CN102506692A - Cement-based intelligent composite material strain sensor and preparation method thereof - Google Patents
Cement-based intelligent composite material strain sensor and preparation method thereof Download PDFInfo
- Publication number
- CN102506692A CN102506692A CN2011103189204A CN201110318920A CN102506692A CN 102506692 A CN102506692 A CN 102506692A CN 2011103189204 A CN2011103189204 A CN 2011103189204A CN 201110318920 A CN201110318920 A CN 201110318920A CN 102506692 A CN102506692 A CN 102506692A
- Authority
- CN
- China
- Prior art keywords
- cement
- composite material
- strain sensor
- intelligent composite
- carbon fiber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000004568 cement Substances 0.000 title claims abstract description 115
- 239000002131 composite material Substances 0.000 title claims abstract description 107
- 238000002360 preparation method Methods 0.000 title claims abstract description 19
- 229920000049 Carbon (fiber) Polymers 0.000 claims abstract description 71
- 239000004917 carbon fiber Substances 0.000 claims abstract description 71
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims abstract description 46
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims abstract description 34
- 229910052802 copper Inorganic materials 0.000 claims abstract description 34
- 239000010949 copper Substances 0.000 claims abstract description 34
- 238000000034 method Methods 0.000 claims abstract description 26
- 230000008569 process Effects 0.000 claims abstract description 17
- 238000001035 drying Methods 0.000 claims abstract description 8
- 239000011148 porous material Substances 0.000 claims abstract description 4
- 239000011398 Portland cement Substances 0.000 claims description 35
- 239000000203 mixture Substances 0.000 claims description 22
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 21
- 239000003638 chemical reducing agent Substances 0.000 claims description 14
- 239000006004 Quartz sand Substances 0.000 claims description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical group O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 9
- 239000002253 acid Substances 0.000 claims description 7
- 239000012615 aggregate Substances 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 4
- 239000002245 particle Substances 0.000 claims description 4
- 238000000465 moulding Methods 0.000 claims description 2
- 230000035945 sensitivity Effects 0.000 abstract description 13
- 238000002156 mixing Methods 0.000 abstract description 6
- 230000002776 aggregation Effects 0.000 abstract description 3
- 239000001913 cellulose Substances 0.000 abstract description 3
- 229920002678 cellulose Polymers 0.000 abstract description 3
- 239000000835 fiber Substances 0.000 abstract description 3
- 239000003469 silicate cement Substances 0.000 abstract description 3
- 238000005054 agglomeration Methods 0.000 abstract 1
- 239000002075 main ingredient Substances 0.000 abstract 1
- 239000004567 concrete Substances 0.000 description 29
- 230000008859 change Effects 0.000 description 19
- 238000012544 monitoring process Methods 0.000 description 18
- 229910000831 Steel Inorganic materials 0.000 description 10
- 239000010959 steel Substances 0.000 description 10
- 239000000463 material Substances 0.000 description 8
- 238000012360 testing method Methods 0.000 description 6
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000006229 carbon black Substances 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000010881 fly ash Substances 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 229920000609 methyl cellulose Polymers 0.000 description 2
- 239000001923 methylcellulose Substances 0.000 description 2
- 235000010981 methylcellulose Nutrition 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 239000002893 slag Substances 0.000 description 2
- 241001549498 Penelope purpurascens Species 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 239000002864 coal component Substances 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 230000001808 coupling effect Effects 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000011900 installation process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000002052 molecular layer Substances 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000003938 response to stress Effects 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 230000004083 survival effect Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
Landscapes
- Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
Abstract
The invention discloses a cement-based intelligent composite material strain sensor, which comprises a carbon-fiber cement-based intrinsic intelligent composite material and four parallel electrodes arranged on the composite material, wherein the electrodes are high-purity copper meshes; the pore diameter of the high-purity copper meshes is larger than 2mm; and the main ingredients of the composite material are PAN-based short-cut carbon fiber and silicate cement, and the electrodes are combined together with the carbon-fiber cement-based intrinsic intelligent composite material by an embedding process. The cement-based intelligent composite material strain sensor has the characteristics of high sensitivity coefficient, high voltage-sensitive characteristic linearity and excellent mechanical property; and the preparation process adopts a drying and mixing process, so that the problems that due to use of cellulose, the strength of the sensor is reduced and the electric performance of the sensor becomes poor are avoided and no phenomenon of fiber agglomeration occurs.
Description
Technical Field
The invention relates to the technical field of sensors, in particular to a cement-based intelligent composite material strain sensor and a preparation method thereof.
Background
At present, in civil engineering structures, a resistance strain gauge is widely used for monitoring the strain of a concrete structure, and the method has the advantages of mature technology, stability and reliability, but the strain gauge has the sensitivity coefficient of only 2-3, poor durability, complex installation process and high manufacturing cost, and cannot meet the technical requirement of long-term monitoring of the whole service life of people on important civil engineering structures. The cement-based intelligent composite material strain sensor has the advantages of high sensitivity coefficient, excellent durability and low cost, is simple in laying process and data acquisition, and is an important means for long-term monitoring of important civil engineering concrete structures such as large-span bridges, water conservancy dams and super high-rise buildings and a main direction for development of the strain sensor.
The defects of immature preparation technology, poor comprehensive mechanical property and high brittleness of the existing cement-based intelligent composite material strain sensor still cause poor stability of volume resistivity and low linearity of pressure-sensitive characteristic of the sensor, and the application and development of the cement-based intelligent composite material strain sensor are seriously influenced. The cement-based intelligent composite material strain sensor for monitoring the concrete structure is prepared by adopting various process methods, avoids the poor linear correlation between the strain and the resistivity and the fluctuation of the resistivity of the sensor caused by the material performance or the preparation method, improves the sensitivity coefficient and the resistivity stability of the cement-based intelligent composite material strain sensor, and becomes one of the key contents of the research in the technical field of the preparation of the current cement-based intelligent composite material strain sensor.
The chinese patent No. ZL 02132967.2 in document 1 discloses an air sensitive concrete sensor. The sensing element is composed of a test block with 1-2 pairs of electrodes, the test block is composed of carbon fiber and cement-based materials, and the sensor is simple in structure and has strain sensitivity to tensile stress and compressive stress. However, the resistivity and the stress of the sensing element in the elastic range show a nonlinear corresponding relation, and the change relation of the strain and the resistivity is not given, so that the measurement accuracy of the sensing element as a concrete strain sensor is influenced.
The chinese patent "application No. 200510031313.4" in document 2 discloses an intelligent concrete test block and a two-stage three-time or two-dry-one-wet manufacturing method thereof, and uses a capacitance value as an electrical property test parameter of a stress and strain sensor, and has the characteristics of sensitive compressive stress response and stable single data test. However, when the intelligent concrete sensor is in a low stress state (less than 4MPa), the increase speed of the stress capacitance value is higher than the increase speed of the stress, the increase is nonlinear, and the accuracy of monitoring the concrete structure in the low stress state is seriously influenced.
Chinese patent No. ZL 03128010.2 in document 3 discloses a high-sensitivity carbon fiber cement-based resistance strain sensing system with temperature compensation. According to the system, carbon fiber cement-based intelligent composite materials are paved on the upper surface and the lower surface of a common concrete beam to form a sandwich structure, and the degree of bending deformation of the concrete beam load is measured through a differential circuit with symmetrical upper and lower surfaces. The strain sensing system eliminates the influence of environmental temperature, improves the strain sensitive stability of the cement-based intelligent composite material strain sensor, and has extremely high strain-resistance sensitivity, but the sensor system has complex composition structure and layout process, can only be used for monitoring the bending deformation of a concrete beam, and limits the application of the cement-based intelligent composite material strain sensor.
The chinese patent "application No. 200510057227.0" of document 4 discloses an smart concrete using steel slag and fly ash containing iron oxide as conductive phases. The smart concrete has the advantages of waste utilization, high stress sensitivity, good mechanical property and simple preparation process, but because of the difference of the steel-making process and raw materials in various regions and the fluctuation of the electric coal components of a power plant, the fluctuation of the content of iron oxide in steel slag and fly ash is very common, so that the fluctuation of the resistivity and the pressure-sensitive property of the smart concrete is also large, and the performance stability of a strain sensor manufactured by using the smart concrete is seriously influenced.
Document 5 ("b.g.han, x.c.guan, j.p.ou, Sensors and Actuators a, 2007, 135: 360-. The cement-based intelligent composite material strain sensor has high stress sensitivity and good mechanical property, and carbon fiber conductive phases are uniformly distributed in the cement-based intelligent composite material. However, the preparation process has other disadvantages: on one hand, in the process of preparing the strain sensor, the viscosity of the carbon fiber cement mixture is increased due to the use of methyl cellulose, so that the water consumption for mixing is increased for obtaining necessary pouring fluidity, and the strength of the final cement-based intelligent composite material and the strain sensor thereof is reduced; on the other hand, the methyl cellulose also remains in the carbon fiber cement-based composite material, and an insulating high molecular layer is formed at the interface of the carbon fiber and the set cement, so that the fluctuation range of the resistivity of the final composite material is enlarged, and the resistivity and the pressure-sensitive performance stability of the cement-based intelligent composite material strain sensor are influenced.
The patent No. ZL 200710072474.7 in the document 7 discloses a pressure-sensitive cement-based composite material with nickel powder as a main functional component, and overcomes the defects that the existing pressure-sensitive cement-based material is low in force-electric coupling effect sensitivity, greatly influenced by humidity, easy to influence matrix polarization on electrical signal testing and the like. However, in the pressure-sensitive cement-based composite material, the higher nickel powder content can increase the water consumption for mixing in the preparation process and reduce the comprehensive mechanical properties of the pressure-sensitive cement-based composite material and the strain sensor thereof.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to provide a cement-based intelligent composite material strain sensor and a preparation method thereof, the strain sensor has the characteristics of high sensitivity coefficient, high pressure-sensitive characteristic linearity and excellent mechanical property of the sensor, a drying and mixing process is adopted in the preparation process, the problems of sensor strength reduction and electric property deterioration caused by cellulose use are avoided, and the phenomenon of fiber aggregation is avoided.
In order to achieve the purpose, the invention adopts the technical scheme that:
a cement-based intelligent composite material strain sensor is composed of a carbon fiber cement-based intelligent composite material and four parallel electrodes arranged on the composite material.
The electrode is a high-purity copper net, the aperture of the high-purity copper net is larger than 2mm, preferably 2-5mm, and the electrode is combined with the carbon fiber cement basic intelligent composite material through a pre-embedding process.
The carbon fiber cement basic intelligent composite material mainly comprises PAN-based chopped carbon fibers and portland cement in a mass ratio of (0.001-0.01) to 1;
or the carbon fiber cement basic intelligent composite material mainly comprises PAN-based chopped carbon fibers, Portland cement and aggregates in a mass ratio of (0.001-0.01) to 1 to (0.5-3.0), wherein the aggregates are quartz sand or a mixture of quartz sand with reasonable gradation and multiple particle size ranges.
The shape of the strain sensor is a cuboid or a cylinder, the four electrodes are arranged perpendicular to the longest side of the cuboid or a cylinder bus, and the four electrodes are symmetrical left and right.
The method for the cement-based intelligent composite material strain sensor comprises the following steps:
firstly, placing four parallel electrodes in a corresponding mould according to the shape of a strain sensor to be manufactured;
and secondly, pouring the carbon fiber cement basic intelligent composite material in a mould, and curing and molding.
The carbon fiber cement basic intelligent composite material mainly comprises PAN-based chopped carbon fibers and portland cement in a mass ratio of (0.001-0.01) to 1;
or the carbon fiber cement basic intelligent composite material mainly comprises PAN-based chopped carbon fibers, Portland cement and aggregate in a mass ratio of (0.001-0.01) to 1 to (0.5-3.0).
The PAN-based chopped carbon fibers are dispersed into a monofilament state in a high-speed stirrer by adopting a drying and dispersing process, then are dried and uniformly mixed with Portland cement in the stirrer, and finally are added with water and stirred to prepare the carbon fiber cement basic intelligent composite material;
or, the PAN-based chopped carbon fiber is dispersed into a monofilament state in a high-speed stirrer by adopting a drying and dispersing process, then is dried and uniformly mixed with the Portland cement and the aggregate in the stirrer, and finally is added with water and stirred to prepare the carbon fiber cement basic intelligent composite material.
After the materials are dried and mixed evenly in the stirrer, a polycarboxylic acid water reducing agent accounting for 0.2 to 1.3 percent of the mass of the used portland cement, a shrinkage reducing agent accounting for 1 to 6 percent of the mass of the used portland cement and water accounting for 25 to 45 percent of the mass of the used portland cement are added. The mechanical property and the pressure-sensitive characteristic linearity of the final cement-based intelligent composite material strain sensor are improved, and internal microcracks are reduced.
Compared with the prior art, the invention has the beneficial effects that:
1) the cement-based intelligent composite material strain sensor takes the cement-based intelligent composite material formed by compounding the PAN-based chopped carbon fibers and the cement as a base material, and has the characteristics of high sensitivity coefficient, high pressure-sensitive characteristic linearity and excellent mechanical property of the sensor. The addition of the PAN-based carbon fiber not only endows the cement-based material with good pressure-sensitive characteristics and improves the mechanical properties of the cement-based intelligent composite material strain sensor, but also inhibits the generation and expansion of microcracks in the sensor under the action of cyclic stress, so that the cement-based intelligent composite material strain sensor has good pressure-sensitive characteristics.
2) The sensor preparation process adopts a drying and mixing process, and the chopped carbon fibers in a monofilament state and the cement powder are directly dried and uniformly mixed, and then water is added to prepare the cement-based intelligent composite sensor, so that the problems of sensor strength reduction and poor electrical performance caused by the use of cellulose are solved, and the carbon fibers are uniformly dispersed in a cement matrix without fiber aggregation.
3) The preparation process of the sensor adopts the polycarboxylic acid high-efficiency water reducing agent, the shrinkage reducing agent and the reasonable quartz sand gradation, is beneficial to improving the comprehensive mechanical property of the strain sensor, reducing internal microcracks, improving the interface combination between carbon fibers and cement stones, improving the sensitivity coefficient and the pressure-sensitive characteristic linearity of the strain sensor and improving the range of the sensor in measuring stress.
Drawings
FIG. 1 is a flow chart of the manufacturing process of the cement-based intelligent composite strain sensor of the present invention.
FIG. 2 is a schematic structural diagram of a cement-based intelligent composite material strain sensor (rectangular parallelepiped shape) of the invention, wherein a dotted line square box represents an electrode, the rectangular parallelepiped represents the strain sensor, two electrodes on the inner side are led out by leads, and two electrodes on the outer side are connected with a constant voltage power supply.
FIG. 3 is a schematic structural diagram of a cement-based intelligent composite material strain sensor (cylindrical shape) of the present invention, wherein a dotted circle represents an electrode, a cylinder represents the strain sensor, two electrodes on the inner side are led out by a lead, and two electrodes on the outer side are connected with a constant voltage power supply.
FIG. 4 is a graph of strain versus rate of change of resistance for a cement-based smart composite strain sensor in accordance with the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples.
Example 1
Referring to fig. 1 and 2, the cement-based intelligent composite material strain sensor is composed of a carbon fiber cement basic intelligent composite material and four parallel high-purity copper mesh electrodes arranged on the composite material, wherein the pore diameter of the high-purity copper mesh is larger than 2mm, the composite material is a mixture of PAN-based chopped carbon fiber and Portland cement in a mass ratio of 0.001: 1, and the strain sensor is cuboid.
The preparation process is as follows:
firstly, preparing a steel mould with a cuboid cavity, and fixing four pieces of high-purity copper mesh in the mould in a parallel and symmetrical manner, wherein the four pieces of high-purity copper mesh are perpendicular to the longest side of the cuboid.
Then, PAN-based chopped carbon fibers and portland cement are taken according to the mass ratio of 0.001: 1, and are dispersed into a monofilament state by using a high-speed stirrer with crossed rubber blades, and then are dried and uniformly mixed with ordinary portland cement in the stirrer. And then adding a polycarboxylic acid water reducing agent accounting for 0.2 percent of the mass of the used portland cement, a shrinkage reducing agent accounting for 1 percent of the mass of the portland cement and water accounting for 25 percent of the mass of the portland cement, and further uniformly stirring to form a carbon fiber cement mixture.
And finally, pouring the carbon fiber cement mixture into a steel mould fixed with four high-purity copper mesh electrodes, and curing and forming in the mould to form the cement-based intelligent composite material strain sensor, wherein the four high-purity copper mesh electrodes are led out by using leads.
The use method is as follows:
in the four high-purity copper mesh electrodes, direct-current voltage is applied between two electrodes positioned on the outer side, and the two electrodes on the inner side are used for detecting the voltage change between the two electrodes on the inner side. The strain of the cement-based intelligent composite material strain sensor in the direction perpendicular to the four mesh electrodes is the input quantity of the sensor, and the voltage detected by the two inner electrodes is the output quantity of the sensor. In the using process of the sensor, the detected voltage change between the two inner electrodes is converted into the resistivity change of the cement-based intelligent composite material by using the current value and the geometric parameters of the sensor, and the strain monitoring of the concrete structure is realized by contrasting the established relation curve or relation between the strain and the resistivity change of the cement-based intelligent composite material sensor.
On the basis of strain monitoring of a concrete structure, the stress monitoring of a cement-based intelligent composite material strain sensor on the concrete structure can be realized by utilizing the modulus relation of cement-based intelligent composite materials.
Example 2
Referring to fig. 1 and 2, the cement-based intelligent composite material strain sensor is composed of a carbon fiber cement basic intelligent composite material and four parallel high-purity copper mesh electrodes arranged on the composite material, wherein the aperture of the high-purity copper mesh is larger than 2mm, the composite material mainly comprises PAN-based chopped carbon fibers with the mass ratio of 0.004: 1: 0.5, a silicate cement mixture and aggregates, the aggregates are quartz sand or a mixture of quartz sand with reasonable grading and multiple particle size ranges, and the shape of the strain sensor is a cuboid.
The preparation process is as follows:
firstly, preparing a steel mould with a cuboid cavity, and fixing four pieces of high-purity copper mesh in the mould in a parallel and symmetrical manner, wherein the four pieces of high-purity copper mesh are perpendicular to the longest side of the cuboid.
Then, PAN-based chopped carbon fibers, a portland cement mixture and aggregate are taken according to the mass ratio of 0.004: 1: 0.5, the PAN-based chopped carbon fibers are dispersed into a monofilament state by using a high-speed stirrer with crossed rubber blades and a high-speed stirrer with crossed rubber blades, and then the monofilament state is dried and uniformly mixed with ordinary portland cement in the stirrer. Then adding aggregate, a polycarboxylic acid water reducing agent accounting for 1.3 percent of the mass of the used portland cement, a shrinkage reducing agent accounting for 6 percent of the mass of the portland cement and water accounting for 45 percent of the mass of the portland cement, and further uniformly stirring to form a carbon fiber cement mixture.
And finally, pouring the carbon fiber cement mixture into a steel mould fixed with four high-purity copper mesh electrodes, and curing and forming in the mould to form the cement-based intelligent composite material strain sensor, wherein the four high-purity copper mesh electrodes are led out by using leads.
The use method is as follows:
in the four high-purity copper mesh electrodes, constant current is applied between two electrodes positioned on the outer side, and the two electrodes on the inner side are used for detecting the voltage change between the two electrodes on the inner side. The strain of the cement-based intelligent composite material strain sensor in the direction perpendicular to the four mesh electrodes is the input quantity of the sensor, and the voltage detected by the two inner electrodes is the output quantity of the sensor. In the using process of the sensor, the detected voltage change between the two inner electrodes is converted into the resistivity change of the cement-based intelligent composite material by using the current value and the geometric parameters of the sensor, and the strain monitoring of the concrete structure is realized by contrasting the established relation curve or relation between the strain and the resistivity change of the cement-based intelligent composite material sensor.
On the basis of strain monitoring of a concrete structure, the stress monitoring of a cement-based intelligent composite material strain sensor on the concrete structure can be realized by utilizing the modulus relation of cement-based intelligent composite materials.
Example 3
Referring to fig. 1 and 3, the cement-based intelligent composite material strain sensor is composed of a carbon fiber cement basic intelligent composite material and four parallel high-purity copper mesh electrodes arranged on the composite material, wherein the pore diameter of the high-purity copper mesh is larger than 2mm, the composite material is a mixture of PAN-based chopped carbon fiber and Portland cement in a mass ratio of 0.006: 1, and the strain sensor is cylindrical in shape.
The preparation process is as follows:
firstly, preparing a steel mould with a cylindrical cavity, and fixing four pieces of high-purity copper mesh in the mould in parallel and symmetrically, wherein the four pieces of high-purity copper mesh are perpendicular to a cylindrical bus.
Then, PAN-based chopped carbon fibers and portland cement are taken according to the mass ratio of 0.006: 1, the PAN-based chopped carbon fibers and the portland cement are dispersed into a monofilament state by using a high-speed stirrer with crossed rubber blades, and then the monofilament state is dried and uniformly mixed with the ordinary portland cement in the stirrer. Then adding a polycarboxylic acid water reducing agent accounting for 1.0 percent of the mass of the used portland cement, a shrinkage reducing agent accounting for 2 percent of the mass of the portland cement and water accounting for 32 percent of the mass of the portland cement, and further uniformly stirring to form a carbon fiber cement mixture.
And finally, pouring the carbon fiber cement mixture into a steel mould fixed with four high-purity copper mesh electrodes, and curing and forming in the mould to form the cement-based intelligent composite material strain sensor, wherein the four high-purity copper mesh electrodes are led out by using leads.
The use method is as follows:
in the four high-purity copper mesh electrodes, constant current is applied between two electrodes positioned on the outer side, and the two electrodes on the inner side are used for detecting the voltage change between the two electrodes on the inner side. The strain of the cement-based intelligent composite material strain sensor in the direction perpendicular to the four mesh electrodes is the input quantity of the sensor, and the voltage detected by the two inner electrodes is the output quantity of the sensor. In the using process of the sensor, the detected voltage change between the two inner electrodes is converted into the resistivity change of the cement-based intelligent composite material by using the current value and the geometric parameters of the sensor, and the strain monitoring of the concrete structure is realized by contrasting the established relation curve or relation between the strain and the resistivity change of the cement-based intelligent composite material sensor.
On the basis of strain monitoring of a concrete structure, the stress monitoring of a cement-based intelligent composite material strain sensor on the concrete structure can be realized by utilizing the modulus relation of cement-based intelligent composite materials.
Example 4
Referring to fig. 1 and 3, the cement-based intelligent composite material strain sensor is composed of a carbon fiber cement basic intelligent composite material and four parallel high-purity copper mesh electrodes arranged on the composite material, wherein the aperture of the high-purity copper mesh is larger than 2mm, the composite material mainly comprises PAN-based chopped carbon fibers with the mass ratio of 0.01: 1: 3, a silicate cement mixture and aggregates, the aggregates are quartz sand or a mixture of quartz sand with reasonable grading and multiple particle size ranges, and the shape of the strain sensor is a cylinder.
The preparation process is as follows:
firstly, preparing a steel mould with a cylindrical cavity, and fixing four pieces of high-purity copper mesh in the mould in parallel and symmetrically, wherein the four pieces of high-purity copper mesh are perpendicular to a cylindrical bus.
Then, taking the PAN-based chopped carbon fibers, the Portland cement mixture and the aggregate according to the mass ratio of 0.01: 1: 3, dispersing the PAN-based chopped carbon fibers into a monofilament state by using a high-speed stirrer with crossed rubber blades and a high-speed stirrer with crossed rubber blades, and then drying and uniformly mixing the PAN-based chopped carbon fibers and the Portland cement in the stirrer. And adding aggregate, a polycarboxylic acid water reducing agent, a shrinkage reducing agent and water, and further uniformly stirring to form the carbon fiber cement mixture.
And finally, pouring the carbon fiber cement mixture into a steel mould fixed with four high-purity copper mesh electrodes, and curing and forming in the mould to form the cement-based intelligent composite material strain sensor, wherein the four high-purity copper mesh electrodes are led out by using leads.
The use method is as follows:
in the four high-purity copper mesh electrodes, direct-current voltage is applied between two electrodes positioned on the outer side, and the two electrodes on the inner side are used for detecting the voltage change between the two electrodes on the inner side. The strain of the cement-based intelligent composite material strain sensor in the direction perpendicular to the four mesh electrodes is the input quantity of the sensor, and the voltage detected by the two inner electrodes is the output quantity of the sensor. In the using process of the sensor, the detected voltage change between the two inner electrodes is converted into the resistivity change of the cement-based intelligent composite material by using the current value and the geometric parameters of the sensor, and the strain monitoring of the concrete structure is realized by contrasting the established relation curve or relation between the strain and the resistivity change of the cement-based intelligent composite material sensor.
On the basis of strain monitoring of a concrete structure, the stress monitoring of a cement-based intelligent composite material strain sensor on the concrete structure can be realized by utilizing the modulus relation of cement-based intelligent composite materials.
Referring to fig. 4, the relation curve of the strain and the resistance change rate of the cement-based intelligent composite material strain sensor is a straight line relation, and the pressure-sensitive characteristic linearity of the strain sensor is very good.
The above description is only one embodiment of the present invention, and not all or only one embodiment, and any equivalent alterations to the technical solutions of the present invention, which are made by those skilled in the art through reading the present specification, are covered by the claims of the present invention.
Claims (10)
1. The strain sensor is characterized by consisting of a carbon fiber cement basic intelligent composite material and four parallel electrodes arranged on the composite material.
2. The cement-based smart composite strain sensor of claim 1, wherein the electrode is a high purity copper mesh.
3. The cement-based smart composite strain sensor of claim 2, wherein the pore size of the high purity copper mesh is 2-5 mm.
4. The cement-based smart composite strain sensor as claimed in any one of claims 1 to 3, wherein:
the carbon fiber cement basic intelligent composite material mainly comprises PAN-based chopped carbon fibers and portland cement in a mass ratio of (0.001-0.01) to 1;
or,
the carbon fiber cement basic intelligent composite material mainly comprises PAN-based chopped carbon fibers, portland cement and aggregate in a mass ratio of (0.001-0.01) to 1 to (0.5-3.0).
5. The cement-based smart composite strain sensor of claim 4, wherein the aggregate is quartz sand or a mixture of reasonably graded quartz sand of multiple particle size ranges.
6. The cement-based intelligent composite material strain sensor according to claim 1, wherein the strain sensor is a cuboid or a cylinder in shape, four electrodes are arranged perpendicular to the longest side of the cuboid or a bus of the cylinder, and the four electrodes are bilaterally symmetrical.
7. A method of making the cement-based smart composite strain sensor of claim 1, comprising the steps of:
firstly, placing four parallel electrodes in a corresponding mould according to the shape of a strain sensor to be manufactured;
and secondly, pouring the carbon fiber cement basic intelligent composite material in a mould, and curing and molding.
8. The method of claim 7, wherein:
the carbon fiber cement basic intelligent composite material mainly comprises PAN-based chopped carbon fibers and portland cement in a mass ratio of (0.001-0.01) to 1;
or,
the carbon fiber cement basic intelligent composite material mainly comprises PAN-based chopped carbon fibers, portland cement and aggregate in a mass ratio of (0.001-0.01) to 1 to (0.5-3.0).
9. The method of claim 8, wherein:
the PAN-based chopped carbon fibers are dispersed into a monofilament state in a high-speed stirrer by adopting a drying and dispersing process, then are dried and uniformly mixed with Portland cement in the stirrer, and finally are added with water and stirred to prepare the carbon fiber cement basic intelligent composite material;
or,
the PAN-based chopped carbon fiber is dispersed into a monofilament state in a high-speed stirrer by adopting a drying and dispersing process, then is dried and uniformly mixed with Portland cement and aggregate in the stirrer, and finally is added with water and stirred to prepare the carbon fiber cement basic intelligent composite material.
10. The preparation method according to claim 9, wherein after the mixture is dried and mixed uniformly in the mixer, 0.2-1.3% by mass of the polycarboxylic acid water reducing agent, 1-6% by mass of the shrinkage reducing agent and 25-45% by mass of water are added to the mixture.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110318920.4A CN102506692B (en) | 2011-10-19 | 2011-10-19 | Cement-based intelligent composite material strain sensor and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110318920.4A CN102506692B (en) | 2011-10-19 | 2011-10-19 | Cement-based intelligent composite material strain sensor and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102506692A true CN102506692A (en) | 2012-06-20 |
| CN102506692B CN102506692B (en) | 2014-04-02 |
Family
ID=46218800
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110318920.4A Expired - Fee Related CN102506692B (en) | 2011-10-19 | 2011-10-19 | Cement-based intelligent composite material strain sensor and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102506692B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104446176A (en) * | 2014-08-25 | 2015-03-25 | 北京建筑大学 | Cement-based composite material and pressure sensor made of same |
| CN106768052A (en) * | 2016-12-27 | 2017-05-31 | 江苏大学 | A kind of intelligent carbon fibre composite sensing element and preparation method thereof |
| CN109357795A (en) * | 2018-12-28 | 2019-02-19 | 吉林建筑大学 | A kind of cement base piezoelectric composite material sensor |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0650830A (en) * | 1992-08-03 | 1994-02-25 | Hiroaki Yanagida | Method of detecting strain and stress by conductive fiber bundle containing plastic composite material, and conductive fiber bundle containing plastic composite material used therefor |
| CN1484027A (en) * | 2002-09-16 | 2004-03-24 | 欧进萍 | Clever concrete sensor component |
| CN101149302A (en) * | 2007-11-06 | 2008-03-26 | 哈尔滨工业大学 | Sensor for monitoring/measuring stress/ strain |
| CN101602590A (en) * | 2009-06-30 | 2009-12-16 | 武汉理工大学 | In mix CCCW carbon fiber and graphite sensitive concrete and application thereof |
-
2011
- 2011-10-19 CN CN201110318920.4A patent/CN102506692B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0650830A (en) * | 1992-08-03 | 1994-02-25 | Hiroaki Yanagida | Method of detecting strain and stress by conductive fiber bundle containing plastic composite material, and conductive fiber bundle containing plastic composite material used therefor |
| CN1484027A (en) * | 2002-09-16 | 2004-03-24 | 欧进萍 | Clever concrete sensor component |
| CN101149302A (en) * | 2007-11-06 | 2008-03-26 | 哈尔滨工业大学 | Sensor for monitoring/measuring stress/ strain |
| CN101602590A (en) * | 2009-06-30 | 2009-12-16 | 武汉理工大学 | In mix CCCW carbon fiber and graphite sensitive concrete and application thereof |
Non-Patent Citations (1)
| Title |
|---|
| 傅正义等: "《先进陶瓷及无机非金属材料》", 31 January 2007, article "智能混凝土", pages: 330-345 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104446176A (en) * | 2014-08-25 | 2015-03-25 | 北京建筑大学 | Cement-based composite material and pressure sensor made of same |
| CN104446176B (en) * | 2014-08-25 | 2016-06-15 | 北京建筑大学 | A kind of cement-base composite material and voltage sensitive sensor thereof |
| CN106768052A (en) * | 2016-12-27 | 2017-05-31 | 江苏大学 | A kind of intelligent carbon fibre composite sensing element and preparation method thereof |
| CN106768052B (en) * | 2016-12-27 | 2023-12-15 | 江苏大学 | Intelligent carbon fiber composite sensing element and manufacturing method thereof |
| CN109357795A (en) * | 2018-12-28 | 2019-02-19 | 吉林建筑大学 | A kind of cement base piezoelectric composite material sensor |
| CN109357795B (en) * | 2018-12-28 | 2023-09-01 | 吉林建筑大学 | Cement-based piezoelectric composite material sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102506692B (en) | 2014-04-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ding et al. | Self-monitoring of smart concrete column incorporating CNT/NCB composite fillers modified cementitious sensors | |
| Deng et al. | Preparation and piezoresistive properties of carbon fiber-reinforced alkali-activated fly ash/slag mortar | |
| Wang et al. | Electrical and piezoresistive properties of carbon nanofiber cement mortar under different temperatures and water contents | |
| Han et al. | Self-sensing concrete in smart structures | |
| Fan et al. | Piezoresistivity of carbon fiber graphite cement-based composites with CCCW | |
| CN100367022C (en) | Intelligent concrete test block and its producing and use | |
| Huang et al. | Self-sensing properties of engineered cementitious composites | |
| CN106673532B (en) | A kind of perception nickel nanofiber cement-base composite material certainly | |
| CN101149302A (en) | Sensor for monitoring/measuring stress/ strain | |
| CN102506692B (en) | Cement-based intelligent composite material strain sensor and preparation method thereof | |
| CN101050985A (en) | Local monitoring pressure sensitive cement base stress and strain sensor of concrete structure | |
| Zhang et al. | Improved output voltage of 0–3 cementitious piezoelectric composites with basalt fibers | |
| AU2020383791A1 (en) | Gradient-type graphene smart-concrete-based corrosion detection apparatus and method | |
| CN102506691B (en) | Cement-based intelligent composite material strain sensor with temperature compensation function | |
| Wang et al. | Health monitoring of C60 smart concrete based on self-sensing | |
| Tian et al. | Self-sensing study of stress in low-doped carbon fiber reinforced hydraulic concrete | |
| Han et al. | Piezoresistive response extraction for smart cement-based composites/sensors | |
| CN113185190A (en) | Self-sensing intelligent conductive asphalt pavement material | |
| Hou et al. | Electrically conductive concrete for heating using steel bars as electrodes | |
| KR102362236B1 (en) | An ultra high performance concrete durability monitoring system using self sensing ability | |
| Wang et al. | Improved conductive and self-sensing properties of cement concrete by PDMS/NCB-impregnated recycled fine aggregate | |
| Wang et al. | Research on the mechanical and conductive properties of carbon nanofiber mortar with quartz sand | |
| Liu et al. | Electrical and piezoresistive properties of steel fiber cement-based composites aligned by a magnetic field | |
| Kumar et al. | Experimental study on optimization of smart mortar with the addition of brass fibres | |
| CN201795880U (en) | Anti-freezing type sensor element of cement base stress |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140402 |