Special fluidity performance testing device for UHPC (Ultra High Performance Concrete)
By setting a flat or convex unit and an anti-sticking strip in the UHPC fluidity performance test device, the problem of UHPC wall sticking is solved, the test precision is improved, and the accuracy of the UHPC fluidity test is ensured.
Patent Information
- Application Number
- CN202422235729.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-11
- Publication Date
- 2025-09-12
- Estimated Expiration
- 2034-09-11
AI Technical Summary
In the existing technology, UHPC is prone to wall sticking during fluidity testing, resulting in large test errors and the inability to accurately control the amount of wall sticking, affecting test accuracy.
A special fluidity performance test device for UHPC was designed. By setting flat units or convex units on the inner wall of the cylinder, the concrete tension was increased and the contact area with the side wall was reduced. Anti-sticking strips and hydrophobic coatings were used to reduce wall sticking.
It effectively reduces the wall sticking during UHPC testing, improves test accuracy, and ensures the accuracy and reliability of test results.
Smart Images
Figure CN223332839U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of concrete testing, in particular to a special fluidity performance testing device for UHPC. Background Art
[0002] Ultra-high performance concrete (UHPC) has ultra-high mechanical properties and durability and is widely used in concrete testing.
[0003] To ensure consistent quality and performance, projects using UHPC often require simultaneous testing of its extrusion. Extrusion testing is a key indicator for evaluating the fluidity of a concrete mix, primarily measuring its ability to flow and fill formwork under its own weight. Currently, UHPC extrusion testing is conducted based on the extrusion testing method outlined in the "Standard for Test Methods for Performance of Ordinary Concrete Mixtures" (GB / T 50080).
[0004] However, due to the high amount of cement and active cementitious materials used in UHPC, even if it is improved with admixtures to meet the requirements of self-leveling, the viscosity of UHPC material is still much greater than that of ordinary concrete. Therefore, when tested with a traditional concrete slump meter, UHPC exhibits uneven adhesion to the wall and cannot be poured out smoothly and completely like ordinary concrete. Moreover, the amount of adhesion to the wall each time cannot be accurately controlled, resulting in large errors in performance testing.
[0005] Therefore, there is an urgent need to develop a simple, efficient and high-precision UHPC fluidity testing equipment tool. Utility Model Content
[0006] The technical problem to be solved by the utility model is to provide a UHPC-specific fluidity performance testing device to reduce the occurrence of wall sticking during the UHPC testing process.
[0007] To solve the above technical problems, the present invention provides a UHPC-specific fluidity performance testing device, comprising a cylinder, a first accommodating chamber provided therein, the first accommodating chamber comprising a sidewall, the sidewall being provided with at least one of a planar unit and a convex unit, the convex unit convex toward the central axis of the cylinder.
[0008] As an improvement to the above solution, the side wall is formed by enclosing a plurality of the planar units, or the side wall is formed by enclosing a plurality of the convex units.
[0009] As an improvement to the above solution, the cross section of the side wall is a closed ring surrounded by wavy lines or zigzag lines.
[0010] As an improvement of the above solution, the convex unit is extended from one end of the cylinder to the other end of the cylinder, and the extension direction of the convex unit forms a preset angle with the central axis of the cylinder.
[0011] As an improvement to the above solution, the preset angle is 15° to 22°.
[0012] As an improvement to the above solution, each of the planar units is equidistant from the central axis of the cylinder.
[0013] As an improvement of the above solution, a second accommodating cavity is provided in the cylinder body, an anti-sticking strip connected to the cylinder body is provided in the second accommodating cavity, and the planar unit or the convex unit is provided on the anti-sticking strip.
[0014] As an improvement to the above solution, the surface of the anti-stick strip is provided with a hydrophobic coating, or the anti-stick strip is made of a hydrophobic material.
[0015] As an improvement to the above solution, the two ends of the anti-sticking strip are flush with the two ends of the cylinder.
[0016] As an improvement to the above solution, the planar unit or the convex unit is formed on the cylinder.
[0017] As an improvement to the above solution, the length of the first accommodating cavity along the central axis of the cylinder is less than 250 mm.
[0018] The implementation of this utility model has the following beneficial effects:
[0019] The utility model discloses a special fluidity performance testing device for UHPC. By changing the cylinder structure of a traditional concrete slump meter, the side wall of a first accommodating cavity in the cylinder is provided with at least one of a plane unit and a convex unit. The plane unit and the convex unit can help increase the tension of ultra-high performance concrete close to the side wall of the first accommodating cavity, help reduce the actual contact area between the ultra-high performance concrete and the side wall, thereby reducing the occurrence of wall sticking during the test and reducing the test error. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is a schematic diagram of the longitudinal cross-section structure of a UHPC-specific fluidity performance testing device through the central axis of the cylinder;
[0021] Figure 2 This is a schematic top view of the first embodiment of a UHPC-specific fluidity performance testing device of the present invention;
[0022] Figure 3 This is a bottom view structural diagram of a first embodiment of a UHPC-specific fluidity performance testing device of the present utility model;
[0023] Figure 4 This is a bottom view structural diagram of a third embodiment of a UHPC-specific fluidity performance testing device of the present invention. DETAILED DESCRIPTION
[0024] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below with reference to the accompanying drawings.
[0025] like Figures 1 to 4 As shown, the present invention discloses two embodiments of a UHPC-specific fluidity performance testing device, comprising a cylinder 1, wherein a first accommodating cavity 1a is provided in the cylinder 1, wherein the first accommodating cavity 1a comprises a side wall, wherein the side wall is provided with at least one of a planar unit 21 and a convex unit 22, wherein the convex unit 22 protrudes toward the central axis of the cylinder 1.
[0026] This embodiment changes the cylinder structure of the traditional concrete slump meter (the inner wall of which is a truncated cone) so that the side wall of the first accommodating cavity 1a in the cylinder 1 is surrounded by a plurality of planar units 21, or is surrounded by a plurality of convex units 22 convex toward the central axis of the cylinder 1. This helps increase the tension of the ultra-high performance concrete c near the side wall of the first accommodating cavity 1a and helps reduce the actual contact area between the ultra-high performance concrete c and the side wall, thereby reducing the occurrence of wall sticking during the test and reducing test errors.
[0027] The side wall of the first accommodating cavity 1a is preferably formed by enclosing a plurality of planar units 21, or enclosing a plurality of convex units 22, so as to evenly expand the tension of the ultra-high performance concrete c.
[0028] like Figure 2 and Figure 3 As shown, in the first embodiment of the UHPC fluidity performance testing device disclosed in the present invention, the sidewall is formed by a plurality of convex surface units 22, and the cross-section of the sidewall is a closed loop surrounded by wavy or zigzag lines. In other words, the convex surface units 22 are convex arc surfaces or zigzag surfaces.
[0029] The convex unit 22 extends from one end of the cylinder 1 to the other end of the cylinder 1. The extension direction of the convex unit 22 forms a preset angle of 15° to 22° with the central axis of the cylinder 1. The length of the first accommodating cavity 1a along the central axis of the cylinder 1 is less than 250mm. This sidewall inclination is greater than the inclination of the inner sidewall of the cylinder 1 of traditional concrete slump testers. While not affecting the test, it can further help reduce the occurrence of wall sticking during the test.
[0030] In this embodiment, the cylindrical body 1 is provided with a second accommodating cavity 1b, which is provided with a release strip 2 connected to the cylindrical body 1. The convex elements 22 are provided on the release strip 2. Both the first and second accommodating cavities 1a and 1b extend through both ends of the cylindrical body 1. In this embodiment, the arc corresponding to each convex element 22 within the second accommodating cavity 1b is 3° to 10°.
[0031] In this embodiment, the cylinder 1 is provided with a second accommodating chamber 1b. Anti-sticking strips 2 are positioned within this second accommodating chamber 1b and secured to the cylinder 1. The strips 2 are arranged circumferentially along the second accommodating chamber 1b, with the convex sections 22 of the strips 2 enclosing and forming the sidewalls of the first accommodating chamber 1a. The ultra-high performance concrete (UHPCC) contained within the cylinder 1 comes into contact with the convex sections 22 of the strips 2. This increases the tension of the UHPCC, reducing sticking to the wall during testing.
[0032] The surface of the anti-sticking strip 2 is provided with a hydrophobic coating, or the anti-sticking strip 2 is made of a hydrophobic material.
[0033] The anti-sticking strip 2 of this embodiment is a stainless steel anti-sticking strip with a hydrophobic coating on the surface, wherein the hydrophobic coating can be a fluorocarbon coating PTFE, FEP, ECTE, ETFE, PFA, etc. The hydrophobic coating reduces the adhesion between UHPC and the side wall, and can further avoid the occurrence of wall sticking.
[0034] The two ends of the anti-sticking strip 2 are flush with the two ends of the cylinder 1 to ensure that the ultra-high performance concrete c in the cylinder 1 can be poured out smoothly.
[0035] like Figure 4 As shown, in the second embodiment of a UHPC-specific fluidity performance testing device disclosed in the present invention, the sidewall is formed by a plurality of planar units 21, each of which is equidistant from the central axis of the cylinder 1. Each planar unit 21 extends from one end of the cylinder 1 to the other end of the cylinder 1. The extension direction of the planar units 21 forms an angle of 15° to 22° with the central axis of the cylinder 1, and the length of the first accommodating cavity 1a along the central axis of the cylinder 1 is less than 250mm. Compared to the inner sidewall of the cylinder 1 of a traditional concrete slump tester, this sidewall has a greater inclination and a smaller height, which does not affect the test while further helping to reduce wall sticking during the test.
[0036] Traditional concrete, due to its inclusion of coarse aggregate, requires layered pouring and compaction through tamping. The height of the traditional dilatometer used for testing and observing slump and expansion is 300±1mm. UHPC, due to its finer aggregate and self-compacting properties, eliminates the need for tamping; instead, it requires self-leveling and observation of expansion over a specified time. However, when testing the fluidity of high-volume UHPC, uneven fiber aggregation and dispersion in the middle can occur, affecting slurry measurement accuracy. This uneven dispersion can be avoided by reducing the height of the cylinder 1 and increasing the inclination angle of the sidewall of the first chamber 1a.
[0037] In this embodiment, the cylindrical body 1 is provided with a second accommodating cavity 1b, which is provided with a non-stick strip 2 connected to the cylindrical body 1. The planar unit 21 is provided on the non-stick strip 2. The first and second accommodating cavities 1a and 1b both extend through both ends of the cylindrical body 1. In this embodiment, the arc corresponding to each planar unit 21 within the second accommodating cavity 1b is 3° to 10°.
[0038] In this embodiment, the cylinder 1 is provided with a second accommodating chamber 1b. Anti-sticking strips 2 are positioned within this second accommodating chamber 1b and secured to the cylinder 1. The strips 2 are arranged circumferentially along the second accommodating chamber 1b, with the planar elements 21 of the strips 2 enclosing the sidewalls of the first accommodating chamber 1a. The ultra-high performance concrete (UHPC) contained within the cylinder 1 comes into contact with the planar elements 21 of the anti-sticking strips 2. Compared to the concave curved sidewalls of the cylinder 1 of conventional concrete slumpmeters, the sidewalls of the second accommodating chamber 1b formed by the planar elements 21 increase the tension of the UHPC in contact with it, thereby reducing the likelihood of sticking during testing.
[0039] The surface of the anti-stick strip 2 is provided with a hydrophobic coating, or the anti-stick strip 2 is made of a hydrophobic material. The anti-stick strip 2 of this embodiment is a stainless steel anti-stick strip with a hydrophobic coating on the surface, wherein the hydrophobic coating can be a fluorocarbon coating PTFE, FEP, ECTE, ETFE, PFA, etc. The hydrophobic coating reduces the adhesion between the UHPC and the side wall, which can further prevent the occurrence of wall sticking.
[0040] The two ends of the anti-sticking strip 2 are flush with the two ends of the cylinder 1 to ensure that the ultra-high performance concrete c in the cylinder 1 can be poured out smoothly.
[0041] In addition to the above two embodiments, the present invention can also directly form the planar unit 21 or the convex unit 22 on the side wall of the first accommodating cavity 1a, that is, the planar unit 21 or the convex unit 22 is integrally formed with the cylinder 1.
[0042] The fluidity performance testing device of the utility model solves the problem of inaccurate expansion test caused by UHPC wall adhesion. It is suitable for measuring UHPC expansion or expansion loss in various environments, while retaining the lightness and simplicity of the traditional slump bucket, laying a foundation for improving production efficiency and ensuring stable project quality.
[0043] When using the fluidity performance testing device of the present invention to test the fluidity performance of UHPC, the steps are as follows:
[0044] ① Take the UHPC dedicated fluidity performance testing device and wet the inner wall of the first accommodating cavity 1a until there are no obvious water drops on the side wall;
[0045] ② Place the fluidity performance test device on a horizontal and flat surface, fill the expansion barrel with UHPC mixture at one time, and use a scraper to smooth the surface;
[0046] ③ Lift the expansion bucket vertically and start timing. The time taken to lift the bucket should be less than 10 seconds.
[0047] ④ 60s-90s after lifting the bucket, test the two expansion length values in the vertical direction and take the average as the expansion degree of UHPC. If the difference between the two values is greater than 100mm, retest.
[0048] The above disclosure is only a preferred embodiment of the present invention and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope covered by the present invention.
Claims
1. A UHPC-specific fluidity performance testing device, characterized in that: The invention comprises a cylinder, wherein a first accommodating cavity is provided in the cylinder, wherein the first accommodating cavity comprises a side wall, wherein the side wall is provided with at least one of a plane unit and a convex unit, and the convex unit convexes toward the central axis of the cylinder.
2. The UHPC-specific fluidity performance testing device according to claim 1, characterized in that: The side wall is formed by enclosing a plurality of the planar units, or the side wall is formed by enclosing a plurality of the convex units.
3. The UHPC-specific fluidity performance testing device according to claim 1 or 2, characterized in that: The cross section of the side wall is a closed ring surrounded by wavy lines or zigzag lines.
4. The UHPC-specific fluidity performance testing device according to claim 1, characterized in that: The convex unit is extended from one end of the cylinder to the other end of the cylinder, and the extending direction of the convex unit forms a preset angle with the central axis of the cylinder.
5. The UHPC-specific fluidity performance testing device according to claim 1, characterized in that: The distances between each of the planar units and the central axis of the cylinder are equal.
6. The UHPC-specific fluidity performance testing device according to claim 1, characterized in that: A second accommodating cavity is provided in the cylinder body, an anti-sticking strip connected to the cylinder body is provided in the second accommodating cavity, and the planar unit or the convex unit is provided on the anti-sticking strip.
7. The UHPC-specific fluidity performance testing device according to claim 6, characterized in that: The surface of the anti-stick strip is provided with a hydrophobic coating, or the anti-stick strip is made of a hydrophobic material.
8. The UHPC-specific fluidity performance testing device according to claim 6, characterized in that: The two ends of the anti-sticking strip are flush with the two ends of the cylinder.
9. The UHPC-specific fluidity performance testing device according to claim 1, characterized in that: The planar unit or the convex unit is formed on the cylinder.
10. The UHPC-specific fluidity performance testing device according to claim 1, characterized in that: The length of the first accommodating cavity along the central axis of the cylinder is less than 250 mm.