JP2019197014A - Testing device and testing method - Google Patents

Abstract

To effectively evaluate water permeability of a sample by directly applying water pressure into the sample.SOLUTION: A testing device for evaluating water permeability of a sample 100 comprises: water pressure pump supplying predetermined pressure water; a percolation mechanism 74 provided within the sample 100 and percolating water supplied from the water pressure pump from the inside of the sample 100; and a funnel with water collection mechanism collecting the water passing through the sample 100.SELECTED DRAWING: Figure 3

Description

  The present disclosure relates to a test apparatus and a test method, and more particularly to a test apparatus and a test method for evaluating water permeability of a specimen.

  In general, in a concrete structure, a joint is generated at a boundary portion between concrete cast in advance and concrete cast in subsequent. In particular, a concrete floating structure installed on the water or the like requires water tightness, so that the water permeability of such a joint is a problem. For this reason, at the time of construction, it is desirable to prepare a concrete specimen in consideration of the construction conditions and to evaluate the water permeability of the specimen beforehand with a test apparatus or the like.

  For example, Patent Document 1 discloses a test apparatus that calculates hydraulic conductivity by applying water pressure from the outside of a concrete specimen accommodated in a container and measuring the amount of water that has permeated through the specimen. .

Japanese Patent Laid-Open No. 08-178828

  By the way, in the technique of the said patent document 1, in order to apply a hydraulic pressure from the outer side of a concrete test body, it is necessary to accommodate a test body in a sealed state in a container. For this reason, there exists a subject which cannot respond to the large-sized concrete specimen which considered construction conditions.

  Further, in order to accurately evaluate the water permeability of the joint, it is desirable to apply the water pressure directly to the inside of the concrete specimen, that is, the joint portion. In the technique described in Patent Document 1, since water pressure is applied from the outside of the concrete specimen, the permeability of the whole specimen can be evaluated, but there is a problem that the permeability of the joint at the joint cannot be accurately evaluated.

  The technology of the present disclosure has been made in view of the above problems, and a test apparatus and a test that can effectively evaluate the water permeability of the test specimen by directly applying a water pressure to the inside of the test specimen. It aims to provide a method.

  The apparatus of the present disclosure is a test apparatus for evaluating water permeability of a specimen, and includes a pumping means that pumps water of a predetermined pressure, and water that is embedded in the specimen and pumped from the pumping means. It comprises water permeation means for permeating water from the inside of the specimen, and water collection means for collecting water that has permeated through the specimen into a measuring means.

  Further, the specimen is a concrete specimen having a primary concrete layer placed in advance and a secondary concrete layer placed in a subsequent manner, and the water-permeable means includes the primary concrete layer, the secondary concrete layer, Preferably, the water is buried in the joint and allows water to pass through the joint, and the water collecting means collects water that leaks through the joint.

  In addition, the water permeable means includes a water permeable member formed of a porous body capable of penetrating water pumped from the pressure feeding means, and a pair of plate members sandwiching the water permeable member and facing each other. Are preferably embedded in the concrete specimen in parallel with the joint.

  Further, the apparatus further includes a water supply pipe having one end connected to the pumping means, the other end fixed to one of the pair of plate members, and an internal flow path communicating with the water permeable member. preferable.

  Also, one end is fixed to either one of the pair of plate members, the internal flow path is communicated with the water permeable member, and the other end is opened to the atmosphere, and the inside of the air discharge pipe It is preferable to further include a valve capable of opening and closing the flow path.

  Moreover, it is preferable that the said water collection means contains the funnel which collects the water leaked from the said joint, and the said measurement means is a measurement container which stores the water dripped from the said funnel.

  The method of the present disclosure is a test method for evaluating the water permeability of a specimen, a pumping process for pumping water of a predetermined pressure into the specimen, and water permeability for allowing the pumped water to permeate from the inside of the specimen. And a measuring step for measuring water that has permeated through the specimen.

  Further, the specimen is a concrete specimen having a primary concrete layer placed in advance and a secondary concrete layer placed in a subsequent manner, and in the pumping step, the primary concrete layer and the secondary concrete layer Water at the predetermined pressure is pumped to the joint, and in the water permeation step, the water to be pumped is made to permeate the joint, and in the metering step, water leaking through the joint is measured. preferable.

  According to the technique of the present disclosure, the water permeability of the specimen can be effectively evaluated by applying the water pressure directly to the inside of the specimen.

(A) is a schematic perspective view showing a test apparatus and a specimen according to the present embodiment, and (B) is a schematic side view showing the test apparatus according to the present embodiment. (A) is a typical perspective view which shows the water-permeable mechanism which concerns on this embodiment, (B) is a typical longitudinal cross-sectional view of the water-permeable mechanism which concerns on this embodiment. It is a typical longitudinal cross-sectional view which shows the state by which the water-permeable mechanism which concerns on this embodiment was embed | buried in a test body. It is a schematic diagram explaining the preparation procedure of the test body which concerns on this embodiment. It is a typical longitudinal cross-sectional view explaining the water-permeable permeability evaluation procedure of the test body using the test apparatus which concerns on this embodiment. It is a typical cross-sectional view explaining the procedure for evaluating water permeability of a specimen using the test apparatus according to the present embodiment. It is a typical longitudinal cross-sectional view of the testing apparatus which concerns on other embodiment.

  Hereinafter, a test apparatus and a test method according to the present embodiment will be described with reference to the accompanying drawings. The same parts are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[overall structure]
FIG. 1A is a schematic perspective view showing a test apparatus 10 and a specimen 100 according to this embodiment, and FIG. 1B is a schematic view showing the test apparatus 10 according to this embodiment. It is a side view. As shown in the figure, the test apparatus 10 includes a storage unit 20 that stores the specimen 100, a mounting table 30 on which the storage unit 20 is mounted, a support frame unit 40 that supports the mounting table 30, a leg unit 50, A pair of water collecting mechanisms 60 </ b> A and 60 </ b> B (water collecting means) and a water supply / discharge mechanism 70 are provided.

  In the following description, the side where the supply / discharge mechanism 70 of the test apparatus 10 is disposed is the front side, and the side opposite to the supply / discharge mechanism 70 is the rear side. Further, when the operator views the test apparatus 10 from the front side (supply / discharge mechanism 70 side) from the front, the left side is the left side and the right side is the right side.

  The specimen 100 is formed in a substantially rectangular parallelepiped shape having a two-layer structure including a primary concrete layer 110 that has been placed in advance and a secondary concrete layer 120 that has been placed in a subsequent manner. The specimen 100 has a length L1 in the front-rear direction of about 400 mm, a length L2 in the left-right direction of about 500 mm, and a length L3 in the up-down direction of about 300 mm. The specimen 100 is installed in the test apparatus 10 so that the joint 130 between the primary concrete layer 110 and the secondary concrete layer 120 is in a substantially vertical direction. A detailed manufacturing procedure of the specimen 100 will be described later.

  The accommodating part 20 is comprised by the metal plate etc. of a total of 4 sheets up and down. Specifically, the storage unit 20 includes an upper plate member 21 that covers the upper surface of the specimen 100, a lower plate member 22 that covers the lower surface of the specimen 100, a front plate member 23 that covers the front surface of the specimen 100, And a rear plate member 24 that covers the rear surface of the specimen 100.

  The upper plate member 21 and the lower plate member 22 are formed in a rectangular shape that is substantially the same shape as the upper and lower surfaces of the specimen 100. The upper plate member 21 and the lower plate member 22 are fixed by fastening a nut (not shown) to an anchor bolt (not shown) embedded in the specimen 100. In addition, the fixing method of the upper side plate member 21 and the lower side plate member 22 is not limited to an anchor bolt, You may fix to the front side plate member 23 and the rear side plate member 24 via a bracket etc.

  The front plate member 23 and the rear plate member 24 are formed in a rectangular shape that is substantially the same shape as the shape of the front and rear surfaces of the specimen 100. The front plate member 23 and the rear plate member 24 are fixed by fastening nuts 160 to four anchor bolts 150 embedded in the specimen 100. The front plate member 23 is provided with a pair of upper and lower through holes 23A and 23B through which pipes 73 and 75 of a supply / exhaust mechanism 70 described later are inserted.

  The mounting table 30 is formed in a substantially rectangular frame shape with, for example, a metal plate or the like, and includes a front plate portion 31, a rear plate portion 32, a left plate portion 33, and a right plate portion 34. The length in the longitudinal direction of the left plate portion 33 and the right plate portion 34 is preferably formed to be approximately the same as the length L1 in the front-rear direction of the specimen 100. The length in the longitudinal direction of the front plate portion 31 and the rear plate portion 32 is preferably shorter than the length L2 in the left-right direction of the specimen 100. The left plate portion 33 and the right plate portion 34 have a pair of left and right fixing members 35 and 36 respectively holding the funnels 62A and 62B of the water collecting mechanisms 60A and 60B described later (the right fixing member 36 is shown in FIG. 1B). Is attached).

  The support frame portion 40 includes a pair of left and right upper frame members 41 and 42, a pair of front and rear lower frame members 43 and 44, and a reinforcing frame member 45.

  The upper frame members 41 and 42 are long plate-like metal plates extending in parallel in the front-rear direction below the mounting table 30, and are fixed to the mounting table 30 via brackets 46. The length of the upper frame members 41, 42 in the longitudinal direction is preferably longer than the length L 1 of the specimen 100 in the front-rear direction.

  The lower frame members 43 and 44 are steel materials having a substantially U-shaped cross section that open downward, and extend below the upper frame members 41 and 42 in the left-right direction. The lower frame members 43 and 44 are fixed to the longitudinal end portions of the upper frame members 41 and 42 via a box-shaped member 47. The length L4 in the longitudinal direction of the lower frame members 43 and 44 is preferably about 600 mm longer than the length L2 in the left-right direction of the specimen 100. The length L5 in the short direction of the lower frame members 43, 44 is preferably about 100 mm. Further, the separation width W between the lower frame members 43 and 44 is set to about 480 mm, which is longer than the length L1 of the specimen 100 in the front-rear direction.

  The reinforcing frame member 45 extends in the front-rear direction below the mounting table 30, and both ends in the longitudinal direction are fixed to the lower frame members 43 and 44. Four leg portions 50 are suspended from both ends of the lower frame members 43 and 44 in the longitudinal direction.

  The water collecting mechanisms 60A and 60B collect water leaking from the joint 130 of the specimen 100 to the outside, and a pair of trough members 61A and 61B, a pair of funnels 62A and 62B, and a pair of measuring containers 63A. , 63B (measuring means).

  The eaves members 61A and 61B are formed of a long plate material that is curved in a substantially U-shaped cross section. The flange members 61A and 61B are held on the left and right side surfaces of the specimen 100 via belt members 64 and the like so that the longitudinal direction thereof is the vertical direction and the opening side thereof is opposed to the joint 130. The length in the longitudinal direction of the flange members 61A and 61B is preferably longer than the length L3 in the vertical direction of the specimen 100 so that the upper and lower ends protrude from the upper and lower surfaces of the specimen 100. . When water leaks vigorously from the joint 130, the water is reliably received by the inner peripheral surfaces of the flange members 61A and 61B.

  The funnels 62 </ b> A and 62 </ b> B are formed in a substantially inverted conical shape whose diameter is reduced from the upper end side toward the lower end side. The funnels 62A and 62B are preferably held by the fixing members 35 and 36 so that the center axis X (see FIG. 1B) substantially coincides with the left and right ends of the joint 130 (see FIG. 1A). Has been. Under the funnels 62A and 62B, measuring containers 63A and 63B such as a graduated cylinder are arranged. That is, water leaking from the left and right ends of the joint 130 is dripped into the lower measuring containers 63A and 63B through the funnels 62A and 62B.

  The supply / discharge mechanism 70 penetrates water into the water pressure pump 71 (pressure feeding means) that pumps water, a pressure gauge 72 that measures water pressure, a water supply pipe 73 that circulates at least water, and the joint 130 of the specimen 100. A water permeation mechanism 74 (water permeation means) for allowing water permeation, an air exhaust pipe 75 through which at least air flows, and an air vent valve 76 capable of opening and closing the flow path of the air exhaust pipe 75 are provided.

  The hydraulic pump 71 is, for example, an electric or manual hydraulic pump that can discharge a water pressure of 0.2 to 5.0 MPa. The discharge port of the water pressure pump 71 is connected to the upstream end of the water supply pipe 73 via a pipe joint (not shown). A pressure gauge 72 is provided in the water supply pipe 73 adjacent to the water pressure pump 71.

  The water supply pipe 73 and the air discharge pipe 75 are formed of, for example, an iron pipe having an inner diameter of 12.7 mm and an outer diameter of 17.3 mm. The downstream side of the water supply pipe 73 and the upstream side of the air discharge pipe 75 are embedded in the specimen 100. A water permeation mechanism 74 is connected to the downstream end of the water supply pipe 73 and the upstream end of the air discharge pipe 75. Further, an air vent valve 76 is provided at the downstream end of the air discharge pipe 75. When the hydraulic pump 71 is driven with the air vent valve 76 open, the internal air of the water permeable mechanism 74 is released to the outside air through the air discharge pipe 75.

[Water permeability mechanism]
Next, based on FIG.2, 3, the detail of the water-permeable mechanism 74 which concerns on this embodiment is demonstrated. FIG. 2A is a schematic perspective view showing the water permeable mechanism 74, and FIG. 2B is a schematic longitudinal sectional view of the water permeable mechanism 74. As shown in the drawing, the water permeable mechanism 74 is configured by sequentially laminating a first plate member 74A, a water permeable member 74B, and a second plate member 74C.

  The first plate member 74A and the second plate member 74C are formed in a substantially rectangular shape by a flat metal plate or the like. The first plate member 74A and the second plate member 74C are preferably formed with a long width W1 of about 240 mm and a short width W2 of about 100 mm. A first through hole 74D for fitting and fixing the downstream end of the water supply pipe 73 is provided at a substantially central portion of the second plate member 74C. Further, a second through hole 74E for fitting and fixing the upstream end of the air discharge pipe 75 is provided at one end of the second plate member 74C. These pipes 73 and 74 are preferably fixed to the second plate member 74C by welding or the like.

  The water permeable member 74B is formed in a substantially rectangular shape with a monolith porous body or the like that can permeate water (for example, a product name “Scotch Bright” manufactured by 3M Japan, preferably two layers). The water permeable member 74B is preferably joined to the first plate member 74A and the second plate member 74C by an adhesive or the like, and communicates with the internal flow paths of the pipes 73 and 74, respectively. Although the dimension of the water permeable member 74B is not particularly limited, the long width W3 is about 230 mm and the short width W2 is about 100 mm.

  As shown in FIG. 3, the water-permeable mechanism 74 configured as described above is embedded in the specimen 100 so that the water-permeable member 74 </ b> B substantially coincides with the joint 130 between the primary concrete layer 110 and the secondary concrete layer 120. Is done. That is, when water pressure is applied by the water pressure pump 71 with the air vent valve 76 closed, the water permeated into the water permeable member 74B from the water supply pipe 73 is opposed to the first and second plate members 74A and 74C. It is comprised so that it may guide | deviate reliably toward the joint line 130, guiding along. In this way, by allowing the water that has permeated into the water permeable member 74B to flow along the first and second plate members 74A and 74C, the water is supplied to other parts (for example, the pipes 73 and 75 and the pipes 73 and 75). It is possible to effectively prevent water permeation between the secondary concrete layer 120 and the like. The detailed procedure of the water permeability test of the specimen 100 will be described later.

[Sample preparation procedure]
Next, based on FIG. 4, the preparation procedure of the specimen 100 which concerns on this embodiment is demonstrated.

  First, as shown in FIG. 4A, concrete is poured into a mold (not shown) to a height of about 200 mm, and a primary concrete layer 110 is placed. At this time, four anchor bolts 150 for attaching front and rear plate members 23 and 24, which will be described later, and further two anchor bolts 170 for attaching upper and lower plate members 21 and 22 are also primary concrete. Embedded in layer 110.

  Next, as shown in FIG. 4 (B), before the primary concrete layer 110 is solidified, the first plate member 74A and the water permeable member 74B of the water permeable mechanism 74 are placed at a substantially central position of the primary concrete layer 110. Arrange to embed part.

  Next, once the primary concrete layer 110 has solidified to such an extent that at least the water permeable mechanism 74 can be self-supported, as shown in FIG. A secondary concrete layer 120 is placed. At this time, two anchor bolts 170 for attaching the upper and lower plate members 21 and 22 are also embedded in the secondary concrete layer 120.

  Finally, as shown in FIG. 4 (D), when the secondary concrete layer 120 is solidified, the specimen 100 is taken out from the mold (not shown), and the nut 160 is fastened to the anchor bolt 150, and the front side and the rear side. The plate members 23 and 24 are attached, the nuts 180 are fastened to the anchor bolts 170 and the upper and lower plate members 21 and 22 are attached, and the preparation of the specimen 100 is completed.

[Evaluation procedure]
Next, based on FIG.5, 6, the evaluation procedure of the specimen 100 using the test apparatus 10 which concerns on this embodiment is demonstrated. In the present embodiment, the water permeability coefficient k, which is one of the water-stopping indexes of the joint 130, is obtained.

[1: Air venting and pumping process]
First, as shown in FIG. 5A, water is pumped from the water pressure pump 71 to the water permeable member 74B through the water supply pipe 73 with the air vent valve 76 opened. When water is supplied to the water permeable member 74B, the internal air having a specific gravity lighter than that of water is released to the atmosphere through the upper air discharge pipe 75. In this way, by applying water pressure by the water pressure pump 71 to push out the internal air, the internal air can be discharged from the water permeable member 74B at an early stage.

  If the internal air of the water permeable member 74B has completely escaped and water has started to leak from the air vent valve 76, the air vent process is terminated by switching the air vent valve 76 to the closed state. In the figure, the black arrow indicates the flow of water, and the white arrow indicates the flow of internal air.

[2: Pressure feeding / water permeability process]
Next, as shown in FIG. 5 (B), water with a desired water pressure is supplied from the water supply pipe 73 to the water permeable member 74B by the water pressure pump 71 with the air vent valve 76 closed. The water pressure may be set to, for example, about 0.2 MPa if a construction condition corresponding to a water depth of 20 m is evaluated, and about 5.0 MPa if a construction condition corresponding to a water depth of 500 m is evaluated. The operation of adjusting the discharge pressure of the water pressure pump 71 may be performed while checking the measurement value of the pressure gauge 72.

  The water supplied in a pressurized state to the water permeable member 74B reaches the joint 130 while penetrating the water permeable member 74B along the opposing surfaces of the first and second plate members 74A and 74C, and enters the joint 130. Gradually begin to permeate. In this embodiment, since the water permeable member 74B is sandwiched between the pair of plate members 74A and 74C substantially parallel to the joint 130, the water that permeates the water permeable member 74B permeates into other parts other than the joint 130. Without being done, it is surely guided toward the joint 130.

[3: Weighing process]
Next, as shown in FIG. 6, if a predetermined time T has passed and water has leaked to the outside from the joint 130, and the leaked water has been collected in the measuring containers 63A and 63B via the funnels 62A and 62B. For example, the water quantity Q in the measuring containers 63A and 63B is measured. For weighing, if the weighing containers 63A, 63B are, for example, a graduated cylinder, the scale of the graduated cylinder may be read.

  If the amount of water Q is measured, the amount of water passing through the unit area of the joint 130 per unit time based on the amount of water Q and the elapsed time T is calculated, and the calculated value and the water pressure value P (or the pressure gauge 72) If the hydraulic pump 71 is an automatic control type, the hydraulic conductivity k is calculated from the relationship with the set pressure value). The hydraulic conductivity k may be calculated based on a formula such as Darcy's law.

  According to this embodiment described in detail above, the water pumped by the hydraulic pump 71 is supplied to the water permeable mechanism 74 embedded in the specimen 100 so as to penetrate the joint 130 and leak from the joint 130. Water is dropped by the funnels 62A and 62B and collected in the measuring containers 63A and 63B. Thereby, it becomes possible to grasp | ascertain the amount of water leakage from the joint 130 correctly, and the water permeability of the joint 130 can be evaluated with high precision.

  Further, since the water pumped by the water pressure pump 71 is infiltrated from the water permeable mechanism 74 embedded in the specimen 100, a container such as a conventional apparatus that completely seals the specimen is not required, and the construction conditions and the like are determined. It is possible to appropriately deal with the large specimen 100 considered.

  It should be noted that the present disclosure is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the spirit of the present disclosure.

  For example, in the above embodiment, the water permeable mechanism 74 has been described as being embedded in the specimen 100 so that the water permeable member 74B substantially coincides with the joint 130, but as shown in FIG. 74A may be embedded so as to be seated on the joint 130 between the primary concrete layer 110 and the secondary concrete layer 120. In this case, the first plate member 74A may be seated on the upper surface of the primary concrete layer 110 when the primary concrete layer 110 is solidified in the step shown in FIG.

  Moreover, although the air discharge piping 75 demonstrated that the upstream end was fixed to the 2nd plate member 74C, you may be fixed to 74 A of 1st plate members. In this case, the upstream side of the air discharge pipe 75 may be embedded in the primary concrete layer 110.

  Further, although the specimen 100 has been described as being installed in the test apparatus 10 such that the joint 130 is in a substantially vertical direction, the specimen 100 may be installed so that the joint 130 is in a horizontal direction. In this case, the upper end openings of the funnels 62A and 62B may be expanded according to the horizontal length of the joint 130, or the number of installations may be increased.

  Moreover, the dimension and shape of the specimen 100 are not limited to the above embodiment, and may be a larger or smaller specimen.

  Moreover, the application range of the specimen 100 is not limited to a concrete specimen, and can be widely applied to other specimens such as a mortar specimen.

DESCRIPTION OF SYMBOLS 10 ... Test apparatus, 20 ... Accommodating part, 30 ... Mounting stand, 40 ... Supporting frame part, 50 ... Leg part, 60A, 60B ... Water collecting mechanism (water collecting means), 61A, 61B ... Scissors member, 62A, 62B ... Funnel, 63A, 63B ... measuring container (measuring means), 70 ... supply / discharge mechanism, 71 ... water pressure pump (pressure feeding means), 72 ... pressure gauge, 73 ... water supply piping, 74 ... water permeation mechanism 74 (water permeation means), 74A ... 1st plate member, 74B ... Permeable member, 74C ... 2nd plate member, 75 ... Air exhaust pipe, 76 ... Air vent valve, 100 ... Specimen, 110 ... Primary concrete layer, 120 ... Secondary concrete layer, 130 ... Joint

Claims (8)

A test device for evaluating the water permeability of a specimen,
A pumping means for pumping water of a predetermined pressure;
A water-permeable means that is embedded in the specimen and allows water to be pumped from the pressure-feeding means to permeate from the inside of the specimen;
And a water collecting means for collecting the water that has permeated through the specimen into a measuring means. The specimen is a concrete specimen having a primary concrete layer placed in advance and a secondary concrete layer placed in a subsequent manner,
The water-permeable means is embedded at the joint between the primary concrete layer and the secondary concrete layer and allows water to permeate the joint.
The test apparatus according to claim 1, wherein the water collecting means collects water leaking through the seam. The water permeable means includes a water permeable member formed of a porous body capable of penetrating water pumped from the pressure feeding means, and a pair of plate members facing each other with the water permeable member interposed therebetween, and a plane of the plate member. The test apparatus according to claim 2, wherein the test apparatus is embedded in the concrete specimen in parallel with the joint. A water supply pipe having one end connected to the pumping means and the other end fixed to one of the pair of plate members and having an internal flow path communicating with the water permeable member. The test apparatus described. One end is fixed to any one of the pair of plate members, and the internal flow path is communicated with the water permeable member, and the other end is opened to the atmosphere,
The test apparatus according to claim 3, further comprising a valve capable of opening and closing an internal flow path of the air discharge pipe. The said water collection means contains the funnel which collects the water which leaks from the said joint, The said measurement means is a measurement container which stores the water dripped from the said funnel. The test apparatus described in 1. A test method for evaluating the water permeability of a specimen,
A pumping step of pumping water of a predetermined pressure into the specimen;
A water permeation step for allowing water to be pumped from the inside of the specimen;
And a measuring step for measuring water that has permeated through the specimen. The specimen is a concrete specimen having a primary concrete layer placed in advance and a secondary concrete layer placed in a subsequent manner,
In the pumping step, the water of the predetermined pressure is pumped to the joint between the primary concrete layer and the secondary concrete layer, and in the water permeation step, the pumped water is permeated to the joint, and in the metering step The test method according to claim 7, wherein water leaking through the seam is measured.

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