A method and system for testing the initial setting time of roller compacted concrete in the field

Abstract

The application provides a kind of roller compacted concrete initial setting time field test method and test system, lack of the technical problem of continuously and effectively carrying out roller compacted concrete layer initial setting time test is solved.System includes: electromotive force sensor, for forming primary cell structure in combination with cement paste in the laying position of concrete, forming the primary cell electromotive force signal source of concrete hydration process;Signal processing module, for controlled acquisition of electromotive force signal, form electromotive force data after analog-digital conversion;Wireless transmission network, for the transmission of downlink acquisition control data and uplink electromotive force data;Remote control analysis host, for controlling the acquisition and reception of parallel electromotive force data, data processing is carried out to electromotive force data to form electromotive force change trend, according to pre-set rule identifies clear state or parameter in change trend, and output on man-machine interface.The identification of concrete initial setting time is determined by calculating the trend curve of the change of electromotive force with time through the collection and measurement of electromotive force.

Description

Technical Field

[0001] This invention relates to the field of signal monitoring technology, specifically to a field testing method and system for the initial setting time of roller-compacted concrete. Background Technology

[0002] In existing technologies, roller-compacted concrete (RCC) dam construction technology transplants large-scale construction machinery used in earth-rock dams onto concrete dams, achieving rapid, large-area compaction. It offers advantages such as saving concrete (i.e., cement), simple and easy construction, short construction period, and low cost, resulting in significant economic and social benefits. During RCC dam construction, strictly controlling the quality of compaction and the quality of layer bonding are reliable guarantees for improving the impermeability and robustness of the RCC dam. The quality of layer bonding directly affects important properties of the dam body, such as seepage characteristics, splitting tensile strength, and shear strength, and will directly affect the safe operation of the dam. The initial setting time of the RCC layer is crucial to ensuring the quality of layer bonding.

[0003] In roller-compacted concrete (RCC) construction, the initial setting time testing methods commonly used in RCC surface control include the degree-time method, setting time control method, and penetration resistance method. While the degree-time method and setting time control method are simple, they cannot reflect the changes in the physicochemical properties of the RCC surface during setting, and cannot accurately obtain the initial setting time under complex site conditions. The penetration resistance method uses selected measurement points, which is slow, has a low sampling rate, and is susceptible to human interference. Currently, an electrical method exists. During the hydration process after water is added to the concrete, the resistance changes abruptly with the setting process. Measuring the change in resistance of the concrete mixture over time can characterize the initial and final setting of the concrete, offering better continuity compared to other testing methods. However, existing electrical methods require specialized equipment, electrode installation and preparation are complex, and factors such as electrode insertion depth and spacing significantly affect the measurement results. During RCC construction, the concrete is in a dynamic state, making it difficult to ensure accurate and stable electrode positioning. Summary of the Invention

[0004] In view of the above problems, embodiments of the present invention provide a field testing method and system for the initial setting time of roller-compacted concrete, solving the technical problem of lacking effective technical means to continuously and effectively test the initial setting time of roller-compacted concrete surfaces.

[0005] The field testing system for the initial setting time of roller-compacted concrete according to an embodiment of the present invention includes:

[0006] An electromotive force sensor is used to combine with cement slurry in concrete at the deployment location to form a galvanic cell structure, thereby creating a galvanic cell electromotive force signal source for the concrete hydration process.

[0007] The signal processing module is used to collect electromotive force signals in a controlled manner and convert them into electromotive force data through analog-to-digital conversion.

[0008] The wireless transmission network is used to form a controlled wireless transmission link between the remote control analysis host and each signal processing module for the transmission of downlink acquisition control data and uplink electromotive force data.

[0009] The remote control analysis host is used to control the acquisition and reception of parallel electromotive force data, process the electromotive force data to form an electromotive force change trend, identify the specific state or parameter in the change trend according to preset rules, and output it on the human-machine interface.

[0010] In one embodiment of the present invention, the galvanic cell structure includes a silver oxide / silver electrode rod and a copper electrode rod, as well as concrete containing cement slurry, and an insulating shell for fixing the electrodes and accommodating part of the electrode rod and the concrete.

[0011] In one embodiment of the present invention, a sealed receiving cavity is further included, the protrusion of the electrode rod is located in the sealed receiving cavity, and the signal processing module, the wireless transmission module and the power supply are fixed in the sealed receiving cavity.

[0012] The signal processing module includes a reading circuit for measuring the electromotive force signal between electrodes, a signal amplification circuit for amplifying the electromotive force signal, an analog-to-digital conversion circuit for signal conversion, a packaging circuit for data encoding, and a memory for buffering data.

[0013] The field testing method for the initial setting time of roller-compacted concrete according to embodiments of the present invention includes:

[0014] A control strategy is formulated to control the periodic acquisition of electromotive force data within the distribution area of ​​the electromotive force sensor.

[0015] The electromotive force data is used to generate electromotive force variation curves for the hydration process in each region based on time-series characteristics and regional identifiers, and the data is then displayed.

[0016] The extreme value of the first potential change and the initial setting time node related to the initial setting of concrete are determined based on the trend of electromotive force change.

[0017] In one embodiment of the present invention, the control strategy includes:

[0018] - Determine the identifier of the wireless transmission module configured in each signal processing module, and establish a region mapping with each area of ​​the roller-compacted concrete layer based on the identifier sequence;

[0019] - Determine the data acquisition cycle, and within each data acquisition cycle:

[0020] A data channel is established with each wireless transmission module in the identification sequence through a wireless transmission network, and the signal processing module is activated to collect electromotive force sensor signals.

[0021] After receiving the parallel electromotive force data with bound timestamps and identifiers, the data channel control signal processing module switches to low-power mode and disconnects the data channel.

[0022] In one embodiment of the present invention, the step of forming electromotive force change curves during the hydration process in each region and displaying the data includes:

[0023] In one embodiment of the present invention, the electromotive force change of the galvanic cell structure in each region during the hydration process is generated through a human-computer interaction interface. The step of determining the extreme value of the first potential change and the initial setting time node related to the initial setting of concrete based on the electromotive force change trend includes:

[0024] -Based on the rate of change of electromotive force with time in the electromotive force change curve of the region, the first extreme value of the rate of change of concrete in the region during the hydration process is estimated, and the initial setting time is formed according to the corresponding time node of the occurrence of the first extreme value of the rate of change.

[0025] In one embodiment of the present invention, it further includes:

[0026] Adjust the construction procedures for each area according to the initial setting time.

[0027] The field testing system for the initial setting time of roller-compacted concrete according to an embodiment of the present invention includes:

[0028] The memory is used to store the program code in the process of the field test method for the initial setting time of roller-compacted concrete as described in any one of claims 4 and 8.

[0029] A processor for executing the program code.

[0030] The field testing system for the initial setting time of roller-compacted concrete according to an embodiment of the present invention includes:

[0031] A sampling control device is used to form a control strategy to control the periodic acquisition of electromotive force data within the distribution area of ​​the electromotive force sensor;

[0032] An interactive control device is used to generate electromotive force change curves for each region's hydration process based on time-series characteristics and regional identifiers, and to display the data.

[0033] The initial setting measurement device is used to determine the extreme value of the first potential change and the initial setting time node related to the initial setting of concrete based on the trend of electromotive force change.

[0034] The field testing method and system for the initial setting time of roller-compacted concrete (RCC) in this invention utilizes the galvanic cell structure formed by the cement paste of the RCC to collect and measure the electromotive force (EMF) of the concrete during the hydration process. By regularly calculating the trend curve of the EMF changing over time, the characteristic state data of the concrete under test in the galvanic cell during the hydration process are estimated, thus identifying and determining the initial setting time of the concrete. This invention, based on the EMF method for measuring the initial setting time of RCC layers, has advantages such as accurate measurement, simple operation, and speed. It can be used in laboratories and directly applied to construction sites. The ease of deployment greatly simplifies the operation procedure for testing the initial setting time of RCC layers on construction sites and shortens the testing time. Under any construction conditions and climatic conditions, this invention can accurately and quickly measure the initial setting time of several test points on each layer, ensuring that the upper layer of concrete can be poured, spread, and compacted in a timely manner before the lower layer sets, further guaranteeing the quality of interlayer bonding. Attached Figure Description

[0035] Figure 1 The diagram shown is a schematic diagram of a field testing system for the initial setting time of roller-compacted concrete according to an embodiment of the present invention.

[0036] Figure 2 The diagram shown is a schematic diagram of the galvanic cell in a field testing system for the initial setting time of roller-compacted concrete according to an embodiment of the present invention.

[0037] Figure 3 The diagram shown is a schematic flowchart of a field test method for the initial setting time of roller-compacted concrete according to an embodiment of the present invention.

[0038] Figure 4 The diagram shows the test data of the initial setting time of roller-compacted concrete in the field according to the embodiment of the present invention, applied to the hydration process of 525# cement sample from Beijing Cement Plant (water-cement ratio 0.285, room temperature 13.8~14.4℃, initial setting time at the factory 142min).

[0039] Figure 5 The diagram shows the test data of the initial setting time of roller-compacted concrete in the field, applied to the hydration process of 525# cement samples from Jidong Cement Plant, using the method of the present invention (water-cement ratio 0.285, room temperature 21.5~23.5℃, initial setting time at the factory 120min).

[0040] Figure 6 The diagram shows the test data of the initial setting time of roller-compacted concrete in the field, applied to the hydration process of 425# cement sample from Baihua Cement Plant, using the method of the present invention (water-cement ratio 0.285, room temperature 21.5~23.5℃, initial setting time at the factory 120min).

[0041] Figure 7The diagram shows the test data of the initial setting time of the roller-compacted concrete in the cement slurry hydration process of Baihua Cement Plant, based on the field test method of the present invention (50% silicate cement, room temperature 23.0-26.4℃, 50% fly ash, water-cement ratio 0.350).

[0042] Figure 8 The diagram shown is a schematic representation of the architecture of a field testing system for the initial setting time of roller-compacted concrete according to an embodiment of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer and more understandable, the invention will be further described below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0044] An embodiment of the present invention provides a field testing system for the initial setting time of roller-compacted concrete, as follows: Figure 1 As shown. In Figure 1 In this embodiment, the following are included:

[0045] The electromotive force sensor 100 is used to form a galvanic cell structure in the concrete at the deployment location, thereby creating a galvanic cell electromotive force signal source for the concrete hydration process.

[0046] Based on electrochemical principles, a galvanic cell structure is formed using cement slurry from localized concrete and positive and negative electrodes. The cell utilizes the objective phenomenon that during cement hydration, free water molecules in the concrete transform into water of crystallization, causing a change in the concentration of ions participating in the cell reaction, thus leading to a change in the cell's electromotive force (EMF). By observing the gradual influence of the concrete hydration process on the EMF, the changes in EMF are used to determine the initial and final setting states of the localized concrete during hydration. The galvanic cell structure mainly relies on electrode rods and a fixed volume of concrete (containing cement), resulting in a simple and stable assembly structure that is not easily affected by construction. Based on the standard composition of the concrete, basic data on the corresponding electrochemical reactions can be collected and statistically analyzed in advance, allowing for accurate quantification of the galvanic cell EMF signal and the time point of the initial setting state during the hydration process.

[0047] The signal processing module 200 is used for controlled acquisition of electromotive force signals and conversion of them into electromotive force data via analog-to-digital conversion.

[0048] The galvanic cell structure, combined with the reading circuit between the electrodes, enables continuous acquisition of electromotive force (EMF) signals during the localized concrete hydration process. By controlling the acquisition frequency of the EMF signal, and in conjunction with analog-to-digital conversion and data buffering, periodic EMF data can be generated. The circuit's operating mode can switch between low power consumption and normal power consumption, reducing power requirements and maintaining durable operation for the continuous hydration process. For analog-to-digital conversion and data buffering, general-purpose high-precision A / D conversion integrated circuits and electrically erasable and rewritable data storage chips can be used, while also providing an external data read interface.

[0049] The wireless transmission network 300 is used to form a controlled wireless transmission link between the remote control analysis host and each signal processing module for the transmission of downlink acquisition control data and uplink electromotive force data.

[0050] The wireless transmission network establishing the wireless transmission link, depending on the communication technology used, may include transmission modules that connect to the signal processing module and the remote control analysis host, as well as gateways, hotspots, or routers that connect to the transmission modules. Transmission modules include, but are not limited to, WLAN technology transmission modules, ZigBee technology transmission modules, 4G / 5G technology transmission modules, and LPWA technology transmission modules. Wireless transmission modules of various technologies can adapt to the distributed deployment of electromotive force sensors, meeting the technical requirements of low bandwidth, long distance, and low power consumption.

[0051] The remote control analysis host 400 is used to control the acquisition and reception of parallel electromotive force data, process the electromotive force data to form an electromotive force change trend, identify the specific state or parameter in the change trend according to preset rules, and output it on the human-machine interface.

[0052] The remote control analysis host establishes and dismantles the wireless data link. Within the wireless data link, control data is transmitted to the signal processing module via the downlink data channel. This module acquires signals to form buffered data and obtains electromotive force (EMF) data via the uplink data channel. Furthermore, the remote control analysis host utilizes computing power to process the parallel-received time-series EMF data. Based on the mapping rules between EMF and the hydration process, it identifies the hydration process trend of the roller-compacted concrete layer at the construction site and marks trend changes or parameter data with clear meanings, such as quantitative changes and abrupt changes. The trend status or parameter data is then displayed in real-time graphically on the host's human-machine interface, and prompts are generated based on threshold values ​​of the trend status or parameter data. The computing power and storage requirements of the remote control analysis host are related to the deployment density of EMF sensors at the construction site. The remote control analysis host can be deployed in a data center or on intelligent devices to achieve remote measurement of the initial setting time of concrete and process management.

[0053] The field testing system for the initial setting time of roller-compacted concrete in this invention utilizes a galvanic cell structure formed by the roller-compacted concrete cement slurry to collect and measure the electromotive force (EMF) of the concrete during the hydration process. By performing regular calculations on the trend curve of the EMF changing over time, the system estimates the characteristic state data of the concrete under test in the hydration process within the galvanic cell, thus identifying and determining the initial setting time of the concrete.

[0054] Compared with traditional time-controlled methods, degree-time methods, and penetration resistance methods, this invention measures the initial setting time of roller-compacted concrete layers based on the electromotive force method. It offers advantages such as accurate measurement, ease of operation, and speed, making it suitable for both laboratory use and direct application on construction sites. The ease of deployment greatly simplifies the operational procedures for testing the initial setting time of roller-compacted concrete layers on construction sites and shortens the testing time. Under any construction conditions and climate, this invention can accurately and quickly measure the initial setting time at several test points on each layer, ensuring that the previous layer of concrete can be poured, spread, and compacted in a timely manner before the next layer begins to set, further guaranteeing the quality of interlayer bonding.

[0055] In an embodiment of the present invention, a galvanic cell is used in the field testing system for the initial setting time of roller-compacted concrete. Figure 2 As shown. In Figure 2 In this embodiment, the galvanic cell structure includes an Ag2O / Ag (silver oxide / silver) electrode rod and a Cu (copper) electrode rod as electrodes, as well as concrete containing cement slurry, and an insulating shell for fixing the electrodes and accommodating the electrodes and concrete. During the hydration process of the concrete, the free water molecules gradually decrease and Ca(OH)2 is generated, forming an alkaline electrolyte.

[0056] The galvanic cell structure in this embodiment inserts two different metal or metal oxide electrodes into OH. - In an ionic solution, a galvanic cell is formed, and the cell equation is as follows:

[0057]

[0058] In the formula: a is the activity coefficient;

[0059] The potential of each electrode is related to the activity (or concentration) of the medium. When a = 1, the electrode potential is the standard electrode potential.

[0060] Inserting electrodes containing OH - After the solution is applied, an electrode reaction begins. The electrode reaction equations are as follows:

[0061] (-)Polar 2Cu + 2OH - -2e - =Cu2O + H2O

[0062] (+)Polar Ag2O+H2O+2e - = 2Ag + 2OH -

[0063] The overall cell reaction is 2Cu + Ag₂O = Cu₂O + 2Ag

[0064] In one embodiment of the present invention, the shape and dimensions of the insulating shell and the required thickness of the roller-compacted concrete layer are determined, and the shape includes, but is not limited to, column shape, flat round box shape, flat circular ring shape or U-shaped connecting pipe shape, etc.

[0065] In one embodiment of the invention, the electrode is fixed to the top of the insulating housing and protrudes outwards. Simultaneously, a coaxial sealed receiving cavity is formed on the top of the insulating housing, and the protruding portion of the electrode rod is located within the sealed receiving cavity. A signal processing module, a wireless transmission module, and necessary power supplies are fixed within the sealed receiving cavity. The signal processing module includes a reading circuit for measuring the electromotive force signal between the electrodes, a signal amplification circuit for amplifying the electromotive force signal, an analog-to-digital conversion circuit for signal conversion, a packaging circuit for data encoding, and a memory for buffering data. Based on common data connection and circuit control technologies, the memory and the wireless transmission module establish a data connection through a data interface. The data / signal interface of the wireless transmission module is connected to the control terminal of the corresponding circuit.

[0066] In one embodiment of the present invention, the constituent circuits of the signal processing module can be integrated circuits or integrated chips. The signal processing module can be a highly integrated potentiometer or digital voltmeter, and can simultaneously integrate a signal display screen and a parameter adjustment interface.

[0067] In one embodiment of the present invention, a temperature sensor is also fixedly housed in the sealed cavity. The temperature sensor is electrically connected to the parallel analog-to-digital conversion circuit in the signal processing module to collect temperature signals during the hydration process.

[0068] In one embodiment of the present invention, other sensors may also be fixed in the sealed cavity and electrically connected to the parallel analog-to-digital conversion circuit in the signal processing module. This forms the basis for acquiring other reference data in the measurement environment, assisting in the quantification of the galvanic cell structure measurement environment.

[0069] The field testing system for the initial setting time of roller-compacted concrete described in the above embodiments can be used to develop a field testing method for the initial setting time of concrete in the construction layer at the construction site.

[0070] An embodiment of the present invention provides a field testing method for the initial setting time of roller-compacted concrete as follows: Figure 3 As shown. In Figure 3 In this embodiment, the following are included:

[0071] Step 510: Formulate a control strategy to control the periodic acquisition of electromotive force data within the distribution area of ​​the electromotive force sensor.

[0072] Electromotive force (EMF) sensors are deployed in zones within the concrete layers at the roller-compacted concrete construction site, forming a distributed deployment. The galvanic cell structure of the EMF sensors generates a signal indicating the continuous change in the galvanic cell EMF during concrete hydration. By setting the data acquisition period, the continuous change data of the galvanic cell EMF can be obtained, which is used to quantify the changes in the physical state of the concrete during hydration.

[0073] In one embodiment of the present invention, the control strategy includes:

[0074] - Determine the identifier of the wireless transmission module configured in each signal processing module, and establish a region mapping with each area of ​​the roller-compacted concrete layer based on the identifier sequence;

[0075] - Determine the data acquisition cycle, and within each data acquisition cycle:

[0076] A data channel is established with each wireless transmission module in the identification sequence through a wireless transmission network, and the signal processing module is activated to collect electromotive force sensor signals.

[0077] After receiving the parallel electromotive force data with bound timestamps and identifiers (via the remote control analysis host), the signal processing module switches to low-power mode through the data channel control and disconnects the data channel.

[0078] Step 520: Generate electromotive force change curves for each region's hydration process based on time-series characteristics and regional identifiers, and then display the data.

[0079] During the storage of received electromotive force (EMF) data, the remote-controlled analysis host performs formatting processing and generates an EMF change curve for the galvanic cell structure in each region during the hydration process via a human-machine interface. The human-machine interface also allows for switching and displaying the EMF change curves for each region.

[0080] Step 530: Determine the extreme value of the first potential change and the initial setting time node related to the initial setting of concrete based on the trend of electromotive force change.

[0081] The electromotive force change trend of the galvanic cell in the electromotive force sensor follows the formation law of the initial setting phenomenon during the hydration process of concrete.

[0082] In one embodiment of the present invention, the specific process of determining the initial solidification time node in the trend of electromotive force change includes:

[0083] -Based on the rate of change of electromotive force E with time t in the electromotive force change curve of the region, the first extreme value of the rate of change of concrete in the region during the hydration process is estimated, and the initial setting time is determined according to the corresponding time node of the occurrence of the first extreme value of the rate of change.

[0084] Specifically, by performing differential calculations on the electromotive force change curve of the region, the first extreme value of ΔE / Δt that appears after the electrode potential reaches the equilibrium potential during the hydration process of the concrete under test is estimated. The corresponding time is the initial setting time of the corresponding concrete (middle cement paste). Therefore, the time corresponding to the first extreme value of ΔE / Δt that appears during the hydration process of the concrete under test can be considered as the initial setting time of the concrete, that is:

[0085] T initial =(ΔE / Δt) min

[0086] The electromotive force (E) of the galvanic cell structure formed by concrete (cement slurry) is related to the concentrations (m) of the reacting substances Cu₂O, Ag, Ag₂O, and Cu. During the cement hydration reaction, due to the decrease in free water molecules, the concentrations of each ion in the solution change, and the value of E also changes continuously.

[0087] The battery electromotive force E is calculated based on the following derivation process:

[0088] The standard battery potential is: In the formula and This can be obtained by referring to a table. At 298.15K (25℃):

[0089] E θ =0.344V - (-0.361V) = 0.705V

[0090] Battery standard potential E θ This is the value when the activity coefficient a = 1. Generally, a ≠ 1, and the cell potential E is a function of activity a or concentration.

[0091] After the electrodes are inserted into an alkaline solution, their potentials continuously change due to varying degrees of reaction. Over time, the electrode potentials gradually move from disequilibrium to equilibrium. The equilibrium potential of the electrodes can be calculated using the Nernst equation:

[0092]

[0093] In the formula: —Equilibrium electrode potential;

[0094] —Standard electrode potential (the value can be found at 298.15K);

[0095] R—Universal gas constant 8.314 J·K -1 ·mol -1 ;

[0096] T — Temperature (t℃ + 273.15K);

[0097] Z—The number of electrons transferred in the electrode reaction. In our chosen electrode reaction, Z = 2;

[0098] F — Faraday constant, 96500 C·mol⁻¹ -1 ;

[0099] a — the activity of the reactant, a is a function of concentration.

[0100] Because in electrochemical reactions:

[0101] [Oxidized state] +Ze — →[Restored state]

[0102] Therefore, at a given temperature, R, T, Z, and F are all constants, and the equilibrium potential of the electrode is... It is only related to the activity 'a' of the substance in the solution.

[0103] Therefore, the electromotive force E of the galvanic cell is the difference between the potentials of the positive and negative electrodes:

[0104] At 25℃ (298.15K),

[0105] Activity *a* is the effective concentration participating in the electrode reaction. The relationship between activity and concentration is as follows:

[0106]

[0107] In the formula: a i —The activity of the substance;

[0108] γ i —The activity coefficient of substance i;

[0109] m i — molar concentration of substance i (mol·kg) -1 );

[0110] m θ —Standard molality, its value is defined as 1 mol·kg⁻¹ -1 ;

[0111] γ i The value is generally less than 1, but approaches 1 when the concentration is very low. The substances participating in the reaction are all sparingly soluble, and their concentrations in solution are very low. Therefore, concentration m can be used instead of activity a. The above formula can be derived as:

[0112]

[0113] like Figure 3 As shown, in one embodiment of the present invention, based on the above embodiments, it further includes:

[0114] Step 540: Adjust the construction procedures for each area according to the initial setting time.

[0115] The initial setting time of the same layer of concrete in different areas during roller-compacted concrete construction is assessed based on the electromotive force change curves of each region. The timing of pouring, spreading, and compaction is adjusted or additional compaction is performed based on the difference in initial setting time to avoid construction defects.

[0116] In practical applications, the dynamic electromotive force of the corresponding galvanic cell is collected for cement paste formed by concrete with different compositions. Using the field testing method for the initial setting time of roller-compacted concrete described in the above embodiment, the time corresponding to the first extreme value of ΔE / Δt after the electrode potential reaches the equilibrium potential during the hydration process of the concrete sample is estimated as the initial setting time of the cement. For example... Figures 4 to 6 As shown, the electromotive force (EMF) values ​​of 525# cement samples produced by Beijing Cement Plant, 525# cement samples produced by Jidong Cement Plant, and 425# cement samples produced by Baihua Cement Plant were collected at fixed time intervals during the hydration process. Differential calculations were performed on the curves showing the EMF changing with time. It can be deduced that the time corresponding to the first extreme value of ΔE / Δt after the electrode potential reaches the equilibrium potential during the hydration process of the tested concrete sample is the initial setting time of the cement. Figure 7 As shown, cement produced by Baihua Cement Plant was mixed with fly ash in a 1:1 ratio. The electromotive force (EMF) of the fly ash cement mixture sample was collected at fixed time intervals during the hydration process. The curve of EMF change over time was calculated by differentiation. The time corresponding to the first extreme value of ΔE / Δt after the electrode potential reaches the equilibrium potential during the hydration process of the concrete sample under test was estimated as the initial setting time of the fly ash cement mixture.

[0117] An embodiment of the present invention provides a field testing system for the initial setting time of roller-compacted concrete, comprising:

[0118] The memory is used to store the program code in the process of the field test method for the initial setting time of roller-compacted concrete in the above embodiments;

[0119] The processor is used to execute the program code in the process of the field test method for the initial setting time of roller-compacted concrete in the above embodiments.

[0120] The processor can be a DSP (Digital Signal Processor), an FPGA (Field-Programmable Gate Array), an MCU (Microcontroller Unit) system board, a SoC (System on a Chip) system board, a PLC (Programmable Logic Controller) minimum system including I / O, or computing power from a remote location or the cloud.

[0121] In one embodiment of the present invention, the field testing system for the initial setting time of roller-compacted concrete adopts the remote control analysis host hardware and software environment described in the above embodiment.

[0122] An embodiment of the present invention provides a field testing system for the initial setting time of roller-compacted concrete, as follows: Figure 8 As shown. In Figure 8 In this embodiment, the following are included:

[0123] The sampling control device 51 is used to form a control strategy to control the periodic acquisition of electromotive force data within the distribution area of ​​the electromotive force sensor.

[0124] Interactive control device 52 is used to generate electromotive force change curves for each region's hydration process based on time-series characteristics and regional identifiers, and to display the data.

[0125] The initial setting measurement device 53 is used to determine the extreme value of the first potential change and the initial setting time node related to the initial setting of concrete based on the trend of electromotive force change.

[0126] like Figure 8 As shown, in one embodiment of the present invention, it further includes:

[0127] The process adjustment device 54 is used to adjust the construction procedures of each area according to the initial setting time.

[0128] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A field testing system for the initial setting time of roller-compacted concrete, characterized in that, include: An electromotive force sensor is used to form a galvanic cell structure in concrete at the deployment location, thereby forming a galvanic cell electromotive force signal source for the concrete hydration process; the galvanic cell structure includes a silver oxide / silver electrode rod and a copper electrode rod, as well as concrete containing cement slurry, and also includes an insulating shell for fixing the electrodes and accommodating part of the electrode rod and concrete. The signal processing module is used to collect electromotive force signals in a controlled manner and convert them into electromotive force data through analog-to-digital conversion. The wireless transmission network is used to form a controlled wireless transmission link between the remote control analysis host and each signal processing module for the transmission of downlink acquisition control data and uplink electromotive force data. The remote control analysis host is used to control the acquisition and reception of parallel electromotive force data, process the electromotive force data to form an electromotive force change trend, identify the specific state or parameter in the change trend according to preset rules, and output it on the human-machine interface. The remote control analysis host is deployed on intelligent devices to realize remote measurement of the initial setting time of concrete and process management; the control strategy includes: Determine the identifier of the wireless transmission module configured in each signal processing module, and establish a region mapping with each area of ​​the roller-compacted concrete layer based on the identifier sequence; Determine the data acquisition cycle, and within each data acquisition cycle: A data channel is established with each wireless transmission module in the identification sequence through a wireless transmission network, and the signal processing module is activated to collect electromotive force sensor signals. After receiving the parallel electromotive force data bound with timestamps and identifiers, the data channel control signal processing module switches to low-power mode and disconnects the data channel. It also includes a sealed cavity, in which the protrusion of the electrode rod is located, and the signal processing module, wireless transmission module and power supply are fixed. The signal processing module includes a reading circuit for measuring the electromotive force signal between electrodes, a signal amplification circuit for amplifying the electromotive force signal, an analog-to-digital conversion circuit for signal conversion, a packaging circuit for data encoding, and a memory for buffering data.

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