CN201191291Y - Concrete durability experiment device - Google Patents

Concrete durability experiment device Download PDF

Info

Publication number
CN201191291Y
CN201191291Y CNU2008201160510U CN200820116051U CN201191291Y CN 201191291 Y CN201191291 Y CN 201191291Y CN U2008201160510 U CNU2008201160510 U CN U2008201160510U CN 200820116051 U CN200820116051 U CN 200820116051U CN 201191291 Y CN201191291 Y CN 201191291Y
Authority
CN
China
Prior art keywords
chuck
concrete
tensional
stress
concrete sample
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.)
Expired - Lifetime
Application number
CNU2008201160510U
Other languages
Chinese (zh)
Inventor
张云升
孙伟
宋鲁光
左晓宝
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Southeast University
Original Assignee
Southeast University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Southeast University filed Critical Southeast University
Priority to CNU2008201160510U priority Critical patent/CN201191291Y/en
Application granted granted Critical
Publication of CN201191291Y publication Critical patent/CN201191291Y/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Landscapes

  • Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)

Abstract

A concrete durability experimental device relates to a multi-factor durability experimental method and a device for concrete under interaction of tensile stress and environment. The lower portion of a pull rod (8) is connected with a lower pull plate (13), the upper portion of the pull rod (8) penetrates through an upper pull plate (7) and a limit plate (4), the upper pull plate (7) is fixed through a locknut (6) while penetrating through the pull rod (8), a screw cap (2) presses a stress sensor (3) on the limit plate through a spherical screw rod (1), a spring (5) sleeved on the spherical screw rod (1) is located between the limit plate and the upper pull plate, an upper tensional chuck (91) and a lower tensional chuck (92) are arranged between the upper pull plate and the lower pull plate (13), the upper tensional chuck (91) is connected with a ball head portion of the spherical screw rod (1), the lower tensional chuck (92) is connected with a ball head portion of a spherical pull rod (12), a dumbbell-shaped concrete sample (10) is located between the upper tensional chuck (91) and the lower tensional chuck (92), and the dumbbell-shaped concrete sample is clamped through the tensional chuck, both sides of the dumbbell-shaped concrete sample (10) are provided with constant force clamping apparatuses (11) which are connected with a non-metal ultrasonic testing instrument (14).

Description

The concrete durability experimental provision
Technical field
The utility model relates to a kind of concrete multi-factors durability experimental technique and device under tension and environment acting in conjunction, belong to the concrete durability measuring technology.Be mainly used in fields such as building, bridge, water conservancy and traffic.
Background technology
Since half a century, xoncrete structure causes owing to permanance is not enough that the xoncrete structure premature failure is destroyed, the accident of the lost of life but is on the increase, and especially Important Project such as dam, road, bridge, harbour and high-rise do not reach accident that design period just destroys and happen occasionally and cause tremendous economic to lose and casualties.Chinese Academy of Engineering's investigation report shows, causes that owing to steel bar corrosion the direct economic loss of xoncrete structure is up to 1,000 hundred million yuan/year in China.Though the research of relevant concrete durability has decades, mostly research work is the permanance under the effect of consideration single environment destructive factor; Yet on the practical work, the concrete permanance of actual engineering should be moved under stress and varying environment acting in conjunction, permanance research under the single factors effect is difficult to reflect truly objective reality, and concrete permanance is multifactor, is the coefficient results of dual factors at least.In addition, inside concrete damage degradation also anything but each destructive factor separately effect cause simply adding and be worth of damage, but factors influence each other, superpose alternately.Usually concrete degradation acts on the summation that causes damage down separately greater than each impairment factor under the effect of multiple-disruption factor, promptly produce the damage stack rule and the super synergistic effect of 1+1>2,1+2>3, cause the concrete works performance to reduce fast and the lost of life.Therefore, according to concrete environment of living in, weather and load situation in the engineering reality, the principal element that influences permanance is carried out reasonable combination, system carry out dual or the effect of multiple-disruption factor under concrete durability research, reciprocation between quantization factor and factor, be the great science and technology and the theoretical difficult problem of current concrete subject, caused the extensive and great attention of international academic community at present, its achievement in research will produce significant impact to concrete structure durability design and life prediction thereof.
The endurance issues of research concrete under dual and multiple-disruption factor effect, top priority are exactly to set up the test method system that can consider 2 or above destructive factor simultaneously.Consider that in actual engineering, structural concrete is all worked and moved under loaded state.Therefore, under research load and other destructive factor acting in conjunction concrete durability have the important theoretical research meaning and widely under the engineering using value, particularly drawing stress effect concrete permanance research for the unusual key of concrete structure durability design and construction.When setting up the concrete multi-factors durability test method of considering load, have 2 key technical problems to solve: the first, design can apply the test loading system of accurate load to concrete sample; The second, foundation can be carried out continuously the concrete sample that loads, nondestructive test method fast and data acquisition system (DAS).
Both at home and abroad concrete permanance research is less under the counter stress effect, the discovery of being not difficult of comprehensive existing documents and materials, and existing charger all is to apply bending stress, Shang Weiyou directly applies the test unit of axial tensile stress.Its main cause has two: the design of test processing that 1. applies drawing stress is very difficult, cannot say for sure to demonstrate,prove in test, the axis of tension sample overlaps with the tensile load active line, occur eccentric phenomena especially easily, cause test findings to have very big discreteness; 2. tension sample and stretching chuck are easy to generate stress in clamping place and concentrate, and cause sample to destroy in clamping place, rather than break in the centre.
Above-mentioned shortcoming has seriously limited the widespread use in the concrete multi-factors durability experiment of direct drawing stress charger.Therefore, development is applicable to concrete sample, and can keep holding for a long time in the lotus process unstressed loose easy to be small and exquisite drawing stress experimental provision has important use and is worth in multi-factors durability research, also provide the experimental apparatus of science for the concrete structure durability evaluation, prospect is very wide.
Summary of the invention
Technical matters: the purpose of this utility model is the deficiency and the defective that exist in the existing durability test technology, utilize spring loading principle and sensor technology, by spherical pull bar connected mode, develop a kind of dumbbell shape concrete sample that is applicable to, and can keep unstressed loose, easy small and exquisite concrete durability experimental provision in the long-term drawing process.
Technical scheme: concrete durability experimental provision of the present utility model comprises: cone worm, nut, strain gauge, limiting plate, spring, set nut, last arm-tie, pull bar, stretching chuck, dumbbell shape concrete sample, constant force clamping instrument, sphere pull bar, lower pulling plate, nonmetal ultrasonic tesint instrument; In this device, the bottom of pull bar is connected with lower pulling plate, arm-tie and limiting plate are passed in the top of pull bar, last arm-tie is through on the pull bar to be fixed by set nut, nut is pressed in strain gauge on the limiting plate by cone worm, spring housing is on the cone worm and between limiting plate and last arm-tie, be provided with the chuck that stretches between last arm-tie and the lower pulling plate, following stretching chuck, last stretching chuck partly is connected with the bulb of cone worm, following stretching chuck partly is connected with the bulb of sphere pull bar, the dumbbell shape concrete sample is positioned at the stretching chuck, between the following stretching chuck, by stretching chuck clamping dumbbell shape concrete sample, be provided with constant force clamping instrument in the both sides of dumbbell shape concrete sample, constant force clamping instrument is connected with nonmetal ultrasonic tesint instrument.Constant force clamping instrument comprises support, stage clip, and support is the U font, and stage clip has two, lays respectively in the U font support to right both sides.
Characteristics of the present utility model are as follows:
1, the solution of eccentricity issues in the drawing process
During stretching experiment, entirely accurate can not be accomplished in the location of anchor clamps or power transmission rod member, and the upper and lower end line of web member exists geometric eccentricity not on same straight line at this moment.The pulling force that applies in order to guarantee is the axle center tensile load, and the utility model reduces from following three aspects or eliminates geometric eccentricity:
1) adopts punching block, process meticulously, guarantee that the specimen molding physical dimension is accurate;
2) the stretching chuck links to each other with two universal spherical joints (spherical pull bar);
3) before stretching experiment formally begins test specimen is carried out repeatedly prestretching.
2, the solution of clamping place problem of stress concentration
Tension sample and stretching chuck are easy to generate stress in clamping place and concentrate, and cause sample to destroy in clamping place, rather than break in the centre.Concentrate the generation that causes the middle phenomenon of breaking of test specimen in order to eliminate stress, the concrete sample that the present invention adopts is a dumbbell shape, and end and center section have reduced stress and concentrated by arc-shaped transition, have avoided the generation of test from chuck destruction.
3, the solution of the stress relaxation problem of tensile loading device in holding the lotus process for a long time
To a certain extent can be although spring is carried in by the loose problem of the distortion release portion component of stress of self, but can not eliminate fully, during particularly for the dual and multiple factor Experimental Investigation on Durability under loading, freeze thawing, the etchant solution compound action, more serious in the later stage owing to concrete sample internal injury deterioration, a large amount of crackles have been produced, test piece deformation is bigger, causes that comparatively serious stress is loose, alleviates by the distortion of spring self this moment can not solve.
For solving the stress relaxation problem of holding for a long time in the lotus process, the utility model specialized designs and made the belt stress sensor, be installed in above the spring by cone worm, its lead-in wire links to each other with computing machine, monitor stress changes in real time, in case stress loss surpasses 5% in holding the lotus process for a long time, then tightening nuts makes it to return to the virgin stress value.
4, the solution of the transmitting terminal of the supersonic sounding instrument and the instrument of moving and receiving terminal and concrete sample contact problems
For the multi-factors durability test, the test of the ultrasound parameter and the modulus of moving is the important indicator of research concrete sample degree of injury.Therefore, significant to its correct test.Discover, when the tester to transmitting terminal and receiving terminal externally applied forces not simultaneously, it is different to cause transmitting terminal and receiving terminal and concrete sample to contact tightness degree, causing has 5% difference approximately to the test result of same test specimen.In order to eliminate test error, processed one " constant force clamping instrument " specially.Two springs that rigidity is identical are arranged in this clamping instrument, when test, closely contact with concrete sample with receiving terminal by the elastic compression detection instrument of ultrasonic spring and the transmitting terminal of the instrument of moving.Because the length of each test specimen is identical, the elastic force that spring applies during therefore each the test is identical, has so just avoided artificial test error.
5, the not solution of degree of injury test problem under the unloaded state
Also special headspace between the stretching chuck of the utility model stretching device and the test specimen end face, be used to place the transmitting terminal and the receiving terminal of the supersonic sounding instrument and the instrument of moving, can carry out direct, continuous moving and ultrasonic performance test to the concrete sample (promptly not unloading) of stress state, need not unload the back test, the process that test is reloaded after finishing again, thus guaranteed that test findings fully reacts the Damage and Failure state under the stress state.
Beneficial effect:
1. charger takies volume little (long 165mm * wide 75mm * high 560mm), can utilize existing carbonization case, freezing-thawing test machine, baking oven, chemical corrosion experimental box etc. to carry out the multi-factors durability test, and satisfy the requirement of test in enormous quantities in a short time.
2. satisfy big test specimen (100mm * 100mm * 400mm), heavily stressed loading requirement than (reaching as high as stress ratio 0.8).
3 adopt stainless steel design fully, avoid charger generation corrosion occurring in process of the test and the appearance that causes the stress loss situation.
4. adopt spring to load, method is simple, and real monitoring STRESS VARIATION during the applied stress sensor, can guarantee in the loading procedure unstressed lax.
5. adopt the sphere bar to link on the stretching chuck, the axis of tension sample overlaps with the tensile load active line in the warranty test.
6. dumbbell shape is made in the end of sample, and end and center section are avoided causing the generation of sample at clamping place breakoff phenomenon because stress is concentrated by arc-shaped transition.
Description of drawings
Concrete multi-factors durability experimental device under Fig. 1 tension and the environment acting in conjunction.
Fig. 2 constant force clamping instrument synoptic diagram.
Fig. 3 adopts the concrete outcome of the case 1 of the utility model device enforcement.A: mass change, b: the modulus change of moving,
Fig. 4 adopts the concrete outcome of the case 2 of the utility model device enforcement.
Embodiment
The utility model is described in further detail below in conjunction with accompanying drawing:
This device comprises: cone worm 1, nut 2, strain gauge 3, limiting plate 4, spring 5, set nut 6, last arm-tie 7, pull bar 8, stretching chuck, dumbbell shape concrete sample 10, constant force clamping instrument 11, sphere pull bar 12, lower pulling plate 13, nonmetal ultrasonic tesint instrument 14; In this device, the bottom of pull bar 8 is connected with lower pulling plate 13, arm-tie 7 and limiting plate 4 are passed in the top of pull bar 8, last arm-tie 7 is through on the pull bar 8 fixing by set nut 6, nut 2 is pressed in strain gauge 3 on the limiting plate 4 by cone worm 1, spring 5 is enclosed within on the cone worm 1 and between limiting plate 4 and last arm-tie 7, between last arm-tie 7 and lower pulling plate 13, be provided with stretching chuck 91, following stretching chuck 92, last stretching chuck 91 partly is connected with the bulb of cone worm 1, following stretching chuck 92 partly is connected with the bulb of sphere pull bar 12, dumbbell shape concrete sample 10 is positioned at stretching chuck 91, between the following stretching chuck 92, by stretching chuck clamping dumbbell shape concrete sample 10, be provided with constant force clamping instrument 11 in the both sides of dumbbell shape concrete sample 10, constant force clamping instrument 11 is connected with nonmetal ultrasonic tesint instrument 14.Constant force clamping instrument 11 comprises support 15, stage clip 16, and support 15 is the U font, and stage clip 16 has two, lays respectively in the U font support 15 to right both sides.
At first process the rectangle lower pulling plate, and in two ends and centre tapping respectively; Thin end and butt end at two pull bars processes screw thread respectively then, and butt end is screwed in the screw at lower pulling plate two ends; The stretching chuck is fixed on the middle part of lower pulling plate by the sphere pull bar, then dumbbell shape concrete sample two ends is installed on the stretching chuck; Two ends and centre at last arm-tie process three circular holes respectively, then it are passed the thin end of two pull bars, and will go up arm-tie with set nut and fix; Cone worm is passed the center of arm-tie, put spring, and the limiting plate that two ends and center have a circular hole is passed the thin end of pull bar be placed on the spring; Be through the ring-type strain gauge on the cone worm respectively then; The nut of screwing on afterwards.For constant force clamping instrument, process U font support earlier; So, be used to pass the test cap lead-in wire of nonmetal ultrasonic tesint instrument at two circular holes of support both sides processing; Then two stage clips are welded on support two surveys respectively, stage clip center and circular hole centres.
When carrying out stress-environment coupling experiment, at first get six concrete samples with proportioning, wherein get three and carry out direct stretching experiment, obtain average tensile strength as one group; Utilize tensile loading device shown in Figure 1 that remaining three concrete samples are applied axial tensile stress then.Adopt Material Testing Machine lentamente cone worm to be applied pulling force until the regulation stress ratio when stress applies, keep this pulling force constant then with constant rate of speed, and rapid tightening nuts.Link to each other with the computing machine variation of real-time monitor stress of the lead-in wire of strain gauge, in case stress loss surpasses 5%, then tightening nuts makes it to return to the virgin stress value.The concrete sample that will have charger behind the loaded places in the test cabin of permanance devices such as standard carbonization case, freezing-thawing test instrument, baking oven and chemical corrosion case, carries out stress, carbonization, freeze thawing, does the coupled in common effect of dual or multiple-disruption factor such as wet and chemical corrosion.Every regular hour or circulation, the concrete sample that will have charger takes out, and test mass changes under situation about not unloading, and utilizes constant force clamping instrument and nonmetal ultrasonic tesint instrument to test the variation of concrete ultrasound parameter then.
Experiment 1:
Concrete mix (kg/m 3): cement-280, flyash-185, sand-705, stone-1117, water-160, high-efficiency water-reducing agent of poly-carboxylic acid-3.2
By said ratio, after adopting forced stirrer to mix thoroughly, with fresh concrete water for internal mold be that (end is 100mm * 100mm * 80mm dumbbell for the punching block of dumbbell shape, the centre is among 70mm * 70mm * 210mm), shaking table vibration 30s, the demoulding after 24h is left standstill in the laboratory, (temperature (20 ± 3 ℃, relative humidity more than 90%) maintenance is taken out to regulation the length of time then then concrete sample to be put into standard curing room.With the MTS810 experimental machine the good concrete sample of maintenance being carried out tensile strength test, is 0.001mm/s by control loaded speed during experiment.According to recording tensile strength, concrete sample is applied 0.35 stress level (tension/ultimate tensile stress that applies) respectively.The concrete sample that will have charger behind the loaded places the fast freeze-thaw experimental box, carries out stress-freeze thawing circulation coupling durability experiment.Record under stress-freeze thawing circulation coupling concrete damage deterioration process as shown in Figure 3.
Experiment 2:
Concrete mix (kg/m 3): cement-280, flyash-185, sand-705, stone-1117, water-160, high-efficiency water-reducing agent of poly-carboxylic acid-3.2
By said ratio, after adopting forced stirrer to mix thoroughly, with fresh concrete water for internal mold be that (end is 100mm * 100mm * 80mm dumbbell for the punching block of dumbbell shape, the centre is among 70mm * 70mm * 210mm), shaking table vibration 30s, the demoulding after 24h is left standstill in the laboratory, (temperature (20 ± 3 ℃, relative humidity more than 90%) maintenance is taken out to regulation the length of time then then concrete sample to be put into standard curing room.With the MTS810 experimental machine the good concrete sample of maintenance being carried out tensile strength test, is 0.001mm/s by control loaded speed during experiment.According to recording tensile strength, concrete sample is applied 0.20,0.35,0.50,0.65,0.80 six stress level (tension/ultimate tensile stress that applies) respectively.The concrete sample that will have charger behind the loaded places the corrosion case that fills NaCl=3.5% (mass percent) solution to soak 12 months, carries out stress-chlorine salt corrosion experiment.Record that stress-the villaumite Diffusion Law as shown in Figure 4.

Claims (2)

1, a kind of concrete durability experimental provision, it is characterized in that in this device, the bottom of pull bar (8) is connected with lower pulling plate (13), arm-tie (7) and limiting plate (4) are passed in the top of pull bar (8), last arm-tie (7) is through pull bar (8) and goes up by set nut (6) fixing, nut (2) is pressed in strain gauge (3) on the limiting plate (4) by cone worm (1), spring (5) is enclosed within on the cone worm (1) and is positioned between limiting plate (4) and the last arm-tie (7), between last arm-tie (7) and lower pulling plate (13), be provided with stretching chuck (91), following stretching chuck (92), last stretching chuck (91) partly is connected with the bulb of cone worm (1), following stretching chuck (92) partly is connected with the bulb of sphere pull bar (12), dumbbell shape concrete sample (10) is positioned at stretching chuck (91), between the following stretching chuck (92), by stretching chuck clamping dumbbell shape concrete sample (10), be provided with constant force clamping instrument (11) in the both sides of dumbbell shape concrete sample (10), constant force clamping instrument (11) is connected with nonmetal ultrasonic tesint instrument (14).
2, the described concrete durability experimental provision of claim 1 is characterized in that constant force clamping instrument (11) comprises support (15), stage clip (16), and support (15) is the U font, and stage clip (16) has two, lays respectively at the introversive right both sides of U font support (15).
CNU2008201160510U 2008-05-16 2008-05-16 Concrete durability experiment device Expired - Lifetime CN201191291Y (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CNU2008201160510U CN201191291Y (en) 2008-05-16 2008-05-16 Concrete durability experiment device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CNU2008201160510U CN201191291Y (en) 2008-05-16 2008-05-16 Concrete durability experiment device

Publications (1)

Publication Number Publication Date
CN201191291Y true CN201191291Y (en) 2009-02-04

Family

ID=40335454

Family Applications (1)

Application Number Title Priority Date Filing Date
CNU2008201160510U Expired - Lifetime CN201191291Y (en) 2008-05-16 2008-05-16 Concrete durability experiment device

Country Status (1)

Country Link
CN (1) CN201191291Y (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101271103B (en) * 2008-05-16 2010-12-22 东南大学 Experimental device for concrete multifactor permanent stability under co-action of pulling stress and surroundings
CN102608296A (en) * 2012-02-17 2012-07-25 浙江大学 Device and method for simulating and monitoring expanding and cracking of concrete
CN103487512A (en) * 2013-09-11 2014-01-01 同济大学 Ultrasonic probe pressing fixing device
CN104330319A (en) * 2014-11-04 2015-02-04 水利部交通运输部国家能源局南京水利科学研究院 Testing device capable of coupling stress field and chemical field
CN104792626A (en) * 2015-04-21 2015-07-22 东南大学 Experimental device of FRP rib durability under stretching stress and environment coupling effect
CN106932276A (en) * 2017-03-16 2017-07-07 沈阳工业大学 The axial tension test device of cement-base composite material test specimen
CN108527640A (en) * 2018-04-25 2018-09-14 湖北沛函建设有限公司 Prestressing force method for preparing fabricated member

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101271103B (en) * 2008-05-16 2010-12-22 东南大学 Experimental device for concrete multifactor permanent stability under co-action of pulling stress and surroundings
CN102608296A (en) * 2012-02-17 2012-07-25 浙江大学 Device and method for simulating and monitoring expanding and cracking of concrete
CN102608296B (en) * 2012-02-17 2014-08-20 浙江大学 Device and method for simulating and monitoring expanding and cracking of concrete
CN103487512A (en) * 2013-09-11 2014-01-01 同济大学 Ultrasonic probe pressing fixing device
CN104330319A (en) * 2014-11-04 2015-02-04 水利部交通运输部国家能源局南京水利科学研究院 Testing device capable of coupling stress field and chemical field
CN104792626A (en) * 2015-04-21 2015-07-22 东南大学 Experimental device of FRP rib durability under stretching stress and environment coupling effect
CN104792626B (en) * 2015-04-21 2018-07-20 东南大学 Tensile stress and FRP tendons endurance quality experimental provision under environment coupled action
CN106932276A (en) * 2017-03-16 2017-07-07 沈阳工业大学 The axial tension test device of cement-base composite material test specimen
CN106932276B (en) * 2017-03-16 2024-02-23 沈阳工业大学 Axial tensile test device of cement-based composite material test piece
CN108527640A (en) * 2018-04-25 2018-09-14 湖北沛函建设有限公司 Prestressing force method for preparing fabricated member

Similar Documents

Publication Publication Date Title
CN101271103B (en) Experimental device for concrete multifactor permanent stability under co-action of pulling stress and surroundings
CN101275892B (en) Concrete multi-factors durability experimental device under bent tension stress and environment coupled action
CN201191291Y (en) Concrete durability experiment device
CN201181268Y (en) Concrete durability test instrument
CN101482477B (en) Test device and method for concrete permeability coefficient under action of pulling stress
CN102980839B (en) Device and method for determination of permeability coefficient of chloride ions in concrete
CN102721637B (en) Multi-functional test system and method for concrete durability under action of continuous pressure
CN102519871B (en) Method and device for measuring bonding strength between reinforcing steel and concrete under action of pre-stress
CN110441145B (en) Tunnel lining concrete durability test method
CN102778389A (en) Concrete test loading device and test method under load and multifactor coupling
CN110702509B (en) Cement-based material continuous loading device for durability test
CN108535100A (en) A kind of damage quantitative evaluation method of armored concrete test specimen
CN205209870U (en) Concrete durability research is with axle load provides device
CN102778397A (en) Loading device and method for durability test of compression concrete
CN112945726B (en) Split Hopkinson bar pulling/pressing-twisting dynamic composite loading device and operation method
CN101915807B (en) Ultrasonic testing auxiliary device in nonmetallic material failure process
CN105699190A (en) Test device for testing stress relaxation of FRP (fiber reinforced plastic) cloth
CN205607767U (en) Test FRP cloth stress relaxation's device
CN202814778U (en) Concrete experiment loading device under coupling effect of load and multiple factors
CN104132878A (en) Method and device for testing permeability of cement-based material under action of axial tension load
CN116359014A (en) System and method for detecting strength of juvenile concrete
CN105716949A (en) Method for testing stress relaxation of FRP (fiber reinforced plastic) fabric
CN201716299U (en) Ultrasonic test auxiliary device for destroying process of nonmetal materials
CN108204921A (en) A kind of device that concrete is made to generate uniform tension damage
CN208076278U (en) A kind of device for making concrete generate uniform tension damage

Legal Events

Date Code Title Description
C14 Grant of patent or utility model
GR01 Patent grant
AV01 Patent right actively abandoned

Granted publication date: 20090204

Effective date of abandoning: 20080516