CN109406346A - A kind of method of indirect determination Chloride Diffusion Coefficient in Concrete - Google Patents
A kind of method of indirect determination Chloride Diffusion Coefficient in Concrete Download PDFInfo
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- CN109406346A CN109406346A CN201710703398.9A CN201710703398A CN109406346A CN 109406346 A CN109406346 A CN 109406346A CN 201710703398 A CN201710703398 A CN 201710703398A CN 109406346 A CN109406346 A CN 109406346A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N13/00—Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects
- G01N13/04—Investigating osmotic effects
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Abstract
The invention discloses a kind of methods of indirect determination Chloride Diffusion Coefficient in Concrete, comprising the following steps: test material preparation；Migration tests: in migration tests, KOH solution is injected in test specimen cylinder, injects the KOH solution containing NaI in test flume；The measurement of iodide ion diffusion depth；Iodide ion diffusion depth is modified, chlorine iodide ion diffusion depth is converted into；Chloride diffusion coefficient is calculated with the chlorine iodide ion diffusion depth of acquisition.The present invention establishes the test method of measurement concrete iodide ion diffusion coefficient, during test, it is not influenced by inside concrete chloride ion, higher data precision is obtained by the amendment to iodide ion diffusion depth, can be used for carrying out durability Design and life prediction to internal doping type concrete structure and by Chloride Attack structure.
Description
[technical field]
The present invention relates to measurement Chloride Diffusion Coefficient in Concrete method more particularly to a kind of indirect determination concrete chlorine from
The method of sub- diffusion coefficient.
[background technique]
The durability of concrete structure is essentially dependent on lewis' acid in the form of liquid or gas into or through material
Process, structural life-time depends on these substances and enters the speed of concrete.The process that harmfulness medium invades concrete is main
It is influenced by concrete permeability." permeability " this word is widely used, and is often referred to influence medium in a general case
The characteristic of intrusion.Chloride diffusion coefficient has crucial influence for prediction diffusion velocity.Most common method also right and wrong
Stable state migration tests (RCM), by the way that measurement anolyte is initial and the average value (T) of final temperature, height of specimen (h),
Chloride diffusion depth (xd) and energizing test time (t) calculate the quick diffusion coefficient of chloride ion of concrete sample, expression
Formula is as follows:
This method test period is short, test apparatus is simple and convenient to operate, and directly invades concrete depth according to chloride ion
Measured value export diffusion coefficient, rather than pass through the measurement of electricity, resistance or conductance, advantage is more, wide in the world
" durability design and the construction guidbook " of general use, China is also recommended to use.But RCM requirement of experiment concrete
Internal not chloride ion-containing.It is internal in the experimentation of RCM if inside concrete has contained chloride ion at the beginning of experiment
Chloride ion will generate two kinds of effects: 1. they can be migrated under electric field environment；2. they are also and indicator reaction.Both
Effect influences whether the accuracy of RCM experimental result, cannot measure chlorine ion binding capacity using the experimental method of RCM when serious
Coefficient.
As described above, chloride ion-containing can also migrate under electric field action in structure during carrying out RCM experiment,
And it can react with indicator.Both act on the accuracy that can all influence RCM experimental result, work as concrete structure
In the chloride ion that includes beyond a threshold value, the chloride diffusion coefficient of structure will cannot be measured using the experimental method of RCM,
Therefore, present test method cannot be used for following two situation: one, the survey of inner introduced chloride concrete structure infiltration coefficient
It is fixed;Two, by the measurement of Chloride Attack concrete structure infiltration coefficient.But in practical projects, this part-structure chlorine
The measurement of ionic diffusion coefficient is particularly important.
The applicant once had submitted a kind of entitled " concrete to State Intellectual Property Office on January 13rd, 2012
The measuring method of middle penetration depth of iodide ions " application for a patent for invention (application No. is: 201210010833.7), the test process
It is not influenced by inside concrete chloride ion, process is simple and quick；But the measurement of penetration depth of iodide ions can't direct generation
It is applied for chloride diffusion coefficient.
Replace the solution of chloride diffusion coefficient in " New method measure using iodide ion diffusion coefficient
the rapid migration coefficient of chloride-contaminated concrete(cement
and
Research, 2004,34:421-427) " it is illustrated in a text.But this article thinks iodide ion diffusion coefficient and chlorine
The effect of ionic diffusion coefficient is identical, iodide ion diffusion coefficient is simply substituted into chloride diffusion coefficient evaluate include chlorine from
Sub- concrete resist ion diffusion ability will necessarily durability Design to concrete and life prediction generate very big error.
[summary of the invention]
It, can be with the technical problem to be solved in the present invention is to provide a kind of method of indirect determination Chloride Diffusion Coefficient in Concrete
For under existence conditions to inner introduced chloride concrete structure and by Chloride Attack concrete structure etc. include chlorine from
The measurement of sub- concrete structure infiltration coefficient, the ability of ion diffusion is resisted with chloride ion-containing concrete in accurate evaluation, and is had
Enough precision.
In order to solve the above-mentioned technical problem, the technical solution adopted by the present invention is that, a kind of indirect determination concrete chloride ion
The method of diffusion coefficient, comprising the following steps:
101) test material preparation；
102) migration tests: in migration tests, KOH solution is injected in test specimen cylinder, injection is containing NaI's in test flume
KOH solution；
103) iodide ion diffusion depth measures；
104) iodide ion diffusion depth is modified, is converted into chlorine iodide ion diffusion depth；
105) chloride diffusion coefficient is calculated with the chlorine iodide ion diffusion depth that step 104 obtains.
Above according to the method for the indirect determination Chloride Diffusion Coefficient in Concrete described in claim 1, in step 102
In, the molar concentration of KOH solution is 0.2 mol/L；In KOH solution containing NaI, the mass percent concentration of NaI is
The molar concentration of 11.89%, KOH are 0.2 mol/L.
The method of above-described indirect determination Chloride Diffusion Coefficient in Concrete, it is deep using diffusion in step 104
Degree correction factor λ is modified iodide ion diffusion depth xid, is converted into chlorine iodide ion diffusion depth xd:
λ=[1.2+(0.55-W/C)]
In formula, W/C is the ratio of mud of concrete.
xd=λxid
The present invention establishes the test method of measurement concrete iodide ion diffusion coefficient, during test, not by inside concrete chlorine
The influence of ion obtains higher data precision by the amendment to iodide ion diffusion depth, can be used for internal doping type coagulation
Soil structure and durability Design and life prediction are carried out by Chloride Attack structure.
[specific embodiment]
The concrete of test specimen uses three kinds of ratio of muds, is respectively: 0.39,0.47 and 0.53.Match ratio is shown in Table 1, is fabricated to straight
Diameter 100mm, the test specimen blank of the cylindrical body of a height of 100mm
1 concrete sample match ratio of table/kg/m3
Step 1: conserving 28d under concrete sample blank standard conditions, each test specimen blank is cut into two diameters
100mm, the test specimen of a height of 50mm carry out the test of RIM(concrete iodide ion diffusion coefficient respectively) and RCM test, wherein
RCM test is carried out by traditional RCM test method, is not described；Below only to RIM of the present invention test process into
Row description.
Step 2: needing to carry out 15 min ultrasonic cleaning and at a distance of 200-300 before carrying out the test specimen installation of RIM test
Hair dryer (using cold wind shelves) drying of mm.Ultrasonic bath need to be rinsed one minute in advance with water (room temperature).The surface of test specimen should be done
Only, without greasy dirt, without sand-lime.
Step 3: the test specimen cylinder for installing test specimen is installed in Tang Shi RCM analyzer test flume, anode plate is installed,
Then the KOH solution that 0.2 mol/L of about 300 ml is injected in test specimen cylinder is immersed in anode plate and surface of test piece molten
In liquid；Solution is injected in test flume, and (NaI mass percent concentration is that the molar concentration of 11.89%, KOH is in solution
0.2mol/L), until it is equal with the liquid level of KOH solution in test specimen cylinder.
Step 4: when measurement electric current, multimeter is transferred to 200 mA grades；When measuring voltage, multimeter is transferred to 200V grades；
The temperature measuring of two kinds of solution should be accurate to 0.2 DEG C, and the conduction time of test specimen 1 and test specimen 2 is determined according to initial current (table 2)
For 8h, the conduction time of test specimen 3 is for 24 hours, after electric field acceleration ion process of osmosis, to use development process respectively, determine iodide ion
Penetration depth, test result such as table 3, calculate the quick diffusion coefficient of concrete iodide ion.
Step 5: before taking out test specimen, first closing power supply, disconnect line, take out test specimen cylinder, remove KOH solution, trip ring
Screw is bound round, then removes test specimen from the top down；Test specimen is split into two halves after the removal of test specimen cylinder on pressure testing machine immediately；?
The surface of test piece rived sprays colored indicator immediately；The potassium iodate solution of first jet quality percent concentration 1% is concrete
In iodide ion be oxidized to iodine, the starch suspension of fill-before-fire 2%, measurement iodide ion seeps after concrete surface colour developing
The inclusion compound of saturating depth, iodide ion and starch displaing amaranth in concrete.
Step 6: concrete iodide ion diffusion coefficient is calculated as follows that (intermediate operations are accurate to four effective digitals, most
Result retains three effective digitals afterwards):
DRIM in formula, the concrete iodide ion diffusion coefficient (m2/s) of 0-RIM method measurement；
The average value (K) of mild final temperature at the beginning of T-anolyte；
H-height of specimen (m)；
Xid-iodide ion diffusion depth (m)；
T-energizing test time (s)；
α-auxiliary variable.
The detailed results of calculating are shown in Table 3.
The relationship of table 2 initial current and test period
3 RIM test result of table
Present invention introduces colour developing adjusting for depth coefficient lambda (diffusion depth correction factor λ), lambda definition is that iodide ion is aobvious in RIM test
The ratio of chloride ion colour developing depth (chloride diffusion depth) in color depth (iodide ion diffusion depth) and RCM test.According to water
Gray scale and the inversely proportional relationship of depth that develops the color, are fitted by data, determine colour developing adjusting for depth coefficient (diffusion depth amendment system
Number) formula it is as follows:
λ=[1.2+(0.55-W/C)]
The colour developing depth of iodide ion is xid in RIM test, and the colour developing depth xd of corresponding RCM chloride ion can be calculated
Are as follows:
xd=λxid
Xd is substituted into formula 1, obtains the formula of the invention by the quick diffusion coefficient of RIM experiment calculation chloride ion:
After introducing colour developing adjusting for depth coefficient, 4 the results are shown in Table to iodide ion colour developing adjusting for depth, the result of RIM after amendment
It is shown in Table 5.As can be seen that RIM tests the result phase that the quick diffusion coefficient of revised chloride ion is measured with RCM for test specimen 1
Difference is less than 5%；For test specimen 2, it is only suitable with the result that RCM is measured that RIM tests revised result；For test specimen 3, RIM
It tests revised result and differs less than 1% with the result that RCM is measured.If the result for defining RCM test is true value, RIM test
The error range of calculating are as follows: 0-5.12%.RIM test result is higher by revised data precision, can meet soil
General error requirements in wood engineering application.
Correction chart of the colour developing coefficient of table 4 to iodide ion colour developing depth:
The revised chloride diffusion coefficient value of table 5 and tradition RCM method measure the comparison of Chloride Diffusion Coefficient in Concrete value
It is as follows:
Firstly, for same test specimen, the colour developing depth of iodide ion is lower than chloride ion, when converting ion penetration depth, the present invention
Colour developing adjusting for depth coefficient (λ) is introduced, the result that can be tested close to RCM by revised iodide ion Permeation Results.
In addition the reagent concentration that the present invention uses is closer to be tested with RCM, the quality percentage of NaI in iodide ion permeability test of the present invention
Specific concentration is 11.89%, and the mass percent concentration of NaCl is 5% in traditional RCM test, can guarantee mole of the two in this way
Concentration is consistent, is comparable the test of the two, correct result can be obtained by converting.
Claims (3)
1. a kind of method of indirect determination Chloride Diffusion Coefficient in Concrete, which comprises the following steps:
101) test material preparation；
102) migration tests: in migration tests, KOH solution is injected in test specimen cylinder, injection is containing NaI's in test flume
KOH solution；
103) iodide ion diffusion depth measures；
104) iodide ion diffusion depth is modified, is converted into chlorine iodide ion diffusion depth；
105) chloride diffusion coefficient is calculated with the chlorine iodide ion diffusion depth that step 104 obtains.
2. the method for the indirect determination Chloride Diffusion Coefficient in Concrete according to claim 1, which is characterized in that
In step 102, the molar concentration of KOH solution is 0.2 mol/L；In KOH solution containing NaI, the quality percentage of NaI
Specific concentration is that the molar concentration of 11.89%, KOH is 0.2 mol/L.
3. the method for the indirect determination Chloride Diffusion Coefficient in Concrete according to claim 1, which is characterized in that in step
In rapid 104, iodide ion diffusion depth xid is modified using diffusion depth correction factor λ, is converted into the expansion of chlorine iodide ion
Dissipate depth xd:
λ=[1.2+(0.55-W/C)]
In formula, W/C is the ratio of mud of concrete；
xd=λxid。
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111077055A (en) * | 2019-12-25 | 2020-04-28 | 四川中核艾瑞特工程检测有限公司 | Chloride ion penetration depth measuring method |
| CN111896428A (en) * | 2020-08-10 | 2020-11-06 | 南京工业大学 | Device and method for measuring diffusion coefficient of sulfate ions in mortar and concrete |
-
2017
- 2017-08-16 CN CN201710703398.9A patent/CN109406346A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111077055A (en) * | 2019-12-25 | 2020-04-28 | 四川中核艾瑞特工程检测有限公司 | Chloride ion penetration depth measuring method |
| CN111896428A (en) * | 2020-08-10 | 2020-11-06 | 南京工业大学 | Device and method for measuring diffusion coefficient of sulfate ions in mortar and concrete |
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