Concrete moisture condition monitoring device, concrete curing device, moisture sensor weight

Abstract

To provide a concrete wet condition monitoring device which accurately detects a wet condition over the whole area of a surface 1602 of placed concrete 16 while reducing costs, so as to improve efficiency of curing work of the concrete 16.SOLUTION: A wet sensor 14 which is made by covering a pair of electrode wires 18 with an insulating material 20 so as to be formed into a linear shape is arranged substantially in contact with a surface 1602 of a placed concrete 16 over the approximately whole area of the surface 1602 of the concrete 16. A concrete curing mat 12 is laid on the surface 1602 of the concrete 16 while having the wet sensor 14 in between. The physical amount changing corresponding to capacitance of the wet sensor 14 is measured so that the surface 1602 of the concrete 16 is determined whether to be in a dry condition on the basis of the measured physical amount. When the surface 1602 of the concrete 16 is determined to be in the dry condition, a display part 30 performs alert display.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a concrete moisture condition monitoring device, a concrete curing device, and a weight for a moisture sensor. [Background technology]

[0002] Concrete develops its strength through a chemical reaction between water and cement called hydration, so when curing poured concrete, it is important to keep the surface of the concrete moist. Therefore, the surface of the poured concrete is covered with a concrete curing mat, water is supplied to the concrete curing mat to keep the surface of the concrete moist, and water is supplied once the concrete curing mat has dried. Patent Document 1 discloses a technique for detecting the wet state of a concrete curing mat in the following manner. That is, the document discloses that two ribbon-shaped metal sheets are prepared as measurement sensors, and two electrodes made of these metal sheets are placed between the surface of the concrete and the concrete curing mat, and a voltage is applied between the two electrodes to charge them, and then the charge is discharged and the residual voltage is measured, and if the residual voltage drops below a predetermined value, it is determined that the concrete curing mat has dried out and is no longer kept wet. Furthermore, Patent Document 2 discloses a technique for detecting the wet state of concrete as follows. That is, the technology disclosed involves installing a sensor consisting of a pair of electrode plates that contact the surface of the concrete slab and an insulator that connects the pair of electrode plates while keeping them spaced apart, between the concrete slab and the concrete curing mat, detecting the capacitance between the two electrode plates by applying a voltage pulse between them, and spraying water when the most recent capacitance falls below a predetermined percentage of the initially detected capacitance, or displaying a red light (dry state), a yellow light (low humidity state), or a blue / green light (wet state) based on the most recent capacitance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-3240 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-165073 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in all of the above-mentioned conventional technologies, the sensor for detecting the wetness of the concrete curing mat or concrete slab uses a pair of metal sheets or a pair of electrode plates, so the range in which the wetness can be detected is locally limited. On the other hand, in order to improve the efficiency of concrete curing work, it is necessary to accurately detect the wetness state over the entire surface of the poured concrete. Therefore, in conventional technology, it is necessary to install a large number of sensors over the entire surface of the poured concrete and to prepare a large number of devices that measure capacitance based on the detection signals from these sensors, which not only increases the cost of the sensors and devices, but also raises concerns about the cost of installing the sensors. The present invention has been made in consideration of the above circumstances, and its object is to provide a concrete moisture condition monitoring device, concrete curing device, and moisture sensor weight that are advantageous in reducing costs, accurately detecting the moisture condition over the entire surface of poured concrete, and improving the efficiency of concrete curing work. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, one embodiment of the present invention is a concrete wetness monitoring device, comprising: a wetness sensor in which a pair of electrode wires are coated with an insulating material and formed into an elongated shape, and are arranged so as to be in substantial contact with the surface of the poured concrete over almost the entire surface of the concrete, and in which the capacitance generated between the pair of electrode wires changes depending on the wetness state of the concrete surface; a concrete curing mat laid on the surface of the concrete above the wetness sensor; a physical quantity measuring unit that measures a physical quantity that changes in response to the capacitance of the wetness sensor; a wetness determination unit that determines whether the surface of the concrete is dry based on the physical quantity measured by the physical quantity measuring unit; and a warning unit that displays a warning on a display unit when the wetness determination unit determines that the surface of the concrete is dry. Furthermore, one embodiment of the present invention is a concrete curing device comprising: a wetness sensor in which a pair of electrode wires are coated with an insulating material and formed into an elongated shape, and the electrode wires are arranged so as to be in substantial contact with the surface of the poured concrete over almost the entire surface of the concrete, and the capacitance generated between the pair of electrode wires changes depending on the wetness state of the concrete surface; a concrete curing mat laid on the surface of the concrete from above the wetness sensor; a water supply unit that supplies water to the concrete curing mat; a physical quantity measurement unit that measures a physical quantity that changes in response to the capacitance of the wetness sensor; a wetness determination unit that determines whether the surface of the concrete is dry based on the physical quantity measured by the physical quantity measurement unit; and a water supply control unit that causes the water supply unit to supply water when the wetness determination unit determines that the surface of the concrete is dry. In addition, one embodiment of the present invention is characterized in that the concrete curing mat has a constant width and a length that is greater than this width, and the moisture sensor comprises a plurality of first extension portions spaced apart along the length of the concrete curing mat and extending over almost the entire width of the concrete curing mat, and a plurality of connecting extension portions connecting the ends of adjacent first extension portions along the length of the concrete curing mat. In addition, one embodiment of the present invention is characterized in that the wetness sensor extends along the entire periphery of the concrete curing mat except for the central portion. In addition, one embodiment of the present invention is characterized in that the concrete curing mat is divided into a plurality of areas, and the wetness sensors are separately and independently arranged corresponding to the plurality of areas. Furthermore, one embodiment of the present invention is characterized in that weights are placed on the moisture sensor at multiple locations spaced apart along the longitudinal direction of the moisture sensor to keep the moisture sensor in a state of approximate contact with the surface of the concrete. Another embodiment of the present invention is a weight that is placed so as to be in almost contact with the surface of poured concrete, covers an elongated moisture sensor that detects the moisture state of the concrete surface, and keeps the moisture sensor in a state of almost contact with the concrete surface, and is characterized in that the weight has an accommodating recess that is open downward, allows the moisture sensor to be accommodated, and penetrates the moisture sensor in the longitudinal direction. Furthermore, one embodiment of the present invention is characterized in that when the wetness sensor is accommodated in the accommodation recess and placed on the surface of the concrete, the upper part of the wetness sensor abuts against the inner surface that constitutes the upper part of the accommodation recess, and the lower surfaces of the weights located on both sides of the wetness sensor are almost in contact with the surface of the concrete. Furthermore, one embodiment of the present invention is characterized in that holding portions for detachably holding the wetness sensor are provided on the inner surfaces of the opposing accommodating recesses. Furthermore, one embodiment of the present invention is characterized in that the weight has an elongated shape, and the accommodating recess is formed in the middle of the weight in the longitudinal direction, penetrating the weight in a direction intersecting the longitudinal direction. In addition, one embodiment of the present invention is characterized in that a concrete curing mat is laid on the surface of the concrete from above the moisture sensor, and clip engagement recesses for a clip that clamps the weight are provided on the concrete curing mat at opposing points on the outer surface of the weight. [Effects of the Invention]

[0006] According to one embodiment of the present invention, the wetness sensor is positioned so that it is in almost contact with the surface of the concrete over almost the entire surface of the concrete, which reduces the costs required for the sensor and device, as well as the costs required for installing the sensor, and is advantageous in accurately detecting the wetness state over almost the entire surface of the concrete. Based on the warning display by the warning unit, the worker can easily and reliably understand that the concrete curing mat is dry and can perform water supply work to the concrete curing mat, which is advantageous for efficiently performing concrete curing work. Furthermore, according to one embodiment of the present invention, it is possible to reduce the costs required for sensors and devices, as well as the costs required for sensor installation work, which is advantageous in accurately detecting the wetness of almost the entire surface of the concrete. When the surface of the concrete becomes dry, the water supply unit automatically supplies water to the concrete curing mat, which reduces the number of people required while allowing water to be supplied to the concrete curing mat, which is advantageous for efficiently carrying out concrete curing work. In addition, according to one embodiment of the present invention, the wetness sensor is provided with a plurality of first extension portions and a plurality of connecting extension portions that connect the ends of adjacent first extension portions, so that the wetness sensors are positioned evenly across the entire surface of the concrete, which is advantageous in reliably determining whether the entire surface of the concrete is dry or not. Furthermore, according to one embodiment of the present invention, the moisture sensor extends along the entire periphery of the concrete curing mat except for the central portion, which is advantageous in that it allows early detection of the dryness of the concrete surface corresponding to the peripheral portion of the concrete curing mat, which is prone to drying out, and allows for quick response, such as supplying water to the concrete curing mat, which is advantageous in that it allows for efficient concrete curing work. Furthermore, according to one embodiment of the present invention, the concrete curing mat is divided into a plurality of regions, and the moisture sensors are separately and independently positioned in correspondence with the plurality of regions, so that it is possible to precisely determine whether the surface of the concrete is dry for each region of the concrete curing mat. Therefore, water can be appropriately supplied to the surface of the concrete corresponding to the area determined to be dry, which is advantageous for carrying out efficient and detailed concrete curing work. Furthermore, according to one embodiment of the present invention, the weight prevents the wetness sensor from floating above the concrete surface, so the wetness sensor is stably maintained in a state where it is almost in contact with the concrete surface. As a result, the capacitance of the wetness sensor changes to accurately reflect the wetness state of the concrete surface, which is advantageous for accurately detecting the wetness state of the concrete surface. Furthermore, according to one embodiment of the present invention, the wetness sensor is housed in a housing recess, which is more advantageous in that the weight can stably maintain the wetness sensor in a state where it is almost in contact with the surface of the concrete. In addition, according to one embodiment of the present invention, the wet sensor is accommodated in the accommodation recess without rattling, which is more advantageous in terms of stably maintaining the wet sensor in a state where it is almost in contact with the surface of the concrete using a weight. In addition, according to one embodiment of the present invention, a holding portion that detachably holds the wetness sensor is provided on the inner surfaces that constitute the opposing accommodating recesses, so that the wetness sensor can be securely held by the weight, which is even more advantageous in stably holding the wetness sensor in a state that is almost in contact with the surface of the concrete using the weight. In addition, according to one embodiment of the present invention, the longitudinal direction of the weight extends in a direction that intersects with the longitudinal direction of the wetness sensor, allowing the wetness sensor to be held stably on the surface of the concrete, which is advantageous in suppressing the effect of the weight on the wetness sensor. Furthermore, according to one embodiment of the present invention, a weight is clamped by a clip from above the concrete curing mat laid on the surface of the concrete, preventing the concrete curing mat from lifting off the surface of the concrete. This allows the concrete curing mat to be stably maintained in a state of almost contact with the concrete surface, which is advantageous for ensuring that water supplied to the concrete curing mat penetrates into the surface of the concrete and for efficiently curing the concrete. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view showing a concrete curing mat according to a first embodiment and a wetness sensor disposed on the surface of poured concrete. FIG. [Figure 2] 1 is a cross-sectional view showing a concrete curing mat according to a first embodiment and a wetness sensor disposed on the surface of poured concrete. FIG. [Figure 3] FIG. 2 is an explanatory diagram of a wetness sensor and a physical quantity measuring unit. [Figure 4] 1 is a block diagram showing the configuration of a concrete moisture condition monitoring device according to a first embodiment. [Figure 5] 4 is a flowchart illustrating a method of using the concrete moisture condition monitoring device according to the first embodiment. [Figure 6] FIG. 10 is a perspective view showing a wetness sensor placed on the surface of poured concrete in a modified example of the first embodiment. [Figure 7] FIG. 10 is a block diagram showing the configuration of a concrete curing apparatus according to a second embodiment. [Figure 8] 10 is a flowchart illustrating a method of using the concrete curing apparatus in the second embodiment. [Figure 9] FIG. 10 is an explanatory diagram showing a state in which moisture sensors are installed separately and independently corresponding to each of a plurality of regions of a concrete curing mat in a third embodiment. [Figure 10]10A and 10B are explanatory views of a state in which a wetness sensor weight according to a fourth embodiment is used, in which (A) is a cross-sectional view and (B) is a perspective view in which a concrete curing mat is omitted. [Figure 11] 10A and 10B are explanatory views of a state in which a wetness sensor weight according to a fifth embodiment is used, in which (A) is a cross-sectional view and (B) is a perspective view in which a concrete curing mat is omitted. [Figure 12] 10A and 10B are explanatory diagrams of the usage state of the moisture sensor weight in the sixth embodiment, where (A) is a cross-sectional view, (B) is an oblique view omitting the concrete curing mat, and (C) is a plan view of (B). [Figure 13] 10A and 10B are explanatory diagrams of the usage state of the moisture sensor weight in the seventh embodiment, where (A) is a cross-sectional view, (B) is a perspective view omitting the concrete curing mat, and (C) is a plan view of (B). [Figure 14] 13A and 13B are explanatory views of the usage state of the wetness sensor weight and clip in the eighth embodiment, where (A) is a cross-sectional view and (B) is a perspective view omitting the concrete curing mat. DETAILED DESCRIPTION OF THE INVENTION

[0008] (First embodiment) Next, a concrete wetness monitoring device according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 4, the concrete moisture condition monitoring device 10 includes a concrete curing mat 12 and a moisture sensor 14. As shown in FIGS. 1 and 2, the concrete curing mat 12 is laid on the surface 1602 of the concrete 16 that has been poured above the wetness sensor 14, and maintains the concrete 16 in a wet state. The concrete curing mat 12 has a water-retaining layer formed in a sheet shape using a material that has water absorption and water retention properties, such as urethane foam, nonwoven fabric, or synthetic fiber, or a water-retaining layer formed in a sheet shape by layering multiple types of these materials. In addition, in order to suppress evaporation of water from the water retentive layer, a film may be attached to the surface of the water retentive layer located opposite to the surface 1602 of the concrete 16. In the following description, the surface of the concrete curing mat 12 opposite the surface 1602 of the concrete 16 will be referred to as the surface 1202, and the surface in contact with the surface 1602 of the concrete 16 will be referred to as the back surface 1204. Therefore, the concrete curing mat 12 stores the supplied moisture and allows the moisture to penetrate from the back surface 1204 of the concrete curing mat 12 to the surface 1602 of the concrete 16, thereby maintaining the surface 1602 of the poured concrete 16 in a moist state. The concrete curing mat 12 has a constant width W and a length L perpendicular to the width W, and is formed with dimensions of, for example, width W=1 m and length L=30 m to 50 m. A variety of concrete curing mats 12 with different materials and performance are commercially available, and any of these various concrete curing mats 12 can be appropriately selected and used.

[0009] As shown in FIG. 3, the wet sensor 14 includes a pair of electrode wires 18 and an insulating material 20 that covers the pair of electrode wires 18, and is formed in an elongated shape and is flexible. In this embodiment, the insulating material 20 (wet sensor 14) is in the shape of a strip having a width in the direction in which the electrode wires 18 are arranged, a thickness smaller than the width, and a length greater than the width. As shown in FIG. 10(A), the cross section of the insulating material 20 (wet sensor 14) has an elliptical shape with a major axis in the width direction and a minor axis in the thickness direction. The pair of electrode wires 18 extend parallel to each other within the insulating material 20 at a fixed interval in the width direction of the insulating material 20 . The wetness sensor 14 changes the capacitance generated between a pair of electrode wires 18 depending on the wetness state of the surface 1602 of the concrete 16. As shown in Figures 1 and 2, the wetness sensor 14 is positioned so as to be in substantial contact with the surface 1602 of the poured concrete 16 over almost the entire surface 1602 of the concrete 16; in other words, it is positioned so as to be in substantial contact with the surface 1602 of the concrete 16 over almost the entire surface 1602 of the poured concrete 16 within the contours of the concrete curing mat 12 laid on the surface 1602 of the concrete 16 from above the wetness sensor 14. In this specification, the phrase "the wetness sensor 14 is almost in contact with the surface 1602 of the concrete 16" includes a state in which the wetness sensor 14 is in contact with the surface 1602 of the concrete 16, and a state in which the wetness sensor 14 is slightly separated from the surface 1602 of the concrete 16 but is close to the surface 1602 of the concrete 16 within a range in which the wetness sensor 14 can detect changes in capacitance that occur between a pair of electrode wires 18 depending on the wetness state of the surface 1602 of the concrete 16.

[0010] As shown in FIG. 1, the wet sensor 14 is configured by connecting a plurality of first extension portions 22 having substantially the same shape to a plurality of connecting extension portions 24 having substantially the same shape. The first extensions 22 are spaced apart in the length L direction of the concrete curing mat 12 and extend over substantially the entire length in the width W direction of the concrete curing mat 12 . The connecting extensions 24 connect the ends of adjacent first extensions 22 in the longitudinal direction of the concrete curing mat 12 at the ends in the width W direction of the concrete curing mat 12 . The first extension portion 22 located at one end of the concrete curing mat 12 in the length L direction protrudes from the end of the concrete curing mat 12 in the width W direction, and the protruding first extension portion 22 is connected to the voltage detection unit 34 (see Figure 3). In this way, the wetness sensors 14 are arranged over almost the entire area of ​​the concrete curing mat 12 in the width W and length L directions. Conversely to the above, the multiple first extension portions 22 may be spaced apart in the width W direction of the concrete curing mat 12 and extend over almost the entire length L direction of the concrete curing mat 12, and the multiple connecting extension portions 24 may connect the ends of adjacent first extension portions 22 in the width W direction of the concrete curing mat 12 at the ends in the length L direction of the concrete curing mat 12. In this case as well, the wetness sensors 14 are arranged over almost the entire area of ​​the concrete curing mat 12 in the width W and length L directions.

[0011] 4, the concrete moisture condition monitoring device 10 includes a concrete curing mat 12, a moisture sensor 14, a physical quantity measuring unit 26, a moisture determining unit 28, a display unit 30, and a warning unit 32. The physical quantity measuring unit 26, the moisture determining unit 28, the display unit 30, and the warning unit 32 are incorporated into a single housing (not shown). In this embodiment, a voltage detection unit 34 (see FIG. 3) which will be described later and which constitutes part of the physical quantity measurement unit 26, the wetness determination unit 28, and the warning unit 32 are all implemented by a computer. That is, a computer is composed of a CPU, a ROM for storing and saving control programs, a RAM for running the control programs, an interface section for interfacing with peripheral circuits, and the like. The computer functions as a voltage detection unit 34, a wetness determination unit 28, and a warning unit 32 as a result of the CPU executing a control program.

[0012] The physical quantity measuring unit 26 measures a physical quantity that changes in response to the capacitance of the wetness sensor 14 . As shown in FIG. 3, in this embodiment, the physical quantity measuring unit 26 includes an input terminal 2602, a DC power supply 2604, a fixed resistor 2606, an output terminal 2608, and a voltage detecting unit . The input terminal 2602 is connected to one end of a pair of electrode wires 18 . A DC power supply 2604 is connected to the input terminal 2602 and applies a constant DC voltage Vin between both electrode wires 18 . The fixed resistor 2606 extracts a charging voltage Et corresponding to the change in capacitance generated between the pair of electrode wires 18 . The output terminal 2608 is connected to both ends of the fixed resistor 2606 . The voltage detection unit 34 detects the output voltage Vout at the output terminal 2608 .

[0013] Between the pair of insulatingly coated electrode wires 18, a capacitor C1 is formed according to the relative dielectric constant of the objects present between and around the pair of electrode wires 18. Here, the relative dielectric constant of air is 1 and the relative dielectric constant of water is 80.4. The capacitors C1 are connected in parallel along the length of the level sensor 24. Therefore, the capacitance of capacitor C1 formed when the surface 1602 of the poured concrete 16 is wet, i.e., when moisture is present around the moisture sensor 14, is greater than the capacitance of capacitor C1 formed when the surface 1602 of the poured concrete 16 is dry, i.e., when no moisture is present around the moisture sensor 14. In other words, the more wet the surface 1602 of the poured concrete 16 is (the more moisture there is), the larger the capacitance of capacitor C1 will be, and the less wet the surface 1602 of the poured concrete 16 is (the less moisture there is), the smaller the capacitance of capacitor C1 will be. In other words, the capacitance of the capacitor C1 changes depending on the amount of moisture on the surface 1602 of the poured concrete 16.

[0014] Therefore, a constant DC voltage Vin is applied between both electrode wires 18 from input terminal 2602 to give an electric charge to both electrode wires 18, and the output voltage Vout between both electrode wires 18 is measured by voltage detection unit 34. In this case, the relationship of output voltage Vout=Et / (R+2r) holds, where R is the resistance value of the fixed resistor 2606, and r is the specific resistance of the electrode wire 18.

[0015] The measurement result of the output voltage Vout by the voltage detection unit 34 changes depending on the magnitude of the capacitance of the capacitor C1. Therefore, the measurement result of the output voltage Vout changes depending on the wet state (water content) of the surface 1602 of the placed concrete 16. Therefore, by experiment, if the value of the output voltage Vout in a state where the wet state (water content) of the surface 1602 of the placed concrete 16 is low and water supply to the placed concrete 16 is necessary is measured and this value is determined as the threshold voltage Vr, it can be determined that the surface 1602 of the placed concrete 16 is in a dry state and water supply is necessary when Vout < Vr. In this embodiment, the case where the physical quantity measurement unit 26 measures the voltage (output voltage Vout) as the physical quantity that changes corresponding to the capacitance of the moisture sensor 14 has been described. However, the physical quantity is not limited, and the physical quantity measurement unit 26 may measure the capacitance of the moisture sensor 14 itself as the physical quantity. However, with the method of this embodiment, the configuration of the physical quantity measurement unit 26 is simplified, which is advantageous for cost reduction.

[0016] As shown in FIG. 4, the wetness determination unit 28 determines whether the surface 1602 of the placed concrete 16 is in a dry state based on the physical quantity (voltage value) measured by the physical quantity measurement unit 26. In this embodiment, the wetness determination unit 28 compares the output voltage Vout with the threshold voltage Vr, and determines that the surface 1602 of the placed concrete 16 is in a dry state and water supply is necessary when Vout < Vr.

[0017] The display unit 30 performs warning display and is configured by an LED lamp in this embodiment. The warning unit 32 performs warning display by the display unit 30 when the wetness determination unit 28 determines that the surface 1602 of the placed concrete 16 is in a dry state. In this embodiment, when the wetness determining unit 28 determines that the surface 1602 of the poured concrete 16 is in a dry state, the warning unit 32 causes the display unit 30 to flash to display a warning. In addition, the warning unit 32 turns off the display unit 30 when the wetness determination unit 28 does not determine that the surface 1602 of the poured concrete 16 is in a dry state (when the surface 1602 of the poured concrete 16 is in a wet state). By displaying such a warning, the wetness (dryness) of the surface 1602 of the poured concrete 16 can be grasped at a glance. The form of the warning display on the display unit 30 is not limited to flashing, and for example, the display unit 30 may be configured with an LED lamp that can emit light in two colors, red and green, and the display unit 30 may light up red if it is determined that the surface 1602 of the poured concrete 16 is dry, and may light up green if it is determined that the surface 1602 is not dry. Furthermore, a speaker may be provided instead of the display unit 30, and a warning sound may be generated from the speaker by the warning unit 32. As the form of warning, various conventionally known warning methods may be used. In addition, the concrete wetness state monitoring device 10 may be provided with a communication unit capable of communicating via a wireless line, and when the wetness determination unit 28 determines that the surface 1602 of the poured concrete 16 is in a dry state, the warning unit 32 may generate warning information indicating that the surface 1602 of the poured concrete 16 is in a dry state. In this case, the warning information may be transmitted from the communication unit via a wireless line to an external terminal, such as a smartphone, tablet terminal, or personal computer, and the warning information may be displayed on the terminal. In this way, even a worker who is located far from the concrete wetness condition monitoring device 10 can know through the terminal that the surface 1602 of the poured concrete 16 is dry, which is advantageous for efficiently carrying out curing work on the concrete 16.

[0018] Next, a method of using the concrete curing mat 12 and the concrete moisture condition monitoring device 10 according to this embodiment will be described with reference to the flowchart of FIG. Once the concrete 16 has been poured into the formwork and hardened to the point where the surface can be touched with a finger without leaving any marks, the wetness sensor 14 is positioned so that it is in substantial contact with the surface 1602 of the concrete 16 over almost the entire area of ​​the upward-facing surface 1602 of the concrete 16 (step S10). Specifically, as shown in FIG. 1, the wetness sensor 14 is positioned so as to be in substantial contact with the surface 1602 of the concrete 16 throughout substantially the entire area within the contours of the concrete curing mat 12 . At this time, the wet sensor 14 is bent and placed so that a plurality of first extending portions 22 and a plurality of connecting extending portions 24 are formed. Next, the concrete curing mat 12 is spread and placed on the surface 1602 of the concrete 16 so as to cover the entire surface 1602 (step S12), one end of the moisture sensor 14 is connected to the voltage detection unit 34 of the physical quantity measurement unit 26, and the concrete moisture state monitoring device 10 is put into operation (step S14). Next, water is supplied to the entire area of ​​the concrete curing mat 12, so that the entire area of ​​the concrete curing mat 12 is kept wet and ready for curing of the concrete 16 (step S16).

[0019] The wetness determining unit 28 determines whether the surface 1602 of the concrete 16 is in a dry state based on whether the output voltage Vout detected by the voltage detecting unit 34 is less than the reference voltage Vr (step S18). If the determination result in step S18 is negative, the process returns to step S18. If the determination result in step S18 is positive, the warning unit 32 causes the display unit 30 to blink, and a warning display is given to indicate that the surface 1602 of the concrete 16 is dry (step S20). The worker, having recognized the warning displayed on the display unit 30, supplies water to the concrete curing mat 12 to make the surface 1602 of the concrete 16 wet (step S22). When the surface 1602 of the concrete 16 becomes wet, the output voltage Vout detected by the voltage detection unit 34 becomes equal to or greater than the reference voltage Vr, and the wetness determination unit 28 determines that the concrete curing mat 12 is not dry. As a result, the warning unit 32 turns off the display unit 30, cancels the warning display (step S24), and the process returns to step S18. By repeating this operation, the concrete 16 is effectively cured by the concrete curing mat 12, and the concrete 16 hardens due to the hydration reaction of the concrete 16, thereby developing strength.

[0020] As described above, according to the concrete moisture condition monitoring device 10 of this embodiment, the moisture sensor 14, which is formed in an elongated shape with a pair of electrode wires 18 covered with insulating material 20, is positioned so as to be in almost contact with the surface 1602 of the poured concrete 16 over almost the entire surface 1602 of the concrete 16, a concrete curing mat 12 is laid on the surface 1602 of the concrete 16 from above the moisture sensor 14, a physical quantity which changes in response to the capacitance of the moisture sensor 14 is measured, and based on the measured physical quantity, it is determined whether the surface 1602 of the concrete 16 is in a dry state, and if it is determined that the surface 1602 of the concrete 16 is in a dry state, a warning is displayed by the display unit 30. Therefore, since the wetness sensor 14 is positioned so as to be in substantial contact with the surface 1602 of the concrete 16 over almost the entire area of ​​the surface 1602 of the concrete 16, the wetness state of almost the entire area of ​​the surface 1602 of the concrete 16 can be accurately detected. Therefore, there is no need to prepare and install a large number of sensors and a large number of devices that measure capacitance based on the detection signals from those sensors, as was done in the past. This not only reduces the costs required for sensors and devices, and the costs required for installing the sensors, but is also advantageous in accurately detecting the wetness of almost the entire surface 1602 of the concrete 16. Furthermore, the worker can easily and reliably understand that the concrete curing mat 12 is dry based on the warning displayed on the display unit 30, and can then perform water supply work to the concrete curing mat 12, which is advantageous for efficiently curing the concrete 16.

[0021] Furthermore, after water is supplied to the concrete curing mat 12, as time passes, the water evaporates from the surface of the concrete curing mat 12 into the air and penetrates from the back surface of the concrete curing mat 12 to the surface 1602 of the poured concrete 16, causing the wetness of the concrete curing mat 12 to change. Although it depends on the temperature and wind conditions, heat is generated during concrete curing, and moisture is consumed by the hydration reaction of the concrete on the surface 1602 of the concrete 16, so even if the surface of the concrete curing mat 12 is wet, the back surface of the concrete curing mat 12 is often dry. In this embodiment, the wetness sensor 14 is positioned so as to be in near contact with the surface 1602 of the poured concrete 16, which is advantageous in accurately detecting the wetness of the surface 1602 of the concrete 16 regardless of the wetness of the concrete curing mat 12 covering the surface 1602 of the concrete 16. Furthermore, since the concrete curing mat 12 and the wetness sensor 14 are separate entities, any commercially available concrete curing mat 12 can be selected and used according to the required performance and cost, which is advantageous in improving usability. Furthermore, since the concrete curing mat 12 and the wetness sensor 14 are separate entities, if the concrete curing mat 12 is partially deteriorated, it is sufficient to cut out only the deteriorated portion of the concrete curing mat 12 and replace it with a new concrete curing mat 12; there is no need to replace the wetness sensor 14, which is advantageous in reducing the operating costs associated with the concrete 16 curing work.

[0022] In addition, in this embodiment, the moisture sensor 14 is equipped with a plurality of first extension portions 22 spaced apart in the length L direction of the concrete curing mat 12 and extending over almost the entire length of the concrete curing mat 12 in the width W direction, and a plurality of connecting extension portions 24 connecting the ends of adjacent first extension portions 22 in the longitudinal direction of the concrete curing mat 12. Therefore, the wetness sensors 14 are arranged evenly across the entire surface 1602 of the concrete 16, which is advantageous in reliably determining whether the entire surface 1602 of the concrete 16 is dry or not.

[0023] Although it depends on the influence of wind and temperature, the moisture contained in the concrete curing mat 12 tends to evaporate more easily from the periphery than from the center of the concrete curing mat 12, and the periphery tends to become drier than the center. Therefore, as shown in Figure 6, if the moisture sensor 14 is extended along the entire periphery of the concrete curing mat 12 except for the central part, this is advantageous in that it will be possible to quickly detect the dryness of the surface 1602 of the concrete 16 corresponding to the peripheral part of the concrete curing mat 12, which is prone to drying out, and it will be possible to take prompt action such as supplying water to the concrete curing mat 12, which is advantageous in efficiently curing the concrete 16. In this case, the wetness sensor 14 corresponding to the center of the concrete curing mat 12 can be omitted, which is also advantageous in terms of reducing the cost of the wetness sensor 14.

[0024] (Second embodiment) Next, a concrete curing apparatus 36 according to a second embodiment will be described with reference to FIG. In the following embodiments, the same parts and members as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will be omitted. The concrete curing device 36 of the second embodiment is designed to automatically supply water using the wetness sensor 14 of the first embodiment.

[0025] As shown in FIG. 7, the concrete curing apparatus 36 includes a concrete curing mat 12, a wetness sensor 14, a physical quantity measuring unit 26, a wetness determining unit 28, a water supply control unit 38, and a water supply unit 40. The concrete curing mat 12, the wetness sensor 14, the physical quantity measuring unit 26, and the wetness determining unit 28 are the same as those in the first embodiment, and therefore a description thereof will be omitted. The water supply unit 40 supplies water to the concrete curing mat 12, and is composed of, for example, a pipeline that supplies water from a water storage tank to the concrete curing mat 12, a sprinkler outlet provided at the end of the pipeline that sprinkles water onto the concrete curing mat 12, and an electromagnetic valve provided in the pipeline. The water supply control unit 38 is configured by a computer, and causes the water supply unit 40 to supply water when the wetness determination unit 28 determines that the surface 1602 of the concrete 16 is in a dry state. That is, when the wetness determination unit 28 determines that the surface 1602 of the concrete 16 is dry, the solenoid valve is opened for a certain period of time to supply water to the concrete curing mat 12. When the wetness determination unit 28 does not determine that the surface 1602 of the concrete 16 is dry, the solenoid valve is closed to stop the supply of water to the concrete curing mat 12.

[0026] Next, a method of using the concrete curing equipment 36 will be described with reference to the flowchart of FIG. Once the concrete 16 has been poured into the formwork and hardened to the point where the surface does not leave any marks when touched with a finger, the wetness sensor 14 is positioned so that it is in substantial contact with the surface 1602 of the concrete 16 over almost the entire surface 1602 of the concrete 16 (step S50). Next, the concrete curing mat 12 is spread and placed on the surface 1602 of the concrete 16 so as to cover the entire surface 1602 (step S52). In addition, a water supply unit 40 is installed so that water can be supplied to the concrete curing mat 12 (step S54). Next, one end of the moisture sensor 14 is connected to the voltage detection unit 34 of the physical quantity measurement unit 26, and the concrete curing device 36 is put into operation (step S56). Next, water is supplied to the entire area of ​​the concrete curing mat 12 by the water supply unit 40, so that the entire area of ​​the concrete curing mat 12 is wetted and ready for curing of the concrete 16 (step S58).

[0027] The wetness determining unit 28 determines whether the surface 1602 of the concrete 16 is in a dry state based on whether the output voltage Vout detected by the voltage detecting unit 34 is less than the reference voltage Vr (step S60). If the result of the determination in step S60 is negative, the process returns to step S60. If the determination result in step S60 is positive, the water supply control unit 38 controls the water supply unit 40 to supply water to the concrete curing mat 12 for a certain period of time (step S62), and the process returns to step S60. By repeating this operation, water is automatically supplied to the concrete curing mat 12, thereby maintaining a moist state on the surface 1602 of the concrete 16. By maintaining a moist state, the concrete 16 is effectively cured, and the hydration reaction of the concrete 16 causes the concrete 16 to harden and develop strength.

[0028] According to the concrete curing device 36 of the second embodiment, as with the first embodiment, it is possible to reduce the costs required for the sensors and device, and the costs required for sensor installation work, and it is also advantageous in accurately detecting the wetness state of almost the entire surface 1602 of the concrete 16. Furthermore, when the surface 1602 of the concrete 16 becomes dry, water is automatically supplied to the concrete curing mat 12, which reduces the number of workers required while still allowing water to be supplied to the concrete curing mat 12, which is advantageous for efficiently curing the concrete 16.

[0029] (Third embodiment) Next, a third embodiment will be described with reference to FIG. The third embodiment differs from the first embodiment in that the concrete curing mat 12 is divided into multiple areas A, and the moisture sensors 14 are arranged separately and independently to correspond to the multiple areas A. In the third embodiment, as shown in FIG. 9, the concrete curing mat 12 has a constant width W and a length L perpendicular to this width. The areas A are set by dividing the concrete curing mat 12 at regular intervals of a length ΔL. In region A, the moisture sensor 14 comprises a plurality of first extension portions 22 spaced apart along the length L of the concrete curing mat 12 and extending over almost the entire length of the concrete curing mat 12 in the width W direction, and a plurality of connecting extension portions 24 that connect the ends of adjacent first extension portions 22 in the longitudinal direction of the concrete curing mat 12 at the ends of the concrete curing mat 12 in the width W direction. In region A, a first extension 22 located at one end of the concrete curing mat 12 in the length L direction protrudes from the end of the concrete curing mat 12 in the width W direction.

[0030] The concrete curing mat 12 and wetness sensor 14 of the third embodiment can precisely determine whether the surface 1602 of the concrete 16 is dry for each area A of the concrete curing mat 12. For example, in the case of a concrete curing mat 12 having a width W of 1 m and a length L of 50 m, the concrete curing mat 12 will not necessarily be in a wet state, i.e., the amount of moisture contained in the concrete curing mat 12 will not necessarily be uniform, throughout the entire length L. Due to the influence of temperature, wind conditions, the volume of the poured concrete 16, etc., it is possible that the surface 1202 of the concrete 16 corresponding to a certain area A will remain wet, while another area A will be dry. In other words, there may be cases where the wetness state of the surface 1202 of the concrete 16 changes significantly locally. In this case, if a single wetness sensor 14 is installed on the surface 1602 of the concrete 16 corresponding to the concrete curing mat 12, it is possible to determine whether the surface 1602 of the concrete 16 corresponding to the entire 50 m of the concrete curing mat 12 is in an average dry state, but it is difficult to determine whether the surface is in a finely tuned dry state. Therefore, by applying the concrete moisture condition monitoring device 10 described in the first embodiment to each area A of the concrete curing mat 12, it is possible to issue a detailed warning to the surface 1602 of the concrete 16 corresponding to the area A that has become dry based on the moisture state of the surface 1602 of the concrete 16 corresponding to each area A of the concrete curing mat 12, and it is possible to appropriately supply water to the surface 1602 of the concrete 16 corresponding to the area A that has been determined to be dry, which is advantageous for carrying out the curing work of the concrete 16 efficiently and carefully. Furthermore, by applying the concrete curing device 36 described in the second embodiment to each area A of the concrete curing mat 12, water can be supplied in a precise manner to the surface 1602 of the concrete 16 corresponding to each area A of the concrete curing mat 12 that is determined to be dry based on the wetness of the surface 1602 of the concrete 16 corresponding to that area A, which is advantageous in that it allows for efficient and precise curing of the concrete 16 while reducing the number of people required.

[0031] In the third embodiment, a concrete curing mat 12 having a constant width W and a length L perpendicular to this width is divided into multiple regions A at constant lengths ΔL of the concrete curing mat 12, but the setting of multiple regions A is arbitrary. However, this embodiment is advantageous in efficiently setting multiple regions A on a concrete curing mat 12 having a constant width W and a length L perpendicular to this width.

[0032] Furthermore, in the third embodiment, in region A, the moisture sensor 14 has a plurality of first extension portions 22 and a plurality of connecting extension portions 24, and the first extension portion 22 located at one end of the length L direction of the concrete curing mat 12 in region A protrudes from the end of the concrete curing mat 12 in the width W direction, but the shape of the moisture sensor 14 arranged corresponding to each region A of the concrete curing mat 12 is not limited to the embodiment and is arbitrary. However, in the present embodiment, the wetness sensors 14 are evenly positioned across the entire surface 1602 of the concrete 16 corresponding to each area A of the concrete curing mat 12, which is advantageous in reliably determining whether the surface 1602 of the concrete 16 corresponding to each area A is dry or not.

[0033] (Fourth embodiment) Next, a fourth embodiment will be described with reference to FIG. In the fourth embodiment, weights (wet sensor weights) 42A are placed on the wet sensor 14 at multiple locations spaced apart along the longitudinal direction of the wet sensor 14 to keep the wet sensor 14 in a state where it is almost in contact with the surface 1602 of the concrete 16. As shown in FIGS. 10(A) and 10(B), the weight 42A has an accommodation recess 44 that is open downwards, allows the wet sensor 14 to be accommodated, and penetrates the wet sensor 14 in the longitudinal direction. The weight 42A has side walls 4402 on both sides facing each other and a top wall 4404 connecting the upper parts of the side walls 4402. The receiving recess 44 is composed of side walls 4402 on both sides and a top wall 4404 . The weight 42A can be easily formed by casting using a metal material with a high specific gravity, for example. If the direction in which the side walls 4402 on both sides face each other is defined as the width of the weight 42A and the direction perpendicular to this width is defined as the length of the weight 42A, then these width and length are determined appropriately depending on the usage environment, and the storage recess 44 penetrates the weight 42A in the longitudinal direction. When the wet sensor 14 placed on the surface 1602 of the concrete 16 is accommodated in the accommodation recess 44 and the weight 42A is placed over the wet sensor 14, the lower surface 1404 of the wet sensor 14 abuts against the surface 1602 of the concrete 16, the upper surface 1402 of the wet sensor 14 abuts against the upper wall 4404, and the lower surfaces 4402A of the side walls 4402 on both sides are almost in contact with the surface 1602 of the concrete 16, and in this embodiment, the lower surfaces 4402A of the side walls 4402 on both sides are slightly spaced upward from the surface 1602 of the concrete 16. In this specification, the expression "the lower surfaces 4402A of the side walls 4402 on both sides are almost in contact with the surface 1602 of the concrete 16" includes a state in which the lower surfaces 4402A of the side walls 4402 on both sides are in contact with the surface 1602 of the concrete 16, and a state in which the lower surfaces 4402A of the side walls 4402 on both sides are close to the surface 1602 of the concrete 16, as shown in Figure 10(A). In other words, when the wet sensor 14 is accommodated in the accommodation recess 44 and placed on the surface 1602 of the concrete 16, the upper part of the wet sensor 14 abuts against the inner surface 4410 that forms the upper part of the accommodation recess 44, and the lower surfaces 4402A of the weights 42A located on both sides of the wet sensor 14 are almost in contact with the surface 1602 of the concrete 16. The weights 42A may be arranged in multiple locations at predetermined intervals on each first extension portion 22 of the wet sensor 14, or may be arranged on each connecting extension portion 24, and the number of weights 42A used and their placement locations are determined appropriately depending on the usage environment.

[0034] According to this fourth embodiment, even in a windy environment, the weight 42A prevents the wet sensor 14 from floating up from the surface 1602 of the concrete 16, so that the wet sensor 14 is stably maintained in a state where it is almost in contact with the surface 1602 of the concrete 16. Therefore, the capacitance of the wetness sensor 14 changes to accurately reflect the wetness state of the surface 1602 of the concrete 16, which is advantageous in accurately detecting the wetness state of the surface 1602 of the concrete 16. Therefore, if the fourth embodiment is applied to the concrete wetness condition monitoring device 10 of the first embodiment, it will be advantageous in accurately reflecting the wetness condition of the surface 1602 of the concrete 16 and accurately warning of the dryness condition of the concrete 16. Furthermore, if the fourth embodiment is applied to the concrete curing apparatus 36 of the second embodiment, it is advantageous in efficiently curing the concrete 16 by supplying water to the concrete curing mat 12 in a manner that accurately reflects the wetness state of the surface 1602 of the concrete 16.

[0035] Furthermore, according to the fourth embodiment, the weight 42A has an open storage recess 44 at the bottom that can accommodate the wet sensor 14. Therefore, by storing the wet sensor 14 in the storage recess 44, the weight 42A is advantageous in stably maintaining the wet sensor 14 in a state that is almost in contact with the surface 1602 of the concrete 16.

[0036] Furthermore, according to the fourth embodiment, when the wet sensor 14 is accommodated in the accommodation recess 44 and placed on the surface 1602 of the concrete 16, the upper part of the wet sensor 14 abuts against the inner surface 4410 that forms the upper part of the accommodation recess 44, and the lower surfaces 4402A of the weights 42A located on both sides of the wet sensor 14 are almost in contact with the surface 1602 of the concrete 16. Therefore, the wetness sensor 14 is accommodated in the accommodation recess 44 without rattling, which is more advantageous in stably maintaining the wetness sensor 14 in a state where it is almost in contact with the surface 1602 of the concrete 16 using the weight 42A. Furthermore, as shown in Figure 10(A), if the underside 4402A of the weight 42A located on both sides of the wetness sensor 14 is slightly spaced upward from the surface 1602 of the concrete 16, the weight of the weight 42A can be more reliably applied to the wetness sensor 14, which is more advantageous in maintaining the wetness sensor 14 in a state where it is almost in contact with the surface 1602 of the concrete 16.

[0037] (Fifth embodiment) Next, a fifth embodiment will be described with reference to FIG. In the following embodiments, the same parts and members as those in the fourth embodiment are denoted by the same reference numerals, and the description thereof will be omitted, and the description will focus on the differences. The fifth embodiment is a modified example of the fourth embodiment, and differs from the fourth embodiment in that a holding portion 46 is provided in the storage recess 44 of the weight 42B to detachably hold the wet sensor 14. As shown in FIGS. 11(A) and (B), the inner surfaces 4410 constituting the opposing accommodating recesses 44 are provided with holding portions 46 for detachably holding the wetness sensor 14. In this embodiment, the storage recess 44 is composed of side walls 4402 on both sides and an upper wall 4404, and the side walls 4402 on both sides are provided with holding portions 46 that detachably hold the wet sensor 14 with the upper surface 1402 of the wet sensor 14 abutting against the upper wall 4404. The holding portion 46 is configured by a pair of protrusions 4602 protruding from the inner surfaces of the side walls 4402 on both sides, which face each other. Therefore, when the wet sensor 14 is pushed into the storage recess 44, the upper surface 1402 of the wet sensor 14 abuts against the upper wall 4404, and both side surfaces 1406 of the wet sensor 14 are clamped by a pair of protrusions 4602, so that the wet sensor 14 is held in a detachable manner. In this state, when the wet sensor 14 with the weight 42B placed on it is placed on the surface 1602 of the concrete 16, the lower surfaces 4402A of the side walls 4402 on both sides of the weight 42B are spaced upward from the surface 1602 of the concrete 16, as in the fourth embodiment.

[0038] According to the fifth embodiment, not only can the same effects as those of the fourth embodiment be achieved, but also, since a holding portion 46 that detachably holds the wet sensor 14 is provided in the storage recess 44 of the weight 42B, the wet sensor 14 can be securely held by the weight 42B, which is even more advantageous in that the weight 42B can stably hold the wet sensor 14 in a state that is almost in contact with the surface 1602 of the concrete 16. In addition, since the holding portion 46 integrates the wetness sensor 14 and the multiple weights 42B, when the wetness sensor 14 is retrieved from the surface 1602 of the concrete 16, the multiple weights 42B are also removed together with the wetness sensor 14, which is advantageous in improving the efficiency of the curing work of the concrete 16. Furthermore, since the recovered wetness sensor 14 and the multiple weights 42B are integrated, when the wetness sensor 14 is installed again on the surface 1602 of the concrete 16, the work of reattaching the multiple weights 42B to the wetness sensor 14 can be avoided, which is advantageous in improving the efficiency of the curing work of the concrete 16.

[0039] (Sixth embodiment) Next, a sixth embodiment will be described with reference to FIG. The sixth embodiment is a modified example of the fifth embodiment, and differs from the fifth embodiment in the shape of the holding portion 46 that detachably holds the wetness sensor 14 provided in the storage recess 44 of the weight 42C. As shown in Figures 12(A) and (B), weight 42C has a flat, truncated cone shape and has an outer surface 4210 that has a circular, flat upper surface, a conical surface hanging down from the outer periphery of the upper surface, and a circular, flat lower surface connecting the lower end of the conical surface. The receiving recess 44 is provided at the center of the lower surface, penetrating the lower surface in the diameter direction and opening downward, and the receiving recess 44 is formed by the inner surface 4212 of the weight 42C. As shown in Figure 12(A), when the wet sensor 14 is accommodated in the accommodating recess 44, both side surfaces 1406 of the wet sensor 14 are held at opposing locations on the inner surface 4212 of the weight 42C, and therefore the holding portion 46 is formed by the inner surface 4410 of the accommodating recess 44.In this embodiment, the holding portion 46 is provided in two locations corresponding to both sides of the wet sensor 14. In other words, the holding portions 46 that detachably hold the wetness sensor 14 are provided on the inner surfaces 4410 that form the opposing accommodating recesses 44 . As shown in Figure 12(A), when the wet sensor 14 is accommodated in the accommodation recess 44 and held by the holding portion 46, the lower surface of the wet sensor 14 is almost in contact with the surface 1602 of the concrete 16, and in this embodiment, is slightly above the surface 1602 of the concrete 16. Therefore, when the wet sensor 14 is pushed into the receiving recess 44, both sides of the wet sensor 14 are sandwiched by the opposing inner surfaces 4410 of the receiving recess 44, and the wet sensor 14 is releasably held. According to the sixth embodiment, the same effects as those of the fifth embodiment can be achieved.

[0040] (Seventh embodiment) Next, a seventh embodiment will be described with reference to FIG. The seventh embodiment differs from the sixth embodiment in the shape of a weight 42D. As shown in FIG. 13, weight 42D has an elongated rectangular shape and an outer surface 4220 having an upper surface that extends along the longitudinal direction and has an upwardly convex cylindrical surface, and a flat lower surface that connects the lower end of the upper surface. The accommodation recess 44 is formed on the underside of the weight 42D at a longitudinally intermediate position thereof, penetrating in a direction intersecting the longitudinal direction of the weight 42D (in this embodiment, a direction perpendicular thereto) and opening downward. The accommodating recess 44 is formed by the inner surface 4222 of the weight 42D, and when the wet sensor 14 is accommodated in the accommodating recess 44, both widthwise side surfaces 1406 of the wet sensor 14 are held at opposing locations on the inner surface 4222 of the weight 42D.Therefore, the holding portion 46 is formed by the inner surface 4410 of the accommodating recess 44, and in this embodiment, the holding portion 46 is provided in two locations corresponding to both sides of the wet sensor 14. In other words, the holding portions 46 that detachably hold the wetness sensor 14 are provided on the inner surfaces 4410 that form the opposing accommodating recesses 44 . Therefore, as in the sixth embodiment, when the wet sensor 14 is accommodated in the accommodation recess 44 and held by the holding portion 46, the lower surface of the wet sensor 14 is almost in contact with the surface 1602 of the concrete 16, whereas in this embodiment it is slightly above the surface 1602 of the concrete 16. Therefore, when the wet sensor 14 is pushed into the receiving recess 44, both sides of the wet sensor 14 are sandwiched by the opposing inner surfaces 4410 of the receiving recess 44, and the wet sensor 14 is releasably held. According to the seventh embodiment, not only can the same effects as those of the sixth embodiment be achieved, but also, since the longitudinal direction of the weight 42D extends in a direction that intersects (is perpendicular to) the longitudinal direction of the wet sensor 14, the length of the weight 42D covering the wet sensor 14 can be minimized, and the wet sensor 14 can be stably held on the surface 1602 of the concrete 16 by the weight 42D with a large volume and weight. Therefore, the effect of the weight 42D on the capacitance of the wetness sensor 14 can be suppressed, which is advantageous in improving the accuracy of the physical quantity (voltage) measured by the physical quantity measuring unit 26 and in improving the accuracy of the wetness determination unit 28 in determining whether the surface 1602 of the concrete 16 is in a dry state.

[0041] (Eighth embodiment) Next, an eighth embodiment will be described with reference to FIG. The eighth embodiment is a modified version of the fourth embodiment, and differs from the fourth embodiment in that when the concrete curing mat 12 is laid on the surface 1602 of the concrete 16 from above the wetness sensor 14, clip engagement recesses 50 for the clips 48 that clamp the weight 42E from above the concrete curing mat 12 are provided at opposing positions on the outer surface 4210 of the weight 42E. In this embodiment, the clip locking recesses 50 are provided on both sides of the top wall 4404 of the weight 42E, but the clip locking recesses 50 may also be provided on the outer surfaces of the side walls 4402 on both sides, spaced apart from each other. The clip 48 is formed from an elastically deformable metal material or synthetic resin material, and comprises a body portion 4802 that is curved into an approximately cylindrical shape, and a pair of bent end portions 4804 that are provided on both sides of the body portion 4802 in the circumferential direction and bent in directions that bring them closer to each other. Such clips 48 are commercially available.

[0042] Next, how to use the weight 42E and clip 48 will be described. With the wetness sensor 14 housed in the housing recess 44, the wetness sensor 14 and the weight 42D are placed on the surface 1602 of the concrete 16. Next, the concrete curing mat 12 is placed over the wetness sensor 14 with the weight 42E attached thereto. Next, while grasping the pair of bent ends 4804 of the clip 48 and elastically deforming the clip 48 in the direction of opening it, place the clip 48 over the weight 42E from above the concrete curing mat 12, position the pair of bent ends 4804 at the position of the clip locking recess 50 via the concrete curing mat 12, and then release the pair of bent ends 4804. As a result, the pair of bent end portions 4804 of the clip 48 are engaged with the clip engaging recesses 50 via the concrete curing mat 12 due to the elasticity of the clip 48, whereby the clip 48 clamps the weight 42E from above the concrete curing mat 12.

[0043] According to the eighth embodiment, the weight 42E is clamped by the clips 48 from above the concrete curing mat 12 laid on the surface 1602 of the concrete 16, so that the concrete curing mat 12 is connected to the weight 42E at multiple locations spaced apart in the width and length directions, which is advantageous in preventing the concrete curing mat 12 from lifting up from the surface 1602 of the concrete 16. Therefore, not only can the same effects as those of the fourth embodiment be achieved, but the back surface 1204 of the concrete curing mat 12 can be stably maintained in a state in which it is almost in contact with the surface 1602 of the concrete 16, which is advantageous in ensuring that the water supplied to the concrete curing mat 12 penetrates into the surface 1602 of the concrete 16, and is advantageous in efficiently carrying out the curing work of the concrete 16.

[0044] Instead of using clips 48 to clamp the concrete curing mat 12 to the weight 42E, a detachable structure for detachably attaching the concrete curing mat 12 may be provided on the top wall 4404 of the weight 42E. A split pin with two legs can be used as the attachment / detachment structure. The head of the split pin is attached to the top wall 4404 of the weight 42E with the two legs of the split pin facing upward. After the two legs of the split pin are inserted into the concrete curing mat 12, the two legs are pushed apart, allowing the curing sheet to be detachably attached to the top wall 4404 of the weight 42E. Furthermore, a male screw portion and a nut can be used as the attachment / detachment structure. A male screw portion is provided protruding upward from the top wall 4404 of the weight 42E. After the tip of the male thread is inserted into the concrete curing mat 12, a nut is fastened to the male thread, thereby allowing the curing sheet to be detachably attached to the top wall 4404 of the weight 42E. Even if such a detachable structure is provided, the same effects as those of the eighth embodiment can be achieved.

[0045] It is to be noted that the clip locking recess 50 of the eighth embodiment may be applied to the weights 42B and 42C of the fifth and sixth embodiments, and it is of course also possible to apply the above-mentioned attachment / detachment structure to the weights 42B and 42C of the fifth and sixth embodiments.

[0046] In addition, in the embodiment, the concrete curing mat 12 is described as being placed on the upward-facing surface (top surface) 1602 of the concrete 16, but it goes without saying that the concrete curing mat 12 may also be placed on top of the side-facing surface (side surface) of the concrete 16. In this case, instead of the weights 42A, 42B, 42C, 42D, and 42D of the fourth to eighth embodiments, if the wetness sensor 14 is adhered to the surface 1602 of the concrete 16 using water-resistant adhesive tape or double-sided tape, this is advantageous in stably maintaining the wetness sensor 14 in a state where it is almost in contact with the surface 1602 of the concrete 16. Furthermore, in the fourth to eighth embodiments, the case where the wetness sensor 14 changes its capacitance depending on the wetness state of the surface 1602 of the concrete 16 has been described, but the wetness sensor may be any sensor that can detect the wetness state of the surface 1602 of the concrete 16, and various conventionally known sensors can be used, such as a moisture sensor that detects the wetness state based on a resistance value that changes depending on the moisture content. [Explanation of symbols]

[0047] 10. Concrete moisture condition monitoring device 12 Concrete curing mat 1202 Surface 1204 Back side 14 Wetness Sensor 1402 Top surface 1404 Bottom surface 1406 Side 16 Concrete 1602 Surface 18 Pair of electrode wires 20 Insulation material 22 1st extension part 24 Connection extension 26 Physical quantity measurement section 28 Wetness determination unit 30 Display section 32 Warning part 34 Voltage detection unit 36 Concrete curing equipment 38 Water supply control unit 40 Water supply section 42A, 42B, 42C, 42D, 42E Weights (Wet Sensor Weights) 4210, 4220 External surface 4212, 4222 inner surface 44 Receiving recess 4402 Side wall 4402A bottom side 4404 Top wall 4410 Inner surface 46 Holding part 4602 Convex part 48 clips 4802 Main body 4804 Bent end 50 Clip locking recess

Claims

1. a wetness sensor in which a pair of electrode wires are coated with an insulating material and formed into an elongated shape, and are arranged in a bent manner so as to form a plurality of first extension portions and a plurality of connecting extension portions connecting ends of adjacent first extension portions so as to come into contact with the surface of the poured concrete over the entire surface of the concrete, and in which the capacitance generated between the pair of electrode wires changes depending on the wetness state of the surface of the concrete; a concrete curing mat laid on the surface of the concrete from above the moisture sensor; a physical quantity measuring unit that measures a physical quantity that changes in response to the capacitance of the wetness sensor; a wetness determination unit that determines whether the surface of the concrete is in a dry state based on the physical quantity measured by the physical quantity measurement unit; a warning unit that displays a warning by a display unit when the wetness determination unit determines that the surface of the concrete is dry; A concrete wetness monitoring device comprising:

2. a wetness sensor in which a pair of electrode wires are coated with an insulating material and formed into an elongated shape, and are arranged in a bent manner so as to form a plurality of first extension portions and a plurality of connecting extension portions connecting ends of adjacent first extension portions so as to come into contact with the surface of the poured concrete over the entire surface of the concrete, and in which the capacitance generated between the pair of electrode wires changes depending on the wetness state of the surface of the concrete; a concrete curing mat laid on the surface of the concrete from above the moisture sensor; a water supply unit that supplies water to the concrete curing mat; a physical quantity measuring unit that measures a physical quantity that changes in response to the capacitance of the wetness sensor; a wetness determination unit that determines whether the surface of the concrete is in a dry state based on the physical quantity measured by the physical quantity measurement unit; a water supply control unit that causes the water supply unit to supply water when the wetness determination unit determines that the surface of the concrete is dry; A concrete curing device comprising:

3. The concrete curing mat has a constant width and a length that is greater than the width, The moisture sensor includes a plurality of first extension portions spaced apart in the longitudinal direction of the concrete curing mat and extending over the entire width of the concrete curing mat, and a plurality of connecting extension portions connecting ends of adjacent first extension portions in the longitudinal direction of the concrete curing mat.

3. The concrete wetness condition monitoring device according to claim 1 or the concrete curing device according to claim 2.

4. The wetness sensor extends along the entire periphery of the concrete curing mat except for the central portion.

3. The concrete wetness condition monitoring device according to claim 1 or the concrete curing device according to claim 2.

5. The concrete curing mat is divided into a plurality of areas, The wetness sensors are separately and independently arranged corresponding to the plurality of regions.

3. The concrete wetness condition monitoring device according to claim 1 or the concrete curing device according to claim 2.

6. Weights are placed on the moisture sensor at multiple locations spaced apart in the longitudinal direction of the moisture sensor to keep the moisture sensor in contact with the surface of the concrete.

3. The concrete wetness condition monitoring device according to claim 1 or the concrete curing device according to claim 2.

7. A weight is placed in contact with the surface of poured concrete, covers an elongated wetness sensor that detects the wetness state of the concrete surface, and keeps the wetness sensor in contact with the surface of the concrete. The weight has an accommodation recess that is open downward and allows the accommodation of the wet sensor, and penetrates the wet sensor in the longitudinal direction. A weight for a wet sensor.

8. When the wetness sensor is accommodated in the accommodation recess and placed on the surface of the concrete, the upper part of the wetness sensor abuts against a portion of the inner surface constituting the upper part of the accommodation recess, and the lower surfaces of the weights located on both sides of the wetness sensor are in contact with the surface of the concrete.

8. The weight for a wet sensor according to claim 7.

9. Holding portions for detachably holding the wetness sensor are provided on the inner surfaces of the housing recesses facing each other.

9. A weight for a wet sensor according to claim 7 or 8.

10. The weight has an elongated shape, The accommodating recess is formed in a longitudinally intermediate portion of the weight in a direction intersecting the longitudinal direction.

10. A weight for a wet sensor according to any one of claims 7 to 9.

11. A concrete curing mat is laid on the surface of the concrete from above the moisture sensor, The weight has clip engagement recesses at opposing locations on its outer surface for a clip that clamps the weight from above the concrete curing mat.

11. The weight for a wet sensor according to any one of claims 7 to 10.

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