CN201535771U - Three-dimensional constrained test device for measuring drying-shrinkage cracking resistance performance of cement concrete - Google Patents
Three-dimensional constrained test device for measuring drying-shrinkage cracking resistance performance of cement concrete Download PDFInfo
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- CN201535771U CN201535771U CN2009200475378U CN200920047537U CN201535771U CN 201535771 U CN201535771 U CN 201535771U CN 2009200475378 U CN2009200475378 U CN 2009200475378U CN 200920047537 U CN200920047537 U CN 200920047537U CN 201535771 U CN201535771 U CN 201535771U
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Abstract
The utility model relates to a three-dimensional constrained test device for measuring the drying-shrinkage cracking resistance performance of cement concrete. Six circular holes are respectively arranged on the circular rings of a top plate and a bottom plate of the device. Firstly, six reinforcing steel bars penetrate through the six circular holes on the bottom plate respectively and then are respectively fixed by using six sleeving nuts, an inner cylinder and an outer cylinder are arranged on the circular ring of the bottom plate, cement concrete is poured into a cylinder cavity between the inner cylinder and the outer cylinder and is compactly tamped by vibration, afterwards the top plate is flatly arranged at the tops of the cylinders, and six reinforcing steel bars are respectively inserted into the six circular holes on the circular ring of the top plate and are respectively screwed and fixed by using six sleeving nuts, wherein the sleeving nuts comprise inner nuts, outer nuts and screws. The device acts as a constraint function to the plastic deformation of the cement concrete in three directions, thereby judging the drying-shrinkage cracking resistance performance of the cement concrete more accurately by observing the generation of cracks. Moreover, the utility model has the characteristics of simple structure and strong practicability.
Description
Technical field
The utility model relates to the cement concrete test unit, specifically relates to a kind of three-dimensional constraining test unit of measuring cement concrete in the anti-dry shrinkage and cracking performance in sclerosis stage.
Background technology
At present, many researchs for the cement concrete plastic shrinkage cracking are arranged both at home and abroad.Yet, often require too high or cost is higher to experimental facilities, as the capacitance micrometer method, be three-dimensional constraining; Or testing equipment is simple but measure rough accuracy deficiency, as ring method, is two-dimensional constrains.Ring method is cast in cement concrete between inner core (7) and the urceolus (1) (accompanying drawing 3), and vertical direction does not retrain cement concrete.And can produce the appearance that drying shrinkage cause crackle in the cement concrete hydration process, if just simple two-dimensional constraint, test specimen can produce deformation at vertical direction and cause directly that crack number is few, the crack is little, even does not observe crackle.
Summary of the invention
The purpose of this utility model is to provide a kind of three-dimensional constraining test unit of measuring the anti-dry shrinkage and cracking performance of cement concrete.
For achieving the above object, understanding existing cement concrete drying shrinkage detecting instrument in depth, careful analysis influences after the basic reason of its cracking, and the utility model combines hydrated cementitious chemistry and reinforced concrete principles of soil mechanics, and original annulus mensuration is improved.The utility model makes the cement concrete test specimen in the ring method rise to three constraints by two-dimensional constrains, has improved the accuracy of measuring, thereby can judge the anti-dry shrinkage and cracking performance of cement concrete more accurately.By in cement concrete, arranging reinforcing bar, and reinforcing bar is fixed on the top board and base plate at annulus two ends, thereby reaches the purpose of the vertical free end constraint of test specimen by nut.This device not only can play the three-dimensional constraining effect, and test unit is simple, cost is lower, easy to operate.
A kind of three-dimensional constraining test unit of measuring the anti-dry shrinkage and cracking performance of cement concrete, the top board (3) and the base plate (4) that it is characterized in that this device are annular, even equidistant 6 circular holes (6) that are drilled with on annulus, earlier 6 reinforcing bars (2) are passed respectively in 6 circular holes (6) on the base plate (4), be enclosed within the lower end of 6 reinforcing bars (2) respectively with 6 cover loading nuts (5), 6 reinforcing bars are tightened, inner core (7) and urceolus (1) are placed on respectively on the annulus of base plate (4), casting cement concrete in the tube chamber (8) between inner core (7) and urceolus (1), and vibration compacting, again top board (3) is lain in the top of inner core (7) and urceolus (1), respectively 6 reinforcing bars (2) are interted in last 6 circular holes of top board (3) (6), be enclosed within the upper end of reinforcing bar respectively with 6 cover loading nuts (5), tighten and fix 6 reinforcing bars.
Described cover loading nut (5) is made of inner nut (9), outer nut (11) and screw, wherein the lateral surface central authorities of the nut head of inner nut (9) are by a round hole of inserting reinforcing bar (2), a screw hole (10) is arranged on the side, and with the circle hole communicate, the medial surface of nut head is threaded Nut pole, outer nut (11) is enclosed within on the Nut pole of inner nut (9), and screws.
The utility model is a kind of three-dimensional constraining test unit of measuring the anti-dry shrinkage and cracking performance of cement concrete, and its problem that mainly solves is how to eliminate the vertical plastic shrinkage of cement concrete test specimen.In specific implementation process, can not carry out the defective of longitudinal restraint to test specimen at the conventional roundabout test unit, improve.Calculate cement in conjunction with the chemistry of cement principle and shrink internal stress, the combined with steel reinforced concrete mechanics principle calculates the rational ratio of reinforcement.Reinforcing bar is evenly distributed in the ring-type cement concrete, has guaranteed that test specimen bears uniform internal stress.The plastic deformation internal force of cement concrete passes to inner core and urceolus by reinforcing bar, thereby operative constraint is carried out in vertical plastic deformation to test specimen, and three-dimensional constraining has been guaranteed in the constraint of inner core and urceolus in addition.In addition, this device application suite nut is fixed on reinforcing bar on top board and the base plate.The application of this cover loading nut has been avoided reinforcing bar itself is carried out complicated screw thread treatment process, has strengthened the practicality of this device.
This device plays effect of contraction from three directions to the plastic yield of cement concrete, thereby can judge the anti-dry shrinkage and cracking performance of cement concrete by the generation of observation crackle more accurately.Anti-shrinkage cracking performance to research and observation water cement concrete has directive significance.
Description of drawings
Fig. 1 is the front elevation of the three-dimensional constraining test unit of the anti-dry shrinkage and cracking performance of measurement cement concrete.
Fig. 2 is the vertical view of base plate or top board.
Fig. 3 is an apparatus main body---the vertical view in urceolus, inner core and tube chamber.
Fig. 4 is the cover loading nut.Wherein, (a-1) for the front view of cover loading nut, (a-2) being the side view of cover loading nut, (b-1) is the front view of the outer nut of cover loading nut, (b-2) for overlapping the vertical view of loading nut.
Reference numeral: 1---urceolus
2---reinforcing bar
3---top board
4---base plate
5---the cover loading nut
6---circular hole is used for reinforcing bar and passes
7---inner core
8---the tube chamber is used for the casting cement concrete
9---inner nut
10---screw hole
11---outer nut.
Embodiment
The utility model attempts at utmost to improve the convenience and the reusability of experimental provision when reducing the test observation error.The utility model has been considered the fluctuation of cement concrete water cement ratio and intensity when design, calculate economical and the satisfactory ratio of reinforcement, and adopts reinforcing bar to be symmetrically distributed, and has guaranteed the even distribution of cement concrete internal stress.
Specific embodiment: at first 6 reinforcing bars 2 are fixed on the base plate 4 by cover loading nut 5, promptly, earlier 6 reinforcing bars 2 are passed 6 circular holes 6 on the base plate 4 respectively, be enclosed within reinforcing bar one end with inner nut 9, and it is fastening that screw is inserted screw hole 10, thereafter outer nut 11 is enclosed within on the inner nut 9 nut outside bars, further fastening.Inner core 7 and urceolus 1 are placed on the base plate 4 casting cement concrete in the tube chamber 8 between inner core 7 and urceolus 1, vibration compacting.Then top board 3 is lain against the tube top of urceolus and inner core, respectively 6 reinforcing bars 2 are inserted on the top boards 3 in 6 circular holes, earlier inner nut 9 is enclosed within the end of reinforcing bar 2, screw is inserted screw hole 10 and tighten, after outer nut 11 is placed on the threaded Nut pole of inner nut 9 outer rims, screw.Because the existence of reinforcing bar 2 makes the cement concrete in the chamber 8 be delivered on inner core 7 and the urceolus 1 by top board 3 and base plate 4 its acting force, so this device has effectively fettered vertical plastic deformation of cement concrete, the requirement of more Pass Test principle.Avoided situation because of crackle that the test specimen longitudinal deformation causes is difficult to observe even portion cracks.When treating form removal, screw off cover loading nut 5, remove inner core 7 and urceolus 1.Subsequently, can adopt equipment such as scanner that situations such as the crackle width on cement concrete test specimen surface, length, density are carried out the statistics of system, the relevant crack requirement of contrast concrete shrinkage cracking can be evaluated this concrete anti-dry shrinkage and cracking performance.
The single unit system of this enforcement adopts steel.Example size is as follows:
Urceolus 1 internal diameter 374mm, wall thickness 20mm, inner core 7 internal diameter 254mm, wall thickness 25mm, top board 3 and base plate 4 internal diameter 250mm, external diameter 420mm, thickness of slab 20mm; Reinforcing bar 2 diameter 6mm, length is 170mm～180mm, cover loading nut 5 comprises inner nut 9, outer nut 11 and screw three parts; Inner nut 9 external diameter 9mm wherein, outer nut 11 internal diameters by 8.8mm to the 9mm even variation, the about 4mm of screw hole 10 diameters.
In addition, the design of cover loading nut has been avoided reinforcing bar is carried out the complicated technology that screw thread is handled in the utility model, makes general testing laboratory just can carry out this test, improved greatly test unit practicality, convenience, reach the popularization of this device in the future.And the detachability of nut also this device possess very high repeatability.
This device plays effect of contraction from three directions to the plastic yield of cement concrete, thereby can judge the anti-dry shrinkage and cracking performance of cement concrete by the generation of observation crackle more accurately.Anti-shrinkage cracking performance to research and observation water cement concrete has directive significance.
Claims (2)
1. three-dimensional constraining test unit of measuring the anti-dry shrinkage and cracking performance of cement concrete, the top board (3) and the base plate (4) that it is characterized in that this device are annular, even equidistant 6 circular holes (6) that are drilled with on annulus, earlier 6 reinforcing bars (2) are passed respectively in 6 circular holes (6) on the base plate (4), be enclosed within the lower end of 6 reinforcing bars (2) respectively with 6 cover loading nuts (5), 6 reinforcing bars are tightened, inner core (7) and urceolus (1) are placed on respectively on the annulus of base plate (4), casting cement concrete in the tube chamber (8) between inner core (7) and urceolus (1), and vibration compacting, again top board (3) is lain in the top of inner core (7) and urceolus (1), respectively 6 reinforcing bars (2) are interted in last 6 circular holes of top board (3) (6), be enclosed within the upper end of reinforcing bar respectively with 6 cover loading nuts (5), tighten and fix 6 reinforcing bars.
2. test unit according to claim 1, it is characterized in that described cover loading nut (5) is made of inner nut (9), outer nut (11) and screw, wherein the lateral surface central authorities of the nut head of inner nut (9) are by a round hole of inserting reinforcing bar (2), a screw hole (10) is arranged on the side, and with the circle hole communicate, the medial surface of nut head is threaded Nut pole, outer nut (11) is enclosed within on the Nut pole of inner nut (9), and screws.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009200475378U CN201535771U (en) | 2009-07-17 | 2009-07-17 | Three-dimensional constrained test device for measuring drying-shrinkage cracking resistance performance of cement concrete |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009200475378U CN201535771U (en) | 2009-07-17 | 2009-07-17 | Three-dimensional constrained test device for measuring drying-shrinkage cracking resistance performance of cement concrete |
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| Publication Number | Publication Date |
|---|---|
| CN201535771U true CN201535771U (en) | 2010-07-28 |
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| CN2009200475378U Expired - Fee Related CN201535771U (en) | 2009-07-17 | 2009-07-17 | Three-dimensional constrained test device for measuring drying-shrinkage cracking resistance performance of cement concrete |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102297821A (en) * | 2011-05-23 | 2011-12-28 | 中国水电顾问集团中南勘测设计研究院 | Detection apparatus for impermeability of hardened concrete under constraint state, and method thereof |
| CN103257220A (en) * | 2012-02-22 | 2013-08-21 | 北京中企卓创科技发展有限公司 | Concrete early-stage crack resistance test device and test method |
| CN103558103A (en) * | 2013-11-08 | 2014-02-05 | 伊犁师范学院 | Method for detecting hydration reaction of cement based on liquid-state reed vibration mechanics spectrum method |
| CN109975120A (en) * | 2019-04-18 | 2019-07-05 | 中国建筑材料科学研究总院有限公司 | Concrete restraint stress and deformational stress measuring device and measuring method |
-
2009
- 2009-07-17 CN CN2009200475378U patent/CN201535771U/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102297821A (en) * | 2011-05-23 | 2011-12-28 | 中国水电顾问集团中南勘测设计研究院 | Detection apparatus for impermeability of hardened concrete under constraint state, and method thereof |
| CN103257220A (en) * | 2012-02-22 | 2013-08-21 | 北京中企卓创科技发展有限公司 | Concrete early-stage crack resistance test device and test method |
| CN103558103A (en) * | 2013-11-08 | 2014-02-05 | 伊犁师范学院 | Method for detecting hydration reaction of cement based on liquid-state reed vibration mechanics spectrum method |
| CN103558103B (en) * | 2013-11-08 | 2015-12-09 | 伊犁师范学院 | The method of hydrated reaction of cement is detected based on liquid spring vibration mechanics spectral method |
| CN109975120A (en) * | 2019-04-18 | 2019-07-05 | 中国建筑材料科学研究总院有限公司 | Concrete restraint stress and deformational stress measuring device and measuring method |
| CN109975120B (en) * | 2019-04-18 | 2021-07-20 | 中国建筑材料科学研究总院有限公司 | Concrete constraint stress and deformation stress measuring device and measuring method |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20100728 Termination date: 20130717 |