JP2011226961A - Neutralization depth measuring method and neutralization determining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a neutralization depth measuring method and a neutralization determining method which can be realized by an extremely simple method without using an exclusive measuring implement after suppressing a drilling depth by a concrete drill even while drilling a concrete surface using it.SOLUTION: On a concrete surface 23, a measuring recess 30 in an inverted conical shape is drilled (S2). After spraying distilled water using an atomizer or the like, the measuring recess 30 is washed to wash off concrete powder (S3), and moisture is removed from there (S4). A neutralization determining reagent is sprayed to the concrete surface inside the measuring recess 30 using an atomizer (S5), and a boundary of a neutralized layer 21 and a non-neutralized layer 22 is discolored and exposed visibly with the naked eye. After the discoloration, the value of the entire diameter d1 of the measuring recess 30 and the value of a non-neutralized area diameter d2 are measured using a general length measuring device such as vernier calipers or a ruler (S6).

Description

  The present invention relates to a neutralization depth measurement method for measuring the neutralization depth of concrete and a neutralization determination method for determining the degree of progress of neutralization in concrete.

  2. Description of the Related Art Conventionally, there is a determination method using a concrete neutralization depth as one of methods for determining a deterioration degree of a concrete structure such as a road bridge. This judgment method using the neutralization depth of the concrete focuses on the phenomenon that the strongly alkaline concrete is gradually changing from the concrete surface to neutrality as the deterioration progresses. This is a method for determining the degree of deterioration of concrete based on the depth (thickness) of the concrete, and is known as a general method for determining the degree of deterioration of a concrete structure.

  Here, sound concrete originally exhibits strong alkalinity (about pH 12) as described above, and this strong alkalinity prevents corrosion of reinforcing steel, but the carbonation of concrete due to carbon dioxide in the atmosphere, etc. When the alkalinity gradually decreases from the concrete surface over time, for example, when the alkalinity component is eluted or the alkali component is eluted from the concrete, the anticorrosive atmosphere in the concrete is destroyed, leading to corrosion of the reinforced steel material. For this reason, it is necessary to grasp the progress of the neutralization of concrete by measuring the neutralization depth of concrete.

  For example, the neutralization depth measurement method described in Patent Document 1 (Japanese Patent No. 3342308) and Patent Document 3 (Japanese Patent Publication No. 7-104339) is a sample for measurement from a concrete structure. After collecting the concrete core and spraying the phenolphthalein solution on the surface of the concrete core, the boundary between the alkaline part (red change part) and the neutralization part (no change part) on the surface of the concrete core is visualized. Measure the distance from the boundary position to the end face of the concrete core (the end face that was the concrete surface of the concrete structure) using a ruler, etc., and use the measured value as the concrete neutralization depth at the measurement point. is there.

  On the other hand, the neutralization depth measuring method described in Patent Document 1 and Patent Document 2 (Japanese Patent Application Laid-Open No. 2005-233819) is a hole of several millimeters to several tens of millimeters by a concrete drill on the concrete surface of a concrete structure. When drilling or applying a phenolphthalein solution into the hole after drilling the hole toward the deep part of the concrete, the boundary between the alkaline part (red change part) and the neutralization part (no change color part) on the inner surface of the hole After visualizing the position, insert a dedicated optical measuring instrument inside the hole, measure the distance from the concrete surface to the boundary position, and use this measurement value as the concrete neutral depth at the measurement point It is.

  In addition, the concrete deterioration inspection method described in Patent Document 3 is a method in which a 10 mm (about 5 to 6 mm) hole is drilled in the concrete surface of a concrete structure with a bit toward the deep part of the concrete, and an inspection reagent is placed in the hole. When the phenolphthalein solution is sprayed and the color of the dust accompanying the perforation that adsorbs the test reagent changes to red indicating alkalinity, the perforation is stopped, and the perforation depth at the time of this suspension is measured The measured value is used as the concrete neutralization depth at the measurement point.

Japanese Patent No. 3342308 Japanese Patent Laying-Open No. 2005-233819 Japanese Examined Patent Publication No. 7-104339

  However, in the conventional neutralization depth measurement method performed using a concrete core, it is necessary to use a dedicated core drilling machine equipped with a core drill in order to extract the concrete core from the concrete structure. The operation is complicated, and there is a problem that the working time and cost required for removing the concrete core increase. In addition, after the core is collected, it is necessary to refill the hole that has been opened after the core is collected, which further complicates the operation and increases the cost.

  In addition, in the method of measuring the neutralization depth using such a concrete core, after spraying the phenolphthalein solution onto the surface of the concrete core, the alkaline part (red change part) and the neutralization part (no change color part) ), Draw a line with a pencil at the boundary, paint the neutralized part with pencil, apply cellophane to this neutralized part, transfer the pencil color painted on the neutralized part to cellophane, this cellophane The average neutralization depth is calculated by obtaining the area of the neutralized portion copied in (1) and dividing the area by the circumference of the concrete core.

  However, such a measuring method has a problem that transfer to a cellophane tends to be unclear and it is difficult to accurately calculate a neutralization depth of about several mm from the concrete surface. In addition, since the properties of the surface of the concrete core may change due to contact with the atmosphere, etc., the measurement of the neutralization depth using the concrete core must be carried out immediately after collecting the concrete core. There is a problem that it is very complicated to draw a cylindrical core with a pencil or the like and transfer it to a cellophane at the sampling site, making it difficult to obtain an accurate measurement result.

  Moreover, also about the neutralization depth measuring method described in patent documents 1 and 2, after drilling a hole in a concrete surface and spraying and adhering a phenolphthalein solution, an optical measuring device dedicated to the hole There is a problem that the working time and cost required for removing the concrete core increase. In particular, for the deterioration inspection method described in Patent Document 3, it is necessary to determine the color change of the dust at the same time while drilling a hole with a bit, and it is difficult to determine the change in the color state of the dust. After drilling has progressed to the non-neutralized part beyond the neutralized part, it is feared that the coloring of the dust will be noticed, and there is a problem that the neutralization depth cannot be measured in a strict sense.

  The present invention has been made in order to solve the above-described problems. While drilling a concrete surface using a concrete drill, the depth of the drilling hole is suppressed, and a dedicated measuring instrument is used. The object is to provide a neutralization depth measurement method and a neutralization determination method that can measure the neutralization depth of concrete by a very simple method without using it.

In order to achieve this object, the neutralization depth measurement method according to claim 1 is a method for measuring the neutralization depth of concrete, wherein the concrete is measured by a drilling tool having a conical cutting edge. From the surface to the concrete conical depth, the conical recess whose inner diameter is reduced at a constant ratio is cut into the concrete surface, and the recess cut by the cutting step, Revealing the non-neutralized layer that appears on the concrete surface in the recess using a reagent that visibly reveals one or both of the neutralized part and / or non-neutralized part A measuring step for measuring a diameter (d2) of a non-neutralized region which is a planar projection image of a non-neutralized layer that has been revealed on the concrete surface in the recess by the revealing step, and the measurement Non-neutral obtained by the process Neutralization depth with diameter area (d2) a (h), and a calculation step of calculating the following equation.
h = K · (d1-d2)
Here, h: neutralization depth, K: tool coefficient of drilling tool (K = H / D (H: height of conical cutting edge of drilling tool, D: conical shape of drilling tool) The maximum outer diameter of the blade edge portion))), d1: the maximum diameter of the recess (the inner diameter of the recess at the concrete surface position), d2: the diameter of the non-neutralized region.

  In addition, in addition to the case where only the non-neutralized layer is revealed on the concrete surface in the recess by using a reagent, the “realization of the non-neutralized layer” described in claim 1 When both the layer and the non-neutralized layer are exposed, when the non-neutralized layer is relatively revealed by revealing the neutralized layer, the neutralized layer and the non-neutralized layer It is used as a term to encompass the case where the boundary is exposed.

  The neutralization depth measurement method according to claim 2 is the neutralization depth measurement method according to claim 1, wherein the measurement step reveals a non-neutralization layer on the concrete surface in the recess by the manifestation step. Then, the diameter (d2) of the non-neutralized region, which is a planar projection image of the non-neutralized layer that has been revealed on the concrete surface in the recess, is directly measured on site.

  The neutralization depth measurement method according to claim 3 is the neutralization depth measurement method according to claim 1, wherein the measurement step reveals a non-neutralization layer on the concrete surface in the recess by the manifestation step. Then, the image of the recess is taken, and the diameter (d2) of the non-neutralized region, which is a planar projection image of the non-neutralized layer that is made visible on the concrete surface in the recess, is measured from the image. To do.

  A neutralization depth measurement method according to a fourth aspect of the present invention is the neutralization depth measurement method according to any one of the first to third aspects, wherein the recess formed by the grinding step is performed before the revealing step. The concrete surface in the place is washed with distilled water, and then a washing and removing step is performed to remove water adhering to the concrete surface in the recess.

  The neutralization depth measurement method according to claim 5 is the neutralization depth measurement method according to any one of claims 1 to 4, wherein the maximum diameter (d1) of the recess is measured before the calculation step. And a calculation preliminary step of calculating the tool coefficient (K) of the drilling tool by measuring the height (H) of the conical cutting edge of the drilling tool and the maximum outer diameter (D) of the cutting tool. .

  A neutralization depth measurement method according to a sixth aspect of the present invention is the neutralization depth measurement method according to any one of the first to fourth aspects, wherein the cutting step includes the recess having a predetermined maximum diameter set in advance. The tool coefficient (K) of the drilling tool used in the drilling process is known.

  The neutralization determination method according to claim 7 is a method for determining the degree of progress of neutralization in concrete, and is formed in a depth direction of the concrete from the concrete surface by a drilling tool having a conical cutting edge. Cutting a reverse conical recess whose inner diameter is reduced at a constant ratio on the concrete surface, and a neutralized part or non-neutral with respect to the recess cut by the cutting process One or both of the neutralized portions or a reagent that makes the boundary thereof visibly visible is sprayed, and one or both of the neutralized layer and / or the non-neutralized layer that appears on the concrete surface in the recess, or these After the revealing process that reveals the boundary of the surface, and after the revealing process, the size of the planar projection image of the neutralized layer or non-neutralized layer that is manifested on the concrete surface in the recess is directly Observe the concrete And a determination step of determining the progress of the neutralization.

  The neutralization determination method according to claim 8 is the neutralization determination method according to claim 7, wherein instead of the determination step, after the revealing step, an image of the recess is captured and captured in the image. And a determination step of determining the progress of the neutralization of the concrete based on the size of the planar projection image of the neutralized layer or the non-neutralized layer that is manifested on the concrete surface in the recess.

  The neutralization determination method according to claim 9 is the neutralization determination method according to claim 7 or 8, wherein the concrete surface in the recess formed by the cutting step is distilled water before the revealing step. And then a cleaning and removing step for removing water adhering to the concrete surface in the recess.

  According to the neutralization depth measurement method of the present invention, the shape of the recess formed on the concrete surface by the drilling tool is made into an inverted cone, so that the fracture location on the concrete surface accompanying such measurement can be determined. Since it can be kept in a very narrow range both in terms of area and depth, it is possible to repair the recess after filling in a very simple and low-cost manner and minimize the impact on the strength of concrete structures. There is an effect that can be done.

  In addition, the recess can be cut using a drilling tool having a conical cutting edge, for example, a general concrete drill, without using a dedicated device such as a core cutter like a concrete core. The labor required for the cutting work can be simplified, the time can be shortened, and the cost can be reduced.

  Further, since the recess has an inverted conical shape, the inner surface in the recess is inclined with a certain angle θ in the depth direction with respect to the concrete surface (see FIG. 1A). For this reason, the width of the planar projection image of the non-neutralized layer appearing in the recess is a width obtained by enlarging the neutralization depth (h) by (1 / tan θ) times, so the neutralization depth is expanded. There is an effect that it is possible to easily measure the very thin neutralization depth (h), which is difficult to measure in the past.

  In addition, in the method of drawing on the concrete core with a pencil and transferring it to the cellophane, there is an individual difference for each measurer in the method of drawing the pencil and the method of transfer, so the error is likely to be inherent in the measurement result, There was a problem that a more accurate measurement result of the neutralization depth (h) could not be obtained. However, according to the neutralization depth measurement method of this example, such drawing and transfer are not necessary. Therefore, there is an effect that the error of the measurement result due to these can be eliminated.

  In addition, as in the methods described in Patent Documents 1 and 2, a recess formed in the concrete surface can be formed without inserting a dedicated optical measuring instrument into the hole drilled in the concrete surface and observing the inside of the hole. Since it is possible to observe directly by visual observation and to save the investigation record by directly photographing the recess using a camera etc., there is an effect that the investigation on the neutralization of concrete can be performed very easily and at low cost. .

  Furthermore, after completing the formation of the recess, the reagent is used to reveal the non-neutralized layer that appeared in the recess, and then to calculate the neutralization depth (h) Since necessary measurement can be performed, there is no need to simultaneously perform drilling and judgment of color change of dust as in the method described in Patent Document 3, and the effect that the neutralization depth of concrete can be measured more accurately. There is.

  In addition, by spraying a reagent on the concrete surface in the recess, the neutralized layer and the non-neutralized layer can appear on the concrete surface in a distinguishable state. Neutralization depth can be measured quickly without the need for extra work such as cellophane transfer, length measurement with an optical measuring instrument, and preparation thereof. For this reason, the effect that it can avoid the situation where the alkaline component in the atmosphere and an acidic component penetrate | infiltrate, and the measurement precision of neutralization depth (h) falls by exposing the concrete surface in a recess to air | atmosphere. There is.

  According to the neutralization depth measurement method of claim 4, the concrete powder generated by the cutting of the recess using the cutting tool is removed from the concrete surface in the recess by the washing and removing process before the revealing process. Can be removed. For this reason, the reagent used in the revealing step reacts with the remaining concrete powder while adhering to the concrete surface in the recess, so that the portion that should originally be a neutralized layer is revealed as a non-neutralized layer. The boundary between the neutralized layer and the non-neutralized layer can be prevented from becoming unclear, and as a result, the measurement accuracy of the neutralized depth can be prevented from being lowered.

  Moreover, since distilled water is used for cleaning in the cleaning and removing process, for example, it is possible to avoid the hydrogen ion concentration on the concrete surface appearing in the recess from being distorted by such cleaning itself, resulting in a neutralization depth. There is an effect that the measurement accuracy can be prevented from being lowered.

  According to the neutralization depth measurement method of claim 5, among the numerical values necessary for the calculation of the neutralization depth in the calculation step, the diameter (d2) of the non-neutralization region is acquired by the measurement step and remains. The tool coefficient (K) of the drilling tool and the maximum diameter (d1) of the recess are obtained by a calculation preliminary process. Therefore, even if it is difficult to cut the recess to a predetermined size due to the shape, structure, usage environment and other conditions of the concrete structure, a recess corresponding to the situation is provided in the concrete surface. As a result, the necessary neutralization depth (h) can be obtained.

  According to the neutralization depth measurement method of claim 6, among the numerical values necessary for the calculation of the neutralization depth in the calculation step, the diameter (d2) of the non-neutralization region is acquired by the measurement step and remains. Since the tool coefficient (K) of the drilling tool and the maximum diameter (d1) of the recess are known, the shape and size of the recess formed in the concrete surface can be made uniform, and a plurality of recesses can be made into concrete. There is an effect that the neutralization depth (h) acquired from each recess can be compared and evaluated by recessing the surface.

  According to the neutralization determination method of the present invention, the neutralization layer, the non-neutralization layer, or the boundary between the neutralization layer that appears on the concrete surface in the recess is revealed by the reagent, so that the concrete surface in the recess The range of the neutralized layer and the range of the non-neutralized layer can be distinguished. And if the neutralization depth of concrete is large, the area of the planar projection image of a neutralization layer will become large, and the area of the planar projection image of a non-neutralization layer will become relatively small. On the other hand, if the neutralization depth of concrete is small, the area of the planar projection image of the neutralization layer becomes small, and the area of the plane projection image of the non-neutralization layer becomes relatively large.

  That is, the size of the area of the planar projection image of the neutralized layer or the non-neutralized layer in the recess serves as an index indicating the degree of neutralization of concrete, that is, the degree of neutralization (deterioration). Therefore, by directly observing the size of the neutralized layer or the non-neutralized layer appearing in the recess on the site, there is an effect that the degree of neutralization of the concrete can be judged very simply. .

  According to the neutralization determination method of claim 8, after the revealing step, an image of the recess is taken, and from this image, the area of the planar projection image of the neutralization layer or the non-neutralization layer in the recess is obtained. If the size is derived by calculation by image processing using a computer, measurement using an area meter, or the like, there is an effect that the degree of neutralization of concrete can be determined very simply from the result.

  According to the neutralization determination method of claim 9, the concrete powder generated by the cutting of the recess using the cutting tool can be removed from the concrete surface in the recess by the washing and removing process before the clarification process. . For this reason, the reagent used in the revealing step reacts with the remaining concrete powder while adhering to the concrete surface in the recess, so that the portion that should originally be a neutralized layer is revealed as a non-neutralized layer. In addition, the boundary between the neutralized layer and the non-neutralized layer can be prevented from becoming unclear, and as a result, the determination result of the degree of progress of neutralization can be prevented from becoming inaccurate.

  Moreover, since distilled water is used for cleaning in the cleaning and removing step, for example, it is possible to avoid the hydrogen ion concentration on the concrete surface appearing in the recess from being distorted by such cleaning itself, and as a result, the degree of progress of neutralization. There is an effect that it is possible to prevent inaccurate determination results.

BRIEF DESCRIPTION OF THE DRAWINGS It is a conceptual explanatory drawing about the neutralization depth measuring method which is one Example of this invention, Comprising: (a) is a front view of a concrete drill, and the cross section of the measurement recess cut by the concrete drill It is a figure and (b) is a top view of a measurement recess. It is the flowchart which showed an example of the process of the neutralization depth measuring method of a present Example. It is the figure explaining the neutralization depth of the concrete structure actually calculated | required using the neutralization depth measuring method of a present Example, (a) is a top view of a measurement recess, The measurement position of the measurement recess was shown, and (b) was used with the measurement results of the overall diameter and non-neutralized region diameter of the measurement recess at the measurement position shown in (a). It is the table | surface which showed the tool coefficient of the concrete drill, and these neutralization depth calculated. It is explanatory drawing about the neutralization determination method of concrete using a measurement recess, (a) to (d) are all plan views of the measurement recess, and (a) to (d) It is illustrated in order from the smallest value of the sexualization depth. It is explanatory drawing which showed the modification regarding the cutting process of a measurement recess.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. FIG. 1 is a conceptual explanatory view of a neutralization depth measuring method according to an embodiment of the present invention. FIG. 1 (a) is a front view of a concrete drill 10 and the concrete drill 10 cuts it. FIG. 1B is a sectional view of the measurement recess 30 formed, and FIG. 1B is a plan view of the measurement recess 30.

  As shown in FIG. 1, in the concrete of the concrete structure 20, a neutralized portion 21 (hereinafter referred to as “neutralized layer 21”) is formed on the surface layer portion on the concrete surface 23 side. There are portions 22 (hereinafter referred to as “non-neutralized layers 22”) that still maintain alkalinity in the deeper layer portions.

  In FIG. 1, the neutralization layer 21 has a substantially uniform thickness (with a neutralization depth h) from the concrete surface 23 in the depth direction (corresponding to the arrow Z direction in FIG. 1 (a); the same applies hereinafter). The same applies hereinafter.), And the boundary between the neutralized layer 21 and the non-neutralized layer 22 is indicated by a two-dot chain line.

  The concrete drill 10 is a rotary tool that cuts concrete and drills the concrete with its conical tip 11 (blade edge), and is rotated at high speed around a central axis by a drive mechanism (not shown). The measurement recess 30 is cut in the concrete surface 23.

This concrete drill 10 has both the maximum outer diameter D (the maximum outer diameter of the conical portion) of the tip cusp portion 11 and the height H (the height of the cone portion) of the conical tip cusp portion 11. Both are known, and based on these, the tool coefficient K of the concrete drill 10 is obtained by the following equation (1).
K = H / D (1)
Here, “/” in the expression is an operator representing division (the same applies hereinafter).

  The measurement recess 30 is a recess provided in the concrete surface 23 of the concrete structure 20 to be measured. The measurement recess 30 is cut into the concrete surface 23 by the concrete drill 10 and conforms to the conical shape of the tip pointed portion 11 of the concrete drill 10.

  That is, the measurement recess 30 is formed in a shallow inverted conical shape whose inner diameter is reduced in a certain ratio in the depth direction (direction from the concrete surface 23 toward the deep portion of the concrete). For this reason, the measurement recess 30 is referred to as one point (hereinafter referred to as “convergence point”) in which the curved surface forming the inner surface thereof is from the opening (upper side in FIG. 1A) to the bottom (lower side in FIG. 1A). ) The shape converges toward P.

  In FIG. 1A, the convergence point P of the curved surface of the measurement recess 30 coincides with the deepest portion of the measurement recess 30.

  Further, in the measurement recess 30, the entire depth h 1 is a depth from the concrete surface 23 to the convergence point P of the measurement recess 30, and the neutralization depth h is the thickness of the neutralization layer 21. The non-neutralization depth h2 is a depth from the boundary position between the neutralization layer 21 and the non-neutralization layer 22 to the convergence point P of the curved surface of the measurement recess 30.

The total depth h1, the neutralization depth h, and the non-neutralization depth h2 have a relationship represented by the following formula (2). The neutralization depth h is the measurement recess 30. The total depth h1 is obtained by dividing the non-neutralization depth h2.
h = h1-h2 (2)

  The overall diameter d1 of the measurement recess 30 is the inner diameter of the measurement recess 30 at the concrete surface 23 position, that is, the maximum diameter of the measurement recess 30, and the non-neutralized region diameter d2 of the measurement recess 30 is , Non-neutralized region 32 (corresponding to the non-neutralized layer 22 inside the boundary line having the boundary line between the neutralized layer 21 and the non-neutralized layer 22 appearing in the measurement recess 30 as an outline The portion is referred to as a planar projection image (the same applies hereinafter) (see FIG. 1A).

  In FIG. 1A, the non-neutralized region 32 is finely hatched, and in FIG. 1B, the non-neutralized region 32 is similarly hatched. This fine hatching represents a state in which the non-neutralized region 32 is colored by a neutralization determination reagent described later (the same applies to FIGS. 3 and 4 below). On the other hand, the rough hatching attached | subjected in the figure in Fig.1 (a) and FIG.5 (a)-FIG.5 (c) all represents the cross section of the concrete structure 20. FIG.

  Here, since the thickness of the neutralization layer 21 is substantially uniform, the non-neutralization region 32 shown in FIG. 1 has a circular shape as shown in FIG. In addition, since the progress of neutralization in the concrete surface layer is considered to be substantially constant, except for a very special situation, the actual non-neutralized region 32 is also circular, or It is considered that the shape is close to a circle.

The measurement recess 30 thus configured itself has an inverted conical shape, and since the thickness of the neutralization layer 21 is substantially uniform, its overall diameter d1 and non-neutralization A similarity relationship is established between the region diameter d2, the overall depth h1, and the non-neutralization depth h2, and the relationship represented by the following expression (3) is established.
h2 = (d2 / d1) · h1 (3)
Here, “·” in the expression is an operator representing multiplication (the same applies hereinafter).

Therefore, the neutralization depth h is expressed by the following equation (4) when the above equation (3) is substituted into the above equation (2).
h = h1 · (1- (d2 / d1)) (4)
Here, “·” in the expression is an operator representing multiplication (the same applies hereinafter).

In addition, since the measurement recess 30 and the conical tip pointed portion 11 of the concrete drill 10 are matched, the overall depth h1 of the measurement recess 30 is the total diameter d1 and the tool coefficient K of the concrete drill 10. And is represented by the following equation (5).
h1 = (d1 / D) · H
= K · d1 (5)

Therefore, the neutralization depth h can be obtained by substituting the above formula (5) into the above formula (4), the tool coefficient K of the concrete drill 10, the overall diameter d1 of the measurement recess 30, and the non-neutralized region. Using the diameter d2, it is expressed by the following equation (6).
h = K · (d1−d2) (6)

  Here, in Equation (6), the tool coefficient K of the concrete drill 10 is obtained by actually measuring the concrete drill 10 that is actually used. Therefore, the overall diameter d1 of the measurement recess 30 and the non-neutralized region diameter d2 By actually measuring, the neutralization depth h of the concrete can be calculated from the above equation (6).

  FIG. 2 is a flowchart showing an example of the steps of the neutralization depth measurement method of this embodiment. As shown in FIG. 2, in this neutralization depth measurement method, first, a numerical value indicating the shape of the tip cusp portion 11 of the concrete drill 10, that is, the maximum outer diameter D of the tip cusp portion 11, The height H of the pointed tip 11 of the conical portion is measured, and the tool coefficient K of the concrete drill 10 is calculated from the above equation (1) using the measured values of the maximum outer diameter D and the height H. A value is determined (S1).

  After obtaining the tool coefficient K of the concrete drill 10, the concrete drill 10 is set in a drive mechanism, and the concrete drill 10 is rotated at a high speed by a drive mechanism (not shown), whereby the concrete of the concrete structure 20 is obtained. As shown in FIG. 1, an inverted conical measurement recess 30 is cut on the surface 23 (S2). Note that when the measurement recess 30 is cut, the measurement recess 30 does not have to be set to a specific value for the entire depth h1, but an inverted cone whose inner diameter is reduced at a constant rate in the depth direction. It must have a shape.

  After the formation of the measurement recess 30, the concrete powder generated by the cutting remains in the measurement recess 30. Therefore, the concrete surface in the measurement recess 30 is removed to remove the concrete powder. By spraying distilled water with a sprayer or the like, the measurement recess 30 is washed to wash away the concrete powder (S3). After this washing, the concrete surface in the measurement recess 30 is wiped with a clean cloth to remove water adhering thereto (S4).

  After the moisture removal, a phenolphthalein solution, which is a kind of acid-base indicator, is sprayed on the concrete surface in the measurement recess 30 as a neutralization determination reagent using a sprayer (S5). By spraying this phenolphthalein solution, the concrete surface in the measurement recess 30 is different in color between the portion corresponding to the neutralized layer 21 and the portion corresponding to the non-neutralized layer 22, and is neutralized. The boundary between the layer 21 and the non-neutralized layer 22 becomes obvious and becomes visible with the naked eye.

  Here, in this example, since the phenolphthalein solution is used as the neutralization determination reagent, the portion corresponding to the neutralization layer 21 in the concrete surface in the measurement recess 30 is neutral. Since there is no discoloration, the portion corresponding to the non-neutralizing layer 22 (referring to the fine hatched portions in FIGS. 1, 3A and 4) is alkaline, so red (red purple or pink) The color changes to the same color. If the color is changed in this way, the general diameter measuring device such as calipers or a ruler is used to measure the value of the overall diameter d1 of the measurement recess 30 and the value of the non-neutralized region diameter d2 (S6). .

  Then, the measured value of the overall diameter d1 and the non-neutralized region diameter d2 regarding the measurement recess 30 and the value of the tool coefficient K of the concrete drill 10 obtained in advance in the step S1 are expressed in the above equation (6). By substituting and calculating, the value of the neutralization depth h at the location of the concrete surface 23 where the measurement recess 30 is cut and formed is obtained (S7).

  FIG. 3 is a diagram for explaining the neutralization depth h of the concrete structure 20 actually obtained by using the neutralization depth measurement method of this embodiment, and FIG. FIG. 3 is a plan view of the recess 30 and shows the measurement position of the measurement recess 30, and FIG. 3B shows the overall diameter of the measurement recess 30 at the measurement position shown in FIG. It is the table | surface which showed the measurement result of d1 and the non-neutralization area | region diameter d2, the tool coefficient K of the used concrete drill 10, and these calculated neutralization depth h. In FIG. 3A, the non-neutralized region 32 is hatched as in FIG.

  As shown in FIG. 3A, the non-neutralized region 32 of the measurement recess 30 has a shape close to a circle, but is not strictly circular. Therefore, the overall diameter d1 of the measurement recess 30 and the non-neutrality The measurement area diameter d2 is measured on two straight lines L1 and L2 orthogonal to each other at the convergence point P of the measurement recess 30 when the measurement recess 30 is viewed in plan. Therefore, in FIG. 3B, the measurement result on the straight line L1 is expressed as “measurement result 1”, and the measurement result on the straight line L2 is expressed as “measurement result 2”.

  As shown in FIG. 3B, in the measurement result 1, the measurement value of the entire diameter d1 of the measurement recess 30 is 27.55 mm, and the measurement value of the non-neutralized region diameter d2 is 7.15 mm. It was. In the measurement result 2, the measurement value of the entire diameter d1 of the measurement recess 30 is also 27.55 mm, but the measurement value of the non-neutralized region diameter d2 is 5.20 mm.

  In such a case, the average value of the measured value of the entire diameter d1 of the measurement recess 30 of the measurement results 1 and 2 is 27.55 mm, and the average value of the measured value of the non-neutralized region diameter d2 is 6.175 mm. These average values were determined as final measured values of the overall diameter d1 and the non-neutralized region diameter d2 of the measurement recess 30.

  Further, the tip sharpened portion 11 of the concrete drill 10 used for forming the measurement recess 30 has a maximum outer diameter D of 26.0 mm and a height H of the conical portion of 7. Since it was 0.2 mm, when these values were substituted into the above formula (1) and calculated, the tool coefficient K of the concrete drill 10 was 0.277.

Therefore, when the tool coefficient K = 0.277, the overall diameter d1 = 27.55 mm of the measurement recess 30, and the non-neutralized region diameter d2 = 6.175 mm are substituted into the above equation (6), the following equation ( 7) As a result, the value of the neutralization depth h of the concrete structure 20 in which the measurement recess 30 was cut and formed was determined as 5.9 mm.
h = 0.277 × (27.55-6.175) = 5.9 [mm] (7)

  Here, in the measurement results 1 and 2, the overall diameter d1 of the measurement recess 30 is larger than the maximum outer diameter D of the concrete drill 10, but this is a fragile concrete compared to a metal material or the like. This is considered to be due to the fact that the concrete at the periphery of the opening in the measurement recess 30 was peeled off when the measurement recess 30 was cut.

  Therefore, when the overall diameter d1 of the measurement recess 30 exceeds the maximum outer diameter D of the concrete drill 10 (d1> D), the value of the overall diameter d1 of the measurement recess 30 is set to the value of the concrete drill. After correcting to the value of the maximum outer diameter D, the value of the neutralization depth h of the concrete structure 20 may be obtained using the above formula (6).

Specifically, in the case of the measurement results 1 and 2 described above, since the overall diameter d1 of the measurement recess 30 is corrected to 26.00 mm, the correction value of the overall diameter d1 and the tool coefficient K = By substituting 0.277 and the non-neutralized region diameter d2 = 6.175 mm into the above equation (6), the neutralization depth of the concrete structure 20 in which the measurement recess 30 is formed by cutting is provided. The value of the length h is 5.5 mm as shown in the following formula (8).
h = 0.277 × (26.00-6.175) = 5.5 [mm] (8)

  As described above, according to the neutralization depth measurement method of the present embodiment, the destruction location (measurement recess 30) of the concrete surface 23 by the concrete drill 10 is extremely narrow in both area and depth. Since it can be suppressed to the range, the measurement recess 30 after the measurement can be repaired easily and at low cost, and the influence on the strength of the concrete structure 20 can be minimized.

  Further, the concrete surface in the measurement recess 30 is inclined at a constant angle θ with respect to the depth direction that is perpendicular to the concrete surface 23, so that the neutralized region 31 (appears in the measurement recess 30. A planar projection image of a portion corresponding to the neutralization layer 21 outside the boundary line between the neutralization layer 21 and the non-neutralization layer 22 (the same applies hereinafter) (see FIG. 1B). It is observed as a ring shape having a width obtained by enlarging the neutralization depth h by (1 / tan θ) times. Since the neutralization depth h can be enlarged and observed through the measurement recess 30 in this way, it is possible to easily measure the neutralization depth h of the extremely thin neutralization layer 21 that was difficult to measure in the past. .

  In addition, in the method of drawing on the concrete core with a pencil and transferring it to the cellophane, there is an individual difference for each measurer in the method of drawing the pencil and the method of transfer, so the error is likely to be inherent in the measurement result, Although there was a problem that a more accurate measurement result of the neutralization depth h could not be obtained, according to the neutralization depth measurement method of this example, such drawing and transfer are not necessary. The error of the measurement result due to these can be eliminated.

  In addition, after the measurement recess 30 is formed and the phenolphthalein solution is sprayed, the above-described drawing or transfer to cellophane is unnecessary, so that the entire diameter d1 and non-neutrality of the measurement recess 30 can be quickly obtained. The measurement area diameter d2 can be measured.

  For this reason, alkaline components and acidic components in the atmosphere penetrate into the concrete surface in the measurement recess 30, and as a result, a portion corresponding to the neutralization layer 21 that appears in the measurement recess 30 or the non-neutralization layer 22. The range of the portion corresponding to is changed, and the situation where the measurement of the non-neutralized region diameter d2 is performed in a state where the original size of the non-neutralized region 32 is lost can be avoided, and more accurate neutralization can be achieved. The chemical depth h can be obtained.

  FIG. 4 is an explanatory view of a method for determining the neutralization of concrete using the measurement recess 30, and FIGS. 4 (a) to 4 (d) are all plan views of the measurement recess 30. In FIG. 4A to FIG. 4D, the neutralization depth h is shown in order from the smallest value. In FIG. 4A to FIG. 4D, the non-neutralized region 32 is hatched in the same manner as in FIG.

  Here, all of the measurement recesses 30 shown in FIGS. 4A to 4D are made through the steps shown in S2 to S5 in FIG. 2, and the tool coefficient K is Using a concrete drill 10 having an equal and conical tip 11, the overall diameter d1 and the overall depth h1 are made to be equal to each other, and the neutralized layer 21 and the non-neutralized layer 21 are made of phenolphthalein solution. The neutralized layer 22 has been revealed so as to be visually distinguishable.

  As shown in FIGS. 4A to 4D, these measurement recesses 30 have an area of the non-neutralized region 32 that decreases as the neutralization depth h increases. The sexifying region 31 is increasing. For this reason, the size of the area of the neutralization region 31 or the non-neutralization region 32 of the measurement recess 30 serves as an index indicating the degree of neutralization (degradation) of the concrete. By observing the size of the neutralized region 31 or the non-neutralized region 32 in a plane, the degree of neutralization (degradation) of the concrete can be determined very simply (determination step according to claim 7).

  For example, in FIG. 4A, the entire measurement recess 30 is a non-neutralized region 32, and since there is no neutralized region 31, the degree of deterioration due to the neutralization of concrete may be low. I understand. 4B, the area of the non-neutralized region 32 occupying the entire measurement recess 30 decreases, and conversely, the area of the neutralized region 31 is shifted from FIG. 4B to FIG. 4D. From this, it can be seen that the deterioration due to the neutralization of concrete is progressing.

  Also, an image of the measurement recess 30 as shown in FIGS. 4A to 4D is taken, and the area of the neutralized region 31 or the area of the non-neutralized region 32 is taken from this image. If the calculation is performed by image processing using a computer, measurement using an area meter, or the like, the degree of neutralization of concrete can be determined very simply from this result as well (determination step according to claim 8). ).

  Next, with reference to FIG. 5, the modification of the cutting process (S2) demonstrated in the said Example is demonstrated. FIG. 5 is an explanatory view showing a modified example regarding the cutting step (S2) of the measurement recess 30. FIG.

  As shown in FIG. 5 (a), in the cutting step of the measurement recess 30, before the measurement recess 30 is cut into the concrete surface 23, the entire depth h1 of the measurement recess 30 is deepened. In addition, the pilot hole 130 is cut into the concrete surface 23 by the concrete drill 110 for the pilot hole.

  The depth of the pilot hole 130 does not necessarily need to exceed the overall depth h1 of the measurement recess 30, but is the same depth as the overall depth h1 of the measurement recess 30 or the entire measurement recess 30. It may be shallower than the depth h1.

  In addition, the inner diameter of the prepared hole 130 cut at this time is sufficiently smaller than the overall diameter d1 of the measurement recess 30. Therefore, it is preferable to use a concrete drill 110 for the pilot hole whose outer diameter D1 is sufficiently smaller than the maximum outer diameter D of the pointed tip portion 11 of the concrete drill 10.

  And after cutting this pilot hole 130, as shown in FIG.5 (b), the front-end | tip sharp part 11 of the concrete drill 10 is match | combined with this pilot hole 130, and as shown in FIG.5 (c), The measurement recess 30 is cut by the concrete drill 10.

  In addition, as shown in FIG. 5C, when the pilot hole 130 has a depth greater than the total depth h <b> 1 of the measurement recess 30, the pilot hole 130 exists, and thus the convergence point of the curved surface of the measurement recess 30. P (corresponding to the position of the point P ′ in FIG. 5C) does not exist and cannot be actually measured. However, according to the neutralization depth measurement method using the above formula (6), the neutralization depth h can be obtained without using the entire depth h1 of the measurement recess 30. There is no inconvenience.

  The present invention has been described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be easily made without departing from the spirit of the present invention. It can be guessed.

  For example, in the above embodiment, when measuring the overall diameter d1 and the non-neutralized region diameter d2 of the measurement recess 30 created on the concrete surface 23 of the concrete structure 20, the actual measurement recess 30 has a dimension such as caliper. However, the measurement format is not necessarily limited to this. For example, after the non-neutralized region 32 is revealed by spraying a phenolphthalein solution, the measurement recess It is also possible to take 30 images and measure the length of the image afterwards at a place other than the site, or analyze and measure the image by image processing using a computer or the like.

  In such a case, a ruler serving as a reference for the length may be imaged together in the image. Further, in the case of such an image, the state of the non-neutralized region 32 immediately after the non-neutralized region 32 is revealed can be stored, so that the entire diameter d1 of the measurement recess 30 and the tool coefficient K are previously stored in the field. If the time after the spraying of the phenolphthalein solution elapses and the contour of the non-neutralized region 32 becomes unclear, an accurate neutralization depth is subsequently determined using the image. h can be obtained.

  In the above examples, a phenolphthalein solution that changes the color of an alkaline part, which is a non-neutralized part, to red is used as a neutralization determination reagent. However, the type of the neutralization determination reagent is not necessarily limited to this. Instead, one or both of the portion corresponding to the neutralized layer 21 and the portion corresponding to the non-neutralized layer 22 appearing in the measurement recess 30 or a boundary thereof can be visually distinguished. Any material that can be realized is acceptable.

  For example, thymol blue (basic side), phenol red, thymolphthalein, cresol red, brothymomol blue and other acid-base indicators (colorants that change color depending on the level of hydrogen ion concentration) may be used.

10 Concrete drill (drilling tool)
11 Pointed tip (blade edge)
20 Concrete structure 21 Neutralized layer 22 Non-neutralized layer 23 Concrete surface 30 Measurement recess (recess)
31 Neutralized region 32 Non-neutralized region h Neutralized depth d1 Overall diameter (maximum diameter of recess)
d2 Non-neutralized region diameter (diameter of non-neutralized region)
K Tool factor H Height of pointed tip (height of conical cutting edge of drilling tool)
D Maximum outer diameter of pointed tip (maximum outer diameter of conical cutting edge of drilling tool)
S1 Part of calculation preliminary process S2 Cutting process S3, S4 Cleaning and removing process S5 Realization process S6 Part of measurement process and preliminary calculation process S7 Calculation process

Claims (9)

In the neutralization depth measurement method for measuring the neutralization depth of concrete,
With a drilling tool having a conical cutting edge, a cutting step of cutting an inverted conical recess whose inner diameter is reduced at a constant ratio from the concrete surface in the depth direction of the concrete on the concrete surface;
Using a reagent that makes the neutralized part and / or the non-neutralized part or both of these, or the boundary thereof visible, with respect to the concave part cut by the cutting process, the concrete in the concave part A manifestation process for revealing the non-neutralized layer that appeared on the surface,
A measuring step of measuring a diameter (d2) of a non-neutralized region which is a planar projection image of a non-neutralized layer that is made visible on the concrete surface in the recess by the revealing step;
A neutralization feature comprising a calculation step of calculating the neutralization depth (h) by the following formula using the diameter (d2) of the non-neutralized region obtained by the measurement step Depth measurement method.
h = K · (d1-d2)
Here, h: neutralization depth, K: tool coefficient of drilling tool (K = H / D (H: height of conical cutting edge of drilling tool, D: conical shape of drilling tool) The maximum outer diameter of the blade edge portion))), d1: the maximum diameter of the recess (the inner diameter of the recess at the concrete surface position), d2: the diameter of the non-neutralized region.   The measurement step is a planar projection image of the non-neutralized layer that is exposed on the concrete surface in the recess after the non-neutralized layer is exposed on the concrete surface in the recess by the revealing step. 2. The neutralization depth measurement method according to claim 1, wherein the diameter (d2) of a non-neutralization region is directly measured on site.   In the measurement step, after the non-neutralization layer is made visible on the concrete surface in the recess by the revealing step, an image of the recess is taken, and the image is made visible on the concrete surface in the recess. 2. The neutralization depth measuring method according to claim 1, wherein the diameter (d2) of the non-neutralized region which is a planar projection image of the non-neutralized layer is measured.   Before the revealing step, the concrete surface in the recess that has been cut by the cutting step is washed with distilled water, and thereafter, a washing and removing step of removing water adhering to the concrete surface in the recess. The neutralization depth measuring method according to any one of claims 1 to 3, wherein the neutralization depth is measured.   Before the calculation step, the maximum diameter (d1) of the recess is measured, and the height (H) of the conical cutting edge part of the drilling tool and the maximum outer diameter (D) of the cutting edge part are measured. The neutralization depth measurement method according to any one of claims 1 to 4, further comprising a calculation preliminary step of calculating a tool coefficient (K) of the drilling tool.   The cutting step is to cut the recess having a predetermined maximum diameter set in advance, and the tool coefficient (K) of the drilling tool used in the drilling step is known. The neutralization depth measuring method according to any one of claims 1 to 4. In the neutralization judgment method for judging the progress of neutralization in concrete,
With a drilling tool having a conical cutting edge, a cutting step of cutting an inverted conical recess whose inner diameter is reduced at a constant ratio from the concrete surface in the depth direction of the concrete on the concrete surface;
A reagent that makes the neutralized part or the non-neutralized part or both of them or a boundary thereof visibly visible is sprayed on the concave part formed by the cutting process, and the inside of the concave part is sprayed. A revealing step of revealing one or both of the neutralized layer or the non-neutralized layer that appeared on the concrete surface, or a boundary thereof;
After the manifestation process, the size of the planar projection image of the neutralized layer or non-neutralized layer that is manifested on the concrete surface in the recess is directly observed on site, and the progress of neutralization of the concrete A neutralization determination method comprising: a determination step of determining a degree.   Instead of the determination step, after the revealing step, an image of the recess is taken, and a neutralized layer or a non-neutralized layer that is revealed on the concrete surface in the recess captured in the image The neutralization determination method according to claim 7, further comprising a determination step of determining the progress of the neutralization of the concrete based on the size of the planar projection image.   Before the revealing step, the concrete surface in the recess that has been cut by the cutting step is washed with distilled water, and thereafter, a washing and removing step of removing water adhering to the concrete surface in the recess. The neutralization determination method according to claim 7 or 8, wherein the neutralization determination method is provided.

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