Field test method and test system for initial setting time of roller compacted concrete

Abstract

The invention provides a field test method and test system for initial setting time of roller compacted concrete, and solves the technical problem that the initial setting time of a roller compacted concrete layer is not continuously and effectively tested. The system comprises an electromotive force sensor which is used for forming a primary battery structure in combination with cement paste in concrete at a layout position and forming a primary battery electromotive force signal source in a concrete hydration process; the signal processing module is used for being controlled to collect electromotive force signals and forming electromotive force data through analog-to-digital conversion; the wireless transmission network is used for transmitting downlink acquisition control data and uplink electromotive force data; and the remote control analysis host is used for controlling acquisition and receiving of parallel electromotive force data, performing data processing on the electromotive force data to form an electromotive force change trend, identifying a clear state or parameter in the change trend according to a preset rule, and outputting the clear state or parameter on a human-computer interaction interface. And calculating a trend curve of electromotive force changing along with time through acquisition and measurement of the electromotive force so as to identify and judge the initial setting time of the concrete.

Description

Technical Field

[0001] The present invention relates to the technical field of signal monitoring, and particularly to a field test method and a test system for the initial setting time of roller compacted concrete. Background Art

[0002] In the prior art, the roller compacted concrete dam construction technology transplant large earth-rock dam construction machinery to concrete dams to achieve rapid and large-bay roller compaction construction, which has the advantages of saving concrete (i.e., cement), simple and easy construction, short construction period, and low cost, with significant economic and social benefits. In the construction of roller compacted concrete dams, strictly controlling the roller compaction construction quality and the quality of layer bonding is a reliable guarantee for improving the impermeability and firmness of roller compacted concrete dams. The quality of layer bonding directly affects important properties such as the seepage characteristics, splitting tensile strength, and shear strength of the dam body, and will directly affect the safe operation of the dam body. The initial setting time of the roller compacted concrete layer is crucial for ensuring the quality of layer bonding.

[0003] At the construction site of roller compacted concrete, the initial setting time test in the layer bonding control method of roller compacted concrete generally adopts the degree-time method, the setting time control method, and the penetration resistance method. Although the degree-time method and the setting time control method are simple, they cannot reflect the change process of the physical and chemical properties of the roller compacted concrete layer during the setting process, and cannot accurately obtain the initial setting time of the layer under complex construction site conditions. The penetration resistance method uses point selection measurement, with slow speed, low sampling rate, and many human interference factors. Currently, there is an electrical method. During the hydration process after the concrete is added with water, the resistance has a quantitative mutation during the concrete setting process. Measuring the change law of the resistance of the concrete mixture over time can characterize the initial setting and final setting of the concrete, and has better continuity advantages compared with other test methods. However, the existing electrical method requires professional equipment, the electrode installation and preparation are complex, and factors such as the insertion depth and spacing of the electrodes have a significant impact on the measurement results. During the construction process of roller compacted concrete, the concrete is in a dynamic change state, and it is difficult to ensure the accuracy and stability of the electrode position. Summary of the Invention

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

[0005] The field test system for the initial setting time of roller compacted concrete in the embodiments of the present invention includes:

[0006] An electromotive force sensor, which is used to form a primary battery structure in combination with the cement paste in the concrete at the layout position, to form a primary battery electromotive force signal source for the concrete hydration process;

[0007] A signal processing module, configured to collect electromotive force signals in a controlled manner and form electromotive force data through analog-to-digital conversion;

[0008] A wireless transmission network, configured to form a controlled wireless transmission link between a remote control analysis host and each signal processing module for transmitting downlink acquisition control data and uplink electromotive force data;

[0009] A remote control analysis host, configured to control the acquisition and reception of parallel electromotive force data, perform data processing on the electromotive force data to form an electromotive force change trend, identify clear states or parameters in the change trend according to preset rules, and output them on a human-machine interaction interface.

[0010] In an embodiment of the present invention, the primary battery structure includes an electrode rod of silver oxide / silver and an electrode rod of copper, as well as concrete containing cement slurry, and further includes an insulating housing for fixing the electrodes and accommodating part of the electrode rods and the concrete.

[0011] In an embodiment of the present invention, it further includes a sealed accommodation cavity, the protruding part of the electrode rod is located in the sealed accommodation cavity, and a signal processing module, a wireless transmission module and a working power supply are fixed in the sealed accommodation cavity;

[0012] 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 caching data.

[0013] The on-site test method for the initial setting time of roller-compacted concrete in an embodiment of the present invention includes:

[0014] Forming a control strategy to control the periodic acquisition of electromotive force data within the distribution area of the electromotive force sensor;

[0015] Forming an electromotive force change curve during the hydration process of each region based on the electromotive force data according to the timing characteristics and area identifiers, and performing data display;

[0016] Determining a first potential change extreme value related to the initial setting of the concrete and an initial setting time node according to the electromotive force change trend.

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

[0018] - Determining the identifiers of the wireless transmission modules configured in each signal processing module, and establishing a regional mapping with each region of the roller-compacted concrete layer according to the identifier sequence;

[0019] - Determining the data acquisition period, and in each data acquisition period:

[0020] Establish data channels with each wireless transmission module in the identification sequence through a wireless transmission network, and activate the signal processing module to collect electromotive force sensor signals;

[0021] After receiving the parallel electromotive force data with bound timestamps and identifications, control the signal processing module to switch to the low-power mode through the data channel and disconnect the data channel.

[0022] In one embodiment of the present invention, the forming of the electromotive force change curve during the hydration process of each region and the data display include:

[0023] Form the electromotive force change during the hydration process of the primary battery structure in each region through the human-computer interaction interface. In one embodiment of the present invention, the determining of the first potential change extreme value related to the initial setting of concrete and the initial setting time node according to the electromotive force change trend includes:

[0024] - Deduce the first change rate extreme value that appears during the hydration process of the concrete in the region according to the change rate of the electromotive force with time in the electromotive force change curve of the region, and form the initial setting time according to the corresponding time node when the first change rate extreme value appears.

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

[0026] Adjust the construction processes of each region according to the initial setting time node.

[0027] The on-site test system for the initial setting time of roller-compacted concrete in the embodiment of the present invention includes:

[0028] A memory for storing the program code during the processing of the on-site test method for the initial setting time of roller-compacted concrete as described in any one of claims 4 to 8;

[0029] A processor for executing the program code.

[0030] The on-site test system for the initial setting time of roller-compacted concrete in the embodiment of the present invention includes:

[0031] A sampling control device for forming a control strategy to control the periodic acquisition of electromotive force data within the distribution area of the electromotive force sensor;

[0032] An interaction control device for forming the electromotive force change curve during the hydration process of each region according to the chronological characteristics and regional identifications of the electromotive force data and performing data display;

[0033] An initial setting calculation device for determining the first potential change extreme value related to the initial setting of concrete and the initial setting time node according to the electromotive force change trend.

[0034] The on-site testing method and testing system for the initial setting time of rolled concrete in the embodiment of the present invention collect and measure the electromotive force of concrete during the hydration process by using the primary cell structure formed by the cement paste of rolled concrete. The trend curve of the electromotive force changing with time is calculated regularly, and the characteristic state data of the concrete to be tested in the primary cell during the hydration process is inferred to form the identification and judgment of the initial setting time of concrete. The present invention measures the initial setting time of the rolled concrete layer based on the electromotive force method, and has the advantages of accurate measurement, simple operation, and fast speed. It can be used in the laboratory and can be directly applied to the construction site. The convenience of deployment greatly simplifies the operating procedures for testing the initial setting time of the rolled concrete layer at the construction site and shortens the test time. Under any construction conditions and climatic conditions, the present invention can accurately and quickly measure the initial setting time of several detection points on each layer, ensuring that the upper layer of concrete can be poured, spread and rolled in time before the initial setting of the next layer, further ensuring the interlayer bonding quality. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0036] Figure 2 The figure shows a schematic structural diagram of a primary cell in a field testing system for initial setting time of rolled concrete according to an embodiment of the present invention.

[0037] Figure 3 It is a schematic flow chart of a field testing method for initial setting time of roller compacted concrete according to an embodiment of the present invention.

[0038] Figure 4 The figure shows the initial setting time test data schematic diagram of the field test method for the initial setting time of rolled concrete according to an embodiment of the present invention applied to the hydration process of 525# cement sample of Beijing Cement Plant (water-cement ratio 0.285, room temperature 13.8-14.4°C, factory initial setting time 142min).

[0039] Figure 5 The figure shows the initial setting time test data schematic diagram of the on-site test method for the initial setting time of rolled concrete according to an embodiment of the present invention applied to the hydration process of the 525# cement sample of Jidong Cement Plant (water-cement ratio 0.285, room temperature 21.5-23.5°C, initial setting time 120min before leaving the factory).

[0040] Figure 6 The figure shows the initial setting time test data schematic diagram of the on-site test method for the initial setting time of rolled concrete according to an embodiment of the present invention applied to the hydration process of the 425# cement sample of Baihua Cement Plant (water-cement ratio 0.285, room temperature 21.5-23.5°C, initial setting time 120min before leaving the factory).

[0041] Figure 7The figure shows a schematic diagram of the initial setting time test data of the cement slurry hydration process of Baihua Cement Factory by applying the on-site test method for the initial setting time of roller-compacted concrete in an embodiment of the present invention (50% portland cement, room temperature 23.0 - 26.4 °C, 50% fly ash, water-binder ratio 0.350).

[0042] Figure 8 The figure shows a schematic diagram of the architecture of the on-site test system for the initial setting time of roller-compacted concrete in an embodiment of the present invention. Specific embodiments

[0043] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0044] An on-site test system for the initial setting time of roller-compacted concrete in an embodiment of the present invention is as Figure 1 shown. In Figure 1 this embodiment, it includes:

[0045] An electromotive force sensor 100, which is used to form a primary battery structure in combination with the cement slurry in the concrete at the installation position, and form a primary battery electromotive force signal source for the concrete hydration process.

[0046] According to the electrochemical principle, a primary battery structure is formed by using the cement slurry of local concrete in combination with positive and negative electrodes. During the cement hydration process, free water molecules in the concrete are transformed into crystal water, causing changes in the ion concentration participating in the battery reaction, thereby causing changes in the battery electromotive force. Through the gradual influence of the concrete hydration process on the primary battery electromotive force, a judgment on the initial setting and final setting states of local concrete during the hydration process is formed by mapping the changes in the electromotive force. The primary battery structure mainly relies on the electrode rod and the concrete (cement) with a determined volume, and the assembly structure is simple and stable, not easily affected by construction. According to the standard composition of the concrete, the basic data of the corresponding electrochemical reaction can be collected and statistically analyzed in advance, which can be used to accurately quantify the primary battery electromotive force signal corresponding to the initial setting time and the time node of the initial setting state during the hydration process.

[0047] A signal processing module 200, which is used to controllably collect the electromotive force signal and form electromotive force data through analog-to-digital conversion.

[0048] The galvanic cell structure, in combination with the measurement and reading circuit between the electrodes, can continuously collect the electromotive force signals during the local concrete hydration process. By controlling the acquisition frequency of the electromotive force signals, and combining analog-to-digital conversion and data caching, periodic electromotive force data can be formed. The working mode of the corresponding circuit can be switched between low power consumption and normal power consumption, reducing the working power demand and maintaining a durable working process corresponding to the continuous hydration process. For analog-to-digital conversion and data caching, a general-purpose high-precision A / D conversion integrated circuit and an electrically erasable data storage chip can be selected, and at the same time, a data reading interface for external use is provided.

[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 transmitting the downlink acquisition control data and the uplink electromotive force data.

[0050] The wireless transmission network for establishing the wireless transmission link, according to the communication technology adopted, may include a transmission module data-connected to the signal processing module and the remote control analysis host, and a gateway, hotspot or router data-connected to the transmission module. The transmission module includes, but is not limited to, a WLAN technology transmission module, a ZigBee technology transmission module, a 4G / 5G technology transmission module, an LPWA technology transmission module, etc. The wireless transmission modules of various types of technologies can adapt to the distributed deployment of the electromotive force sensors and meet the technical requirements of low traffic, 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, perform data processing on the electromotive force data to form the trend of electromotive force changes, identify the clear states or parameters in the change trend according to the preset rules, and output them on the human-machine interaction interface.

[0052] The remote control analysis host controls the establishment and removal of the wireless data link. In the wireless data link, control data of the signal processing module is sent through the downlink data channel to control the signal processing module to perform signal acquisition to form cached data, and the electromotive force data is obtained through the uplink data channel. Further, the remote control analysis host uses its computing power to process the sequential electromotive force data received in parallel, forms the hydration process trend of the roller-compacted concrete layer at the construction site according to the mapping rule between the electromotive force and the hydration process, and identifies the trend change states or parameter data with clear meanings such as quantitative changes and sudden changes. Further, the trend state or parameter data is displayed in real time in the form of graphics and text on the human-machine interaction interface of the host, and prompt information is formed according to the threshold value of the trend state or parameter data. The computing power demand and storage demand of the remote control analysis host are related to the deployment density of the electromotive force sensors at the construction site. The remote control analysis host can be deployed in a data center or an intelligent device to realize the remote determination of the initial setting time of the concrete and the process management.

[0053] The on-site testing system for the initial setting time of rolled concrete in the embodiment of the present invention collects and measures the electromotive force of concrete during the hydration process by using the galvanic cell structure formed by the rolled concrete cement slurry. The trend curve of the electromotive force changing with time is calculated regularly to infer the characteristic state data of the concrete to be tested in the galvanic cell during the hydration process, so as to form the identification and judgment of the initial setting time of concrete.

[0054] Compared with the traditional time control method, degree time method and penetration resistance method, the present invention measures the initial setting time of the rolled concrete layer based on the electromotive force method, which has the advantages of accurate measurement, simple operation and rapidity. It can be used in the laboratory and can be directly applied to the construction site. The convenience of deployment greatly simplifies the operating procedures for testing the initial setting time of the rolled concrete layer on the construction site and shortens the test time. Under any construction conditions and climatic conditions, the present invention can be used to accurately and quickly measure the initial setting time of several detection points on each layer, ensuring that the upper layer of concrete can be poured, spread and rolled in time before the initial setting of the next layer, further ensuring the quality of interlayer bonding.

[0055] In the field test system for the initial setting time of rolled concrete according to one embodiment of the present invention, the primary battery is as follows Figure 2 As shown. Figure 2 In the embodiment, the primary battery 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 also includes 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 produced to form an alkaline electrolyte.

[0056] The galvanic cell structure of this embodiment inserts two different metal or metal oxide electrodes into the OH - In the ion solution, a primary cell is formed, and the battery formula of the battery is expressed as follows:

[0057]

[0058] Where: 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] Insert the electrode containing OH - After the solution is added, the electrode reaction begins. The electrode reaction formula is as follows:

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

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

[0063] Total battery reaction: 2Cu + Ag2O = Cu2O + 2Ag

[0064] In an embodiment of the present invention, the shape and dimension of the insulating housing are determined according to the layer construction thickness requirement of roller-compacted concrete, and the shape includes but is not limited to columnar, flat round box-shaped, flat round ring-shaped, U-shaped communicating pipe-shaped, etc.

[0065] In an embodiment of the present invention, the electrode is fixed on the top of the insulating housing and protrudes. At the same time, a coaxial sealed accommodation cavity is formed on the top of the insulating housing, and the protruding part of the electrode rod is located in the sealed accommodation cavity. A signal processing module, a wireless transmission module, and a necessary working power supply are fixed in the sealed accommodation cavity. 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 caching data. Based on general data connection technology and circuit control technology, the memory establishes a data connection with the wireless transmission module through a data interface. The data / signal interface of the wireless transmission module is connected to the control end of the corresponding circuit.

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

[0067] In an embodiment of the present invention, a temperature sensor is also fixed in the sealed accommodation cavity, and the temperature sensor is electrically connected to the parallel analog-to-digital conversion circuit in the signal processing module to form the acquisition of temperature signals during the hydration process.

[0068] In an embodiment of the present invention, other sensors can also be fixed in the sealed accommodation cavity and are electrically connected to the parallel analog-to-digital conversion circuit in the signal processing module. The acquisition of other reference data in the measurement environment is formed to assist in quantifying the measurement environment of the primary battery structure.

[0069] Using the on-site test system for the initial setting time of roller-compacted concrete in the above embodiments, an on-site test method for the initial setting time of concrete in the construction layer at the construction site can be formed.

[0070] An on-site test method for the initial setting time of roller-compacted concrete in an embodiment of the present invention is as Figure 3 shown. In Figure 3 it, this embodiment includes:

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

[0072] The electromotive force sensors are deployed in the concrete layer at the roller compacted concrete construction site in a zoned manner to form a distributed deployment. The primary battery structure of the electromotive force sensors can form a continuously changing signal of the primary battery electromotive force during the concrete hydration process. By setting the acquisition period of the electromotive force data, the continuously changing data of the primary battery electromotive force can be obtained, which is used to quantify the physical state changes during the concrete hydration process.

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

[0074] - Determine the identifiers of the wireless transmission modules configured in each signal processing module, and establish a regional mapping with each area of the roller compacted concrete layer according to the identifier sequence;

[0075] - Determine the data acquisition period. In each data acquisition period:

[0076] Establish a data channel with each wireless transmission module in the identifier sequence through the wireless transmission network, and activate the signal processing module to collect the electromotive force sensor signals;

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

[0078] Step 520: Form the electromotive force change curves during the hydration process of each area according to the chronological characteristics and regional identifiers of the electromotive force data and perform data display.

[0079] (Remote control analysis host) During the process of storing the received electromotive force data, perform formatting processing on the electromotive force data, and form the electromotive force change curve of the primary battery structure in each area during the hydration process through the human-computer interaction interface. Form the switching display of the electromotive force change curves of each area through the human-computer interaction interface.

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

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

[0082] In an embodiment of the present invention, the process of specifically determining the initial setting time node in the electromotive force change trend includes:

[0083] - Deduce the first change rate extreme value that appears in the concrete during the hydration process in the area according to the change rate of the electromotive force E with respect to time t in the electromotive force change curve of the area, and determine the initial setting time according to the corresponding time node when the first change rate extreme value appears.

[0084] Specifically, by performing differential calculation 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 to be measured is deduced, and the corresponding time is the initial setting time of the corresponding concrete (cement paste in it). Therefore, by measuring the time corresponding to the first extreme value of ΔE / Δt that appears during the hydration process of the concrete to be measured, it 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 the concrete (cement paste in it) is related to the concentrations m of the substances Cu2O, Ag, Ag2O, and Cu participating in the reaction. During the cement hydration reaction process, due to the reduction of free water molecules, the concentrations of various ions in the solution are all changing, and the E value is also constantly changing.

[0087] The electromotive force E of the battery is calculated according to the following derivation process:

[0088] The standard potential of the battery is: In the formula, and can be obtained by looking up the table. At 298.15K (25°C):

[0089] E θ =0.344V - (-0.361V)=0.705V

[0090] The standard electromotive force E of the battery θ is the value when the activity coefficient a = 1. Generally, a ≠ 1, and the battery potential E is a function of the activity a or concentration.

[0091] After the electrode is inserted into the alkaline solution, due to different degrees of electrode reactions, the electrode potential also changes continuously. After a period of time, the electrode potential gradually tends to balance from being unbalanced. The equilibrium potential of the electrode can be calculated by the Nernst formula:

[0092]

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

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

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

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

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

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

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

[0100] Since in the electrochemical reaction:

[0101] [Oxidation state] + Ze — → [Reduction state]

[0102] Therefore, at a certain temperature, R, T, Z, and F are all constants, and the equilibrium potential of the electrode is only related to the activity a of the substances in the solution.

[0103] Therefore, the electromotive force E of the primary battery is the difference between the positive and negative electrode potentials:

[0104] At 25 °C (298.15 K),

[0105] The activity a is the effective concentration participating in the electrode reaction. The relationship between activity and concentration is

[0106]

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

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

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

[0110] m θ —— The standard molality, and its value is specified as 1 mol·kg -1 ;

[0111] γ i The value is generally less than 1 and approaches 1 when the concentration is very low. The substances participating in the reaction are all poorly soluble substances and have a very low concentration in the solution. Therefore, the concentration m can be used to replace the activity a. The above formula can be deduced as:

[0112]

[0113] As Figure 3 shown, in an embodiment of the present invention, on the basis of the above embodiment, it further includes:

[0114] Step 540: Adjust the construction processes of each area according to the initial setting time node.

[0115] Evaluate the initial setting time of different areas of the same layer of roller-compacted concrete during construction according to the initial setting time nodes determined by the electromotive force change curves of each area, and adjust the time of material pouring, paving, and rolling or supplementary compaction according to the initial setting time and the difference in initial setting time to avoid construction defects.

[0116] In practical applications, collect the dynamic electromotive force of the corresponding primary battery for the cement paste formed by concrete with different compositions, and use the on-site test method for the initial setting time of roller-compacted concrete in the above embodiments to deduce that the time corresponding to the first ΔE / Δt extreme value after the electrode potential reaches the equilibrium potential during the hydration process of the concrete sample to be tested is the initial setting time of the cement. As Figures 4 to 6 shown, collect the electromotive force values of the 525# cement samples produced by Beijing Cement Factory, the 525# cement samples produced by Jidong Cement Factory, and the 425# cement samples produced by Baihua Cement Factory during the hydration process at fixed time intervals, and perform differential calculation on the curve of the electromotive force changing with time. It can be deduced that the time corresponding to the first ΔE / Δt extreme value after the electrode potential reaches the equilibrium potential during the hydration process of the concrete sample to be tested is the initial setting time of the cement. As Figure 7 shown, mix the cement produced by Baihua Cement Factory and fly ash in a ratio of 1:1, collect the electromotive force values of the fly ash cement mixture sample during the hydration process at fixed time intervals, and perform differential calculation on the curve of the electromotive force changing with time. Deduce that the time corresponding to the first ΔE / Δt extreme value after the electrode potential reaches the equilibrium potential during the hydration process of the concrete sample to be tested is the initial setting time of the fly ash cement mixture.

[0117] An on-site test system for the initial setting time of roller-compacted concrete according to an embodiment of the present invention includes:

[0118] A memory for storing the program code during the processing of the on-site test method for the initial setting time of roller-compacted concrete in the above embodiments;

[0119] A processor for executing the program code during the processing of the on-site test method for the initial setting time of roller-compacted concrete in the above embodiments.

[0120] The processor can adopt a DSP (Digital Signal Processor) digital signal processor, an FPGA (Field-Programmable Gate Array) field programmable gate array, an MCU (Microcontroller Unit) system board, an SoC (system on a chip) system board, a PLC (Programmable Logic Controller) minimum system including I / O, or computing power remotely or in the cloud.

[0121] In an embodiment of the present invention, the on-site test system for the initial setting time of roller-compacted concrete adopts the software and hardware environment of the remote control analysis host in the above embodiment.

[0122] An on-site test system for the initial setting time of roller-compacted concrete in an embodiment of the present invention is as Figure 8 shown. In Figure 8 this, this embodiment includes:

[0123] A sampling control device 51, configured to form a control strategy and control the periodic acquisition of electromotive force data within the distribution area of the electromotive force sensor;

[0124] An interaction control device 52, configured to form an electromotive force change curve during the hydration process of each area based on the timing characteristics and area identification of the electromotive force data and perform data display;

[0125] An initial setting calculation device 53, configured to determine a first potential change extreme value related to the initial setting of the concrete and an initial setting time node according to the electromotive force change trend.

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

[0127] A process adjustment device 54, configured to adjust the construction processes of each area according to the initial setting time node.

[0128] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A field testing system for initial setting time of roller compacted concrete, characterized in that: include: The electromotive force sensor is used to form a galvanic cell structure in combination with cement paste in concrete at the layout location, thereby forming a galvanic cell electromotive force signal source in the concrete hydration process; A signal processing module is used to collect electromotive force signals in a controlled manner and form electromotive force data through analog-to-digital conversion; A wireless transmission network is used to form a controlled wireless transmission link between the remote control analysis host and each signal processing module to transmit downlink acquisition control data and uplink electromotive force data; The remote control analysis host is used to control the collection and reception of parallel electromotive force data, process the electromotive force data to form the electromotive force change trend, identify the clear state or parameters in the change trend according to preset rules, and output them on the human-computer interaction interface.

2. The on-site testing system for initial setting time of roller compacted concrete according to claim 1, characterized in that: 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 the concrete.

3. The on-site testing system for initial setting time of RCC as claimed in claim 2, characterized in that: It also includes a sealed accommodating cavity, in which the protruding portion of the electrode rod is located, and in which a signal processing module, a wireless transmission module and a working power supply are fixed; The signal processing module includes a measuring circuit for measuring the electromotive force signal between electrodes, a signal amplifying 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 caching data.

4. A field test method for initial setting time of roller compacted concrete, characterized in that: include: Form a control strategy to control the periodic collection of electromotive force data within the electromotive force sensor distribution area; The electromotive force data is converted into the electromotive force change curve of each region during the hydration process according to the time series characteristics and regional identification, and the data is displayed; The first potential change extreme value and the initial setting time node related to the initial setting of concrete are determined according to the electromotive force change trend.

5. The on-site testing method for initial setting time of roller compacted concrete according to claim 4, characterized in that: The control strategy includes: -determine the identification of the wireless transmission module configured in each signal processing module, and establish a regional mapping with each area of ​​the RCC layer according to the identification sequence; -Determine the data collection cycle. In each data collection cycle: Establishing a data channel with each wireless transmission module in the identification sequence through the wireless transmission network, activating the signal processing module to collect the electromotive force sensor signal; After receiving the parallel electromotive force data bound with the timestamp and the identifier, the signal processing module is controlled to switch to the low power consumption mode through the data channel and the data channel is disconnected.

6. The on-site testing method for initial setting time of roller compacted concrete according to claim 4, characterized in that: The forming of the electromotive force variation curve during the hydration process of each region and the data display comprises: The electromotive force variation curve of the galvanic cell structure in each area during the hydration process is formed through the human-computer interaction interface, and the switching display of the electromotive force variation curve of each area is formed through the human-computer interaction interface.

7. The on-site testing method for initial setting time of roller compacted concrete according to claim 4, characterized in that: The method of determining the first potential change extreme value and the initial setting time node related to the initial setting of concrete according to the electromotive force change trend includes: -According to the rate of change of electromotive force with time in the electromotive force change curve of the region, the first extreme value of change rate that occurs in the hydration process of concrete in the region is estimated, and the initial setting time is determined according to the corresponding time node where the first extreme value of change rate occurs.

8. The on-site testing method for initial setting time of roller compacted concrete according to claim 4, characterized in that: Also includes: Adjust the construction procedures of each area according to the initial setting time node.

9. A field testing system for initial setting time of roller compacted concrete, characterized in that: include: A memory for storing program codes in the process of processing the on-site test method for initial setting time of rolled concrete as claimed in any one of claims 4 to 8; A processor is used to execute the program code.

10. A field testing system for initial setting time of roller compacted concrete, characterized in that: include: A sampling control device for forming a control strategy to control the periodic collection of electromotive force data within the distribution area of ​​the electromotive force sensors; An interactive control device, used to convert the electromotive force data into an electromotive force variation curve during the hydration process of each region according to the time series characteristics and the region identification and to display the data; The initial setting measuring device is used to determine the first potential change extreme value and the initial setting time node related to the initial setting of concrete according to the trend of electromotive force change.

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