JP6691519B2 - Method for measuring coating film consumption of structures - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a method for measuring the amount of consumption of a coating film that can accurately grasp the progress of the amount of consumption of a coating film applied to a structure such as a bridge due to ultraviolet deterioration and the like.

  As a system for diagnosing deterioration of a coating film applied to a structure such as a bridge, for example, as described in Patent Document 1, the surface of the coating film applied to the structure is photographed by a camera, There is known a method of evaluating a deterioration state by transmitting captured image data to a diagnosis place and performing image processing.

  On the other hand, in Patent Document 2, although not a steel structure such as a bridge, as a film thickness measuring method of a coating film coated on the surface of a resin component, a coating film for measuring the film thickness at the tip of a cutting blade is disclosed. By moving the cutting blade along the surface of the coating film in a state where the cutting blade passed over and entered the base material, a cutting groove having a V-shaped cross section was formed on the base material and exposed on the cutting surface of the cutting groove. A method of reading the width of the coating film in the horizontal direction and calculating the film thickness from this width and the inclination angle of the cutting surface is disclosed.

JP, 2005-283519, A JP-A-5-296702

  However, according to the deterioration diagnosis system for a coating film applied to a structure such as a bridge described in Patent Document 1, it is possible to diagnose the occurrence of peeling or rust of the coating film that occurs over time. However, it is not possible to diagnose the rate of consumption of the coating film on the entire structure due to ultraviolet deterioration and the like, and therefore it is not possible to determine the timing for repainting the structure such as a bridge.

  Similarly, since the invention described in Patent Document 2 relates to a method for measuring the film thickness of a coating film, a cutting groove must be formed by a cutting blade to a depth reaching the inside of the substrate from the coating film surface. , When cutting grooves are formed in the coating film of a structure by such a film thickness measuring method, not only is the structure itself scratched and a great deal of cost is required for post-treatment, but also because of the thickness of the coating film. Therefore, it is impossible to judge the consumption amount and the consumption speed of the coating film.

  The present invention has been made in view of such problems, and an object thereof is to easily and accurately grasp the consumption amount and the consumption speed due to ultraviolet deterioration of a coating film applied to a structure such as a bridge. It is possible to provide a method for measuring the amount of coating film consumption of a structure that can reduce the coating cost during repainting.

  In order to achieve the above object, the method for measuring the amount of coating film consumption of the structure of the present invention is as described in claim 1, wherein a masking material is layered on the surface of the coating film applied to the structure at appropriate places. After a certain period of time, install a cutting device on the coating film, and while rotating the drill equipped in this cutting device, let the cutting edge of this drill enter the coating film, and then cut at a constant cutting depth. While holding the drill, the drill is moved from the exposed coating portion to the inside of the coating portion covered with the masking material to cut a groove having a V-shaped cross section, The width of the coating film exposed in the groove provided on the exposed side of the film surface is compared with the width of the coating film exposed in the groove provided on the masking material side. It is characterized by measuring the amount of wear.

  In the method for measuring the amount of coating film wear of the structure configured as described above, the invention according to claim 2 is such that the end surface of the masking material is orthogonal to the exposed coating film portion of the coating film surface applied with the drill. It is characterized in that a groove having a V-shaped cross section is cut in the coating film by linearly moving the coating film portion covered with the masking material.

  According to a third aspect of the present invention, the coating film applied to the structure includes a base applied to the surface of the structure made of steel, an undercoat layer applied to the base, and an undercoat layer applied to the undercoat layer. A middle coat layer and an upper coat layer applied on the middle coat layer, and cutting a groove having a V-shaped cross section while maintaining the state in which the tip of the cutting edge of the drill penetrates into the undercoat layer. Is characterized by.

  According to the first aspect of the present invention, the coating film portion of the structure covered with the masking material does not wear out and retains the initial film thickness applied to the structure, while the coating film surface is exposed. The coating film portion that is being worn is consumed due to deterioration of ultraviolet rays and the like. When a groove having a V-shaped cross section with a constant depth is cut from the exposed coating film portion of the coating film surface to the coating film portion covered with the masking material, it is provided on the exposed portion side. The width of the coating film exposed on the masking material side is smaller than the width of the coating film exposed on the groove, and the width is smaller than that on the masking material side. Compare these widths. This makes it possible to easily and accurately measure the amount of wear of the coating film.

  Furthermore, in the exposed coating area, the amount of consumption of the coating increases in proportion to the passage of time, so a certain period of time such as a dozen years from the time it was applied to the structure By measuring the amount of wear of the coating film after the lapse of time, the consumption rate of the coating film, which is the most important factor in the repainting plan of the structure, can be easily grasped, and the optimum timing of the entire film recoating Can be predicted, and a repainting cycle can be set in which repainting can be economically performed.

  Further, according to the invention of claim 2, the coating film, which is formed by applying the drill of the above cutting device to the structure, is exposed, and the end surface of the masking material is orthogonally crossed from the coating film portion to be coated with the masking material. Since a straight groove having a V-shaped cross section is cut in these coating portions by linearly moving them into the coating portion, the coating portion covered with the masking material and the groove portion provided in the coating portion on the exposed portion side. The boundary with the groove provided in the part can be clearly discriminated, and the consumption of the coating film can be measured easily and accurately.

  Further, according to the invention of claim 3, the coating film applied to the structure includes a base applied on the surface of the structure made of steel, an undercoat layer applied on the base, and A groove having a V-shaped cross section, which is composed of an intermediate coat layer applied on the undercoat layer and an upper coat layer applied on the intermediate coat layer, with the cutting edge of the drill being penetrated into the undercoat layer. Since it cuts, it is possible to form a cutting groove of a predetermined depth that reaches from the top coat layer to the inside of the undercoat layer without damaging the surface of the undercoat or structure, and to coat the undercoat layer that protects the underlayer. You can determine when to change.

The simplified side view of the state where the cutting device is arranged on the coating film on the surface of the structure. The simplified perspective view of a cutting device. FIG. 4 is an enlarged vertical cross-sectional side view of a main part showing a consumption state of a coating film. FIG. 4 is a vertical cross-sectional side view showing a state in which the tip of the drill is inserted into the coating film portion whose surface is exposed. FIG. 6 is a vertical cross-sectional side view of a state in which a groove having a V-shaped cross section is cut from a coating film portion whose surface is exposed by a drill to a coating film portion covered with a masking material. The top view of the cutting groove. FIG. 3 is an enlarged vertical sectional front view of a cutting groove in a coating film portion where the coating film surface is exposed. FIG. 6 is an enlarged vertical sectional front view of a cutting groove in a coating film portion covered with a masking material.

  A specific embodiment of the present invention will be described with reference to the drawings. In FIG. 1, the surface of a structure 1 such as a bridge made of steel (in the figure, a part of the surface layer of the structure made of steel is shown in section) is shown. Is applied with a coating film 2 having a constant thickness, and when the coating film 2 is applied to the surface of the structure 1, a masking material 3 having an appropriate size is applied to an appropriate place on the surface of the coating film 2. The coating film portion 2a which is mounted and covered with the masking material 3 is protected by the masking material 3, and as shown in FIG. 3, maintains the initial film thickness without deterioration or wear. On the other hand, in the coating film portion 2b where the surface of the coating film is exposed without being covered with the masking material 3, the film thickness becomes thin due to deterioration due to UV deterioration for many years or deterioration due to flying sea salt particles. Has become.

  The coating film 2 is a base made of a coating layer of an inorganic zinc rich paint (paint containing a high concentration of metallic zinc powder) applied to the surface of the steel material constituting the structure 1 and having an excellent rust preventive effect. 21, an undercoat layer 22 composed of a coating layer of an epoxy resin coating applied on the underlayer 21, an intermediate coating layer 23 composed of a coating layer of an epoxy resin coating applied on the undercoat layer 22, and this intermediate coating The masking material 3 which is composed of a top coat layer 24 formed of a coating layer of a fluororesin paint or a polyurethane resin coat applied on the layer 23, and the masking material 3 applied at a proper position on the top coat layer 24 of the coating film 2 is formed by a black pigment. It consists of a coating layer of a colored fluororesin paint having excellent weather resistance.

  In this way, the coating film inspection for determining the time for recoating the entire surface of the coating film 2 applied to the structure 1 is performed by using the coating film cutting device 4 as shown in FIGS. The coating film 2 applied to the surface of the structure 1 is deteriorated or consumed after a certain period of time such as ten years or more, and the exposed film surface 2b is covered with the masking material 3 from the exposed film portion 2b. It is performed by cutting the groove 5 having a V-shaped cross section with a constant depth over the inside of 2a.

  The cutting device 4 is provided with leg portions 4b and 4b each having a flat lower surface at both ends of the main body 4a, and the central portion of the main body 4a is between the leg portions 4b and 4b. A drill 4c protruding toward the inside of the space is provided, and the drill 4c is rotated by a rotation driving means having a motor as a drive source provided in the main body 4a, and the leg body is moved by a lateral moving means. It is possible to reciprocate in the direction perpendicular to the axial direction of the drill 4c across the portions 4b, 4b, that is, when the drill 4c is in the vertical state, and to reciprocate in the horizontal direction. The drill 4c is moved in the axial direction by the adjusting means so that the cutting depth of the coating film by the lower cutting edge 4c1 can be adjusted.

  Incidentally, as the rotation driving means and the lateral moving means of the drill 4c, and the cutting depth adjusting means, conventionally known means, for example, a horizontal pedestal guide rail that supports the drill 4c so as to be rotatable and vertically movable. The means and the like arranged so as to be able to reciprocate are adopted. Further, the lower end cutting edge 4c1 of the drill 4c has a tip angle for cutting the groove 5 having a V-shaped cross section in the coating film 2.

  Further, side plate parts 6, 6 are provided on the side surfaces of the leg parts 4b, 4b of the cutting device 4, and these side plate parts 6, 6 are provided on both side surfaces of the leg parts 4b, 4b. The side plates 6 are attached to the structure 1 by the attraction force of the magnets arranged in the legs 4b, 4b, which are mounted so as to be movable in the direction in which they move toward and away from the lower surface. Is configured.

  The cutting device 4 is provided with a knob 7 for adjusting the vertical movement of the drill 4c, a knob 8 for adjusting the magnetic force of a magnet with respect to the structure 1, a power switch 9, and the like. Although not shown, the body 4a of the cutting device 4 is provided with a switch for adjusting the lateral movement of the drill 4c and the grinding speed.

  As shown in FIG. 1, the cutting device 4 configured in this manner coats the two leg bodies 4b, 4b so as to straddle the masking material 3 layered in place on the coat 2 of the structure 1. It is installed on the coating film parts 2b, 2b whose surface is exposed, and the magnetic force adjustment knobs 8, 8 are operated to magnetically attach both leg parts 4b, 4b to the structure 1 via the side plate parts 6, 6. By doing so, it is fixed between the coating film portions 2b, 2b.

  Then, as shown in FIG. 4, the drill 4c is lowered while rotating, and as shown in FIG. 4, the undercoat layer of this coating film portion 2b in one coating film portion 2b in which the tip surface of the cutting edge 4c1 is exposed 5 is shown in FIG. 5 in a state where the tip of the drill 4c maintains a constant cutting depth from the surface of the coating film portion 2b to the inside of the undercoat layer 22. As described above, by moving the drill 4c parallel to the steel surface of the structure 1 toward the coating film portion 2a covered with the masking material 3, the masking material 3 is masked from the coating film portion 2b not layered. A groove 5 having a V-shaped cross section having a constant depth is cut across the coating film portion 2a covered with the material 3.

  At this time, in the coating film portion 2a covered with the masking material 3 while intersecting the drill 4c from the exposed coating film portion 2b side to the end surface of the masking material 3 at an appropriate angle. Although the groove 5 having a V-shaped cross section is cut while being moved over, the drill 4c is moved while intersecting the end face of the masking material 3 at a substantially right angle to cut the groove 5 having a V-shaped cross section. Preferably. The drill 4c may be moved from the coating film portion 2a side covered with the masking material 3 toward the coating film portion 2b whose surface is exposed to cut the groove 5 having a V-shaped cross section.

  As described above, by the drill 4c of the cutting device 4, the V-shaped cross-section having a constant depth extends from the exposed coating film portion 2b of the coating film surface to the coating film portion 2a covered with the masking material 3. After the groove 5 is cut, the cutting device 4 is removed from the structure 1, and then the coating film surface exposed in the groove 5 having the V-shaped cross section is photographed by a microscope camera (not shown).

  6 is a plan view diagrammatically showing the coating film surface exposed in the V-shaped groove 5 photographed by a microscope camera, and FIG. 7 shows the coating film surface in the groove 5 exposed. FIG. 8 is a cross-sectional view schematically showing a cross-sectional photograph of the coating film portion 2b, and FIG. 8 is a cross-sectional view schematically showing a cross-sectional photograph of the coating film portion 2a covered with the masking material 3 in the cutting groove 5. is there.

  Since the coating film portion 2a covered with the masking material 3 is protected by the masking material 3, as shown in the right part of FIG. 6 and FIG. In the coating film portion 2b where the coating film surface is exposed although it is held, it is consumed due to deterioration due to ultraviolet rays for many years and deterioration due to flying sea salt particles. As shown, the film thickness is thin. In the figure, the coating film is wasted in the coating film portion 2b in the portion of the overcoat layer 24, and as shown in FIG. The difference between the thickness and the thickness of the overcoat layer 24 'of the coating film portion 2b exposed on the coating film surface appears as the consumption amount t of the coating film 2.

  Further, the film thickness a of the coating film 2 is b, where the projection width from the tip of the groove bottom of the groove 5 having a V-shaped cross section to the surface of the coating film 2 is b, and the inclination angle of the groove 5 is α. , A = btan α, it can be calculated from the projected width b1 of the coating film portion 2a covered with the masking material 3 and the projected width b2 of the coating film portion 2b exposed on the coating film surface. By calculating the respective film thicknesses a1 and a2 of the coating film portions 2a and 2b, the consumption amount t can be known from the difference between the film thicknesses.

  Further, the consumption rate of the coating film 2 can be known by dividing the consumption amount t by the number of years from the beginning of coating the structure to the measurement date.

  In the above-mentioned coating film 2 applied to the structure 1, the base 21 is made of an inorganic zinc rich paint coating layer having excellent durability, but when the base 21 is exposed, the adhesive force is secured for repainting. In-situ blast processing is required to do so, which requires a great deal of cost.

  For this reason, as described above, the wear and deterioration state of the coating film 2 is periodically and continuously measured, and the structure 1 is set to be repainted before the consumption amount of the coating film reaches this base. However, since the setting time can be set from the consumption speed of the coating film 2 to the time when it reaches as close to the substrate 21 as possible, the repainting cycle can be extended and the repainting cost due to the huge repainting area of the structure. It is possible to reduce the maintenance cost while suppressing the above.

1 structure 2 coating film 3 masking material 4 cutting device
4a Drill 5 Cutting groove with V-shaped cross section
21 groundwork
22 Undercoat layer
23 Middle coat
24 Overcoat layer

Claims (3)

  The masking material is layered on the surface of the coating film applied to the structure, and after a certain period of time, a cutting device is installed on the coating film and the drill equipped with this cutting device is rotated while rotating. After the tip of the cutting edge of is inserted into the coating film, a drill is held in a state where a constant cutting depth is maintained, and the coating surface is exposed from the exposed coating portion to the coating portion covered with a masking material. A groove having a V-shaped cross section is cut by moving the groove across the surface of the coating film, and the width of the coating film portion exposed on the side of the exposed surface of the coating film and the masking material side are provided. A method for measuring the amount of coating film consumption of a structure, which comprises measuring the amount of coating film consumption by comparing the width of the coating film portion exposed in the groove.   V-shaped cross section on the coating film by moving the end surface of the masking material orthogonally to the inside of the coating material part where the masking material is exposed The method for measuring the amount of coating film wear of a structure according to claim 1, wherein the groove is cut.   The coating applied to the structure is a base applied to the surface of the structure made of steel, an undercoat layer applied on the base, and an intermediate coating layer applied on the undercoat layer, 2. A groove having a V-shaped cross section, which is composed of an upper coating layer applied on an intermediate coating layer, and which maintains a state in which the tip of the cutting edge of the drill has penetrated into the lower coating layer. A method for measuring the amount of coating film wear of a structure according to.

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