CN111596000A - Testing device and method for electro-osmosis dehumidification and corrosion prevention of conductive mortar - Google Patents
Testing device and method for electro-osmosis dehumidification and corrosion prevention of conductive mortar Download PDFInfo
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- 238000005370 electroosmosis Methods 0.000 title claims abstract description 75
- 238000012360 testing method Methods 0.000 title claims abstract description 69
- 239000004570 mortar (masonry) Substances 0.000 title claims abstract description 45
- 238000007791 dehumidification Methods 0.000 title claims abstract description 43
- 238000005536 corrosion prevention Methods 0.000 title claims abstract description 16
- 238000000034 method Methods 0.000 title claims abstract description 15
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims abstract description 34
- 230000008859 change Effects 0.000 claims abstract description 21
- 238000013508 migration Methods 0.000 claims abstract description 11
- 230000005012 migration Effects 0.000 claims abstract description 11
- 230000008569 process Effects 0.000 claims abstract description 7
- 238000010998 test method Methods 0.000 claims abstract description 7
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(I) nitrate Inorganic materials [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 claims description 34
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 24
- 229910001961 silver nitrate Inorganic materials 0.000 claims description 12
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 10
- 238000004448 titration Methods 0.000 claims description 10
- 239000000843 powder Substances 0.000 claims description 9
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 8
- 229920000049 Carbon (fiber) Polymers 0.000 claims description 7
- 239000004917 carbon fiber Substances 0.000 claims description 7
- -1 chlorine ions Chemical class 0.000 claims description 6
- 238000005553 drilling Methods 0.000 claims description 6
- 239000011231 conductive filler Substances 0.000 claims description 5
- 238000006073 displacement reaction Methods 0.000 claims description 5
- 239000002244 precipitate Substances 0.000 claims description 5
- 239000011780 sodium chloride Substances 0.000 claims description 5
- 230000009471 action Effects 0.000 claims description 4
- 239000011449 brick Substances 0.000 claims description 4
- 239000000460 chlorine Substances 0.000 claims description 4
- 229910052801 chlorine Inorganic materials 0.000 claims description 4
- VWDWKYIASSYTQR-UHFFFAOYSA-N sodium nitrate Chemical compound [Na+].[O-][N+]([O-])=O VWDWKYIASSYTQR-UHFFFAOYSA-N 0.000 claims description 4
- QLOKJRIVRGCVIM-UHFFFAOYSA-N 1-[(4-methylsulfanylphenyl)methyl]piperazine Chemical compound C1=CC(SC)=CC=C1CN1CCNCC1 QLOKJRIVRGCVIM-UHFFFAOYSA-N 0.000 claims description 3
- 238000004364 calculation method Methods 0.000 claims description 3
- 238000002791 soaking Methods 0.000 claims description 3
- 229910021607 Silver chloride Inorganic materials 0.000 claims description 2
- 239000011083 cement mortar Substances 0.000 claims description 2
- 238000006243 chemical reaction Methods 0.000 claims description 2
- 239000012153 distilled water Substances 0.000 claims description 2
- 239000000203 mixture Substances 0.000 claims description 2
- 239000004033 plastic Substances 0.000 claims description 2
- 229910021487 silica fume Inorganic materials 0.000 claims description 2
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 claims description 2
- 239000006228 supernatant Substances 0.000 claims description 2
- 239000004567 concrete Substances 0.000 abstract description 20
- 239000000463 material Substances 0.000 abstract description 19
- 230000035945 sensitivity Effects 0.000 abstract description 7
- 238000005260 corrosion Methods 0.000 abstract description 2
- 230000007797 corrosion Effects 0.000 abstract description 2
- 230000007646 directional migration Effects 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 8
- 238000005516 engineering process Methods 0.000 description 7
- 239000004568 cement Substances 0.000 description 5
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- 239000010936 titanium Substances 0.000 description 4
- 229910052719 titanium Inorganic materials 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 230000005684 electric field Effects 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 239000012488 sample solution Substances 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 150000001768 cations Chemical class 0.000 description 2
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- 229910052709 silver Inorganic materials 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000036626 alertness Effects 0.000 description 1
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- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 description 1
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- 238000011161 development Methods 0.000 description 1
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- OJKANDGLELGDHV-UHFFFAOYSA-N disilver;dioxido(dioxo)chromium Chemical compound [Ag+].[Ag+].[O-][Cr]([O-])(=O)=O OJKANDGLELGDHV-UHFFFAOYSA-N 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N31/00—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods
- G01N31/16—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods using titration
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D33/00—Testing foundations or foundation structures
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/06—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a liquid
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/38—Concrete; Lime; Mortar; Gypsum; Bricks; Ceramics; Glass
- G01N33/383—Concrete or cement
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Abstract
The invention provides a test device and a method for electro-osmosis dehumidification and corrosion prevention of conductive mortar, wherein the device comprises a conductive mortar test piece, an electro-osmosis pulse device, a temperature and humidity measuring device and a current and voltage measuring device which are connected with the conductive mortar test piece, directional migration of moisture and corrosion media in hardened concrete is realized in an electro-osmosis pulse drainage mode, the electro-osmosis dehumidification and corrosion prevention efficiency of the conductive mortar is calculated according to the drainage quantity and the chloride ion content change degree at different depths, a temperature and humidity change curve and a chloride ion migration rule curve chart in the electro-osmosis process are drawn, and a humidity sensitive change curve chart is drawn according to the humidity and resistivity test result. The invention provides a test method for researching the relationship between humidity and temperature under electroosmosis pulse, the humidity sensitivity relationship between humidity and resistivity, the relationship between material components and dehumidification efficiency and the like, so as to further optimize the electroosmosis system and electroosmosis body parameters.
Description
Technical Field
The invention relates to the field of concrete electroosmosis, in particular to a test device and a test method for electroosmosis, dehumidification and corrosion prevention of conductive mortar.
Background
The structure of underground engineering building structure and other wet environment is eroded by water vapor, medium water and other matter for long period, and its dehumidifying, moisture-proof and corrosion-proof technology is an important link difficult to control. At present, the moisture-proof technology for underground tunnels and the like is mainly started from structural moisture-proof, and is divided into structural self-moisture-proof and additional moisture-proof, the structural self-moisture-proof is considered based on the crack resistance and impermeability of concrete, the additional moisture-proof is realized by paving waterproof coiled materials on the surface of a structure, arranging moisture-proof layers, post-pouring belts, embedded parts and other moisture-proof nodes to realize moisture permeation, the traditional structural moisture-proof method has a certain barrier effect on moisture invasion, but moisture and corrosive media are still inevitable to permeate from capillary channels of the concrete, the capillary water absorption is huge, the durability of structural materials is influenced for a long time, the requirements of underground building spaces, instruments and equipment on the dryness rise are met, the humidity of the concrete structure is effectively reduced, the corrosive media such as chloride are reduced, the structural corrosion is slowed down, and the durability and the maintenance performance of the materials have very important.
The concrete electroosmosis technology belongs to a novel dehumidification system, and the principle is that positive and negative electroosmosis pulses are respectively applied to two sides of a structure, capillary channels are used as molecule transportation channels, and cations and combined water molecules move towards a cathode end along the direction of reverse hydraulic gradient under the action of an electric field to realize directional movement of moisture and chloride ions, as shown in attached figure 3. At present, most of application objects of the electroosmosis technology in concrete are drained concrete slurry and grouted concrete slurry, namely, the excessive moisture of the concrete slurry is removed before the concrete is initially set so as to solve the contradiction between the construction requirement of large water-cement ratio and the use requirement of small water-cement ratio, but the application of the electroosmosis technology in hardened concrete is not reported, the electroosmosis technology is applied to the hardened concrete of an underground tunnel, the impermeability, the moisture resistance and the durability of the structure are improved, the electroosmosis MPS dehumidification system has an important engineering application value, the humidity improvement effect is obvious, but a test method of the electroosmosis dehumidification system aiming at the conductive concrete is not formed, and a plurality of test parameters are yet to be researched and improved.
The conductive mortar is a conductive cement-based material prepared by mixing a carbon-series conductive functional material, a cementing material and medium sand, and the carbon fiber conductive cement-based material has excellent conductivity, mechanics and alertness. The percolation threshold of the carbon fiber in the concrete is 1% vt, and the conductive carbon black is mixed into the slurry at a substitution rate of 50%, so that the unit material cost is reduced, and the excellent conductivity is also kept. The carbon-based conductive mortar is electrified to generate heat, can be applied to indoor heating and road snow melting and deicing, and when the carbon-based conductive mortar is used as an agile material, the structure resistivity can generate agile change along with the external condition changes such as temperature, humidity, load and the like, so that the carbon-based conductive mortar is applied to the intelligent monitoring of the structure. When being applied to dehumidification of underground structure with electrically conductive mortar, electrically conductive mortar circular telegram themogenesis makes inside steam be heated and evaporate and can play a certain role to the dehumidification, in addition, when the water content is great, the mortar that is full of liquid phase environment can be as the electro-osmosis body and remove moisture under impulse voltage, the existence of conducting component has promoted moisture evaporation and electro-osmosis route in the base member and has built, be favorable to the dehumidification, and the mortar resistivity will produce the regularity change along with the change of base member humidity, make the representation material humidity become possible with the dehumidification effect.
Currently, the method for measuring the content of chloride ions in concrete includes a silver nitrate spraying method and a titration method. The silver nitrate spraying method is to cut the concrete test block, spray silver nitrate on the cross section and observe the diffusion depth of chloride ions through a color developing agent. The titration method comprises the steps of drilling a core on the surface of concrete for sampling, preparing a sample solution by using the obtained sample, titrating by using reagents such as potassium chromate, silver nitrate and the like, and calculating the content of chloride ions in the solution by using the amount of the silver nitrate solution when brick red precipitates appear, so as to realize the calculation of the content of the chloride ions at a certain point in the concrete. The first method is generally used for qualitative analysis, and the color development boundary of the section is not clear, so that errors are easily caused, and the content of chloride ions at a certain point of the section cannot be determined; the titration end point of the titration method is visual, the content of chloride ions at a certain point in the structure can be quantitatively measured, the precision is good, and the rule that the chloride ions in the mortar migrate along with the depth under electroosmosis is conveniently researched.
Disclosure of Invention
The invention provides a test device and a test method for electro-osmosis dehumidification and corrosion prevention of conductive mortar, aiming at solving the problems in the prior art, and providing a test method for researching the relation between humidity and temperature, the humidity and resistivity humidity sensitivity relation, the material component and dehumidification efficiency relation and the like under electro-osmosis pulse so as to further optimize an electro-osmosis system and electro-osmosis body parameters.
The invention provides a test device for electro-osmosis dehumidification and corrosion prevention of conductive mortar, which comprises a conductive mortar test piece, an electro-osmosis pulse device, a temperature and humidity measuring device and a current and voltage measuring device, wherein the electro-osmosis pulse device, the temperature and humidity measuring device and the current and voltage measuring device are connected with the conductive mortar test piece; the conductive mortar is prepared by mixing 0.8-1.2 vt% of conductive filler by volume and 1: 3. the cement mortar contains 3-10% of silica fume, the water-to-gel ratio is 0.45-0.55, the conductive filler contains 5-10 mm short carbon fibers and conductive carbon black powder, and the conductive carbon black powder partially replaces the short carbon fibers in a ratio of 50%.
Further improved, the size of the conductive mortar test piece is 56 × 56 × 280mm3Two electrodes connected with an electroosmosis pulse device are respectively attached to the two ends of the test piece, and two electrodes connected with a current and voltage measuring device are respectively embedded at the position 40mm away from the center of the test piece.
The improved electroosmosis pulse device is an electroosmosis pulse generator, the temperature and humidity measuring device is an embedded temperature and humidity sensor and a temperature and humidity signal acquisition instrument, and the current and voltage measuring device is a universal meter.
The invention also provides a test method for electro-osmosis dehumidification and corrosion prevention of the conductive mortar, which comprises the following steps:
1) soaking the conductive mortar test piece in 2.5% sodium chloride solution for 3 days, taking out the test piece, wiping the surface of the test piece, and wrapping 4 surfaces of the test piece except the drainage end surface by using a plastic waterproof film;
2) connecting the conductive mortar test piece with an electroosmosis pulse device, a water collecting system, a temperature and humidity measuring device and a current and voltage measuring device, starting a power supply to perform electroosmosis pulse dehumidification, wherein the test time is 6h, and the water discharge, the current and voltage readings, the temperature and humidity readings and the quality difference of the test piece before and after electroosmosis are recorded at intervals of 20min in the test process;
3) respectively drilling a core and taking powder for a test piece which is not electroosmosis and a test piece which is electroosmosis, and testing the content of chloride ions at different depths of the test piece;
4) calculating the electro-osmosis dehumidification and corrosion prevention efficiency of the conductive mortar according to the water displacement and the change degree of the chloride ion content at different depths, drawing a temperature and humidity change curve and a chloride ion migration rule curve graph in the electro-osmosis process, and drawing a humidity sensitive change curve according to the humidity and resistivity test result.
The method for testing the content of chloride ions at different depths of the test piece in the step 3) comprises the following steps:
3.1) drilling cores at different depth positions of the electroosmosis test piece to obtain powder Gg, and adding V1Preparing chloride ion titration solution by ml of distilled water;
3.2) taking the supernatant V after the sample is settled2ml, the concentration of the mixture is cAgNO3Standard silver nitrate solution V3ml and 10 drops of potassium chromate indicator are titrated, and the reaction is as follows:
AgNO3+NaCl=AgCl↓+NaNO3;(1)
2AgNO3+K2CrO4=Ag2CrO4↓+2KNO3;(2)
3.3) inversely calculating the content P% of free chlorine ions at different depths according to the volume of the silver nitrate solution consumed when brick red precipitates appear, and finally quantitatively analyzing the migration efficiency of the chlorine ions under the action of electroosmosis, wherein the calculation formula is as follows:
the principle of the invention is as follows:
(1) the principle of electroosmosis, dehumidification and corrosion prevention is as follows: positive and negative electroosmosis pulses are respectively applied to two sides of the structure, a capillary channel is used as a molecule transportation channel, and the cations and the bound water molecules move towards the cathode end along the direction of the reverse hydraulic gradient under the action of an electric field, so that the directional movement of the water and the chloride ions is realized.
(2) The humidity sensitive principle: the conductive mortar inner cementing material, the aggregate and the carbon-series conductive filler jointly form a conductive network of the matrix, and when the structure is influenced by external factors such as load, moisture and the like, the change of a material microstructure can be caused, the construction of the conductive network is influenced, and the change of the resistivity is further caused. Therefore, the resistivity value of the conductive mortar in the electroosmosis process can change along with the change of the humidity inside the structure and shows certain regularity, namely certain sensitivity to the humidity.
(3) Principle of chloride ion titration: the sample solution contains chloride ions with a certain concentration, when the silver nitrate standard solution is dripped into the sample solution, silver ions and the chloride ions preferentially react and combine into silver nitrate white precipitate, when the chloride ions are consumed, the excessive silver ions and chromate ions react to generate silver chromate brick red precipitate, namely reaching the titration end point, and the content of the chloride ions can be inversely calculated by the titration amount of the silver nitrate.
The invention has the beneficial effects that:
(1) compared with the common hardened cement-based material, the high-conductivity conductive mortar is used as an electroosmosis body, so that the electric field intensity in the matrix can be enhanced, the migration of moisture and chloride ion plasma in a capillary channel is accelerated, and the dehumidification and corrosion prevention efficiency is improved.
(2) When the moisture in the matrix is less and the liquid environment is deficient, the moisture can be completely removed by utilizing the effect of conducting mortar to generate heat and remove water under the condition that the electroosmosis pulse cannot fully play a dehumidification role.
(3) The testing device can be used for scientifically measuring the dehumidification capacity, and provides a testing method for researching the relation between humidity and temperature, the humidity-sensitive relation between humidity and resistivity, the relation between material components and dehumidification efficiency and the like under electroosmosis pulses so as to further optimize parameters of an electroosmosis system and electroosmosis bodies.
Drawings
FIG. 1 is a schematic view of an electro-osmotic dehumidification anticorrosion test experimental device.
Figure 2 is a schematic of an electroosmotic pulse waveform.
FIG. 3 is a schematic diagram of concrete electro-osmotic dehumidification technology.
FIG. 4(a) is a graph showing the cumulative water discharge of electrode plates made of different materials as a function of electroosmosis time.
FIG. 4(b) is a graph showing the cumulative water discharge with the same voltage level and pulse frequency as a function of electroosmosis time.
Detailed Description
The invention is further described with reference to the following figures and detailed description.
Example 1
1) Preparing carbon fiber/carbon black conductive mortar with the thickness of 56 × 56 × 280mm3Pouring and molding in a mold, and respectively externally sticking and internally embedding 4 pieces of 50 × 65mm2A titanium electrode plate with holes;
2) 6 test pieces which are cured for 28 days are soaked in a sodium chloride solution with the concentration of 2.5 percent for 7 days;
3) taking out the test piece from the solution, and wrapping the periphery of the test piece except the drainage end face with a plastic film;
4) connecting the 3 test pieces with an electroosmosis pulse device and a performance test system, and adjusting the pulse voltage to 60V, the pulse frequency to 10s and the electroosmosis time to 6 h;
5) recording electroosmosis water displacement, a temperature and humidity value and a current and voltage value in an electroosmosis process, calculating dehumidification efficiency, and analyzing a humidity-sensitive relation between temperature and humidity along with time change and resistivity along with humidity change;
6) and (3) performing core drilling and powder taking on the test piece before and after electroosmosis, measuring the content of chloride ions at a position which is 10mm from the section and begins to be 10mm away by a chemical titration method, and summarizing the migration rule of the chloride ions under electroosmosis.
Example 2
The titanium electrode plate with holes in the step 1 of the embodiment 1 is changed into a ferroelectric electrode plate with holes, other parameters and steps are kept unchanged, and the dehumidification efficiency is calculated, and the humidity sensitivity and the chloride ion migration rule are analyzed.
Example 3
The titanium electrode plate with holes in the step 1 of the embodiment 1 is changed into a copper electrode plate with holes, other parameters and steps are kept unchanged, and the dehumidification efficiency is calculated, and the humidity sensitivity and the chloride ion migration rule are analyzed.
Example 4
The pulse voltage of 60V in step 4 of example 1 is adjusted to 30V, the other parameters and steps are kept unchanged, and the dehumidification efficiency, the humidity sensitivity and the chloride ion migration rule are calculated and analyzed.
Example 5
The pulse frequency of 10s in step 4 of example 1 was adjusted to 20s, the remaining parameters and steps were kept constant, and the dehumidification efficiency, the moisture sensitivity and the chloride ion migration law were calculated.
The five examples tested the moisture removal performance indicators versus water displacement as shown in the following table/ml:
examples the water displacement test curves are as follows:
FIG. 4 is a curve of the accumulated water discharge of each case with the change of the electroosmosis time, and the average mass difference of the test piece before and after soaking is 31.5g, which respectively shows the influence of the permeation pulse voltage and the pulse frequency (FIG. 4b) of the porous electrode plate (FIG. 4a) made of different materials on the electroosmosis accumulated water discharge. It can be seen that the contribution of the electrode plate material to the dehumidification efficiency is that titanium is higher than iron, which is higher than copper. The dehumidification efficiency of high pulse voltage (60V) is higher than that of low voltage (30V) under the same condition, and the influence degree is higher than the dehumidification efficiency change caused by the pulse frequency change. The dehumidification efficiency of high pulse frequency (10s) is higher than that of low frequency (20s) under the same condition, and the influence degree is not greatly different. In five cases, the 6h highest dehumidification efficiency reaches 69.8%, and the rest electroosmosis indexes are not detailed.
While the invention has been described in terms of its preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
Claims (5)
1. The utility model provides a test device for it is anticorrosive that is used for electric osmosis dehumidification of conducting mortar, its characterized in that: the device comprises a conductive mortar test piece, and an electroosmosis pulse device, a temperature and humidity measuring device and a current and voltage measuring device which are connected with the conductive mortar test piece, wherein one side of the conductive mortar test piece is a drainage end face connected with a water collecting system, and the other three sides and the bottom of the conductive mortar test piece are wrapped by waterproof films; the conductive mortar is prepared by mixing 0.8-1.2 vt% of conductive filler by volume and 1: 3. the cement mortar contains 3-10% of silica fume, the water-to-gel ratio is 0.45-0.55, the conductive filler contains 5-10 mm short carbon fibers and conductive carbon black powder, and the conductive carbon black powder partially replaces the short carbon fibers in a ratio of 50%.
2. The test device for electro-osmotic dehumidification and corrosion prevention of conductive mortar according to claim 1, wherein the size of the conductive mortar test piece is 56 × 56 × 280mm3Two electrodes connected with an electroosmosis pulse device are respectively attached to the two ends of the test piece, and two electrodes connected with a current and voltage measuring device are respectively embedded at the position 40mm away from the center of the test piece.
3. The testing device for electro-osmotic dehumidification corrosion prevention of conductive mortar according to claim 1, wherein: the electroosmosis pulse device is an electroosmosis pulse generator, the temperature and humidity measuring device is an embedded temperature and humidity sensor and a temperature and humidity signal acquisition instrument, and the current and voltage measuring device is a universal meter.
4. A test method for electro-osmosis dehumidification corrosion prevention of conductive mortar is characterized by comprising the following steps:
1) soaking the conductive mortar test piece in 2.5% sodium chloride solution for 3 days, taking out the test piece, wiping the surface of the test piece, and wrapping 4 surfaces of the test piece except the drainage end surface by using a plastic waterproof film;
2) connecting the conductive mortar test piece with an electroosmosis pulse device, a water collecting system, a temperature and humidity measuring device and a current and voltage measuring device, starting a power supply to perform electroosmosis pulse dehumidification, wherein the test time is 6h, and the water discharge, the current and voltage readings, the temperature and humidity readings and the quality difference of the test piece before and after electroosmosis are recorded at intervals of 20min in the test process;
3) respectively drilling a core and taking powder for a test piece which is not electroosmosis and a test piece which is electroosmosis, and testing the content of chloride ions at different depths of the test piece;
4) calculating the electro-osmosis dehumidification and corrosion prevention efficiency of the conductive mortar according to the water displacement and the change degree of the chloride ion content at different depths, drawing a temperature and humidity change curve and a chloride ion migration rule curve graph in the electro-osmosis process, and drawing a humidity sensitive change curve according to the humidity and resistivity test result.
5. The testing method for electro-osmotic dehumidification corrosion prevention of conductive mortar according to claim 4, wherein: the method for testing the content of chloride ions at different depths of the test piece in the step 3 comprises the following steps:
3.1) drilling cores at different depth positions of the electroosmosis test piece to obtain powder Gg, and adding V1Preparing chloride ion titration solution by ml of distilled water;
3.2) taking the supernatant V after the sample is settled2ml, the concentration of the mixture is cAgNO3Standard silver nitrate solution V3ml and 10 drops of potassium chromate indicator are titrated, and the reaction is as follows:
AgNO3+NaCl=AgCl↓+NaNO3; (1)
2AgNO3+K2CrO4=Ag2CrO4↓+2KNO3; (2)
3.3) inversely calculating the content P% of free chlorine ions at different depths according to the volume of the silver nitrate solution consumed when brick red precipitates appear, and finally quantitatively analyzing the migration efficiency of the chlorine ions under the action of electroosmosis, wherein the calculation formula is as follows:
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CN112540104A (en) * | 2020-12-17 | 2021-03-23 | 成都龙之泉科技股份有限公司 | Concrete matrix corrosion control quality detection method |
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CN115594788A (en) * | 2022-10-13 | 2023-01-13 | 中路交科科技股份有限公司(Cn) | Grouting material for waterproofing of tunnel lining upstream face and grouting method thereof |
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