CN104062220A - Method for measuring concrete chloride penetration coefficient through electrodeless electrical measuring method - Google Patents
Method for measuring concrete chloride penetration coefficient through electrodeless electrical measuring method Download PDFInfo
- Publication number
- CN104062220A CN104062220A CN201410313202.1A CN201410313202A CN104062220A CN 104062220 A CN104062220 A CN 104062220A CN 201410313202 A CN201410313202 A CN 201410313202A CN 104062220 A CN104062220 A CN 104062220A
- Authority
- CN
- China
- Prior art keywords
- concrete
- resistivity
- electrodeless
- sodium chloride
- slices
- 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.)
- Pending
Links
Abstract
The invention discloses a method for measuring a concrete chloride penetration coefficient through an electrodeless electrical measuring method. The method comprises the steps that hardened concrete with any age is cut into concrete slices; salt saturation treatment is carried out on the vacuum the concrete slices through a sodium chloride solution; the resistivity of the sodium chloride solution and the resistivity of a sodium chloride solution and concrete slice series connection model are respectively tested through an electrodeless resistivity meter, and then the resistivity of the concrete slices is calculated on the basis of a resistivity formula; on the basis of the Nernst-Einstein equation, the penetration coefficient of chloride ions in the concrete slices is calculated. According to the method, the penetration coefficient of the chloride ions in the hardened concrete slices with any age is determined, the problem that the concrete chloride penetration coefficient cannot be accurately measured at present is solved, and the more accurate basis is provided for durability estimation and service life prediction of reinforced concrete.
Description
Technical field
The invention belongs to concrete performance examination technical field, relate to a kind of method that electrodeless electrical measuring method is measured concrete chloride ion infiltration coefficient.
Background technology
In order to assess concrete permanance, existing method of testing comprises naturally osmotic method ASTM C1556 (2004), coulometry ASTM C1202-94, coefficient method (researcher Luping Tang, K.Stanisha), NEL method (Lu Xinying of Tsing-Hua University) etc.
Chlorion natural diffusion method (ASTM C1556), be that concrete is immersed in sodium chloride solution, through segmentation, cut the experimental procedures such as concrete abrasive dust, leaching, electrometric titration, set up the relation of chlorine ion concentration and diffusion length, utilize Fick second theorem, calculate coefficient of diffusion.The method is similar to actual conditions, but test required time is long, especially for the high concrete of packing; Meanwhile, long soak time can cause concrete perviousness in test process to change, and causes larger test error.
Electric flux method (ASTM C1202, ASSHTO T277), is in the concrete sample both sides of Φ 100 * 50mm, to apply the DC voltage of 60V, by detecting the electric weight size flowing through in 6 hours, evaluates concrete perviousness.Existing a large amount of report, the DC voltage of 60V can cause obvious electrode polarization reaction, and in test process, the problem such as conducting solution temperature rising causes measuring error.
Electromigration (NT Build492) adopts higher voltage (10V～60V), the complete taking-up test specimen of switching on, by its cleave in two, by the diffusion depth of silver nitrate titration chlorion, according to the Nernst-Planck equation in aqueous solution electrochemical, calculate the coefficient of diffusion of chlorion.Electrode reaction consumes the ion in hole solution, and after the full water of concrete, grow (6h～96h) conduction time, not only hole solution is in continuous variation, and considerable part electric current can be consumed in electrode reaction, not entirely for chlorion, move, the same with electric flux method, its birth defect also cannot be eradicated.
The High Level DC Voltage adopting due to above-mentioned two kinds of methods brings obvious polarization problem, therefore, some scholars improve the method for above-mentioned electricity, representational is the NEL method of the Lu Xinying of Tsing-Hua University, NEL method is used low-voltage DC (1V～5V), before test, sample is carried out to the full salt processing of vacuum with the NaCl solution of 4M, based on Nernst-Einstein equation, calculate the coefficient of diffusion of concrete chloride ion.
Existing electrical measuring method is all to test electrical property with electrode, electrode polarization consumes the ion in hole solution, cause hole solution in continuous variation, and considerable part electric current can be consumed in electrode reaction, not entirely for chlorion, move, also have the material of above-mentioned electrode and the problem of size, so the birth defect of electrode method cannot be eradicated.
Zhejiang University takes electrodeless method to test concrete electric conductivity, is concrete is dried to the time of testing the conducting of concrete intermediate ion in solution that is placed on.Concrete, in drying course, has the change that drying shrinkage etc. causes micromechanism especially in early days, and the result of measuring is the time, can not obtain chloride permeability coefficient.
Summary of the invention
The object of the invention is to solve to shrink to produce with the polarization reaction of eliminating the existence of current electrode method test chloride ion permeability, electrode and contact resistance, hydrated cementitious between cement matrix and contact the larger problem of test error that the factors such as cracking are brought, and a kind of method of electrodeless electrical measuring method mensuration concrete chloride ion infiltration coefficient is provided.
Electrodeless electrical measuring method is measured the method for concrete chloride ion infiltration coefficient, comprises the following steps:
The maturing in any length of time is cut into concrete section;
With sodium chloride solution, concrete is cut into slices and carried out the full salt processing of vacuum;
With electrodeless resistivity meter, test respectively connect with the concrete section resistivity of model of sodium chloride solution resistivity, sodium chloride solution, then according to resistivity formula, calculate the resistivity that concrete is cut into slices;
According to Nernst-Einstein equation, calculate the infiltration coefficient of chlorion in concrete section.
Press such scheme, the thickness of described concrete section is 40-60mm.
Press such scheme, described concentration of sodium chloride solution is 8～12wt%.
Press such scheme, the full salt of described vacuum is processed vacuum tightness 2～5KPa, full 1～3 hour salt time.
Beneficial effect of the present invention is:
Do not use in the present invention any electrode, thereby thoroughly eliminated the measuring error that electrode method is brought, improved test accuracy and precision; And adopt the former liquid phase in the sodium chloride solution displacement sample of high concentration to test perviousness, and do not need to dry sample, avoid drying course to the infiltrative change of sample, and can directly obtain the permeability coefficient of chlorion.
The invention provides the method for the chloride permeability coefficient of the maturing section of determining any length of time, solved at present cannot Accurate Determining concrete chloride ion infiltration coefficient a difficult problem, for assessment and the life prediction of reinforced concrete permanance provides foundation more accurately, and extend in the mensuration, other porous medium pore structure and infiltrative research of concrete pore rate.From the full salt of sample, process and be completed, required time is shorter, needs 2～5 hours, 1～2 minute test duration.
Embodiment
Following examples are explaination technical scheme of the present invention further, but not as the restriction to protection domain.
Electrical measuring method that the present invention is electrodeless is measured the method for concrete chloride ion infiltration coefficient, and process is as follows:
The maturing in any length of time is cut into the concrete section of thickness 40-60mm;
With the sodium chloride solution of 8～12wt%, concrete is cut into slices and carried out the full salt processing of vacuum, vacuum tightness: 2～5kPa, 1～2 hour pumpdown time, full 1～3 hour salt time; The inspection of the full salt effect of vacuum: get the sample that perviousness is less, survey the resistivity of a period of time, observe resistivity temporal evolution, show that porous nickel in sample is chlorinated sodium solution saturated when being horizontal linear, the full salt of vacuum is effective.1～2 minute each sample proper testing time.
With electrodeless resistivity meter, test respectively connect with the concrete section resistivity of model of sodium chloride solution resistivity, sodium chloride solution, then according to resistance series connection model formation and resistivity formula below, calculate the resistivity that concrete is cut into slices;
According to Nernst-Einstein equation, calculate the infiltration coefficient of chlorion in concrete.
Series connection model formation: R
solution+ R
section=R
series connection(1)
Annular sample resistivity formula:
Nernst-Einstein equation: D
i=RT σ t
i/ Z
i 2f
2c
i=RTt
i/ Z
i 2f
2c
iρ (3)
H is the height of testing sample, and f (r) is relevant to the cross sectional shape of sample, is the function of sectional dimension.
Embodiment 1:
Use P.O42.5 cement, 0.6～5mm sand, 5～10mm stone and water, with match ratio cement: water: sand: stone=0.4:1:1.25:2.49 concrete batching sample, be cast in resistivity annular die for molding, after standard curing 28 days, with cutting machine, the good annular sample of maintenance is cut into 51.2mm slab, with the full salt of 10% sodium chloride solution vacuum, process the sample of well cutting, resistance with electrodeless resistivity method difference test solution and (solution+section) series connection model, according to connect model formation (1) and resistivity formula (2), calculating the resistivity of concrete sample the 28 day length of time is 34.89 ohm-meter, according to Nernst-Einstein equation (3), obtaining chloride permeability coefficient is 0.4378 * 10
-7cm
2/ s.
Embodiment 2:
With P.O42.5 cement and water, with water cement ratio 0.30 preparation cement paste sample, be cast in resistivity annular die for molding, after standard curing 28 days, with cutting machine, the good sample of maintenance is cut into 47.9mm slab, with the full salt of 10% sodium chloride solution vacuum, process the sample of well cutting, resistance with electrodeless resistivity method difference test solution and (solution+section) series connection model, the resistivity of the cement paste sample that calculates water cement ratio 0.30 according to series connection model formation and resistivity formula the 28 day length of time is 13.66 ohm-meter, according to Nernst-Einstein equation, obtaining chloride permeability coefficient is 1.1187 * 10
-7cm
2/ s.
Embodiment 3:
The chloride permeability coefficient of three samples of test.With P.O42.5 cement and water, with water cement ratio 0.40 preparation cement paste sample, be cast in resistivity annular die for molding, after standard curing 28 days, with cutting machine, the good sample of maintenance is cut into 47.5mm slab, with the full salt of 10% sodium chloride solution vacuum, process the sample of well cutting, resistance with electrodeless resistivity method difference test solution and (solution+section) series connection model, the resistivity of the cement paste sample that calculates water cement ratio 0.40 according to series connection model formation and resistivity formula the 28 day length of time is 9.11 ohm-meter, according to Nernst-Einstein equation, obtaining chloride permeability coefficient is 1.3776 * 10
-7cm
2/ s.
Measurement result contrasts with actual result, and error is in Table 1.
Table 1
| Embodiment 1 | Embodiment 2 | Embodiment 3 |
| 1.41％ | 3.81％ | 1.76％ |
Claims (4)
1. electrodeless electrical measuring method is measured the method for concrete chloride ion infiltration coefficient, it is characterized in that comprising the following steps:
The maturing in any length of time is cut into concrete section;
With sodium chloride solution, concrete is cut into slices and carried out the full salt processing of vacuum;
With electrodeless resistivity meter, test respectively connect with the concrete section resistivity of model of sodium chloride solution resistivity, sodium chloride solution, then according to resistivity formula, calculate the resistivity that concrete is cut into slices;
According to Nernst-Einstein equation, calculate the infiltration coefficient of chlorion in concrete section.
2. electrodeless electrical measuring method is measured the method for concrete chloride ion infiltration coefficient as claimed in claim 1, it is characterized in that the thickness of described concrete section is 40-60mm.
3. electrodeless electrical measuring method is measured the method for concrete chloride ion infiltration coefficient as claimed in claim 1, it is characterized in that described concentration of sodium chloride solution is 8～12wt%.
4. electrodeless electrical measuring method is measured the method for concrete chloride ion infiltration coefficient as claimed in claim 1, it is characterized in that the full salt of described vacuum processes vacuum tightness 2～5KPa, full 1～3 hour salt time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410313202.1A CN104062220A (en) | 2014-07-02 | 2014-07-02 | Method for measuring concrete chloride penetration coefficient through electrodeless electrical measuring method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410313202.1A CN104062220A (en) | 2014-07-02 | 2014-07-02 | Method for measuring concrete chloride penetration coefficient through electrodeless electrical measuring method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104062220A true CN104062220A (en) | 2014-09-24 |
Family
ID=51550035
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410313202.1A Pending CN104062220A (en) | 2014-07-02 | 2014-07-02 | Method for measuring concrete chloride penetration coefficient through electrodeless electrical measuring method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104062220A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105842141A (en) * | 2014-12-16 | 2016-08-10 | 天津大学 | Method for measuring infiltration rate of ions in concrete |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103175764A (en) * | 2013-03-08 | 2013-06-26 | 石家庄铁道大学 | Method for rapidly determining chloride ion permeation resistance of concrete |
-
2014
- 2014-07-02 CN CN201410313202.1A patent/CN104062220A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103175764A (en) * | 2013-03-08 | 2013-06-26 | 石家庄铁道大学 | Method for rapidly determining chloride ion permeation resistance of concrete |
Non-Patent Citations (2)
| Title |
|---|
| 李宗津等: "用于混凝土外加剂质量评议和选择的新方法——无电极电阻率测定方法", 《2009中国国际混凝土周系列活动之——混凝土外加剂新技术及装备研讨会》, 24 February 2009 (2009-02-24) * |
| 马颖: "凝石混凝土的抗氯离子渗透性能分析", 《沈阳建筑大学学报(自然科学版)》, vol. 30, no. 1, 31 January 2014 (2014-01-31) * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105842141A (en) * | 2014-12-16 | 2016-08-10 | 天津大学 | Method for measuring infiltration rate of ions in concrete |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Andrade et al. | Test methods for on-site corrosion rate measurement of steel reinforcement in concrete by means of the polarization resistance method | |
| CN104568732B (en) | A kind of experimental provision and test method of quick measure reinforcement corrosion speed | |
| CN103175764A (en) | Method for rapidly determining chloride ion permeation resistance of concrete | |
| Angst et al. | On the Applicability of the Wenner Method for Resistivity Measurements of Concrete. | |
| CN101226167B (en) | Method for rapidly measuring reinforcing steel tarnishing criticality chlorine ion concentration | |
| CN103674807B (en) | A kind of cement-based material chloride permeability depth test method | |
| CN103424313B (en) | In-situ tensile and hydrogen content monitoring device, and method for monitoring content of hydrogen by using same | |
| US20170089851A1 (en) | Method of ascertaining fully grown passive film formation on steel rebar embedded in concrete | |
| CN100510735C (en) | Evaluating method for hydrogen penetrating quality of coating material | |
| CN110361302A (en) | A method of measurement Chloride Diffusion Coefficient in Concrete | |
| CN108680469A (en) | A kind of ion penetration resistance of concrete measurement method | |
| KR101207612B1 (en) | Testing cell for sensing of electric corrosion used galvanic sensor for sensingof electric corrosion of steel-concrete structure | |
| KR102013636B1 (en) | Method for Evaluating Self-Healing Performance of Cracked Cementitious Material | |
| CN203275253U (en) | Cement-based material permeability evaluation system based on non-contact resistivity | |
| CN104374813A (en) | Method for determining concentration of critical chloride ion in concrete reinforcing bars | |
| CN102621041A (en) | Method for testing calcium ion diffusion coefficient of concrete | |
| CN103698259B (en) | A kind of cement-based material sulfate radical erosion depth method of testing | |
| CN105466814B (en) | A kind of Chloride Diffusion Coefficient in Concrete assessment system and method | |
| CN104062220A (en) | Method for measuring concrete chloride penetration coefficient through electrodeless electrical measuring method | |
| CN103487480A (en) | Method for rapidly predicting service life of reinforced concrete in chlorine salt environment | |
| CN101210871A (en) | Soil erosion researching device | |
| JPH09196876A (en) | Detecting method for corroded spot of steel material in concrete | |
| CN103308443A (en) | Accelerated corrosion testing method for simulating soil corrosion process | |
| CN102297821B (en) | Detection apparatus for impermeability of hardened concrete under constraint state, and method thereof | |
| CN103487570B (en) | Method for testing accelerated life of reinforced concrete in chloride environment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20140924 |