1. The preparation device of the centrifugal concrete standard test piece is characterized by comprising a test piece mold mounting fixing frame (3), a power device (1) and a speed change device (4), wherein a plurality of test piece mold bins (31) are uniformly embedded into the outer edge of the test piece mold mounting fixing frame (3), each test piece mold bin (31) is used for fixing a corresponding test piece mold (311), and concrete is injected into each test piece mold (311);

the central shaft fixed mounting of test piece mould installation mount (3) has transmission shaft (11), power device (1) is connected with transmission shaft (11) transmission through speed change gear (4), power device (1) is used for driving transmission shaft (11) and rotates to through the direction of rotation and the slew velocity of speed change gear (4) control test piece mould installation mount (3), speed change gear (4) are used for controlling the drive ratio between power device (1) and transmission shaft (11).

2. The apparatus for preparing a centrifugal concrete standard specimen according to claim 1, wherein: and a limiting device is arranged in the test piece mold bin (31), and is used for applying pressure to the outer wall of the test piece mold (311) and fixing the test piece mold (311) at a preset position.

3. The apparatus for preparing a centrifugal concrete standard specimen according to claim 2, wherein: the limiting device comprises a plurality of threaded rods and fixing bolts (312), the fixing bolts (312) are arranged on the side wall of the test piece mold bin (31), the threaded rods penetrate through the fixing bolts (312) and extend into the inner space of the test piece mold bin (31), and the threaded rods are in threaded connection with the fixing bolts (312) and are used for controlling the length of the threaded rods extending into the inner space of the test piece mold bin (31);

after the test piece mold (311) is placed at a preset position in the test piece mold bin (31), the end part of the threaded rod is utilized to compress the side wall of the test piece mold (311) to complete the positioning of the test piece mold (311) by adjusting the extending lengths of the threaded rods in different directions.

4. The apparatus for preparing a centrifugal concrete standard specimen according to claim 3, wherein: the test piece mold (311) comprises a cylindrical side wall, a cover plate (3111) and a compacting plate (3112), wherein the section of the cylindrical side wall comprises a polygon and a circle; the cover plate (3111) is detachably connected with the cylindrical side wall and used for sealing the cylindrical side wall; the compacting plate (3112) is arranged in the columnar side wall, the cover plate (3111) and the compacting plate (3112) are connected through a compression spring (3113), the extending direction of the compression spring (3113) is the centrifugal force direction when the test piece mold mounting fixing frame (3) rotates, and a gap exists between the compacting plate (3112) and the columnar side wall.

5. The apparatus for preparing a centrifugal concrete standard specimen according to claim 1, wherein: test piece die holding mount (3) vertical setting, bearing (111) are all installed at transmission shaft (11) both ends, and bearing (111) at transmission shaft (11) both ends are all installed on fixed baseplate (2), fixed baseplate (2) be used for supporting test piece die holding mount (3).

6. The apparatus for preparing a centrifugal concrete standard specimen according to claim 5, wherein: the transmission shaft (11) is fixedly connected with the test piece die mounting fixing frame (3) through a positioning pin, and the transmission shaft (11) and the test piece die mounting fixing frame (3) synchronously rotate.

7. The apparatus for preparing a centrifugal concrete standard specimen according to claim 5, wherein: the fixed base (2) adopts a steel truss framework, the bottom of the fixed base (2) is fixedly provided with or provided with a balance weight, and the height of the bearing (111) in the fixed base (2) is larger than the maximum rotating radius of the test piece die mounting fixing frame (3).

8. The apparatus for preparing a centrifugal concrete standard specimen according to claim 1, wherein: the speed change device (4) comprises a driving wheel and a driven wheel which are coaxially arranged, an output shaft of the power device (1) is in transmission connection with the driving wheel of the speed change device (4) through a transmission belt, the driven wheel of the speed change device (4) is in transmission connection with the transmission shaft (11) through the transmission belt, the transmission ratio of the driving wheel to the driven wheel is a preset value, and the power device (1) comprises an electric drive motor and a fuel engine.

9. The method for preparing a centrifugal concrete standard specimen using the centrifugal concrete standard specimen preparation device according to claim 1, characterized in that: the method comprises the following specific steps:

step 1, adopting a mixed concrete mixture with the same mixing ratio for producing the centrifugal hollow pile, accurately calculating the concrete consumption required by preparing a standard test piece according to the size of the standard test piece, pouring concrete into a test piece mold (311) according to the calculated concrete consumption, and sealing the test piece mold (311) by using a cover plate (3111) and a compacting plate (3112);

step 2, placing the test piece mold (311) into the test piece mold bin (31), and fixing the test piece mold (311) in the test piece mold bin (31) through a threaded rod and a fixing bolt (312);

and 3, enabling the standard test piece to have the same r x w as the hollow pile in centrifugal rotation according to the same principle of centrifugal effect²Wherein r is a rotation radius, w is a rotation angular velocity, the power device (1) is driven, the speed change device (4) is adjusted to enable the test piece die mounting fixing frame (3) to rotate according to the rotation angular velocity obtained through calculation, and the rotation time is consistent with the rotation time of the centrifugal hollow pile;

and 4, taking down the standard test piece formed under the action of the rotary centrifugal action, and curing under the same curing conditions as those of the centrifugal hollow pile to finally obtain the centrifugal concrete standard test piece.

Background

The uplift pile is widely applied to the anti-floating of a large basement, the uplift of a wharf platform, the anchor pile foundation of a suspension bridge and a cable-stayed bridge, the pile foundation of a dock floor of a large ship and the like, and generally comprises a hollow square pile and a hollow tubular pile. The hollow square pile and the hollow tubular pile are usually formed by centrifugation, the concrete of the pile body is formed compactly by strong centrifugal force, higher strength can be obtained in early age, and the method is obviously different from the common concrete vibration forming. Therefore, the concrete standard sample formed by vibration is used for detecting the strength and the durability of the hollow pile concrete, and a large error exists. And carry out the compressive strength test through cutting the pile body, on the one hand, the cutting of stake needs professional equipment, and the transportation cutting is inconvenient, and on the other hand, because pile body cross section size is great, the concrete intensity is high, and the load value of required loading equipment is big very much, generally needs 10000 kN's load-carrying capacity, will bring equipment expensive, detects inconvenient problem. In addition, because the whole service cycle of the pile is underground, especially under the marine environment or other erosion environments, the durability of the pile body is also a problem which needs to be considered, and the development of durability tests of impermeability, freeze thawing and the like of hollow pile concrete is also urgently needed. The standard samples required by durability tests such as impermeability, freeze thawing and the like are more difficult to prepare by cutting the hollow pile, no implementation case is found at present, and the practical difficulties greatly obstruct the performance detection of the concrete of the hollow pile, restrict the economic production activity of the hollow pile and bring certain hidden danger to the safety of pile foundation engineering.

Therefore, the concrete standard sample with the same performance as the centrifugal hollow pile is prepared, corresponding performance tests are carried out, and the method has important significance for obtaining effective parameters of the bearing capacity and the durability of the pile body and guiding the safe and economic production of the hollow pile.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a preparation device of a centrifugal concrete standard test piece, and the preparation device of the centrifugal concrete standard test piece can be used for preparing a concrete standard test piece with the performance similar to that of the centrifugal hollow pile body concrete through the same centrifugal process, so that the quality of the centrifugal hollow pile can be detected more truly.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

the preparation device of the centrifugal concrete standard test piece is characterized by comprising a test piece mold mounting fixing frame, a power device and a speed change device, wherein a plurality of test piece mold bins are uniformly embedded into the outer edge of the test piece mold mounting fixing frame, each test piece mold bin is used for fixing a corresponding test piece mold, and concrete is injected into the test piece mold;

the central shaft of the test piece die mounting fixing frame is fixedly provided with a transmission shaft, the power device is in transmission connection with the transmission shaft through a speed change device, the power device is used for driving the transmission shaft to rotate and controlling the rotation direction and the rotation speed of the test piece die mounting fixing frame through the speed change device, and the speed change device is used for controlling the transmission ratio between the power device and the transmission shaft.

And a limiting device is arranged in the test piece mold bin and is used for applying pressure to the outer wall of the test piece mold and fixing the test piece mold at a preset position.

The limiting device comprises a plurality of threaded rods and fixing bolts, the fixing bolts are arranged on the side wall of the test piece mold bin, the threaded rods penetrate through the fixing bolts and extend into the internal space of the test piece mold bin, and the threaded rods are in threaded connection with the fixing bolts and are used for controlling the length of the threaded rods extending into the internal space of the test piece mold bin;

after the test piece mold is placed at the preset position in the test piece mold bin, the threaded rods in different directions are adjusted to stretch into the test piece mold bin, and the end portions of the threaded rods are used for tightly pressing the side wall of the test piece mold to complete positioning of the test piece mold.

The test piece mold comprises a columnar side wall, a cover plate and a compacting plate, wherein the section of the columnar side wall comprises a polygon and a circle; the cover plate is detachably connected with the columnar side wall and is used for sealing the columnar side wall; the compaction plate is arranged in the columnar side wall, the cover plate is connected with the compaction plate through a compression spring, the extension direction of the compression spring is the centrifugal force direction when the test piece die mounting fixing frame rotates, and a gap exists between the compaction plate and the columnar side wall. In the centrifugation process, concrete mixture is because centrifugal force is closely knit gradually, and the volume reduces gradually, and compression spring obtains the extension to push down the compacting plate under the effect of centrifugal force and paste closely with the concrete surface all the time, guarantee that the concrete surface is level and smooth, unnecessary thick liquid is discharged from the clearance between compacting plate and the lateral wall.

The vertical setting of test piece die holding mount, the bearing is all installed at the transmission shaft both ends, and the bearing at transmission shaft both ends is all installed on fixed baseplate, fixed baseplate be used for supporting test piece die holding mount.

The transmission shaft is fixedly connected with the test piece die mounting fixing frame through the positioning pin, and the transmission shaft and the test piece die mounting fixing frame synchronously rotate.

The fixed base adopts steel truss framework, and fixed the setting in fixed base's bottom or install the counter weight, and the height of fixed base inner bearing is greater than the maximum radius of rotation of test piece mould installation mount.

The speed change device comprises a driving wheel and a driven wheel which are coaxially arranged, an output shaft of the power device is in transmission connection with the driving wheel of the speed change device through a transmission belt, the driven wheel of the speed change device is in transmission connection with a transmission shaft through the transmission belt, the transmission ratio of the driving wheel to the driven wheel is a preset value, and the power device comprises an electric drive motor and a fuel engine.

The method for preparing the centrifugal concrete standard test piece by using the preparation device of the centrifugal concrete standard test piece is characterized by comprising the following steps of: the method comprises the following specific steps:

step 1, adopting a mixed concrete mixture with the same mixing ratio for producing a centrifugal hollow pile, accurately calculating the concrete consumption required for preparing a standard test piece according to the size of the standard test piece, pouring concrete into a test piece mold according to the calculated concrete consumption, and sealing the test piece mold by using a cover plate and a compacting plate;

step 2, placing the test piece mold into a test piece mold bin, and fixing the test piece mold in the test piece mold bin through a threaded rod and a fixing bolt;

and 3, enabling the standard test piece to have the same r x w as the hollow pile in centrifugal rotation according to the same principle of centrifugal effect²Wherein r is a rotation radius, w is a rotation angular velocity, a power device is driven, and a speed change device is adjusted to enable a test piece die mounting fixing frame to rotate according to the calculated rotation angular velocity, wherein the rotation time is consistent with the rotation time of the centrifugal hollow pile;

and 4, taking down the standard test piece formed under the action of the rotary centrifugal action, and curing under the same curing conditions as those of the centrifugal hollow pile to finally obtain the centrifugal concrete standard test piece.

The preparation device for the centrifugal concrete standard test piece has the following beneficial effects that: in the prior art, hollow piles are usually produced by a centrifugal process, and concrete formed by the centrifugal process is obviously different from concrete poured by a common vibration mode, so that a concrete sample formed by conventional vibration is difficult to accurately reflect the real performance of the concrete of the hollow pile, and great uncertainty is brought to engineering design and safety evaluation. And the mode of cutting the test piece on the pile body has the disadvantages of difficult operation, excessive cost and difficult popularization and application. The preparation facilities of centrifugal concrete standard test piece disclosed in this application can prepare the standard test piece with the same performance of centrifugal hollow pile concrete, adopts the centrifugal concrete standard test piece that the preparation obtained to develop the experiment, and the performance of centrifugal hollow pile concrete is cut off in reaction that can be more true, provides real reference for design and production unit.

Drawings

FIG. 1 is a front view of a device for preparing a centrifugal concrete master specimen according to the present invention.

FIG. 2 is a schematic side view of a test piece mold mounting fixing frame and a fixing base mounting combination in the device for preparing a centrifugal concrete standard test piece of the present invention.

FIG. 3 is a schematic structural diagram of a specimen mold installed and fixed in a specimen mold bin in the device for preparing a centrifugal concrete standard specimen of the present invention.

FIG. 4 is a schematic structural diagram of a transmission shaft in the device for preparing a centrifugal concrete standard specimen according to the present invention.

Description of the drawings: 1. a power plant; 11. a drive shaft; 12. a transmission belt; 111. a bearing; 2. a fixed base; 3. a test piece die is provided with a fixing frame; 31. a test piece mold bin; 311. a test piece mold; 312. fixing the bolt; 3111. a cover plate; 3112. compacting the plate; 3113. a compression spring; 4. a transmission device.

Detailed Description

The invention is further described below with reference to the drawings and specific preferred embodiments.

As shown in fig. 1 and 2, the test piece mold mounting device comprises a test piece mold mounting fixing frame 3, a power device 1 and a speed changing device 4, wherein a plurality of test piece mold bins 31 are uniformly embedded in the outer edge of the test piece mold mounting fixing frame 3, each test piece mold bin 31 is used for fixing a corresponding test piece mold 311, and concrete is injected into each test piece mold 311;

a transmission shaft 11 is fixedly installed on a central shaft of the test piece die installation fixing frame 3, the power device 1 is in transmission connection with the transmission shaft 11 through the speed change device 4, the power device 1 is used for driving the transmission shaft 11 to rotate and controlling the rotation direction and the rotation speed of the test piece die installation fixing frame 3 through the speed change device 4, and the speed change device 4 is used for controlling the transmission ratio between the power device 1 and the transmission shaft 11.

And a limiting device is arranged in the test piece mold bin 31 and used for applying pressure to the outer wall of the test piece mold 311 and fixing the test piece mold 311 at a preset position.

In this embodiment, as shown in fig. 3, the limiting device includes a plurality of threaded rods and fixing bolts 312, the fixing bolts 312 are disposed on the side wall of the test piece mold bin 31, the threaded rods pass through the fixing bolts 312 and extend into the internal space of the test piece mold bin 31, and the threaded rods are in threaded connection with the fixing bolts 312 and are used for controlling the length of the threaded rods extending into the internal space of the test piece mold bin 31;

after the test piece mold 311 is placed at a preset position in the test piece mold bin 31, the test piece mold 311 is positioned by adjusting the extending lengths of the threaded rods in different directions and pressing the side wall of the test piece mold 311 by the end part of the threaded rod.

In this embodiment, the specimen mold 311 includes a cylindrical sidewall, a cover plate 3111 and a compacting plate 3112, and the section of the cylindrical sidewall includes a polygon and a circle; the cover plate 3111 is detachably connected with the cylindrical side wall and is used for sealing the cylindrical side wall; the compacting plate 3112 is arranged in the column-shaped side wall, and is connected through compression spring 3113 between apron 3111 and the compacting plate 3112, and the extending direction of compression spring 3113 is the centrifugal force direction when the test piece mould installation mount 3 rotates, compacting plate 3112 and column-shaped side wall between have the clearance. In the centrifugation process, concrete mixture is because centrifugal force is closely knit gradually, and the volume reduces gradually, and compression spring obtains the extension to push down the compacting plate under the effect of centrifugal force and paste closely with the concrete surface all the time, guarantee that the concrete surface is level and smooth, unnecessary thick liquid is discharged from the clearance between compacting plate and the lateral wall.

In this embodiment, as shown in fig. 2 and 4, the test piece mold mounting fixing frame 3 is vertically arranged, the bearings 111 are respectively mounted at two ends of the transmission shaft 11, the bearings 111 at two ends of the transmission shaft 11 are respectively mounted on the fixing base 2, and the fixing base 2 is used for supporting the test piece mold mounting fixing frame 3.

In this embodiment, transmission shaft 11 passes through locating pin and test piece die holding mount 3 fixed connection, and transmission shaft 11 rotates with test piece die holding mount 3 synchronous.

In this embodiment, the fixing base 2 is made of a steel truss framework, a counterweight is fixedly arranged or installed at the bottom of the fixing base 2, and the height of the bearing 111 in the fixing base 2 is greater than the maximum rotation radius of the test piece mold installation fixing frame 3.

In this embodiment, the speed changing device 4 includes a driving wheel and a driven wheel which are coaxially arranged, an output shaft of the power device 1 is in transmission connection with the driving wheel of the speed changing device 4 through a transmission belt, the driven wheel of the speed changing device 4 is in transmission connection with the transmission shaft 11 through the transmission belt, the transmission ratio of the driving wheel and the driven wheel is a preset value, and the power device 1 includes an electric driving motor and a fuel engine.

Furthermore, because the fixed base 2 can adopt a triangular or square truss framework, the fixed base is fixed on a concrete or steel structure foundation through embedded bars or bolts, and the stability of the structure in the centrifugal process is ensured.

Further, every side of test piece mould storehouse 31 all is provided with the threaded rod, and the threaded rod is perpendicular with the side that test piece mould storehouse 31 corresponds, and the tip of many threaded rods has formed a plurality of strong points, can support test piece mould 311 different shapes, different positions through the multiple spot support.

Furthermore, the preparation device of the centrifugal concrete standard test piece can prepare the standard test piece with the same performance as the centrifugal hollow pile concrete, and the defect that the test piece is obtained by cutting on the pile body in the traditional scheme is avoided.

The method for preparing the centrifugal concrete standard test piece by using the preparation device of the centrifugal concrete standard test piece is characterized by comprising the following steps of: the method comprises the following specific steps:

step 1, adopting the same mixing proportion of the produced centrifugal hollow pile to mix concrete mixture, accurately calculating the concrete consumption required by preparing a standard test piece according to the size of the standard test piece, pouring concrete into a test piece mold 311 according to the calculated concrete consumption, and sealing the test piece mold 311 by using a cover plate 3111 and a compacting plate 3112;

step 2, placing the test piece mold 311 into the test piece mold bin 31, and fixing the test piece mold 311 in the test piece mold bin 31 through a threaded rod and a fixing bolt 312;

and 3, enabling the standard test piece to have the same r x w as the hollow pile in centrifugal rotation according to the same principle of centrifugal effect²Wherein r is a rotation radius, w is a rotation angular velocity, the power device 1 is driven, the speed change device 4 is adjusted to enable the test piece die mounting fixing frame 3 to rotate according to the calculated rotation angular velocity, and the rotation time is consistent with the rotation time of the centrifugal hollow pile;

and 4, taking down the standard test piece formed under the action of the rotary centrifugal action, and curing under the same curing conditions as those of the centrifugal hollow pile to finally obtain the centrifugal concrete standard test piece.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may be made by those skilled in the art without departing from the principle of the invention.