443 A1
    CA1, CA2, CA3, CA4Li, L2, L3, L4, L5, Le θη , θη+1 , θΐ - θ2 - θ3 > θ4ΔΟ^acc, ηCapacity availableProduction lineConcrete temperatureChange of accumulated energy in the concrete5ΔΟ- ηChange of transmitted energy from the concrete CContent of cement PcDensity of concrete CcSpecific heat of the concrete fc, n , fc, n+1Output from box wall transducer10 mcWeight of the concrete sample a tCalibration factor QHeat development Δίη, Δί1, Δί2, Δί3 Time interval (tn+i-tn) Bi, B2, B3, B4, B5Measurement point15Ai, A2, A3, A4Theoretical point (100% insulation) A5, A6, A7Theoretical point (100% insulation) Z1, Z2, Z3, Z4, Z5, Z6Projected point XEnvironmental influence ICalculation of maturity20IIProjection of internal energy IIIApplying environmental influencing factors IVEstimating concrete temperature
    权利要求:
    Claims (11)
    [1] Claims
    1. A method for predicting the maturity of a concrete (36) during the curing process, characterised in that the method comprises the following steps:
    - predicting at least one future temperature (θη+1) within the concrete (36);
    - performing at least one temperature measurement (B1, B2, B3, B4, B5), preferably a real-time temperature measurement (B1, B2, B3, B4, B5) of the concrete (36);
    - determining the energy production (AQn) within the concrete (36).
    [2] 2. A method according to claim 1, characterised in that the method comprises the step of determining one or more environmental parameters influencing the temperature of the concrete (36).
    [3] 3. A method according to claim 1 or 2, characterised in that the determination of the energy production (AQn) within the concrete (36) is performed by using the flowing formula:
    Q = AQ ace, n + ÄQ trans, n = (θη+1 ~θη ) Cc -P +
    At ' Pc fc, n + fe
    Me C 2 n where:
    AQA ,n is the change of accumulated energy in the concrete during the interval Atn;
    AQtrans,n is the change of transmitted energy from the concrete to the surroundings during the time interval Atn;
    θη and θη+1 is the concrete temperature at the beginning and end of the time interval Atn;
    DK 2017 00443 A1
    C is the content of cement per m3 concrete measured in kg/m3;
    pc is the density of concrete measured in kg/m3;
    Cc is the specific heat of the concrete;
    fc N and fc N+1 is the output from box wall transducer at the beginning and end of the time interval;
    mc is the weight of the concrete sample (measured in kg);
    at is a calibration factor, and
    Atn is the time interval = tn+1-tn
    [4] 4. A method according to one of the preceding claims, characterised in that the environmental parameters are saved to form historical data.
    [5] 5. A method according to one of the preceding claims, characterised in that the environmental parameters include:
    - one or more environmental temperatures and/or
    - one of more air circulation measurements and/or
    - one or more humidity measurements.
    [6] 6. A method according to one of the claims 4-5, characterised in that at least some of the historical data are used for predicting at least one future temperature (Tf1, Tf2) within the concrete (36).
    [7] 7. A system (50) for predicting the maturity of a concrete (36) during the curing process, characterised in that the system (50) comprises:
    - a predicting unit configured to predict at least one future temperature (θη+1) within the concrete (36);
    - at least one temperature sensor (26, 26') configured to perform temperature measurements, preferably real-time temperature measurements of the concrete (36);
    - an energy production estimator configured to estimate the energy
    DK 2017 00443 A1 production (AQacc,n) within the concrete (36).
    [8] 8. A system (50) according to claim 7, characterised in that the system (50) comprises:
    5 - one or more environmental parameter determination units configured to determination of one or more environmental parameters influencing the temperature of the concrete (36).
    [9] 9. A system (50) according to claim 7 or 8, characterised in that the 10 system (50) is configured to store one or more environmental parameters to form historical data.
    [10] 10. A system (50) according to one of the claim 9, characterised in that the system (50) is configured to predict at least one future tem-
    [11] 15 perature (Tf1, Tf2) within the concrete (36) on the basis of the historical data.
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    同族专利:
    公开号 | 公开日
    CA3072381A1|2019-02-21|
    US20200182812A1|2020-06-11|
    DK179490B1|2019-01-07|
    WO2019034217A1|2019-02-21|
    EP3669188A1|2020-06-24|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US20140353864A1|2013-05-28|2014-12-04|Chester Grochoski|System, method and apparatus for controlling ground or concrete temperature|CN111964807A|2020-08-28|2020-11-20|烟台大学|Cement concrete pavement joint cutting detection device and method|
    法律状态:
    2019-01-04| PAT| Application published|Effective date: 20190104 |
    2019-01-07| PME| Patent granted|Effective date: 20190107 |
    优先权:
    申请号 | 申请日 | 专利标题
    DKPA201700443A|DK179490B1|2017-08-15|2017-08-15|Method and System for Prediction of Concrete Maturity|DKPA201700443A| DK179490B1|2017-08-15|2017-08-15|Method and System for Prediction of Concrete Maturity|
    EP18759850.3A| EP3669188A1|2017-08-15|2018-08-02|Method and system for prediction of concrete maturity|
    CA3072381A| CA3072381A1|2017-08-15|2018-08-02|Method and system for prediction of concrete maturity|
    PCT/DK2018/050188| WO2019034217A1|2017-08-15|2018-08-02|Method and system for prediction of concrete maturity|
    US16/792,029| US20200182812A1|2017-08-15|2020-02-14|Method and system for prediction of concrete maturity|
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