Automatic rapid freeze-thaw test device for concrete

Abstract

The application discloses the technical fields of concrete freeze-thaw test and relates to a kind of automatic quick freeze-thaw test device of concrete, comprising: including refrigeration component, low-temperature medium temporary storage component, water storage component, test piece box component, spoiler component, medium-temperature medium component, the technical scheme can be freeze-thaw test to multiple concrete test pieces once by being set to spoiler, even if concrete test piece is placed dense, by spoiler, water storage component, low-temperature medium temporary storage component makes medium uniform steady flow through the clearance of concrete test piece, and temperature transition is carried out by being set medium-temperature medium component, medium-temperature medium and water and low temperature are not compatible, and there is no convection between each other, so as to reduce heat transfer in medium replacement process, and make the freeze-thaw process of concrete test piece more smoothly, prevent the test deviation caused by temperature sudden drop.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete freeze-thaw test, in particular to a kind of automatic rapid freeze-thaw test device of concrete. BACKGROUND

[0002] At present, with the development of construction industry, people's requirements for the quality of building are more and more strict, the quality of concrete is a key factor for the quality of building, in order to detect the freeze resistance of concrete, test pieces are often selected in concrete for freeze-thaw test, and freeze-thaw test machine is often used to simulate the natural environment of outside world during freeze-thaw test process, and the freeze resistance of concrete is represented by the number of rapid freeze-thaw cycles that concrete test pieces can withstand under water freezing and thawing conditions. The application field is the detection of durability of various concrete engineering such as marine engineering, hydraulic engineering, bridge, tunnel, industrial and civil building.

[0003] The operation procedures of concrete rapid freeze-thaw test are as follows:

[0004] 1. If there is no special provision, the freeze-thaw test of test pieces should start at the age of 28 days. Four days before freeze-thaw test, test pieces should be taken out from the curing site, and then the appearance is checked, and then the test pieces are soaked in water with a temperature of 15-20℃ (including temperature measurement test pieces). The water surface should be at least 20mm higher than the top surface of the test pieces during soaking, and the test pieces are soaked for 4 days before freeze-thaw cycle.

[0005] 2. After soaking, the test pieces are taken out, the surface water is wiped off with a wet cloth, and the initial value of transverse fundamental frequency is measured.

[0006] 3. Before test, the test pieces are placed in test piece boxes, in order to make the test pieces receive uniform temperature and eliminate the additional pressure caused by ice formation around the test pieces, the side surface and the bottom of the test pieces should be padded with rubber plates with appropriate width and thickness.

[0007] 4. The test pieces are placed in freeze-thaw box, and freeze-thaw cycle starts.

[0008] 5. The freeze-thaw cycle process should meet the following requirements: A. Each freeze-thaw cycle should be completed within 2-4 hours, and the time for thawing should not be less than 1 / 4 of the whole freeze-thaw time; B. At the end of freezing and thawing, the center temperature of the test pieces should be controlled at-17±2℃ and 8±2℃ respectively; C. The time for each test piece to drop from 6℃ to-15℃ should not be less than 1 / 2 of the freezing time, and the time for each test piece to rise from-15℃ to 6℃ should not be less than 1 / 2 of the whole thawing time, and the temperature difference between the inside and outside of the test pieces should not exceed 28℃; D. The transition time between freezing and thawing should not exceed 10 minutes.

[0009] 6. The test pieces should be measured every 25 cycles, and the surface scum of the test pieces should be cleaned before measurement, the surface water should be wiped off, and the external damage and weight loss should be checked.

[0010] The existing concrete freeze-thaw device has the following disadvantages: repeated heating and refrigeration of the medium, high energy consumption; the concrete test pieces are placed at a large interval, resulting in a small number of test samples per test, and if the test pieces are placed densely, the freezing and thawing process of the test pieces is slow, and the temperatures of the test pieces are difficult to keep consistent. SUMMARY

[0011] The purpose of the present application is to provide an automatic and rapid freeze-thaw test device for concrete to solve the problems raised in the background art.

[0012] To achieve the above purpose, the present application provides the following technical solution: an automatic and rapid freeze-thaw test device for concrete, comprising:

[0013] A refrigeration assembly, comprising a test box with a cover plate, a flange arranged on the side wall of the test box, a float ball one-way valve downwardly connected to the surface of the flange, and a refrigeration main unit arranged at the bottom of the test box;

[0014] A test piece box assembly arranged inside the test box for storing concrete test pieces, comprising a coverless box seated on the flange, the coverless box being through-penetrated from top to bottom and provided with a mesh plate at the bottom end;

[0015] A water storage assembly for injecting / extracting water into / from the test box to thaw the concrete test pieces;

[0016] A low-temperature medium temporary storage assembly for injecting / extracting low-temperature medium into / from the test box;

[0017] A turbulence assembly for increasing the flow of the medium, comprising a cylinder arranged below the cover plate and a turbulence plate arranged in close contact with the inner wall of the coverless box at the output end of the cylinder, the surface of the turbulence plate being provided with upwardly connected one-way valves.

[0018] A medium-temperature medium assembly arranged on the surface of the cover plate, the medium-temperature medium assembly comprising a box arranged above the cover plate, the medium-temperature medium having a density smaller than that of water and low-temperature medium, and the medium-temperature medium being immiscible with water and low-temperature medium, the surface of the cover plate being provided with a plurality of valve holes in communication with the box, the surface of the turbulence plate being provided with a plurality of valve balls corresponding to the valve holes through connecting ropes, the valve balls having a density smaller than that of water and low-temperature medium and higher than that of the medium-temperature medium.

[0019] Further improvement lies in that a close sealing member is arranged between the test box and the cover plate, and the upper end of the test box is provided with a pressing member for pressing the cover plate, the purpose of arranging the pressing member is to make the cover plate have good sealing performance and not leak under the pressure of the internal medium.

[0020] Further improvement lies in that the water storage assembly comprises a water storage tank and a first pipeline communicated between the water storage tank and the bottom end of the test box, a second electromagnetic valve and a second bidirectional pump are arranged in the middle section of the first pipeline, a second pipeline for backflow is further communicated between the top end of the test box and the water storage tank, a one-way pressure valve for guiding in the direction of the water storage tank is arranged in the middle section of the second pipeline, the water storage assembly is used for injecting water into the test box for thawing, in order to increase the continuity of the thawing and heating process, the water storage assembly is used for circulating water supply to the test box through the second bidirectional pump, and the low-temperature water is recycled through the second pipeline.

[0021] Further improvement lies in that the pressure valve comprises a valve block, a spring, a valve cavity corresponding to the valve block and a guiding groove, the pressure valve needs a certain pressure to push away the valve block, the pressure is provided by the second bidirectional pump, and the pressure valve is in the closed state when the water pressure in the test box is insufficient during the circulating water thawing process.

[0022] Further improvement lies in that the low-temperature medium temporary storage assembly comprises an insulation box and a third pipeline communicated between the insulation box and the bottom end of the test box, a first electromagnetic valve and a first bidirectional pump are arranged in the middle section of the third pipeline, the low-temperature medium temporary storage assembly is arranged to take out the low-temperature medium during thawing, and then inject the low-temperature medium into the test box for the next freezing, so that the medium can be repeatedly frozen and heated and the power consumption is reduced.

[0023] Further improvement lies in that the floating ball one-way valve comprises a guiding groove arranged on the surface of the flange, the upper end of the guiding groove is in a cylindrical shape, the bottom end of the guiding groove is in a semispherical shape, a guide rod is arranged in the guiding groove, a floating ball valve corresponding to the bottom end of the guiding groove is arranged at the bottom end of the guide rod, and a limiting rod is further arranged at the top end of the guide rod, the floating ball valve is arranged to block the upward flow of the medium at the guiding groove, when the medium below the floating ball valve is filled, the floating ball one-way valve is in the closed state under the action of the buoyancy, so that the medium can better pass through the concrete test piece when flowing upward.

[0024] Further improvement lies in that the top wall of the coverless box is provided with a frame-shaped filter screen, the edge frame of the filter screen is in contact with the bottom end of the cover plate, and the side surface of the coverless box is provided with a protrusion facilitating lifting out of the coverless box, and the screen plate and the filter screen are arranged to prevent the concrete test piece from polluting and clogging other assemblies.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] The technical scheme sets the spoiler, can freeze and thaw test multiple concrete test pieces at a time, even if the concrete test pieces are densely placed, the medium uniformly and stably flows through the gap of the concrete test pieces through the spoiler, the water storage assembly and the low-temperature medium temporary storage assembly, the medium is not mixed with water and low temperature, and there is no convection between them, so that heat transfer in the medium replacement process is reduced, and the freeze and thaw process of the concrete test piece is smoother, and test deviation caused by sudden temperature drop and rise is prevented. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a structure schematic view of the concrete automatic rapid freeze and thaw test device of the present application;

[0028] Figure 2 It is a test box and related assembly disassembly schematic view of the concrete automatic rapid freeze and thaw test device of the present application;

[0029] Figure 3 It is a concrete automatic rapid freeze and thaw test device of the present application Figure 1 It is an enlarged view of the structure of part A;

[0030] Figure 4 It is a concrete automatic rapid freeze and thaw test device of the present application Figure 1 It is an enlarged view of the structure of part B;

[0031] Figure 5 It is a concrete automatic rapid freeze and thaw test device of the present application Figure 2 It is an enlarged view of the structure of part C.

[0032] In the figure: 1, refrigeration assembly; 11, test box; 12, refrigeration host; 13, flange; 14, cover plate; 15, pressing part; 16, through groove; 17, guide rod; 18, floating ball valve; 19, limiting rod; 2, low-temperature medium temporary storage assembly; 21, heat preservation box; 22, first electromagnetic valve; 23, first bidirectional pump; 3, water storage assembly; 31, water storage box; 32, second bidirectional pump; 33, second electromagnetic valve; 34, pressure valve; 35, valve block; 36, spring; 4, test piece box assembly; 41, coverless box; 42, mesh plate; 43, concrete test piece; 44, filter screen; 45, protrusion; 5, spoiler assembly; 51, air cylinder; 52, spoiler; 53, one-way valve; 6, medium temperature medium assembly; 61, box body; 62, valve hole; 63, valve ball; 64, connecting rope. DETAILED DESCRIPTION

[0033] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by those skilled in the art without creative efforts belong to the scope of the present application.

[0034] Embodiment 1

[0035] The concrete automatic rapid freeze-thaw test device comprises a refrigeration assembly 1, a low-temperature medium temporary storage assembly 2, a water storage assembly 3, a test piece box assembly 4, a turbulence assembly 5 and a medium temperature medium assembly 6.

[0036] The refrigeration assembly 1 comprises a test box 11 with a cover plate 14, a flange 13 arranged on the side wall of the test box 11, a float ball single-way valve downwardly communicated on the surface of the flange 13 and a refrigeration main machine 12 arranged at the bottom of the test box 11.

[0037] The test piece box assembly 4 is arranged in the test box 11 and used for storing concrete test pieces 43, and comprises a coverless box 41 arranged on the flange 13, wherein the coverless box 41 is through-penetrated from top to bottom and is provided with a mesh plate 42 at the bottom end.

[0038] The water storage assembly 3 is used for injecting / extracting water into / from the test box 11 to thaw the concrete test pieces 43, and comprises a water storage tank 31 and a first pipeline communicated between the water storage tank 31 and the bottom end of the test box 11, wherein a second electromagnetic valve 33 and a second bidirectional pump 32 are arranged at the middle section of the first pipeline, and a second pipeline for backflow is further communicated between the top end of the test box 11 and the water storage tank 31, a one-way pressure valve 34 is arranged at the middle section of the second pipeline and is communicated to the water storage tank 31, and the one-way pressure valve 34 comprises a valve block 35, a spring 36, a valve cavity corresponding to the valve block 35 and a communication groove.

[0039] The low-temperature medium temporary storage assembly 2 is used for injecting / extracting low-temperature medium into / from the test box 11, and comprises an insulation box 21 and a third pipeline communicated between the insulation box 21 and the bottom end of the test box 11, wherein a first electromagnetic valve 22 and a first bidirectional pump 23 are arranged at the middle section of the third pipeline.

[0040] The turbulence assembly 5 is used for increasing the flow of the medium, and comprises a cylinder 51 arranged below the cover plate 14 and a turbulence plate 52 arranged in abutment with the inner wall of the coverless box 41 at the output end of the cylinder 51, wherein a one-way valve 53 is arranged on the surface of the turbulence plate 52 and is communicated upwardly.

[0041] The float ball single-way valve is used to form the inner circulation together with the turbulence assembly 5, and comprises a through slot 16 formed on the surface of the flange 13, the upper end of the through slot 16 being in a cylindrical shape and the bottom end being in a hemispherical shape, a guide rod 17 arranged in the through slot 16, and a float ball valve 18 arranged at the bottom end of the guide rod 17.

[0042] The top wall of the coverless tank 41 is provided with a frame-shaped filter screen 44, the frame of the filter screen 44 is in contact with the bottom end of the cover plate 14, and the side surface of the coverless tank 41 is provided with a protrusion 45 for facilitating lifting out of the coverless tank 41.

[0043] The medium assembly 6 of medium temperature comprises a tank body 61 arranged above the cover plate 14, the medium of medium temperature has a density smaller than that of water and the low-temperature medium, and is not mixed with water and the low-temperature medium, a plurality of valve holes 62 are formed in the surface of the cover plate 14 and are communicated with the tank body 61, a plurality of valve balls 63 corresponding to the valve holes 62 are arranged on the surface of the turbulence plate 52 through connecting ropes 64, the density of the valve balls 63 is smaller than that of water and the low-temperature medium and is higher than that of the medium of medium temperature, in order to prevent the cover plate 14 from leaking the medium, a close sealing piece is arranged between the test tank 11 and the cover plate 14, and the upper end of the test tank 11 is provided with a pressing piece 15 for pressing the cover plate 14.

[0044] Working principle: first, the concrete test pieces 43 are evenly placed in the coverless tank 41, gaps are reserved between the concrete test pieces 43, the coverless tank 41 is lifted into the test tank 11 and is seated on the flange 13, then the cover plate 14 is covered, the cover plate 14 is pressed by the pressing piece 15, the medium of medium temperature is injected into the tank body 61 (the medium of medium temperature is a medium whose temperature is between that of water and the low-temperature medium during operation, the medium is not dissolved in water and the low-temperature medium and has a lower density, for example, silicon oil can be used as the medium of medium temperature, in order to prevent the medium from freezing, a proper amount of antifreezing agent is added according to the physical properties of each medium), the medium of medium temperature is completely injected into the test tank 11 through the valve holes 62 and fills the test tank.

[0045] Freezing: the first bidirectional pump 23 injects low-temperature medium into the inside of the test box 11, and the temperature of the low-temperature medium is not low at the first time, and the temperature will be reduced after being refrigerated by the refrigeration host 12, the density of the low-temperature medium is greater than that of the medium-temperature medium and they are not mixed with each other, and the medium-temperature medium is slowly squeezed back into the box body 61, when the liquid level of the low-temperature medium reaches the valve hole 62, the valve ball 63 is floated to block the valve hole 62 under the action of buoyancy, so as to isolate the low-temperature medium and the medium-temperature medium and prevent temperature transmission, in order to facilitate the one-to-one correspondence between the valve hole 62 and the valve ball 63, the valve ball 63 is connected to the surface of the cover plate 14 through the connecting rope 64, and the connecting rope 64 is pre-arranged with a length so that the valve ball 63 is just corresponding to the valve hole 62 directly above, the refrigeration host 12 operates to refrigerate, and at the same time, the air cylinder 51 drives the spoiler 52 to move upward, when the spoiler 52 moves upward, the low-temperature medium with a lower temperature below is uniformly passed through the gap of the concrete test piece 43, and then is returned to the bottom end of the test box 11 through the filter screen 44 and the through slot 16, so that the low-temperature medium can continuously and uniformly pass through the concrete gap, and the cooling effect is stable and synchronous.

[0046] Thawing: the first bidirectional pump 23 draws back the low-temperature medium, and the medium-temperature medium in the box body 61 flows into the test box 11, because the density of the medium-temperature medium is different from that of the low-temperature medium and they are not mixed with each other, so the heat transfer is less, after the medium-temperature medium fills the test box 11, the spoiler 52 drives the concrete test piece 43 to be initially thawed, when the temperature difference between the medium-temperature medium and the concrete test piece 43 is small, the second bidirectional pump 23 operates to inject water into the test box 11, and the medium-temperature medium returns to the box body 61 again, the first bidirectional pump 23 continuously circulates water, when the pressure in the test box 11 is large, the pressure valve 34 is opened, the water passing through the concrete test piece 43 returns to the water storage tank 31, in this process, the through slot 16 is in a closed state, and the spoiler 52 slowly moves to increase the uniformity of the water flow.

[0047] Re-freezing: the first bidirectional pump 23 draws back the water, and the medium-temperature medium enters the test box 11 again to pre-cool the concrete test piece 43, after the pre-cooling is completed, the low-temperature medium is injected again to cooperate with the refrigeration host to freeze.

[0048] In this way, the freezing and thawing test is completed through multiple cycles of freezing, in order to further reduce energy consumption, the water, the medium-temperature medium and the low-temperature medium can all be provided with heat exchange devices to exchange heat with the atmospheric environment, for example, when the atmospheric environment is at a high temperature, the water in the water storage tank 31 can be heated by using the heat exchange device, and when the atmospheric environment is at an ultra-low temperature, the low-temperature medium in the heat preservation box can be cooled by using the heat exchange device.

[0049] Although the embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A device for automatically and rapidly freeze-thaw testing concrete, characterized by: The application relates to a refrigeration device for concrete test pieces, which comprises the following components: a refrigeration assembly (1) comprising a test box (11) with a cover plate (14), a flange (13) arranged on the side wall of the test box (11), a float ball one-way valve arranged on the surface of the flange (13) and downwardly leading, and a refrigeration main machine (12) arranged at the bottom of the test box (11); a test piece box assembly (4) arranged in the test box (11) and used for storing concrete test pieces (43), which comprises a coverless box (41) arranged on the flange (13), wherein the coverless box (41) is through-penetrated and provided with a mesh plate (42) at the bottom end; a water storage assembly (3) used for injecting / extracting water into / from the test box (11) to thaw the concrete test pieces (43); a low-temperature medium temporary storage assembly (2) used for injecting / extracting low-temperature medium into / from the test box (11); a turbulence assembly (5) used for increasing the flow of the medium, which comprises a cylinder (51) arranged below the cover plate (14) and a turbulence plate (52) arranged on the output end of the cylinder (51) and abutting against the inner wall of the coverless box (41), wherein the surface of the turbulence plate (52) is provided with upwardly leading one-way valves (53); a medium of medium temperature assembly (6) arranged on the surface of the cover plate (14), which comprises a box body (61) arranged above the cover plate (14), wherein the medium of medium temperature has a density smaller than that of water and low-temperature medium, and the medium of medium temperature is not mixed with water and low-temperature medium, a plurality of valve holes (62) are arranged on the surface of the cover plate (14) and communicated with the box body (61), a plurality of valve balls (63) corresponding to the valve holes (62) are arranged on the surface of the turbulence plate (52) through connecting ropes (64), and the density of the valve balls (63) is smaller than that of water and low-temperature medium and higher than that of the medium of medium temperature. The water storage assembly (3) comprises a water storage box (31) and a first pipeline communicated between the water storage box (31) and the bottom end of the test box (11), a second electromagnetic valve (33) and a second bidirectional pump (32) are arranged in the middle section of the first pipeline, a second pipeline for backflow is further communicated between the top end of the test box (11) and the water storage box (31), and a one-way pressure valve (34) leading to the water storage box (31) is arranged in the middle section of the second pipeline. A sealing element is arranged between the test box (11) and the cover plate (14), and a pressing element (15) for pressing the cover plate (14) is arranged at the upper end of the test box (11). The pressure valve (34) comprises a valve block (35), a spring (36), a valve cavity corresponding to the valve block (35) and a leading groove. The low-temperature medium temporary storage assembly (2) comprises a heat preservation box (21) and a third pipeline communicated between the heat preservation box (21) and the bottom end of the test box (11), and a first electromagnetic valve (22) and a first bidirectional pump (23) are arranged in the middle section of the third pipeline. ​ ​ ​ 2. The automatic rapid freeze-thaw test device for concrete according to claim 1, characterized in that: ​ 3. The automatic rapid freeze-thaw test device for concrete according to claim 1, characterized in that: ​ 4. The automatic rapid freeze-thaw test device for concrete according to claim 1, characterized in that: ​ 5. The automatic rapid freeze-thaw test device for concrete according to claim 1, characterized in that: The floating ball single-way valve comprises a through groove (16) formed on the surface of the flange (13), the upper end of the through groove (16) is in a cylindrical shape, the bottom end is in a hemispherical shape, a guide rod (17) is arranged in the through groove (16), the bottom end of the guide rod (17) is provided with a floating ball valve (18) matched with the bottom end of the through groove (16), and a limiting rod (19) is further arranged at the top end of the guide rod (17).

6. The automatic rapid freeze-thaw test device for concrete according to claim 1, characterized in that: The top wall of the cover-free box (41) is provided with a frame-shaped filter screen (44), the frame of the filter screen (44) is in contact with the bottom end of the cover plate (14) along the same, and the side surface of the cover-free box (41) is provided with a protrusion (45) facilitating lifting out of the cover-free box (41).

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