CN108956684A - A kind of embedded type concrete early freezc icing lossless detection method - Google Patents
A kind of embedded type concrete early freezc icing lossless detection method Download PDFInfo
- Publication number
- CN108956684A CN108956684A CN201810849736.4A CN201810849736A CN108956684A CN 108956684 A CN108956684 A CN 108956684A CN 201810849736 A CN201810849736 A CN 201810849736A CN 108956684 A CN108956684 A CN 108956684A
- Authority
- CN
- China
- Prior art keywords
- concrete
- test device
- resistivity
- temperature
- icing
- 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
Classifications
-
- 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
- G01N25/02—Investigating or analyzing materials by the use of thermal means by investigating changes of state or changes of phase; by investigating sintering
- G01N25/04—Investigating or analyzing materials by the use of thermal means by investigating changes of state or changes of phase; by investigating sintering of melting point; of freezing point; of softening point
-
- 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
- G01N27/041—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body
Abstract
A kind of embedded type concrete early freezc icing lossless detection method, the invention belongs to concrete NDT technical fields.Endure cold ice condition of the present invention to monitor concrete different parts in winter construction, it is ensured that the quality of winter construction concrete.Method and step of the invention is as follows: step 1: the concrete in setting insulating box identical with on-site concrete match ratio is as a control group, the variation of the resistivity of the variation and control group concrete of resistivity and temperature at monitoring field concrete different depth respectively；Step 2: judge whether on-site concrete enters state at negative temperature by on-site concrete temperature change, whether endured cold icing by the concrete of on-site concrete Yu the ratio in judgement of control group the concrete resistivity position, if there is icing phenomenon, it may determine that concrete enters the time in each icing stage from the curvilinear trend of resistivity ratio.The present invention is used for the non-destructive testing of concrete early freezc damage.
Description
Technical field
The invention belongs to concrete NDT fields, and in particular to a kind of embedded type concrete early freezc icing non-destructive testing
Method.
Background technique
There are about 3 × 10 every year in China7m3Concrete needs to carry out winter construction, and task amount is huge.However cold temperature pair
Concrete works are very unfavorable, and winter construction quality accident often occurs, caused by economic loss it is very surprising, therefore concrete
Health monitoring just seem particularly significant.Concrete nondestructive testing technology can make construction personnel not destroy the important knot of concrete
The information such as structural development and the damage of inside concrete are learnt in the case where structure, so as to adopt remedial measures in time.For
Concrete in winter construction, the concrete especially for early stage containing a large amount of unhydrated water, for commenting for its frost damege
Valence mostly uses the same conditional maintenance test specimen, tests the compression strength of different larval instar concrete, needs to form a large amount of concrete examinations
Part, it is time-consuming and laborious, and be generally considered that cured under same condition test specimen compression strength and actual components intensity due to temperature transmitting,
The influence of scantling is not also completely the same.Therefore, engineers and technicians are unanimously seeking efficient non-destructive monitoring method
Evaluate the frost damege of concrete in winter construction.
Resistivity method test is used as a kind of lossless detection method, and fast and easy is cheap, the advantages that can remotely monitoring
It is set to find broad application in recent years.Currently, having there is many resistivity Successful utilizations in the case of concrete health monitoring.
Resistivity method is commonly used to evaluate the degree of hydration of positive warm concrete, interior humidity, strength development and reinforcing bar rust in concrete
Erosion etc., it is also possible to evaluate durability of the concrete under freeze-thaw cycles.But not yet discovery utilizes resistivity method at present
To monitor and evaluate the early freezc damage of negative temperature concrete.
About the measurement to concrete resistivity, current most important measurement method is two electrode methods, four electrode method and nothing
Electrode eyes with non-contact method, common four electrode method are measured to concrete surface resistivity, and electrodeless eyes with non-contact method is to use
The degree of hydration of cement-based material is monitored, is suitable for studying in laboratory and use, two electrode methods pass through columnar electrode, pellet electrode
Or some specific position measures in mesh electrode Transducers Embedded in Concrete.However, for the mass concrete of winter construction
For, the feature of some privileged site or certain depth can not represent the global feature of concrete, because with depth
The degree of enduring cold of difference, concrete also can be different.In addition, when measurement concrete resistivity, the general multiselect columnar electrode of electrode,
Perhaps relative to column or pellet electrode, mesh electrode can have with concrete preferably to be contacted mesh electrode pellet electrode.
Summary of the invention
The object of the present invention is to provide a kind of embedded type concrete early freezc icing lossless detection methods, to monitor winter
Ice condition of enduring cold in construction at concrete different location, ensures the construction quality of concrete.
Device selected by the present invention is provided with mesh electrode (electrode network) at the different depth of concrete, with more smart
Change in resistance of the true measurement concrete at different depth.
The purpose of the present invention is what is be achieved through the following technical solutions:
A kind of embedded type concrete early freezc icing lossless detection method, the method are based on temperature measuring device, resistivity
What tester and two test devices were realized, described two test devices are test device one and test device two respectively；
The test device one and test device two include quadrangular frame 1, and the test device one further includes more thermoelectricity
Even and multipair electrode network, the test device two further include a pair of electrodes net；
The specific structure of test device one is: two opposite sides in the quadrangular frame are respectively fixed with multipair electrode network,
And the multipair electrode network is from top to bottom arranged, and conducting wire, the other end of the conducting wire and the electricity are all connected on each pair of electrode network
Resistance rate tester is connected, and the resistivity tester is connected with computer input terminal, fixed on the lateral surface of quadrangular frame
Have more thermocouples, the measuring point height of more thermocouples is located at the middle part of multipair electrode net height, more thermocouples it is another
One end is connected with temperature measuring device, and the temperature measuring device is connected with computer input terminal, and test device one is used for test site
Concrete resistivity and temperature；
The specific structure of test device two is: two opposite sides in the quadrangular frame are fixed with a pair of electrodes net, this is right
Electrode network is connect by conducting wire with the resistivity tester；Test device two is for testing control group concrete electric in insulating box
Resistance rate；
The method comprises the following steps:
Step 1: as a control group, monitoring is existing respectively for the concrete in setting insulating box identical with on-site concrete match ratio
The change in resistance of resistivity and temperature change and control group concrete at the concrete different depth of field；
The step 1 comprises the concrete steps that,
(1) test device one is put into the tested point at scene, the test device two is put into insulating box, the constant temperature
The temperature setting of case is+20 DEG C, and thermocouple is connected with moisture recorder, conducting wire is connected with resistivity tester, and will be electric
Resistance rate tester and temperature measuring device are connected with computer input terminal respectively, while pouring pair in on-site concrete and insulating box
According to a group concrete, when pouring, test device one and test device two should be vertically arranged, should sufficiently be vibrated after concreting is complete
So that the concrete near test device one and test device two is sufficiently closely knit；
(2) from pouring constantly, the resistivity and temperature of continuous monitoring field concrete are denoted as R respectively1i And T1i ,iFor test
The sequence number of electrode network pair from top to bottom in device 1；The resistivity of continuous monitoring control group concrete simultaneously, is denoted as R2；Meter
Calculate R1i /R2Ratio at various moments draws its relation curve with the time；
Step 2: it may determine that whether on-site concrete enters subzero temperature by on-site concrete temperature monitoring, pass through live coagulation
Soil and the ratio between control group concrete resistivity judge at this whether concrete endures cold icing；
The step 2 comprises the concrete steps that:
Observe T1i Variation, if T1i > 0, then on-site concreteiA electrode network is in positive warm area to the concrete of depth,
Without a possibility that freezing of enduring cold；If T1i < 0, then on-site concreteiA electrode network is in subzero temperature area to the concrete of depth
Between, a possibility that freezing of enduring cold observes R at this time1i /R2Curvilinear motion, if R1i /R2Curve is not present and flies up situation,
Then illustrate not endure cold in concrete at this time；If R1i /R2Extend the presentation of its value at any time to fly up, then the concrete of the depth
At this moment R may be analyzed at this time with the presence of icing phenomenon of enduring cold1i /R2Ratio；If R1i /R2When rising to several hundred or thousands of, sentence
Disconnected inside concrete at this time largely freezes, and R1i /R2Numerical value is bigger, and icing amount is bigger；If R1i /R2Only tens even more
Hour, only a part of ice crystal generates inside concrete at this time at this time for judgement, the not a large amount of glaciations of the water of inside concrete.
It would know that concrete enters the time in each icing stage from the slope of a curve catastrophe point, which, which flies up, represents concrete
At the time of starting to freeze, curve no longer increases representated by concrete at the time of reach maximum icing amount.
The present invention has the advantages that compared with the existing technology
1, the invention avoids scenes to reserve a large amount of cured under same condition test specimens, is not required to these reserved examinations by universal test machine testing
The compression strength of part can evaluate the frost damege of concrete, time saving and energy saving.
2, it can detecte whether inside concrete freezes for currently without test method, the present invention can effectively judge
The icing condition of inside concrete is concrete nondestructive testing technology.Two test device structures of the invention are simple and design
Rationally, at low cost；Measurement method is easy to operate and accurate and reliable.
It 3, can be with the present invention overcomes detection concrete surface state is only capable of in existing concrete resistivity measurement
Concrete at test concrete different depth is endured cold state, while obtaining the temperature and resistivity number of each depth of concrete
Value.
4, test device one need to be only put into the tested point at scene by the present invention before concreting, hereafter can pass through meter
The automatic monitoring record of calculation machine realizes and is easy that flexible design is time saving and energy saving, can remotely monitor for a long time.
5, in test device one of the invention multipair electrode network setting, can according to the structure size of on-site concrete,
Design electrode network logarithm and per adjacent two pairs of electrodes net spacing, the position of electrode network is arbitrarily adjustable, can meet depth (
Can be described as height) different measuring accuracies require on direction concrete endures cold the monitoring of icing.
6, the present invention is suitable for the test of enduring cold in each stage of concrete, is particularly suitable for early stage, because early age is mixed
Solidifying soil its resistivity value of enduring cold when freezing has significant characteristic.
7, test device one and temperature measuring device, resistivity tester are used in combination and can also be used for severe cold area in the present invention
The soil body from outward appearance to inner essence freezes and the long-term long-range monitoring of melting process, obtains the winter by the resistivity of comparison summer and the winter soil body
Endure cold depth and the degree of enduring cold of Ji Tuti.
To sum up, resistivity can be very good ice condition when detection concrete is endured cold as a kind of lossless detection method,
Mesh electrode (electrode network) is selected to come by the present invention so that it has with concrete preferably contacts, and selects the electricity arranged in ladder type
Polar net carrys out the resistivity at test site concrete different depth.Detection device of the invention is divided into two, and one is at the scene
It is detected in environment, one is detected in+20 DEG C of isoperibols.Each depth temperature at position to be measured in measure field environment respectively
And resistivity, the resistivity for analyzing this depth when at a temperature below 0 DEG C and the concrete resistance in+20 DEG C of environment of constant temperature
The ratio between rate.If on-site concrete will be flown up with the presence of ice condition, the ratio versus time curve slope, numerical value is fast
Speed increases.Icing, icing amount reach the maximum required time since the situation of change of the curve also would know that concrete, can refer to
Lead the improvement of later period winter construction of concrete scheme.Therefore, the present invention is used for the non-destructive testing of concrete early freezc.In addition,
The present invention can be obtained by the comparison of the foundation soil resistivity for the summer and winter that severe cold area measures winter frost penetration with
And degree of enduring cold, present invention may also apply to the detections of severe cold area frozen soil.
Detailed description of the invention
Fig. 1 is operation schematic diagram of the present invention；
Fig. 2 is one structural schematic diagram of test device of the invention；
Fig. 3 is the structural schematic diagram of test device two in concrete sample of the present invention；
Fig. 4 is the relation curve of resistivity ratio, temperature and time when concrete is endured cold；
Fig. 5 is the ratio between 0.6 ratio of mud concrete resistivity, temperature versus time curve；
Fig. 6 is to add NaNO2Concrete resistivity ratio, temperature versus time curve；
Component names involved in above-mentioned figure and label are summarized as follows:
Quadrangular frame 1, electrode network 2, temperature measuring device 3, thermocouple 4, conducting wire 5, insulating box 6, control group concrete sample 7,
Test device 1, test device 29, measuring point 10, resistivity tester 11, computer 12.
Specific embodiment
In order to make the objectives, technical solutions and advantages of the present invention clearer, below by shown in the accompanying drawings specific
Embodiment describes the present invention.However, it should be understood that these descriptions are merely illustrative, and it is not intended to limit model of the invention
It encloses.In addition, in the following description, descriptions of well-known structures and technologies are omitted, it is of the invention to avoid unnecessarily obscuring
Concept.
Here, it should also be noted that, in order to avoid having obscured the present invention because of unnecessary details, in the accompanying drawings only
Show the structure and/or processing step closely related with the solution of the present invention, and be omitted with relationship of the present invention less its
His details.
Specific embodiment 1: as shown in Figure 1-Figure 3, a kind of embedded type concrete early freezc icing non-destructive testing side
Method, the method are realized based on temperature measuring device 3, resistivity tester 11 and two test devices, described two tests
Device is test device 1 and test device 29 respectively；
The test device 1 and test device 29 include quadrangular frame 1, and the test device 1 further includes more heat
Galvanic couple 4 and multipair electrode network 2, the test device 29 further include a pair of electrodes net 2；
The specific structure of test device 1 is: two opposite sides in the quadrangular frame 1 are respectively fixed with multipair electrode network
2, and the multipair electrode network 2 is from top to bottom arranged, be all connected with conducting wire 5 on each pair of electrode network 2, the other end of the conducting wire 5 with
The resistivity tester 11 is connected (the contact portion insulating cement of the exposed position and conducting wire 5 of conducting wire 5 and electrode network 2
Sealing, but should ensure that conducting wire 5 and electrode network 2 have good contact), the resistivity tester 11 and 12 input terminal phase of computer
Even (record and analyze the resistivity data of each depth of on-site concrete in real time), it is fixed on the lateral surface of quadrangular frame 1
More thermocouples 4, the measuring point height of more thermocouples 4 are located at the middle part of multipair 2 height of electrode network, more thermocouples 4
The other end is connected (with the temperature change of each depth of monitoring field concrete) with temperature measuring device 3, the temperature measuring device 3 with
12 input terminal of computer is connected (record and analyze the temperature change of each depth of on-site concrete in real time), and test device 1 is used
In test site concrete resistivity and temperature；
The specific structure of test device 29 is: two opposite sides in the quadrangular frame 1 are fixed with a pair of electrodes net 2, should
It connect (the exposed position and conducting wire 5 and electrode network 2 of conducting wire 5 with the resistivity tester 11 by conducting wire 5 to electrode network 2
Contact portion sealed with insulating cement, but should ensure that conducting wire 5 and electrode network 2 have good contact)；Test device 29 is for surveying
Try control group concrete resistivity in insulating box 6；
The method comprises the following steps:
Step 1: as a control group, monitoring is existing respectively for the concrete in setting insulating box 6 identical with on-site concrete match ratio
The resistivity development of resistivity and temperature development and control group concrete at the concrete different depth of field；
The step 1 comprises the concrete steps that,
(1) test device 1 is put into the tested point at scene, the test device 29 is put into insulating box 6, it is described
The temperature setting of insulating box 6 is+20 DEG C (it is required that the inner space of insulating box 6 is sufficiently large, so that the concrete sample of its maintenance
Size be at least in test device 293 times of the size of concrete between a pair of electrodes net 2), thermocouple 4 and temperature are remembered
Record instrument 3 be connected, conducting wire 5 is connected with resistivity tester 11, and by resistivity tester 11 and temperature measuring device 3 respectively with meter
12 input terminal of calculation machine is connected, while pouring the control group concrete in on-site concrete and insulating box 6, when pouring, should will test
Device 1 and test device 29 are vertically arranged, and should be sufficiently vibrated after concreting is complete so that test device 1 and test dress
The concrete set near 29 is sufficiently closely knit；(resistivity tester and temperature measuring device are test equipments, can be remote with concrete
Cheng Xianglian, it is not necessary to be put into insulating box or construction site)
(2) from pouring constantly, the resistivity and temperature of continuous monitoring field concrete are denoted as R respectively1i And T1i ,iFor test
The sequence number of electrode network pair from top to bottom in device 1；The resistivity of continuous monitoring control group concrete simultaneously, is denoted as R2；Meter
Calculate R1i /R2Value at various moments simultaneously does its relation curve with the time；
Step 2: judging whether on-site concrete enters subzero temperature by on-site concrete temperature development, by on-site concrete with
The ratio between control group concrete resistivity judges at this whether concrete endures cold icing；
The step 2 comprises the concrete steps that:
Observe T1i Variation, if T1i > 0, then on-site concreteiA electrode network is in positive warm environment to the concrete of depth,
Without a possibility that freezing of enduring cold；If T1i < 0, then on-site concreteiA electrode network is in subzero temperature ring to the concrete of depth
Border, a possibility that freezing of enduring cold, observes R at this time1i /R2Curve evolution, if R1i /R2Curve is not present and flies up situation,
Then illustrate not endure cold in concrete at this time；If R1i /R2Develop its value at any time to fly up, then the concrete of the depth is herein
Shi Keneng observes R with the presence of ice condition of enduring cold at this time1i /R2Numerical value；If R1i /R2When rising to several hundred or thousands of, this is judged
When inside concrete largely freeze, and R1i /R2Numerical value is bigger, and icing amount is bigger；If R1i /R2Only tens is even more small
When, only a part of ice crystal generates inside concrete at this time at this time for judgement, the not a large amount of glaciations of the water of inside concrete.From
The slope of a curve catastrophe point would know that concrete enters the time in each icing stage, which, which flies up, represents concrete and open
At the time of beginning to freeze, curve no longer increases representated by concrete at the time of reach maximum icing amount.
Specific embodiment 2: as shown in Figure 1-Figure 3, present embodiment be specific embodiment one is made it is further
Illustrate, the spacing between each pair of electrode network 2 in the test device 1 and test device 29 should be at least more than concrete most
(2 spacing of each pair of electrode network, size and material in test device 29 are homogeneous with test device 1 for 3 times of big aggregate size
Together, influenced with to avoid caused by setting difference), the presence to avoid the big aggregate of concrete causes contingency to test data
It influences.
Specific embodiment 3: as shown in Figure 1, Figure 3, present embodiment be specific embodiment one or two is made into
One step illustrates that the installation site of a pair of electrodes net 2 in the test device 29 should be located at control group concrete sample 7 just
Centre, and the size of the control group concrete sample 7 should be at least this to 3 times of the size of concrete block between electrode network 2,
So that the range of transmission path of the electric current in device 29 is identical as the range of the transmission path of device 1, because of the biography of ion
The defeated concrete not only by between electrode network pair directly transmits, and transmission path can also expand to certain outside concrete
Space propagation.
Specific embodiment 4: as shown in Figure 1-Figure 3, this embodiment discloses herein a kind of embedded type concrete early freezc knots
Ice lossless detection method；The method is:
After test device 1 is assembled, the tested point for being put into scene is put into constant temperature after assembling test device 29
In case 6, while the concrete in on-site concrete and insulating box 6 is poured, the concrete in on-site concrete and insulating box 6 is same
One match ratio need to guarantee that test device 1 and test device 29 are in vertical state during pouring.Sufficiently vibrate
Concrete makes the concrete near test device 1 and test device 29 sufficiently closely knit.From pouring constantly, real-time monitoring
Resistivity R at on-site concrete tested point different depth1i With temperature T1i (iFor electrode network from top to bottom in test device 1
Pair sequence number) and insulating box 6 in+20 DEG C of environment the concrete of identical match ratio resistivity R2(as control group is mixed
Coagulate the resistivity of soil), according to T1i Judge on-site concrete tested pointiWhether the temperature of a depth enters subzero temperature；If T1i >
0, then judge that the concrete of the depth is in positive temperature state, a possibility that freezing of not enduring cold；If T1i < 0, then judge concrete
Into state at negative temperature, a possibility that freezing of enduring cold at this time is analyzed the resistivity to concrete as follows.
The resistivity R of each depth of real-time monitoring on-site concrete tested point1i It is identical in+20 DEG C of environment of insulating box to match
The resistivity R of composition and division in a proportion concrete2, and calculate separately the resistance for mutually descending each depth of on-site concrete tested point in the same time and perseverance
The ratio R of the resistivity of identical proportion concrete in+20 DEG C of environment of incubator1i /R2, the relation curve of the ratio and time are made,
Observe the variation tendency of curve.
Come the relation curve of its resistivity ratio and time when illustrating that on-site concrete is endured cold for organizing concrete substantially
Feature.Applying voltage to each pair of electrode network is 1v, and frequency is the alternating current of 1kHz.Electrode network 2 is square, electrode network 2
Length × wide=100mm × 100mm, the distance between each pair of electrode network 2 are 60mm, and the material of electrode network 2 is 316L stainless steel.It is mixed
The ratio of mud for coagulating soil is 0.5, and match ratio is water 165kg/m3, cement 330kg/m3, sand 715kg/m3, stone 1165kg/m3,
In, the partial size (mm of 10 mm≤partial size≤20, that is, diameter) of great Shi and the ratio of gravelstone partial size (5mm≤partial size < 10mm)
For 6:4.The concrete of this match ratio is divided into two groups, one group be placed in immediately after concrete mixes and stirs in -20 DEG C of environment into
Row negative temperature conservation, another group is placed in the positive temperature maintenance of progress in+20 DEG C of environment.By test device 1 in each depth institute
The processing method of obtained resistivity is identical, only enumerates measured by a depth in present embodiment as a result, other depth
Interpretation of result process is identical.Its temperature of negative temperature concrete T is surveyed with test device 11With resistivity R1, measured with test device 29
+ 20 DEG C of resistivity R2, calculate each moment R1/R2And acquired results are drawn in the curve such as Fig. 4.
At the time of 0 moment in Fig. 4 is concreting.0-t1When, the temperature of concrete is higher than 0 DEG C or equal to 0 DEG C,
Concrete does not enter state at negative temperature, R1/R2For 1 or be slightly larger than 1, be greater than 1 because negative temperature concrete resistivity R1With temperature
Reduction and increase, but temperature reduce caused by R1/R2Incrementss are no more than 2, can ignore in this curve.t1Moment mixes
Solidifying soil enters state at negative temperature, at this time R1/R2Start to be gradually increasing until t2, at the time of this representative has just enter into subzero temperature, inside concrete
There is ice crystal to start to generate.Continue to reduce with temperature, R1/R2Climbing speed increase suddenly, until t3Moment negative temperature concrete temperature
When degree is close to -20 DEG C of environment temperature, the ratio between concrete resistivity R1/R2Biggish climbing speed is kept, from t2To t3Short
Ratio rises to 562 by 7 within short 0.34d, resistivity ratio R1/R2The rate of rise be up to 1878, R1/R2Climbing speed
The ice crystal represented inside negative temperature concrete is increased suddenly to mushroom out, inside a large amount of freeze.t3R after moment1/
R2Increase start become slow, R1/R2The slope of rising is kept to 582, and the temperature of concrete is moved closer in environment temperature at this time
- 20 DEG C of degree, the reduction of temperature also gradually slows down, in t3-t4Stage, since the temperature of negative temperature concrete gradually tends towards stability, coagulation
The icing rate of soil gradually decreases.t4After moment, the temperature of negative temperature concrete is kept constant, and inside concrete is not at this time
It is further continued for freezing, R1It keeps constant and R2Since the effect of aquation continues to increase, R1/R2It is reduced with the time.
Be above on-site concrete endure cold icing after R1/R2The characteristic feature changed over time.Wherein, t2To t3R1/R2
Slope increases faster, and it is faster to represent inside concrete icing rate, R1/R2Peak value it is bigger, represent concrete and endure cold the total of icing
It measures bigger.From resistivity ratio R1/R2The curve changed over time also would know that concrete enters the time in each icing stage,
t1Inside concrete does not have ice presence, t before moment1There are ice crystal generation, t after moment in concrete2Moment rapid ice crystal growth,
t3Moment ice-crystal growth is slowed by, t4Moment ice-crystal growth stops, and concrete has reached icing critical at this temperature at this time.
The present invention can judge the situation of enduring cold of concrete according to the resistivity value surveyed.
Specific embodiment 5: as shown in Figure 1, the test device one can also be used in the severe cold area soil body from outward appearance to inner essence freezes
The long-term long-range monitoring of knot and melting process analyzes the high-speed railway subgrade permafrost region roadbed depth of freezing and freezes degree.It will
4 other end of conducting wire in assembled test device 1 is all connected with resistance meter 11, by the thermocouple 4 of test device 1
The other end connects temperature measuring device 3, and test device 1 is embedded in the soil body to be measured, and measurement obtains summer and winter roadbed respectively
For resistance value with the relationship of change in depth, measured resistance is denoted as R respectivelysiAnd Rwi,iIt represents in test device 1 from top to bottom
The sequence number of electrode network pair.The temperature for monitoring each depth of winter roadbed simultaneously, is denoted as Twi。
Work as TwiWhen < 0, the resistance that resistance and summer that winter measures measure is compared, in same depth, if RwiCompare Rsi
It is order of magnitude greater, then it may determine that the roadbed of this depth is endured cold in winter, if RwiWith RsiIn the same order of magnitude, then this
The roadbed of depth is not endured cold in winter.And RwiBigger, roadbed is endured cold more serious.With can obtaining severe cold by this test method
Endure cold depth and the degree of enduring cold of area's winter soil.
Embodiment 1: applying voltage to each pair of electrode network in the present embodiment is 1v, and frequency is the alternating current of 1kHz.Electrode network 2
Length × wide=100mm × 100mm, the distance between each pair of electrode network 2 is 60mm, and the material of electrode network 2 is 316L stainless steel.
The ratio of mud of concrete is 0.6, and match ratio is water 198kg/m3, cement 330kg/m3, sand 715kg/m3, stone 1165kg/m3,
Wherein, the ratio of big stone grain diameter (mm of 10 mm≤partial size≤20) and gravelstone partial size (5mm≤partial size < 10mm) are 6:4.By this
The concrete of match ratio is divided into two groups, and one group is placed in -20 DEG C of environment immediately after concrete mixes and stirs and carries out negative temperature conservation,
Another group is placed in the positive temperature maintenance of progress in+20 DEG C of environment.Utilize resistance measured by test device 1 and test device 29
The ratio between rate and temperature development are shown in Fig. 5.It starts the clock from the concreting moment.
Negative temperature concrete temperature after the completion of pouring starts to reduce, until initially enter subzero temperature environment after 0.23d, resistance at this time
Rate ratio R1/R22.53 are increased to by 1.a1Negative temperature concrete ice crystal starts to generate after point, R1/R2Curve start gradually to increase
It is long, until b133.53 are increased to when point.b1After point 0.30d, R1/R2It increases sharply suddenly, until R when 0.88d1/R2It increases to
1179, it largely freezes in the inner concrete of 0.30d to 0.88d.From R1/R2It can see in growth curve, b1e1The growth speed of section
Rate is higher than d1c1The rate of rise of section, illustrates in b1e1Period inner concrete icing rate be greater than e1c1The knot of section concrete
Ice rate.c1d1Stage R1/R2Rate of rise slow down, represent concrete at this moment already close to freeze be saturated, R1/R2Value
Increase to 1193.1.03d R later1/R2Value be gradually reduced, inside concrete has not continued to freeze at this time.The ratio of mud is
0.6 concrete R1/R2Peak value is 1193, and 0.5 concrete R of the ratio of mud1/R2Peak value be 730,0.6 ratio of mud concrete R1/
R2Peak value be 0.5 ratio of mud concrete R1/R21.63 times, illustrate its inner icing amount of the big concrete of the ratio of mud than water ash
It is more much bigger than small concrete.In addition, concrete (the specific embodiment that concrete and the ratio of mud that the ratio of mud is 0.6 are 0.5
Four) start largely to freeze in 0.30d, the protected working of concrete need to be after concreting in -20 DEG C of environment
It is carried out in preceding 0.3d, otherwise concrete starts largely to freeze to cause to freeze and damage.
Embodiment 2: applying voltage to each pair of electrode network of concrete block in the present embodiment is 1v, and frequency is the exchange of 1kHz
Electricity.The size of electrode network 2 is length × wide=100mm × 100mm, and the distance between each pair of electrode network 2 is 60mm, the material of electrode network 2
Matter is 316L stainless steel.Antifreezing agent NaNO is added in concrete2, volume 5%, remaining Stock allotment right is water 165kg/m3, water
Mud 330kg/m3, sand 715kg/m3, stone 1165kg/m3, wherein big stone grain diameter (mm of 10 mm≤partial size≤20) and gravelstone partial size
The ratio of (5mm≤partial size < 10mm) is 6:4.The concrete of this match ratio is divided into two groups, one group after concrete mixes and stirs
It is placed in -20 DEG C of environment immediately and carries out negative temperature conservation, another group is placed in the positive temperature maintenance of progress in+20 DEG C of environment.Utilize survey
The ratio between resistivity measured by one 8 and test device 29 is set in trial assembly and temperature development is shown in Fig. 6.Since the concreting moment
Calculate the time.
Concrete a from pouring constantly in Fig. 62The temperature decline of point, concrete leads to R1/R21.69 are increased to, due to mixed
NaNO is added in solidifying soil2, freezing point of solution is reduced, the temperature of concrete does not have apparent platform, only in a2The point corresponding moment
The fall off rate of temperature slows down when 0.21d, which is -4.3 DEG C.Hereafter R1/R2Start to increase, inside concrete
Begin with ice crystal generation.NaNO2Addition obviously inhibit the growth of ice crystal so that ice crystal generation phase and rapid ice crystal growth
The differentiation in stage is not obvious, R1/R2Although in a2Compared to 0-a after point2Period rises rapidly, but the amplitude risen
Very small, the R of benchmark group (specific embodiment four) for the benchmark group for not adding antifreezing agent1/R2Peak value is 730, and
Add antifreezing agent NaNO2The R of concrete1/R2Peak value is only 12.25, thus can determine whether do not have in the concrete of addition antifreezing agent
A large amount of continuous ice generates, R1/R2In a2c2The growth in stage is to be generated slowly to develop with it by micro ice crystal to cause
, until c2Point ice crystal development reaches saturation, c2Ice crystal does not continue to grow after point.From this it can be concluded that in addition 5%
NaNO2Concrete in, even if the temperature of negative temperature concrete is at -20 DEG C, inside concrete will not largely freeze.
Claims (3)
1. a kind of embedded type concrete early freezc icing lossless detection method, it is characterised in that: the method is based on temperature
What tester (3), resistivity tester (11) and two test devices were realized, described two test devices are test device respectively
One (8) and test device two (9)；
The test device one (8) and test device two (9) include quadrangular frame (1), and the test device one (8) is also wrapped
More thermocouples (4) and multipair electrode network (2) are included, the test device two (9) further includes a pair of electrodes net (2)；
The specific structure of test device one (8) is: two opposite sides in the quadrangular frame (1) are respectively fixed with multipair electricity
Polar net (2), and the multipair electrode network (2) is from top to bottom arranged, and is all connected with conducting wire (5), the conducting wire on each pair of electrode network (2)
(5) the other end is connected with the resistivity tester (11), and the resistivity tester (11) and computer (12) input
End is connected, and more thermocouples (4), the measuring point height difference of more thermocouples (4) are fixed on the lateral surface of quadrangular frame (1)
Positioned at the middle part of multipair electrode network (2) height, the other end of more thermocouples (4) is connected with temperature measuring device (3), the temperature
Tester (3) is connected with computer (12) input terminal, and test device one (8) is used for test site concrete resistivity and temperature；
The specific structure of test device two (9) is: two opposite sides in the quadrangular frame (1) are fixed with a pair of electrodes net
(2), this connect electrode network (2) by conducting wire (5) with the resistivity tester (11)；Test device two (9) is for testing
Control group concrete resistivity in insulating box (6)；
The method comprises the following steps:
Step 1: the concrete in setting insulating box (6) identical with on-site concrete match ratio monitors respectively as a control group
The change in resistance of resistivity and temperature change and control group concrete at on-site concrete different depth；
The step 1 comprises the concrete steps that,
(1) test device one (8) is put into the tested point at scene, the test device two (9) is put into insulating box (6)
In, the temperature setting of the insulating box (6) is+20 DEG C, thermocouple (4) is connected with moisture recorder (3), by conducting wire (5) and
Resistivity tester (11) is connected, and resistivity tester (11) and temperature measuring device (3) are inputted with computer (12) respectively
End is connected, while pouring the control group concrete in on-site concrete and insulating box (6), should be by test device one (8) when pouring
It is vertically arranged, should sufficiently vibrate after concreting is complete so that test device one (8) and test device two with test device two (9)
(9) nearby concrete is sufficiently closely knit；
(2) from pouring constantly, the resistivity and temperature of continuous monitoring field concrete are denoted as R respectively1i And T1i ,iFor test dress
Set in one (8) sequence number of electrode network pair from top to bottom；The resistivity of continuous monitoring control group concrete simultaneously, is denoted as R2；Meter
Calculate R1i /R2Ratio at various moments draws its relation curve with the time；
Step 2: it may determine that whether on-site concrete enters subzero temperature by on-site concrete temperature monitoring, pass through live coagulation
Soil and the ratio between control group concrete resistivity judge at this whether concrete endures cold icing；
The step 2 comprises the concrete steps that:
Observe T1i Variation, if T1i > 0, then on-site concreteiA electrode network is in positive warm area to the concrete of depth,
Without a possibility that freezing of enduring cold；If T1i < 0, then on-site concreteiA electrode network is in subzero temperature area to the concrete of depth
Between, a possibility that freezing of enduring cold observes R at this time1i /R2Curvilinear motion, if R1i /R2Curve is not present and flies up situation,
Then illustrate not endure cold in concrete at this time；If R1i /R2Extend the presentation of its value at any time to fly up, then the concrete of the depth
At this moment R may be analyzed at this time with the presence of icing phenomenon of enduring cold1i /R2Ratio；If R1i /R2When rising to several hundred or thousands of, sentence
Disconnected inside concrete at this time largely freezes, and R1i /R2Numerical value is bigger, and icing amount is bigger；If R1i /R2Only tens even more
Hour, only a part of ice crystal generates inside concrete at this time at this time for judgement, the not a large amount of glaciations of the water of inside concrete,
It would know that concrete enters the time in each icing stage from the slope of a curve catastrophe point, which, which flies up, represents concrete
At the time of starting to freeze, curve no longer increases representated by concrete at the time of reach maximum icing amount.
2. a kind of embedded type concrete early freezc icing lossless detection method according to claim 1, it is characterised in that:
The spacing between each pair of electrode network (2) in the test device one (8) and test device two (9) should be at least more than concrete most
(3) times of big aggregate size.
3. a kind of embedded type concrete early freezc icing lossless detection method according to claim 1 or 2, feature exist
In: the installation site of a pair of electrodes net (2) in the test device two (9) should be located at control group concrete sample (7) just
Centre, and the size of the control group concrete sample (7) should be at least this to the size of concrete block between electrode network (2)
3 times.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810849736.4A CN108956684B (en) | 2018-07-28 | 2018-07-28 | Embedded concrete early-stage freezing and icing nondestructive testing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810849736.4A CN108956684B (en) | 2018-07-28 | 2018-07-28 | Embedded concrete early-stage freezing and icing nondestructive testing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108956684A true CN108956684A (en) | 2018-12-07 |
| CN108956684B CN108956684B (en) | 2020-11-03 |
Family
ID=64466075
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810849736.4A Active CN108956684B (en) | 2018-07-28 | 2018-07-28 | Embedded concrete early-stage freezing and icing nondestructive testing method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108956684B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109443450A (en) * | 2018-12-24 | 2019-03-08 | 哈尔滨工程大学 | A kind of embedded type concrete resistivity and temperature monitoring device |
| CN109725055A (en) * | 2018-12-30 | 2019-05-07 | 哈尔滨工业大学 | A method of concrete early freezc performance is evaluated using impact elasticity wave |
| CN109740252A (en) * | 2018-12-30 | 2019-05-10 | 哈尔滨工业大学 | It is a kind of to evaluate concrete early freezc performance methodology using Analysis On The Transient Temperature |
| WO2020208471A1 (en) * | 2019-04-09 | 2020-10-15 | Politecnico Di Milano | System for measuring the electrical resistivity of concrete, at different depths, in new and existing structures |
| CN112227155A (en) * | 2020-10-23 | 2021-01-15 | 重庆市交通工程监理咨询有限责任公司 | Winter construction method for highway concrete |
| CN113702713A (en) * | 2021-08-27 | 2021-11-26 | 华北科技学院(中国煤矿安全技术培训中心) | Intelligent monitoring device and method for determining resistivity of grouting material |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2888443Y (en) * | 2006-04-28 | 2007-04-11 | 四川大学 | Concrete damage detector based on impedance imaging |
| CN101382535A (en) * | 2008-09-17 | 2009-03-11 | 东南大学 | Method for testing dough recovery of ecological type porous concrete |
| CN101576587A (en) * | 2009-06-30 | 2009-11-11 | 北京冶建特种材料有限公司 | Measurement method of concrete resistivity and device thereof |
| CN101750167A (en) * | 2009-12-17 | 2010-06-23 | 中国矿业大学 | Freezing temperature sensor and measuring method thereof |
| CN102269725A (en) * | 2011-05-10 | 2011-12-07 | 交通运输部公路科学研究所 | Device and method for testing concrete pouring uniformity and compactness |
| CN102407942A (en) * | 2011-09-06 | 2012-04-11 | 中国商用飞机有限责任公司 | Ice formation condition detector |
| CN102854384A (en) * | 2011-06-30 | 2013-01-02 | 中国科学院寒区旱区环境与工程研究所 | Device for measuring temperature and resistivity distribution in phase-changing process in frozen soil test |
| CN203231994U (en) * | 2013-05-22 | 2013-10-09 | 中山大学 | Device for determining water content of concrete |
| CN104808247A (en) * | 2015-05-11 | 2015-07-29 | 中煤邯郸特殊凿井有限公司 | Detection method of freezing effect |
| US9263170B2 (en) * | 2008-02-20 | 2016-02-16 | Nonwoven Networks Llc | Composite material, heating products and method for making |
-
2018
- 2018-07-28 CN CN201810849736.4A patent/CN108956684B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2888443Y (en) * | 2006-04-28 | 2007-04-11 | 四川大学 | Concrete damage detector based on impedance imaging |
| US9263170B2 (en) * | 2008-02-20 | 2016-02-16 | Nonwoven Networks Llc | Composite material, heating products and method for making |
| CN101382535A (en) * | 2008-09-17 | 2009-03-11 | 东南大学 | Method for testing dough recovery of ecological type porous concrete |
| CN101576587A (en) * | 2009-06-30 | 2009-11-11 | 北京冶建特种材料有限公司 | Measurement method of concrete resistivity and device thereof |
| CN101750167A (en) * | 2009-12-17 | 2010-06-23 | 中国矿业大学 | Freezing temperature sensor and measuring method thereof |
| CN102269725A (en) * | 2011-05-10 | 2011-12-07 | 交通运输部公路科学研究所 | Device and method for testing concrete pouring uniformity and compactness |
| CN102854384A (en) * | 2011-06-30 | 2013-01-02 | 中国科学院寒区旱区环境与工程研究所 | Device for measuring temperature and resistivity distribution in phase-changing process in frozen soil test |
| CN102407942A (en) * | 2011-09-06 | 2012-04-11 | 中国商用飞机有限责任公司 | Ice formation condition detector |
| CN203231994U (en) * | 2013-05-22 | 2013-10-09 | 中山大学 | Device for determining water content of concrete |
| CN104808247A (en) * | 2015-05-11 | 2015-07-29 | 中煤邯郸特殊凿井有限公司 | Detection method of freezing effect |
Non-Patent Citations (4)
| Title |
|---|
| DOUGLAS TOMLINSON等: "Early age electrical resistivity behaviour of various concrete mixtures subject to low temperature cycling", 《CEMENT AND CONCRETE COMPOSITES》 * |
| H. CAI等: "FREEZE-THAW DURABILITY OF CONCRETE: ICE FORMATION PROCESS IN PORES", 《CEMENT AND CONCRETE RESEARCH》 * |
| 秦建敏等: "冰层厚度传感器及其检测方法", 《水科学进展》 * |
| 隋同波等: "电阻率法研究水泥早期行为", 《硅酸盐学报》 * |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109443450A (en) * | 2018-12-24 | 2019-03-08 | 哈尔滨工程大学 | A kind of embedded type concrete resistivity and temperature monitoring device |
| CN109725055A (en) * | 2018-12-30 | 2019-05-07 | 哈尔滨工业大学 | A method of concrete early freezc performance is evaluated using impact elasticity wave |
| CN109740252A (en) * | 2018-12-30 | 2019-05-10 | 哈尔滨工业大学 | It is a kind of to evaluate concrete early freezc performance methodology using Analysis On The Transient Temperature |
| CN109725055B (en) * | 2018-12-30 | 2021-01-26 | 哈尔滨工业大学 | Method for evaluating early-stage freezing performance of concrete by using impact elastic wave |
| CN109740252B (en) * | 2018-12-30 | 2022-05-06 | 哈尔滨工业大学 | Method for evaluating early-stage freezing performance of concrete by utilizing transient temperature field analysis |
| WO2020208471A1 (en) * | 2019-04-09 | 2020-10-15 | Politecnico Di Milano | System for measuring the electrical resistivity of concrete, at different depths, in new and existing structures |
| CN112227155A (en) * | 2020-10-23 | 2021-01-15 | 重庆市交通工程监理咨询有限责任公司 | Winter construction method for highway concrete |
| CN113702713A (en) * | 2021-08-27 | 2021-11-26 | 华北科技学院(中国煤矿安全技术培训中心) | Intelligent monitoring device and method for determining resistivity of grouting material |
| CN113702713B (en) * | 2021-08-27 | 2023-06-13 | 华北科技学院(中国煤矿安全技术培训中心) | Intelligent monitoring device and method for resistivity determination of grouting material |
Also Published As
| Publication number | Publication date |
|---|---|
| CN108956684B (en) | 2020-11-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108956684A (en) | A kind of embedded type concrete early freezc icing lossless detection method | |
| US11454606B2 (en) | Method and systems relating to construction material assessment | |
| CN104631517B (en) | Cast-in-situ bored pile concrete interface monitoring device and method | |
| Barroca et al. | Wireless sensor networks for temperature and humidity monitoring within concrete structures | |
| JP6437645B2 (en) | Real-time test system and test method for cement content of cement stir pile | |
| CN102749386B (en) | System and method for in-situ hydration monitoring and damage detection of concrete structure and sensors used by system and method | |
| KR101433787B1 (en) | Damage Assessment System of In-situ Rock Mass using Acoustic Emission Technique and Assessment Method thereof | |
| CN106970036B (en) | A kind of determination method of pollution severity of insulators degree | |
| RU2580316C1 (en) | Method for determining the number of unfrozen water content in frozen soil | |
| CN108548757B (en) | Method for testing curing temperature curve of continuous reinforced concrete pavement | |
| Michel et al. | 5 years of in situ reinforcement corrosion monitoring in the splash and submerged zone of a cracked concrete element | |
| CN110501386B (en) | Rock burst early warning method based on carbon fiber concrete | |
| CN108709980A (en) | A kind of determination method of fast freeze-thaw cycle and natural Frozen-thawed cycled relationship in concrete room | |
| CN113433155B (en) | Real-time monitoring system and method for unfrozen water of roadbed in cold area | |
| CN107894437B (en) | Method for monitoring hydration process of concrete expansion joint construction in severe cold area | |
| US20230047417A1 (en) | A system for monitoring at least one property of concrete in real time | |
| CN106680315A (en) | Compactness detection method of steel pipe concrete | |
| CN109507400A (en) | A method of utilizing maturity assessment concrete early freezc performance | |
| Fiala et al. | Application of TDR method for moisture profiles measurement in cellular concrete | |
| CN109060870B (en) | Device and method for monitoring early-stage freezing and icing of concrete | |
| Fraile-Garcia et al. | Implementing a technically and economically viable system for recording data inside concrete | |
| Ha et al. | Monitoring concrete compressive strength using IoT-based wireless sensor network | |
| CN108196038A (en) | The test equipment and method of coagulation soil scene mechanics parameter under a kind of practical curing condition | |
| Cheng et al. | Temperature and boundary influence on cement hydration monitoring using embedded piezoelectric transducers | |
| CN109725055A (en) | A method of concrete early freezc performance is evaluated using impact elasticity wave |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |