CN108490160A - A kind of detection method of cement mortar early-age shrinkage - Google Patents
A kind of detection method of cement mortar early-age shrinkage Download PDFInfo
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- CN108490160A CN108490160A CN201810190345.6A CN201810190345A CN108490160A CN 108490160 A CN108490160 A CN 108490160A CN 201810190345 A CN201810190345 A CN 201810190345A CN 108490160 A CN108490160 A CN 108490160A
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- 239000011083 cement mortar Substances 0.000 title claims abstract description 39
- 238000001514 detection method Methods 0.000 title claims abstract description 25
- 238000005259 measurement Methods 0.000 claims abstract description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 12
- 239000002002 slurry Substances 0.000 claims description 9
- 239000010445 mica Substances 0.000 claims description 8
- 229910052618 mica group Inorganic materials 0.000 claims description 8
- 239000004033 plastic Substances 0.000 claims description 8
- 229920003023 plastic Polymers 0.000 claims description 8
- 239000011888 foil Substances 0.000 claims description 7
- 239000000463 material Substances 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 4
- 239000002985 plastic film Substances 0.000 claims description 4
- 229920006255 plastic film Polymers 0.000 claims description 4
- 238000007789 sealing Methods 0.000 claims description 4
- 239000000853 adhesive Substances 0.000 claims description 3
- 230000001070 adhesive effect Effects 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 3
- 210000002615 epidermis Anatomy 0.000 claims description 2
- 238000005070 sampling Methods 0.000 claims description 2
- 238000012546 transfer Methods 0.000 claims description 2
- 230000005611 electricity Effects 0.000 claims 1
- 238000000034 method Methods 0.000 abstract description 15
- 239000004568 cement Substances 0.000 abstract description 10
- 238000012360 testing method Methods 0.000 abstract description 8
- 230000008602 contraction Effects 0.000 abstract description 7
- 238000005516 engineering process Methods 0.000 abstract description 3
- 239000004035 construction material Substances 0.000 abstract description 2
- 239000004570 mortar (masonry) Substances 0.000 description 8
- 238000001723 curing Methods 0.000 description 5
- 239000003638 chemical reducing agent Substances 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 238000006703 hydration reaction Methods 0.000 description 4
- 239000002518 antifoaming agent Substances 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 230000036571 hydration Effects 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 238000010998 test method Methods 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000010881 fly ash Substances 0.000 description 1
- 238000013007 heat curing Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000011017 operating method Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000001029 thermal curing Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Classifications
-
- 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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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Medicinal Chemistry (AREA)
- Food Science & Technology (AREA)
- Ceramic Engineering (AREA)
- Physics & Mathematics (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- On-Site Construction Work That Accompanies The Preparation And Application Of Concrete (AREA)
Abstract
The invention belongs to construction material detection technology fields, and in particular to a kind of detection method of cement mortar early-age shrinkage solves the test problem of cement mortar early-age shrinkage.It mainly by electronic gauge and corollary equipment automatic measurement and records the length of cement mortar and changes with time, reflect the contraction size of cement mortar early stage.It can relatively accurately be measured under various curing conditions using this method, the contraction that cement mortar early stage occurs（Or expansion）, it is also suitable in the early-age shrinkage for measuring cement paste（Or expansion）.The present invention is suitable for actual production and scientific research.
Description
Technical field
The invention belongs to construction material detection technology fields, and in particular to a kind of detection side of cement mortar early-age shrinkage
Method.It is always shunk because of caused by the reasons such as hydrated cementitious, drying, temperature change suitable for test cement mortar early stage（Or it is swollen
It is swollen）.
Background technology
In recent years, China's economy is grown rapidly, and building industry goes from strength to strength, application of the cement mortar in technical field of buildings
Increasingly extensively.The major gelled material of cement mortar is cement, the early stage caused by cement itself aquation and curing condition etc.
It shrinks, many obstacles is brought in practical application to cement mortar.The early-age shrinkage of cement mortar mainly include chemical shrinkage, from
Contraction, dry contraction and temperature shrinkage, chemical shrinkage refer to the reduction for the substance volume in hydration process for participating in hydration reaction,
Self-constriction and dry contraction are to cause free water amount in pore to reduce due to hydration reaction consumption water and dry dehydration respectively,
So that slurry internal relative humidity reduces, internal capillary tension is caused to increase to form internal stress, to the Mortar shrinkage generated
Deformation, temperature shrinkage is due to hydration heat or care environments make inside mortar or surface temperature changes to the heat generated
Swollen shrinkage phenomenon.In cement mortar condensation hardened early, its structure has had certain intensity, and shrinks so that slurry volume subtracts
It is small, stress is formed inside cement paste structure, eventually leads to structure crack.It is big in construction industry from efficient and high-performance water reducing agent
Since range applications, the water-cement ratio of cement mortar significantly declines, and problem of Cracking is more serious caused by early-age shrinkage.
Existing Mortar shrinkage detection method is roughly divided into volumetric method and length, two class of height method：Volumetric method directly measures
The external volume of slurry calculates the contraction of slurry by the variation of external volume；Length, height method are by by cement slurry body
Long-pending variation is converted to the measurement of length or height to calculate the contraction of slurry.Volumetric method is intuitive and variable is less, so it is surveyed
Test result is more accurate for length, height method, but method implements more difficulty；Although the operation letter of length, height method
List and result is easy to get, but because converting volume change to length or height change, Transformation Program and variable are excessive, last experiment
As a result accuracy is relatively low.These types of method is not suitable for cement mortar early-age shrinkage under heat curing condition（Or expansion）Survey
Examination, and operation is more complex, the degree of automation is low, more demanding to experimenter's operative skill.Further, since by mortar early stage
The limitation of stability and complexity is shunk, industry there is no generally acknowledged detection mortar early-age shrinkage accurately and effectively method.
Invention content
It is an object of the invention to solve the problems, such as current cement mortar early-age shrinkage detection, one kind is provided in different maintenances
Under the conditions of, it can accurately measure and the detection method of simple and practical cement mortar early-age shrinkage.
The detection method of cement mortar early-age shrinkage proposed by the present invention, is detected using detection device, the detection
Device is made of measurement pipe, temperature control system and measurement-recording system, wherein：Measurement pipe by hard tube body and the close fitting of pipe cap,
Adhesive seal is used in combination, has graduation mark away from sealing at pipe end 250mm, applies and oil in stereoplasm tube body, it will be in 30cm × 22cm
The heat-sealing of layer plastic foil side is put into stereoplasm tube body, is bonded with hard inboard wall of tube body, is poured the slurry upper cover upper epidermis after jolt ramming
Plastic foil is used in combination mica sheet to be adjacent to compacting；Electronic gauge is accurate to 0.001mm, using battery powered, can connect data line,
Its data measured is received and is recorded by the USB of computer by data box in real time.The detection device can be in 20 DEG C~90 DEG C temperature
It is used under the conditions of degree.It is as follows：
（1）Electronic gauge, data line, data box, VGA are turned into USB converter, computer is sequentially connected, open detection module and
Whether checking data line transfer normally, the time interval of record data is arranged in electronic gauge after errorless；
（2）Oiling in measurement pipe, then it is inserted in ready interior plastic film, so that it is bonded with inside pipe wall is measured；
（3）Cement mortar is poured into measurement pipe at graduation mark, covers table by the cement mortar that mixing need to detect as requested
Layer plastic foil, and upper mica sheet is pressed to make its fitting；
（4）The measurement pipe for being loaded into cement mortar puts temperature controlled water bath case into, and fixed plate is used in combination to fix, and electronics is fixed with magnetic stand
Micrometer makes its gauge head perpendicular to horizontal plane, surveys screw top and live mica sheet and be pressed into 2-3mm；
（5）Temperature controlled water bath case parameter is opened and is arranged on demand, and each electronic gauge registration resets and clicks " opening for software immediately
Begin to sample ", automatically record data；
（6）Stop sampling to the time for needing to detect, preserves data.The shrinkage value of surveyed cement mortar is calculated, unit mass
Cement mortar is from moment t0It is as follows to the accumulative shrinkage value calculation formula generated of certain moment t：ε =× 1000, whereinεTo receive
Contracting value, unit 10-3, result of calculation is accurate to 0.01 × 10-3, s and s0Respectively t moment and t0The data of moment record.
In the present invention, step（1）Middle sample is tested by group, and every group of at least three sample takes the average value conduct of its measured value
The shrinkage value of this group of sample（Or swell value）, result of calculation is accurate to 0.01 × 10-3。
It is had the following advantages using this test method detection cement mortar early-age shrinkage：
1. the measurement of data and recording fully automated, operating method is simple, of less demanding to experimenter's operative skill, centainly
Reduce in degree since the error in experimenter's operative skill is to resulting adverse effect, to improving the accurate of result
Property is advantageous.
2. the data channel due to data box is more, it can generally be carried out at the same time 4 groups or more of Mortar shrinkage detection work
Make, do not interfere with each other between data channel, according to experiment needs, while different groups measured can be compared, and improve experiment material
The service efficiency of material and instrument.
3. since gauge head has been pressed into 2-3mm, range 10mm to electronic gauge before start recording, therefore the device was both
The early-age shrinkage value of cement paste or mortar can be tested, its early expansion value can be also tested, heat is supported in being tested with reply
The demand of shield.
3. experimental rig is all simple and easy to get, measuring cylinder making is simple and of low cost, and data line and data box etc. can be repeatedly
Using the long period, and interface has versatility, is suitable for other experimental provisions.
4. testing, the data obtained precision is higher, and for error within the scope of permission, test repeatability is preferable, and reliability is high.
5. measurement pipe is elongated and surface area is big, when experiment needs thermal curing, interior temperature is managed compared to the temperature in temperature controlled water bath case
Degree variation lag is small.
6. being cement mortar and cement paste early-age shrinkage（Or expansion）Detection provide a kind of reliable method.
Description of the drawings
Fig. 1 is schematic structural view of the invention.
Fig. 2 is 1 shrinkage value of embodiment（Or swell value）Datagram.
Fig. 3 is 2 shrinkage value of embodiment（Or swell value）Datagram.
Fig. 4 is 3 shrinkage value of embodiment（Or swell value）Datagram.
Figure label：1 is electronic gauge, and 2 be measurement pipe, and 3 be temperature controlled water bath case, and 4 be hard tube body, and 5 be pipe cap, 6
It is surface layer plastic foil for interior plastic film, 7,8 be mica sheet, and 9 be magnetic stand, and 10 be stomata, and 11 be data box, and 12 be USB,
13 be fixed plate.
Specific implementation mode
It is further illustrated the present invention below by embodiment.
Embodiment 1
As shown in Figure 1, detection device is made of measurement pipe 1, electronic gauge 2, temperature controlled water bath case 3 and data transmission set, pipe
Body and pipe cap cover merging adhesive seal, and mortar by plastic film wrapped and is bonded completely.
To moisten inside pipe wall with oil immersion first and to be inserted in plastic foil for use, 3 groups of data channel of connection simultaneously open electronic gauge, if
It sets every 30s and records a data.It according to the match ratio mixing cement mortar of table 1, pours into pipe, is carved until in slurry surface and pipe
Line is spent to overlap.Plastic foil and mica sheet are covered, fixed each electronic gauge resets start recording after registration.Curing temperature heats up
120min to 85 DEG C, constant temperature 480min, it is naturally cooling to 25 DEG C later, overall process about 18h.Test data such as Fig. 2.
1 embodiment of table, 1 cement mortar mix ratio
| Number | Cement/g | Slag powders/%* | Flyash/%* | Sand/g | Water/g | Plain edition water-reducing agent/%* |
| 1 | 1215 | 0 | 0 | 1350 | 422.82 | 0.25 |
| 2 | 850.5 | 10 | 20 | 1350 | 422.82 | 0.25 |
| 3 | 850.5 | 20 | 10 | 1350 | 422.82 | 0.25 |
* the percentage of cementitious material quality is accounted for
Embodiment 2
Test method and embodiment 1 are consistent, and from embodiment 1 difference lies in the match ratio of cement mortar is different, plain edition is subtracted
Aqua is changed to early-strength water-reducing agent, and is not spiked with admixture.Coordinate such as table 2, curing condition and embodiment 1 in the present embodiment
In it is consistent.Test data such as Fig. 3.
2 embodiment of table, 2 cement mortar mix ratio
* the percentage of cementitious material quality is accounted for
Embodiment 3
That difference lies in cement mortar mix ratios is different from embodiment 1, mixes antifoaming agent by trial, studies different antifoaming agent volumes
To cement mortar under the curing condition early-age shrinkage（Or expansion）Influence.Coordinate such as Fig. 3.Curing condition in the present embodiment
With it is consistent in embodiment 1.Test data such as Fig. 4.
3 embodiment of table, 3 match ratio
| Number | Cement/g | Normal sand/g | Water/g | Plain edition water-reducing agent/%* | Antifoaming agent/%* |
| 1 | 1215 | 1350 | 422.82 | 0.25 | 0 |
| 2 | 1215 | 1350 | 422.82 | 0.25 | 0.04 |
| 3 | 1215 | 1350 | 422.82 | 0.25 | 0.05 |
* the percentage of cementitious material quality is accounted for
Claims (2)
1. a kind of detection method of cement mortar early-age shrinkage, is detected, the detection device is by measuring using detection device
Pipe, temperature control system and measurement-recording system composition, it is characterised in that：Measurement pipe is used in combination by hard tube body and the close fitting of pipe cap
Adhesive seal has graduation mark away from sealing at pipe end 250mm, applies and oil in stereoplasm tube body, the inner layer of 30cm × 22cm is moulded
The heat-sealing of material film side is put into stereoplasm tube body, is bonded with hard inboard wall of tube body, is poured the slurry upper cover upper epidermis plastics after jolt ramming
Film is used in combination mica sheet to be adjacent to compacting；Electronic gauge is accurate to 0.001mm, using battery powered, can connect data line, surveys
The data obtained are received and are recorded by the USB of computer by data box in real time, and the detection device can be in 20 DEG C~90 DEG C temperature strips
It uses, is as follows under part：
（1）Electronic gauge, data line, data box, VGA are turned into USB converter, computer is sequentially connected, open detection module and
Electronic gauge checks data line transfer, and record data time interval is arranged；
（2）Oiling in measurement pipe, then it is inserted in ready interior plastic film, so that it is bonded with inside pipe wall is measured；
（3）Cement mortar is poured into measurement pipe at graduation mark, covers table by the cement mortar that mixing need to detect as requested
Layer plastic foil, and upper mica sheet is pressed to make its fitting；
（4）The hard tube body for being loaded into cement mortar puts temperature controlled water bath case into, and fixed plate is used in combination to fix, and electricity is fixed with magnetic stand
Sub- micrometer makes its gauge head perpendicular to horizontal plane, surveys screw top and live mica sheet and be pressed into 2-3mm；
（5）Temperature controlled water bath case parameter is opened and is arranged on demand, and each electronic gauge registration resets and clicks " opening for software immediately
Begin to sample ", automatically record data；
（6）Stop sampling to the time for needing to detect, preserve data, calculates the shrinkage value of surveyed cement mortar, unit mass
Cement mortar is from moment t0It is as follows to the accumulative shrinkage value calculation formula generated of certain moment t：ε=× 1000, whereinεTo receive
Contracting value, unit 10-3, result of calculation is accurate to 0.01 × 10-3, s and s0Respectively t moment and t0The data of moment record.
2. a kind of cement mortar Early self-shrinkage detection method according to claim 1, it is characterised in that：Step（1）In
Sample is tested by group, and every group of at least three sample takes shrinkage value of the average value of its measured value as this group of sample（Or expansion
Value）, result of calculation is accurate to 0.01 × 10-3。
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810190345.6A CN108490160A (en) | 2018-03-08 | 2018-03-08 | A kind of detection method of cement mortar early-age shrinkage |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810190345.6A CN108490160A (en) | 2018-03-08 | 2018-03-08 | A kind of detection method of cement mortar early-age shrinkage |
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| CN108490160A true CN108490160A (en) | 2018-09-04 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111323567A (en) * | 2020-03-16 | 2020-06-23 | 同济大学 | Cement paste chemical shrinkage testing device and application thereof |
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| CN102226803A (en) * | 2011-04-06 | 2011-10-26 | 同济大学 | Detection method of early autogenous shrinkage of cement mortar |
| CN202267429U (en) * | 2011-09-28 | 2012-06-06 | 浙江省交通工程建设集团有限公司 | Tester for vertical expansion ratio of prestressed grouting |
| CN103163286A (en) * | 2013-03-13 | 2013-06-19 | 浙江建设职业技术学院 | Measuring system for self-constriction of early-age concrete |
| CN203101381U (en) * | 2012-12-25 | 2013-07-31 | 郭健 | Novel concrete early-age shrinkage deformation tester |
| CN205280718U (en) * | 2015-10-12 | 2016-06-01 | 广西交通科学研究院 | Device of precision measurement cement concrete dry shrinkage |
| CN106932559A (en) * | 2017-04-06 | 2017-07-07 | 燕山大学 | A kind of test method for evaluating cement paste shrinkage |
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2018
- 2018-03-08 CN CN201810190345.6A patent/CN108490160A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1963503A (en) * | 2006-11-03 | 2007-05-16 | 北京工业大学 | Measuring apparatus for rate of self-contraction of cement concrete |
| CN101122596A (en) * | 2007-09-04 | 2008-02-13 | 中交四航工程研究院有限公司 | Concrete cracking sensitivity test device and anti-crack ability evaluation method |
| CN201508358U (en) * | 2009-09-23 | 2010-06-16 | 交通部公路科学研究所 | Early expansion and contraction tester of concrete road slab bottom grouting material |
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| CN202267429U (en) * | 2011-09-28 | 2012-06-06 | 浙江省交通工程建设集团有限公司 | Tester for vertical expansion ratio of prestressed grouting |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111323567A (en) * | 2020-03-16 | 2020-06-23 | 同济大学 | Cement paste chemical shrinkage testing device and application thereof |
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