JP5611417B1 - Quality evaluation method based on permeability test of concrete structures - Google Patents

Abstract

The present invention provides a quality evaluation method based on a water permeability test capable of working in a field where a concrete structure exists. A close contact body having an inner chamber and an outer chamber is brought into contact with a concrete surface, and the inside of the outer chamber is decompressed and brought into close contact. The water permeability test is performed by supplying the water W in the water reservoir 21 into the inner chamber 11 while pressurizing the water W in the water reservoir 21 with the pressurizing means 22. After a predetermined time, the water permeability is calculated, the water permeability index is calculated, and the quality of the concrete structure is evaluated. [Selection] Figure 1

Description

  The present invention relates to a quality evaluation method based on a permeability test of a concrete structure such as a bridge girder and a building outer wall.

  In recent years, aged and aged concrete structures are increasing, and there is concern about the occurrence of accidents due to deterioration of concrete structures. Therefore, as a premise for repairing the concrete structure, it is necessary to evaluate the quality of the concrete constituting the concrete structure, for example, the quality such as compressive strength, durability, water tightness, etc. Proposed.

  In this respect, the deterioration of the concrete structure proceeds significantly by the entry of harmful substances from the surface (surface layer portion) of the concrete. For example, when salt enters a concrete covering a steel material such as a reinforcing bar, the steel material is corroded and deterioration of the concrete structure proceeds (salt damage). Further, when carbon dioxide in the atmosphere enters the concrete, the concrete becomes neutral and the deterioration of the concrete structure proceeds.

  Therefore, it is now recognized that there is a need to evaluate the density of concrete, especially the surface layer, and the resistance to gas and water movement in the concrete surface layer is measured, and the quality of the concrete is determined based on this measured value. Various evaluation methods have been proposed. Specifically, as a method for measuring the air permeability of the concrete surface layer portion (air permeability test) and evaluating the quality of the concrete structure, for example, a drilling method or a single chamber method has been proposed. The present inventor (Toyofuku Toyofuku) has also proposed a so-called double chamber method (for example, see Patent Document 1).

  In addition, concrete structures affected by rainwater, seawater, etc., such as bridge girders, RC floor slabs, wall railings, building outer walls, etc., undergo significant deterioration compared to concrete structures that are not affected by rainwater, seawater, etc. . Therefore, various methods for evaluating the quality of concrete by measuring the water permeability of the concrete (permeability test) apart from the quality evaluation method based on the air permeability test of the concrete structure have been proposed.

  As a quality evaluation method based on the permeability test of this concrete structure, for example, water is directly applied to a concrete core specimen at a predetermined pressure, and the amount of water passing through the unit area per unit time (water amount) is measured. The method of evaluating quality from the relationship between the measured value and water pressure (output method), or the amount of water permeated (permeated) per unit time by allowing water to act directly on the concrete core specimen at a given pressure (water volume) ), Or a method (input method) for measuring the water penetration area and water penetration depth and evaluating the quality from these measured values.

  However, in these evaluation methods, it is necessary to measure water permeability using a concrete core specimen cut from a concrete structure, and there are cases where it is not suitable for evaluating an existing concrete structure. Then, the proposal of the quality evaluation method based on the water permeability test of the concrete structure classified into a nondestructive test is anticipated.

  In this regard, as a nondestructive testing method for evaluating the quality of concrete structures, water permeability is based on “JIS A 6909 (finishing coating material for construction) 7.12 Permeability test B method” established in June 1972. There are a method of performing a property test (head height 25 cm) and evaluating the quality of the upper surface of the concrete structure, a method of improving this test and evaluation method, and the like. However, none of these test / evaluation methods allow water to act (permeate) on the concrete structure at a predetermined pressure.

In addition, as a test / evaluation method for allowing water to act (permeate) on concrete structures at a specified pressure, it conforms to “JIS A 1404 (Test method for waterproofing cement for construction)” established in August 1960. Then, a water permeability test is performed (294.0 kPa = 3 kf / cm ² = 3 atm = water head height 3000 cm), and there is a method for evaluating the quality of the concrete structure. However, this test / evaluation method assumes an indoor test and does not assume an on-site test for an existing concrete structure.

JP 2003-262578 A

The main problem to be solved by the present invention is that it is not necessary to damage the concrete structure to be evaluated (non-destructive), and it is possible to work on the site where the concrete structure exists, and concrete An object of the present invention is to provide a quality evaluation method based on a water permeability test of a concrete structure classified into a method of allowing water to act on a structure at a predetermined pressure continuously (permeability) for a predetermined time.
More preferably, not only when the surface of the concrete structure to be evaluated faces upward (upper surface), but also when facing downward (lower surface), sideward (side surface), diagonally upward or An object of the present invention is to provide a quality evaluation method based on a water permeability test of a so-called omnidirectional concrete structure that can be employed even when facing obliquely downward (inclined surface).

The present invention for solving this problem is as follows.
[Invention of Claim 1]
A quality evaluation method based on a permeability test of a concrete structure,
An adhesion body comprising an inner chamber having a water-permeable opening, and an outer chamber having an adhesion opening that extends in a ring shape outside the water-permeable opening;
A source of water to be supplied into the inner chamber;
A pressurizing means for pressurizing the water of the water supply source;
Decompression means for decompressing the inside of the outer chamber;
A water permeability test apparatus having
The contact body is brought into contact with the concrete surface such that the water-permeable opening and the contact opening face the concrete surface, and the inside of the outer chamber is depressurized by the pressure-reducing means to thereby bring the contact body into the concrete surface. Closely
On the other hand, after filling the inner chamber with water,
Pressurizing the water of the water supply source to a predetermined pressure by the pressurizing means;
Under this pressure, water from the water supply source is supplied into the inner chamber, and a water permeability test of the concrete is performed.
After a predetermined time, the water permeability of the concrete is calculated based on the following formula (1), and the water permeability index of the concrete is calculated based on the following formula (2):
Evaluating the quality of the concrete structure based on the water permeability and the water permeability index,
A quality evaluation method based on a permeability test of a concrete structure characterized by :
Prepare a plate material of a predetermined thickness having a notch of the same shape as the portion of the concrete surface that contacts the adhesion body,
Prior to abutting the contact body against the concrete surface, the plate material is abutted against the concrete surface,
Filling the notch with a sealing material having water-stopping property and peelability to form a seal layer at a site in contact with the adhesion body of the concrete surface,
A quality evaluation method based on the permeability test of concrete structures.
w = w ₁ −w ₀ (1)
P = ((G · ρ · w ² ) / (2 · t · A ² · P _u )) × 10 ⁻⁴ (2)
In the above formula, “w” is the water permeability (cm ³ ), “w ₁ ” is the volume of water permeating the concrete at the end of the water permeability test (cm ³ ), and “w ₀ ” is the water permeability. The volume of water permeating the concrete at the start of the property test (cm ³ ), “P” is the permeability index (m / sec), “G” is the acceleration of gravity (m / sec ² ), and “ρ” is Unit volume mass (g / cm ³ ) of water, “t” is the time (seconds) from the start of the water permeability test to the end of the water permeability test, “A” is the area (cm ² ) of the water permeability opening, “P _u "Is the pressure (kPa) of water applied to the concrete surface.

[Invention of Claim 2]
The smaller the water permeability and the water permeability index, the stronger the compressive strength of the concrete, the lower the neutralization depth, and the lower the chloride penetration depth,
A quality evaluation method based on a water permeability test of the concrete structure according to claim 1.

[Invention of Claim 3 ]
Prepare at least two types of the adhesion body,
As these two types of adhesion bodies,
Both have an air vent channel communicating with the inside of the inner chamber,
One contact body has an inner surface of the inner chamber inclined with respect to the water-permeable opening,
The other contact body uses a material in which the bottom surface of the inner chamber is parallel to the water-permeable opening and the side surface is orthogonal to the water-permeable opening.
The quality evaluation method based on the water permeability test of the concrete structure of any one of Claim 1 or 2 .

  According to the present invention, it is not necessary to damage the concrete structure to be evaluated (non-destructive), and it is possible to work on the site where the concrete structure exists, and water is supplied to the concrete structure. It is a quality evaluation method based on a permeability test of concrete structures classified as a method of continuously acting (permeability) for a predetermined time at a pressure of.

It is a side view of a water permeability test device. It is a top view of a water permeability test device. It is a side view of an air bleeding auxiliary tool. It is a side view of the state which installed the air bleeding auxiliary tool in the close_contact | adherence body. It is a top view of the state which installed the air bleeding auxiliary tool in the contact | adherence body. It is a conceptual diagram of the water permeability test using a contact body. It is explanatory drawing using properly two types of contact bodies. It is a top view of a water stop jig. It is a side view of a water stop jig. It is a top view of a spatula. It is a figure (1) which shows the relationship between a water transmission pressure and water transmission time, and the amount of water transmission, and a figure (2) which shows the relationship between the water transmission amount in 20 minutes of water transmission time, and an average water penetration (water transmission) depth. It is a figure which shows the relationship between water permeability and compressive strength. It is a figure which shows the relationship between a water permeability index and compressive strength. It is a figure which shows the relationship between water permeability and the neutralization depth. It is a figure which shows the relationship between a water permeability index and neutralization depth. It is a figure which shows the relationship between a water permeability and a chloride ion penetration depth. It is a figure which shows the relationship between a water permeability index and a chloride ion penetration depth.

Next, the form for implementing this invention is demonstrated.
[Permeability test equipment]
1 and 2 show a water permeability test apparatus 1 used in the present embodiment (quality evaluation). This water permeability test apparatus 1 has an adhesion body 10 that is in close contact with the surface Cx of the concrete C constituting the concrete structure.

  Examples of the concrete structure to be evaluated include bridge girders, RC floor slabs, wall rails, building outer walls, and the like. Further, by using it together with a second adhesion body 10x described later, the concrete surface Cx is, for example, as shown in FIG. 7, an upper surface Cx1 facing upward or a lower surface Cx2 facing downward. Even the side surface Cx3 facing sideward, the upper inclined surface Cx4 facing obliquely upward, or the lower inclined surface Cx5 facing obliquely downward can be tested. The inclination angle of the inclined surfaces Cx4, 5 is not particularly limited, and is a so-called omnidirectional test / evaluation method.

  As shown in FIG. 2, the contact body 10 has a circular cylindrical shape in plan view. Moreover, the contact | adherence body 10 has the inner side chamber 11 and the outer side chamber 12, as shown in FIG.1 and FIG.2. The inner chamber 11 has a water permeable opening 11x. For example, the water-permeable opening 11x has a perfect circle shape as shown in the drawing. On the other hand, the outer chamber 12 has a contact opening 12x that extends in a ring shape outside the water-permeable opening 11x. The contact opening 12x has, for example, a donut shape as illustrated.

  The bottom surface 11a that is the inner surface of the inner chamber 11 is a conical surface that is inclined so that the center side is far from the water-permeable opening 11x. The inclination angle of the bottom surface (conical surface) 11a is, for example, 0 to 52 °, preferably 45 °. Similarly, the side surface 11b which is the inner surface of the inner chamber 11 is also inclined. However, the side surface 11b is inclined so that the center side is close to the water-permeable opening 11x. The inclination angle of the side surface 11b is, for example, 0 to 52 °, preferably 45 °.

  The close contact body 10 has a water supply flow path 24 having one end facing the inside of the inner chamber 11 and the other end opening on the peripheral surface of the close contact body 10. In addition, a connecting pipe 23 that protrudes radially outward from the peripheral surface is attached to the peripheral surface of the contact body 10 by a method such as screwing. The connection pipe 23 communicates with the other end of the water supply flow path 24 (hereinafter, also referred to as “water supply flow path 24” including the connection pipe 23). The connection pipe 23 is provided with an open / close lever 23x as shown in the drawing as necessary. A hose or the like can be connected to the tip of the connection pipe 23.

  The close contact body 10 has an air vent channel 34 having one end facing the inner chamber 11 and the other end opening on the peripheral surface of the close contact body 10. The air vent channel 34 is formed so as to be point-symmetric with the water supply channel 24 about the axis of the contact body 10. A connecting pipe 31 that protrudes radially outward from the peripheral surface is attached to the peripheral surface of the contact body 10 by a method such as screwing. The connection pipe 31 communicates with the other end of the air vent flow path 34 (hereinafter also referred to as “air vent flow path 34” including the connection pipe 31). The connecting pipe 31 is provided with an open / close lever 31x as shown in the drawing as necessary. A hose or the like can be connected to the distal end portion of the connection pipe 31, but air A can also be directly released into the atmosphere from the distal end opening without connecting a hose or the like.

  The close contact body 10 has a second air vent channel 33 whose one end faces the inside of the inner chamber 11 and the other end opens on the peripheral surface of the close contact body 10. The air vent channel 33 is formed along the axis of the contact body 10. A connecting pipe 32 protruding upward from the top surface is attached to the top surface of the contact body 10 by a method such as screwing. The connection pipe 32 communicates with the other end of the second air vent flow path 33 (hereinafter, also referred to as “air vent flow path 33” including the connection pipe 32). Although not shown in particular, the connection pipe 32 may be provided with an opening / closing lever, as with the connection pipe 31. A hose or the like can be connected to the distal end portion of the connecting pipe 32, but the air A can also be directly released into the atmosphere from the distal end opening without connecting the hose or the like.

  The close contact body 10 has a pressure reducing flow path 52 having one end facing the inside of the outer chamber 12 and the other end opening on the peripheral surface of the close contact body 10. The pressure reducing flow path 52 is formed in a direction orthogonal to the direction in which the water supply flow path 34 and the air vent flow path 34 are formed. A hose or the like can be connected to the other end portion of the pressure reducing flow path 52 directly or via a connection pipe similar to the connection pipes 23, 31, and 32.

  The water permeability test apparatus 1 has a water reservoir 21 that is a supply source (water supply source) of water W supplied into the inner chamber 11 in addition to the above-described contact body 10. For example, a test tube capable of measuring the water level can be used as the water reservoir 21. The water reservoir 21 is connected to the connection pipe 23 by a hose or the like, and the water W stored in the water reservoir 21 is supplied to the inner chamber 11 via the hose, the connection pipe 23, the water supply channel 24, or the like. Supplied in. The supply of water W can be stopped by closing the opening / closing lever 23x.

  The water permeability test apparatus 1 further includes a pressurizing unit 22 that pressurizes the water W in the water reservoir 21. As this pressurization means 22, a compressor etc. can be used, for example. By the pressurization by the pressurizing means 22, the water W supplied into the inner chamber 11 is also pressurized. This pressurization can be performed such that the water pressure applied to the concrete surface Cx is, for example, 1 to 100 kPa so as to be a predetermined pressure. Thus, by controlling the water pressure applied to the concrete surface Cx by the pressurizing means 22, the concrete surface Cx is applied to the concrete surface Cx according to the progress of the water permeability test, that is, as the water W in the water reservoir 21 decreases. Such a problem that the water pressure decreases does not occur.

  The water permeability test apparatus 1 further includes a decompression means 51 such as a vacuum pump that decompresses the inside of the outer chamber 12. As this decompression means 51, a vacuum pump etc. can be used, for example. The decompression means 51 is communicated with the decompression flow path 52 by a hose or the like. When the decompression means 51 is operated, the air (air) in the outer chamber 12 is sucked through the decompression flow path 52, the hose and the like.

  As shown in FIGS. 3 to 5, the water permeability test apparatus 1 has an air venting auxiliary tool 70 disposed in the inner chamber 11. The air bleeding aid 70 has an air bleeding pipe 71. As shown in FIG. 4, the air vent pipe 71 is inserted into the connection pipe 32 at the base end side. A conical support member 72 is provided at the tip of the air vent pipe 71. The inclination angle α (see FIG. 3) of the conical surface of the support member 72 is, for example, 12 to 52 °, preferably 45 °.

  A porous plate 73 made of a porous stone or the like is attached to the bottom surface of the support material 72. For example, as shown in FIG. 5, the porous plate 73 has a perfect circle shape in plan view. The porous plate 73 is located at the center of the water-permeable opening 11x in the arrangement state. The air in the hole of the porous plate 73 can be sucked through the air vent pipe 71. The separation distance L (see FIG. 4) between the periphery of the porous plate 73 and the periphery of the water-permeable opening 11x is preferably 2 to 3 mm.

[Water permeability test and evaluation method]
In conducting a water permeability test using the above water permeability test apparatus 1, first, the adhesion body 10 is brought into contact with the concrete surface Cx. This contact is performed so that the water-permeable opening 11x and the contact opening 12x face the concrete surface Cx.

  Next, in this state, the decompression means 51 is operated to suck the air A in the outer chamber 12 through the decompression flow path 52. By this suction, as conceptually shown in FIG. 6, the inside of the outer chamber 12 is depressurized and the adhesion body 10 adheres to the concrete surface Cx. In the contact body 10y shown in FIG. 6, the air A is sucked from the top surface of the contact body 10y through the decompression flow path 52x. However, the decompression flow path 52 from the side surface of the contact body 10 is shown. This is conceptually similar to the present embodiment in which air A is sucked through. 6 shows a form in which water W is supplied from the top surface of the contact body 10y through the water supply flow path 24x, but the water supply flow path 24 from the side surface of the contact body 10 is shown. This is conceptually similar to this embodiment in which the water W is supplied through.

  In this embodiment, a sealing material 15 is provided on the bottom surface of the contact body 10 as shown in FIG. The thickness of the sealing material 15 is, for example, 3 to 5 mm.

  The sealing material 15 can be constituted by, for example, a rubber sheet or the like, preferably an ultra-low hardness rubber sheet. As the ultra-low hardness rubber sheet, for example, a rubber sheet having a hardness (JIS-A) of 1 to 5 can be used. Moreover, as a raw material, EPDM (ethylene propylene diene rubber), silicone rubber, etc. can be illustrated. Further, the sealing material 15 is formed by laminating two or more rubber sheets, and preferably has a hardness (JIS-A) of “rubber sheet on the adhesive body 10 side”> “rubber sheet on the concrete surface Cx side”. It can be configured by stacking.

  The sealing material 15 is bonded to the bottom surface of the contact body 10 with an adhesive or the like. By this adhesion, it is possible to prevent the air W and water A from leaking between the bottom surface of the contact body 10 and the sealing material 15 or the air A from flowing in. However, this bonding is preferably performed so that the sealing material 15 can be peeled off from the adhesion body 10. By allowing the sealing material 15 to be peeled off, even when the sealing material 15 is consumed or deteriorated, the main body of the adhesion body 10 can be continuously used by replacing the sealing material 15. In addition, the coating thickness of an adhesive agent can be 0.2-0.3 mm, for example.

  By the way, depending on the properties such as the smoothness of the concrete surface Cx, water W, air A, etc. may leak or the air A may flow from between the concrete surface Cx and the sealing material 15. In particular, in this embodiment, since the water permeability test is performed by applying pressure to the water W, there is a high possibility that the pressurized water (pressurized water) W leaks. Therefore, in this embodiment, prior to the contact body 10 coming into contact with the concrete surface Cx, the seal layer 15y is formed on the portion of the concrete surface Cx coming into contact with the contact body 10.

  The seal layer 15y is preferably formed using a seal material having a water-repellent property to prevent the leakage of the pressurized water W and having a peelability that can be easily removed from the concrete surface Cx after completion of the water permeability test. is there. As a sealing material having such water-stopping properties and peelability, it is preferable to use extremely soft paper clay. Extremely soft paper clay has the characteristics of being extremely soft and less sticky.

  However, since extremely soft paper clay is soft, it may be difficult to form it in an appropriate range (region) with an appropriate thickness, and it may take time for formation. Therefore, in particular, when the sealing layer 15y is formed using a sealing material such as extremely soft paper clay, it is preferable to use the coating jig 80 shown in FIGS. 8 and 9 and the spatula 83 shown in FIG. .

  The coating jig 80 includes a flat plate material 81 and a gripping material 82 protruding from the surface of the plate material 81. The plate material 81 has a first notch 81a and a second notch 81b. The first notch 81a and the second notch 81b have a donut shape in plan view, and have the same shape as a portion that contacts the contact body 10 of the concrete surface Cx. Further, the thickness L2 of the plate material 81 is the same as the thickness (predetermined thickness) of the seal layer 15y, and is, for example, 0.1 to 1.0 mm.

  In forming the seal layer 15y using the coating jig 80, first, the back surface of the plate material 81 is brought into contact with the concrete surface Cx by gripping the gripping material 82 or the like. Then, the sealing material is filled into the first notch 81a and the second notch 81b. This filling is performed using a spatula 83, and the sealing material that rises above the surface of the plate material 81 is scraped off at the tip 83 </ b> A of the spatula 83. Thereby, the seal layer 15y having a predetermined thickness made of the seal material is formed. In addition, the site | part between the water-permeable opening 11x of the contact body 10 and the contact opening 12x contacts the seal layer 15y formed through the first notch 81a. Further, a portion outside the contact opening 12x of the contact body 10 contacts the seal layer 15y formed through the second notch 81b. Further, as shown in FIG. 6, the seal layer 15y may be slightly wider than the contact portion of the concrete surface Cx with the adhesion body 10, but in order to conduct a water permeability test more accurately, a water permeability opening is provided. It is preferable not to form the portion where 11x is located.

  When the contact body 10 is brought into close contact with the concrete surface Cx as described above, the inner chamber 11 is filled with water W. The filling of the water W can be performed by supplying the water W stored in the water reservoir 21 into the inner chamber 11. When the water W is supplied, the air in the inner chamber 11 is discharged from the air vent channels 33 and 34.

  However, when the concrete surface Cx is a lower surface Cx2 facing downward as shown in (2) of FIG. 7, water W is put into the inner chamber 11 before the contact body 10 abuts against the concrete surface Cx. It can also be charged.

  Further, when the water permeability test / evaluation method of this embodiment is an omnidirectional type, at least two types of adhesion bodies different from the above adhesion body 10 (hereinafter also referred to as “first adhesion body”) are used. Prepare a close contact body. Hereinafter, a description will be given with reference to FIG.

  A second adhesion body different from the first adhesion body 10 is denoted by reference numeral 10x in FIG. In the second contact body 10x, the bottom surface 11a of the inner chamber 11 is parallel to the water permeable opening (concrete surface), and the side surface 11b is orthogonal to the water permeable opening. That is, the second adhesion body 10x differs from the first adhesion body 10 in that the bottom surface 11a and the side surface 11b of the inner chamber 11 are not inclined with respect to the water-permeable opening.

  For example, as shown in (1) to (3) of FIG. 7, the two types of adhesion bodies 10 and 10x are the first adhesion bodies 10 when the concrete surface Cx is the upper surface Cx1, the lower surface Cx2, or the side surface Cx3. As shown in (4) and (5) of FIG. 7, when the concrete surface Cx is the inclined surfaces Cx4 and Cx5, the concrete surface Cx is oriented so that the second adhesion body 10x is used. Use properly depending on the direction.

  According to this proper use method, bubbles (air) or the like generated when water W is supplied into the inner chamber 11 rises along the bottom surface 11a and the side surface 11b as indicated by arrows in the drawing. Therefore, the air in the inner chamber 11 can be surely extracted. As a result, even if the water permeability of the concrete C is measured based on the capacity rather than the mass of the water W, this measurement result is accurate, for example, only the water level of the water W existing in the water reservoir 21 is measured. Thus, the water permeability of the concrete C can be accurately grasped.

  Here, bubbles or the like in the inner chamber 11 rise along the bottom surface 11a and the side surface 11b when the bottom surface 11a and the side surface 11b are inclined by 12 ° or more with respect to the horizontal plane. Therefore, the first contact body 10 having the inclination angle of the bottom surface 11a and the side surface 11b with respect to the water-permeable opening 11x is 45 °, for example, when the concrete surface Cx is a complete upper surface (horizontal plane) Cx1 ((1 in FIG. 7 )) As well as in the case of tilting at an angle β as shown in FIG. 7 (6), it can be used if β ≦ 33 °. Therefore, as shown in the figure as a usable range, the range in which the first contact body 10 can be used overlaps the range in which the second contact body 10x can be used, and the concrete surface Cx facing all directions is formed. Can be tested and evaluated.

  When the concrete surface Cx is the upper surface Cx1, the air in the inner chamber 11 is discharged through the air vent channel 33 as shown in (1) of FIG. When the concrete surface Cx is the side surface Cx3 and the upper inclined surface Cx4, as shown in (3) and (4) of FIG. 7, the air in the inner chamber 11 is passed through the air vent channel 34. Is discharged. Further, when the concrete surface Cx is the lower surface Cx2 and the lower inclined surface Cx5, as shown in (2) and (5) of FIG. The air in the inner chamber 11 is discharged by sucking the air accumulated in the portion where the porous plate 73 is located through the air vent pipe 71.

  When the inner chamber 11 is filled with water W while taking care not to leave air in the inner chamber 11 as described above, as shown in FIG. Pressure is applied to the water W inside to apply water pressure to the concrete surface Cx.

  As described above, this water pressure is, for example, 1 to 100 kPa. For example, as shown in FIG. 1, the water pressure can be confirmed by measuring the water pressure in the inner chamber 11 through a water pressure hole 42 with a water pressure gauge 41. Further, as shown in FIG. 6, a drain pipe 43 having a valve body 43 a is provided on the top surface of the contact body 10 y, and the water pressure in the drain pipe 43 can be measured by a water pressure gauge 41. .

  Under this pressurization, a water permeability test for allowing water W to permeate into the concrete C from the concrete surface Cx is advanced. And if this water permeability test is performed for the predetermined time, the pressurization by the pressurizing means 22 is terminated, and the amount of water permeated into the concrete C (water permeation amount) is calculated based on the following formula (1). The water permeability index is calculated based on the following formula (2).

w = w ₁ −w ₀ (1)
P = ((G · ρ · w ² ) / (2 · t · A ² · P _u )) × 10 ⁻⁴ (2)

In the above formula, “w” is the water permeability (cm ³ ), “w ₁ ” is the volume of water penetrating the concrete C at the end of the water permeability test (cm ³ ), and “w ₀ ” is the water permeability. The volume of water penetrating the concrete C at the start of the test (cm ³ ), “P” is the permeability index (m / sec), “G” is the acceleration of gravity (m / sec ² ), “ρ” is the water Unit volume mass (g / cm ³ ) of W, “t” is the time (seconds) from the start of the water permeability test to the end of the water permeability test, “A” is the area (cm ² ) of the water permeability opening 11x, “P _u "Is the water pressure (kPa) applied to the concrete surface Cx.

  Further, in this embodiment, since air does not remain in the inner chamber 11, the capacity (water amount) of water W penetrating into the concrete C at the end of the water permeability test or at the start of the water permeability test is the water level of the water reservoir 21. Can be calculated based on Furthermore, when the water permeability test is started, the time when the water W in the water reservoir 21 starts to be supplied into the inner chamber 11 (at the time of starting the water supply) can be set in the water reservoir 21 by the pressurizing means 22. It is also possible to start the pressurization of the water W (at the start of pressurization). However, from the viewpoint of further improving test accuracy, the time when the water W in the water reservoir 21 is started to be pressurized by the pressurizing means 22 is set to the start of the water permeability test, and from the start of water supply to the start of pressurization. It is preferable to correct in consideration of the time and water permeability.

The water permeability index was defined as follows.
That is, first, the relationship between the water permeation (penetration) depth (see FIG. 6) and the water permeation amount is assumed as in the following equation (3).
x = w / (ε · A) (3)
x: Permeation depth (cm)
w: Water permeability (cm ³ )
A: Pressurized area (cm ² )
The water permeability w (cm ³ ) is a value calculated by the above formula (1).
And if water flows according to Darcy's law in concrete, following Formula (4) will be guide | induced.
dx / dt = (p · P _u ′) / (ρ ′ · x) (4)
t: Permeation time (seconds)
p: Permeability index (m / sec)
P _u ′: hydraulic pressure (kgf / cm ² )
ρ ′: Unit volume mass of water (gf / cm ³ )
The above formula (3) and the above formula (4) are appropriately differentiated, etc., and P = p · ε ² (P is a new water permeability index (m / sec)), and the unit volume mass of water When the unit of ρ ′ (gf / cm ³ ) is converted to ρ (g / cm ³ ) and the unit of the hydraulic pressure P _u ′ (kgf / cm ² ) is converted to P _u ′ (kPa), the above formula (2) Street.

By the way, as described above, the water permeability test can be started at the start of water supply or at the start of pressurization. In any case, the water permeability index of the present invention is useful.
That is, first, when the time from the start of water supply to the start of pressurization can be ignored, the water permeability index P (m / second) is measured by measuring the water permeability time t (seconds) and the water permeability w (cm ³ ). ) Can be calculated.

On the other hand, if the time from the start of water supply to the start of pressurization cannot be ignored, subtract (cm ³ ) the time (seconds) from the start of water supply to the start of pressurization The water permeability index P (m / sec) can be calculated.

  When the water permeability and the water permeability index are calculated as described above, the quality of the concrete structure is evaluated based on these calculated values. More specifically, for example, it is evaluated that the smaller the water permeability and the water permeability index, the stronger the compressive strength of the concrete, the shallower the neutralization depth, and the shallower the chloride penetration depth.

Next, the fact that the above evaluation is possible will be described based on various test examples.
Using the water permeability test apparatus 1 described above, the water permeability and the water permeability index of the concrete specimen were measured. The measured compressive strength, neutralization depth and chloride ion penetration depth were subjected to regression analysis as objective variables, and the compressive strength, neutralization depth and chloride ion penetration depth were determined from the water permeability and permeability index. An estimation formula for estimation was obtained. The types of concrete specimens, the conditions of the permeability test, and the actual measurement methods of compressive strength, neutralization depth and chloride ion penetration depth were as follows.

(Type of specimen)
Concrete types: N15, N22, N30, N40, N45, N60
Water-to-cement ratio (W / C): 86%, 68%, 61%, 54%, 52%, 45%, 38%, 37%, 30%
Age: 1 year, 2 years, 4 years, 6 years, 7 years Materials: Column members (height 60 x 50 x 20 cm), floor members (height 20 x 50 x 60 cm)
Curing method: Indoor (air curing), indoor (wet curing), outdoor (air curing), outdoor (humid curing)

(Conditions for water permeability test)
Diameter of water-permeable opening: φ5.0cm
Hydraulic pressure: 55 kPa (equivalent to a head height of 5.5 m)
Time to start pressurization: 30 seconds Permeability time: 20 minutes

(Measurement method)
The compressive strength of the concrete specimen was measured based on JIS A 1108. Moreover, about the neutralization depth, the phenolphthalein liquid was sprayed on the whole side surface of the concrete core test body based on JISA1152, and the length from the member surface to the colored part was measured. Furthermore, about the penetration depth of chloride ions, after immersion for 10 days based on JSCE G572-2003, the aqueous solution of silver nitrate was sprayed on the entire split surface of the concrete core specimen, and the length from the surface of the member to the portion colored grayish white. The thickness was actually measured.

(Test results)
FIG. 11 (1) shows the relationship between the water permeation time and the water permeation amount for each water permeation pressure / pressurization start time (the time from the start of the water supply until the start of pressurization) and the water permeation amount. The relationship between the water permeation amount and the average water permeation (water permeation) depth at a water permeation time of 20 minutes for each water permeation pressure / pressurization start time is shown in FIG. Table 1 shows the water permeability and water permeability index of each concrete specimen.

(Evaluation of compressive strength)
FIG. 12 shows the relationship between the water permeability and the compressive strength, and FIG. 13 shows the relationship between the water permeability index and the compressive strength. The single regression equation related to FIG. 11 is shown in the following equation (5), and the single regression equation related to FIG. 12 is shown in the following equation (6). In the following formula, “FC” indicates compressive strength (N / mm ² ), “w” indicates water permeability (cm ³ ), and P indicates water permeability index (× 10 ⁻¹⁰ m / sec). .
FC = 59.5589 · w ^-0.4760 (5)
(N = 97, R = 0.709)
FC = 40.2498 · P ^-0.2380 (6)
(N = 97, R = 0.709)

  From the above, it can be seen that the compressive strength decreases as the water permeability and water permeability index increase. Therefore, it can be evaluated that the smaller the water permeability and the water permeability index, the higher the compressive strength.

(Evaluation of neutralization depth)
FIG. 13 shows the relationship between the water permeability and the neutralization depth, and FIG. 14 shows the relationship between the water permeability index and the neutralization depth. The single regression equation related to FIG. 13 is shown in the following equation (7), and the single regression equation related to FIG. 14 is shown in the following equation (8). In the following formula, “CaD” represents the neutralization depth (mm), “w” represents the water permeability (cm ³ ), “P” represents the water permeability index (× 10 ⁻¹⁰ m / sec), Each is shown.
CaD = 6.6592 · log (w) −3.9327 (7)
(N = 97, R = 0.833)
CaD = 3.3296 · log (P) +1.5499 (8)
(N = 97, R = 0.833)
From the above, it can be seen that as the water permeability and water permeability index decrease, the neutralization depth also decreases. Therefore, it can be evaluated that the neutralization depth is smaller as the water permeability and the water permeability index are smaller.

(Evaluation of chloride ion penetration depth)
FIG. 15 shows the relationship between the water permeability and the chloride ion penetration depth, and FIG. 16 shows the relationship between the water permeability index and the chloride ion penetration depth. The single regression equation related to FIG. 15 is shown in the following equation (9), and the single regression equation related to FIG. 16 is shown in the following equation (10). In the following formula, “ChPD” is chloride ion penetration depth (mm), “w” is water permeability (cm ³ ), “P” is permeability index (× 10 ⁻¹⁰ m / sec). , Respectively.
ChPD = 14.24 · log (w) −2.6559 (9)
(N = 97, R = 0.768)
ChPD = 7.1198 · log (P) +9.0677 (10)
(N = 97, R = 0.768)

  From the above, it can be seen that the chloride ion penetration depth decreases as the water permeability and the water permeability index decrease. Therefore, it can be evaluated that the smaller the water permeability and the water permeability index, the smaller the chloride ion penetration depth.

  The present invention can be applied as a quality evaluation method based on a permeability test of concrete structures such as bridge girders and building outer walls.

  DESCRIPTION OF SYMBOLS 1 ... Water permeability test apparatus, 10 ... (1st) adhesion body, 10x ... 2nd adhesion body, 11 ... Inner chamber, 11x ... Opening for water permeability, 12 ... Outer chamber, 12x ... Opening for adhesion, 21 ... Water Reservoir, 22 ... pressurizing means, 51 ... depressurizing means, 70 ... air venting aid, 80 ... water stop jig, 83 ... spatula, A ... air, C ... concrete, Cx ... concrete surface.

Claims (3)

A quality evaluation method based on a permeability test of a concrete structure,
An adhesion body comprising an inner chamber having a water-permeable opening, and an outer chamber having an adhesion opening that extends in a ring shape outside the water-permeable opening;
A source of water to be supplied into the inner chamber;
A pressurizing means for pressurizing the water of the water supply source;
Decompression means for decompressing the inside of the outer chamber;
A water permeability test apparatus having
The contact body is brought into contact with the concrete surface such that the water-permeable opening and the contact opening face the concrete surface, and the inside of the outer chamber is depressurized by the pressure-reducing means to thereby bring the contact body into the concrete surface. Closely
On the other hand, after filling the inner chamber with water,
Pressurizing the water of the water supply source to a predetermined pressure by the pressurizing means;
Under this pressure, water from the water supply source is supplied into the inner chamber, and a water permeability test of the concrete is performed.
After a predetermined time, the water permeability of the concrete is calculated based on the following formula (1), and the water permeability index of the concrete is calculated based on the following formula (2):
Evaluating the quality of the concrete structure based on the water permeability and the water permeability index,
A quality evaluation method based on a permeability test of a concrete structure characterized by :
Prepare a plate material of a predetermined thickness having a notch of the same shape as the portion of the concrete surface that contacts the adhesion body,
Prior to abutting the contact body against the concrete surface, the plate material is abutted against the concrete surface,
Filling the notch with a sealing material having water-stopping property and peelability to form a seal layer at a site in contact with the adhesion body of the concrete surface,
A quality evaluation method based on the permeability test of concrete structures.
w = w ₁ −w ₀ (1)
P = ((G · ρ · w ² ) / (2 · t · A ² · P _u )) × 10 ⁻⁴ (2)
In the above formula, “w” is the water permeability (cm ³ ), “w ₁ ” is the volume of water permeating the concrete at the end of the water permeability test (cm ³ ), and “w ₀ ” is the water permeability. The volume of water permeating the concrete at the start of the property test (cm ³ ), “P” is the permeability index (m / sec), “G” is the acceleration of gravity (m / sec ² ), and “ρ” is Unit volume mass (g / cm ³ ) of water, “t” is the time (seconds) from the start of the water permeability test to the end of the water permeability test, “A” is the area (cm ² ) of the water permeability opening, “P _u "Is the pressure (kPa) of water applied to the concrete surface. The smaller the water permeability and the water permeability index, the stronger the compressive strength of the concrete, the lower the neutralization depth, and the lower the chloride penetration depth,
A quality evaluation method based on a water permeability test of the concrete structure according to claim 1. Prepare at least two types of the adhesion body,
As these two types of adhesion bodies,
Both have an air vent channel communicating with the inside of the inner chamber,
One contact body has an inner surface of the inner chamber inclined with respect to the water-permeable opening,
The other contact body uses a material in which the bottom surface of the inner chamber is parallel to the water-permeable opening and the side surface is orthogonal to the water-permeable opening.
The quality evaluation method based on the water permeability test of the concrete structure of any one of Claim 1 or 2 .

Images