JP7208090B2 - Concrete structure deterioration diagnosis tool - Google Patents

Description

The present invention relates to a deterioration diagnosis tool for concrete structures.

Various developments have been made so far on the deterioration diagnosis technology of concrete structures.
As this type of technology, for example, the technology described in Patent Literature 1 is generally known. Patent Literature 1 describes a destructive inspection method for coring and analyzing concrete from a concrete structure.

However, the coring operation requires partial destruction of the concrete structure. There is also a demand for a simpler method.
Development of non-destructive inspection methods is currently underway. For example, in Patent Document 2, a concrete structure is installed by attaching a mortar pan to a concrete structure with a liquid epoxy adhesive, peeling it off after a certain period of time, collecting it, and measuring the amount of salt. A method has been proposed to evaluate the amount of salinity at the location where

JP 2010-230383 A JP 2014-105136 A

However, as a result of investigation by the present inventor, it has been found that the mortar panel described in Patent Document 2 has room for improvement in terms of variation in adsorption characteristics.

Variations in the pore properties of mortar panels can lead to variations in their adsorption properties. Although the detailed mechanism is not clear, it is thought that the adsorption characteristics vary due to internal air bubbles and surface irregularities of the mortar panel. As a result, there may be variations in measured values, such as the amount of ionized substance permeation, which are used as criteria for evaluating deterioration.

As a result of further investigation by the present inventor, the pore diameter having the maximum peak in the differential pore volume distribution, its differential pore volume, and the pore diameter at 10% cumulative pore volume in the cumulative pore volume are used as indices. , it was found that the adsorption properties of mortar panels can be evaluated stably. As a result of further intensive research based on such findings, the present inventors have found that variation in the adsorption properties of mortar panels can be suppressed by keeping the above indices within an appropriate range, and have completed the present invention.

According to the invention,
A concrete structure composed of a plate-like mortar panel having a main surface exposed to the environment in which the concrete structure is placed and a back surface serving as an attachment surface for the concrete structure or a structure existing in the vicinity thereof. A tool for diagnosing deterioration of objects,
In the mortar panel, when the differential pore volume distribution and cumulative pore volume were calculated based on the pore size distribution measured by the mercury porosimetry,
5. The pore diameter having the maximum peak in the differential pore volume distribution is in the range of 1.0×10 ⁻² μm or more and 5.0 μm or less, and the differential pore volume at the maximum peak in the differential pore volume distribution is 5. 0×10 ⁻² ml/g or more and 2.0 ml/g or less,
In the cumulative pore volume distribution, the pore diameter at 10% cumulative pore volume is in the range of 1.0 × 10 ^-1 μm or more and 3.0 μm or less.
A deterioration diagnosis tool for concrete structures is provided.

ADVANTAGE OF THE INVENTION According to this invention, the degradation diagnostic tool of the concrete structure with which the dispersion|variation in adsorption property was suppressed is provided.

1(a) is a perspective view schematically showing an example of a deterioration diagnosis tool of this embodiment, and FIG. 1(b) is a cross-sectional view taken along the line AA in FIG. 1(a). It is a figure for demonstrating the deterioration diagnosis method of the concrete structure using a deterioration diagnosis tool. (a) is a side view schematically showing a modification of the deterioration diagnosis tool of the present embodiment, and (b) is a top view of the back side of (a). 1 is a perspective view schematically showing an example of a mold used for manufacturing a mortar panel; FIG. FIG. 3 is a schematic diagram showing an example of a package containing a deterioration diagnostic tool in a packaging bag; 4 is a diagram showing differential pore volume distribution and integrated pore volume distribution of the panel of Example 1. FIG. 5 is a diagram showing the differential pore volume distribution and integrated pore volume distribution of the panel of Comparative Example 1. FIG. FIG. 10 is a diagram showing the differential pore volume distribution and integrated pore volume distribution of the panel of Comparative Example 2;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in all the drawings, the same constituent elements are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. Also, the drawings are schematic diagrams and do not correspond to actual dimensional ratios. In this embodiment, the front, back, left, right, up, and down directions are specified as shown in the drawings. However, this is defined for convenience in order to simply explain the relative relationship of the constituent elements. Therefore, there is no limitation to the orientation during manufacture or use of the product embodying the present invention.

An overview of the concrete structure deterioration diagnosis tool of the present embodiment will be described.

FIG. 1(a) is a perspective view schematically showing an example of a deterioration diagnosis tool, and FIG. 1(b) is a sectional view taken along line AA in FIG. 1(a).

A deterioration diagnostic tool 100 of FIG. 1 includes a plate-like mortar panel 10 and an adhesion layer 20 provided on the back surface 14 of the mortar panel 10 .

The mortar panel 10 has a main surface 12 that is exposed to the environment in which the concrete structure is placed, and a back surface 14 that serves as an attachment surface to the concrete structure or a structure existing in the vicinity thereof.

The adhesion layer 20 is composed of adhesive surfaces that can be adhered on both sides, and has a main surface 22 that adheres to the back surface 14 of the mortar panel 10 and a back surface 24 that can be adhered to the structure.

By using the deterioration diagnosis tool 100 of the present embodiment, the adhesion stability to the concrete structure can be improved and the deterioration of the adherend can be suppressed, so the deterioration diagnosis of the concrete structure can be stably performed. In addition, when diagnosing deterioration, the work of attaching and collecting the deterioration diagnosis tool 100 becomes easier.

FIG. 2 is a diagram for explaining a concrete structure deterioration diagnosis method using a deterioration diagnosis tool.

An outline of the deterioration diagnosis method is, for example, to attach and fix the deterioration diagnosis tool 100 to the surface of the concrete structure 200 or the structure 210 in FIG. 2, collect and analyze after a certain measurement period.

Deterioration diagnosis targets concrete structures such as roads, railways, bridges, civil engineering structures, buildings, port facilities, plants, and power facilities that are maintained and managed for a long period of time. It is possible to evaluate the degree of deterioration of concrete structures exposed to salt damage environments such as near the coast, near the bay, and in the ocean.

The place where the deterioration diagnosis tool 100 is installed may be the surface of the concrete structure 200 or the surface of the structure 210 (for example, PWRI-type scattered salt collector) existing in the vicinity of the concrete structure 200 . The installation surface should be a flat surface without curved surfaces, steps, or irregularities. Moisture and dirt may be removed from the installation surface by washing before the deterioration diagnosis tool 100 is installed.

As for the specific installation location, when the concrete structure 200 is a bridge, examples of the concrete structure 200 include a bridge girder 202, a pier floor plate 204, a pier wall surface 206, and the like. The deterioration diagnosis tool 100 may be installed on the wall surface of the structure 210 existing near the concrete structure 200 . Alternatively, any portion in the concrete structure 200 may be installed on both the sea side and the mountain side. The number of installations in the investigation target is not particularly limited, but may be plural (for example, three or more).

The fixed period may be, for example, about one month, or may be several months to about one year.

In the analysis, the amount of chloride ions and/or the neutralization depth of the degradation diagnosis tool 100 after exposure to the environment is measured, and the degree of degradation of the installed concrete structure 200 can be estimated with high accuracy.

<Deterioration diagnosis tool 100>
The mortar panel 10 that constitutes the deterioration diagnosis tool 100 can be used without any particular limitation as long as it has a plate shape. good. Production variation between lots can be suppressed.

The thickness of the mortar panel 10 is, for example, 3 mm to 20 mm, preferably 4 mm to 15 mm, more preferably 5 mm to 10 mm. By making it equal to or greater than the above lower limit, it is possible to use the sensor even during a long measurement period. On the other hand, if the value is equal to or less than the above upper limit, it can be installed even in a narrow place, so that evaluation can be performed in a state close to the actual environment.

In the present specification, "-" means including upper and lower limits unless otherwise specified.

The area of the main surface 12 and the back surface 14 of the mortar panel 10 may be, for example, 5 cm ² to 100 cm ² , preferably 10 cm ² to 50 cm ² . Analysis accuracy improves by making it more than the said lower limit. Moreover, manufacturing stability can also be made high. On the other hand, by making it equal to or less than the above upper limit value, the handleability is improved.

The compressive strength of the mortar panel 10 is, for example, 15N/mm ² to 30N/mm ² , preferably 16N/mm ² to 28N/mm ² , more preferably 17N/mm ² to 25N/mm ² . By making it equal to or greater than the above lower limit value, damage to the mortar panel 10 during recovery can be suppressed. On the other hand, by setting it to the upper limit value or less, it becomes easier to pulverize the mortar panel 10 at the time of analysis such as measurement of the amount of chloride ions, and preparation of a measurement sample is facilitated.
The compressive strength of the mortar panel 10 is measured according to JIS A 1108.

The apparent diffusion coefficient of chloride ions in the mortar panel 10 is, for example, 10 cm ² /year or more and 50 cm ² /year or less, preferably 20 cm ² /year or more and 45 cm ² /year or less. This makes it possible to stably evaluate the state of the concrete structure.
The apparent diffusion coefficient of chloride ions in the mortar panel 10 is JSCE-G 572-2018

The adhesion layer 20 provided on the back surface 14 of the mortar panel 10 may be in the form of a sheet, and may be composed of a double-sided tape having adhesive surfaces on both sides thereof.

The adhesion layer 20 may be provided with an adhesive layer made of an adhesive. The adhesive layer may be provided at least on each of the main surface 22 and the back surface 24, and may be composed of a single layer or multiple layers. The adhesion layer 20 may have a base material such as non-woven fabric or acrylic foam between multiple adhesive layers.

As the adhesive, a known adhesive material is used, and for example, an acrylic adhesive, a silicone adhesive, an epoxy adhesive, or the like is used. Among these, acrylic adhesives are used from the viewpoint of adhesion to concrete structures and durability.

The adhesion layer 20 may be composed of a single layer or a plurality of layers in the in-plane direction of one mortar panel 10 when viewed from the direction perpendicular to the back surface 14 .

The shape of the adhesion layer 20 may be a shape along the outer shape of the mortar panel 10 when viewed in a direction perpendicular to the back surface 14, and may be, for example, a substantially square shape or a substantially rectangular shape.

The thickness of the adhesion layer 20 is, for example, 0.3 mm to 3.0 mm, preferably 0.4 mm to 2.5 mm, more preferably 0.5 mm to 2.0 mm. By making it equal to or greater than the above lower limit, it is possible to use the sensor even during a long measurement period. On the other hand, if the value is equal to or less than the above upper limit, it can be installed even in a narrow place, so that evaluation can be performed in a state close to the actual environment.

The adhesion layer 20 may cover the entire back surface 14 of the mortar panel 10 or may cover a part thereof. That is, when viewed from the direction perpendicular to the back surface 14 of the mortar panel 10, at least a part of the peripheral region of the back surface 14 may have a portion where the adhesion layer 20 is not attached. Furthermore, there may be a region where the adhesion layer 20 is not formed around the entire circumference of the peripheral region of the back surface 14 .
As a result, when the mortar panel 10 is attached to the concrete structure 200 via the adhesion layer 20, a gap is formed between the concrete structure 200 and the mortar panel 10, so that the mortar panel 10 cannot be peeled off. easier. Therefore, the workability of the deterioration diagnosis tool 100 can be improved.

When viewed in a direction perpendicular to the back surface 14 of the mortar panel 10, the coverage area of the adhesion layer 20 covering the back surface 14 is, for example, 85% to 95%, preferably 85% to 95% of the total area of the back surface 14. 87% to 93%. By making it equal to or greater than the above lower limit, it is possible to use the sensor even during a long measurement period. On the other hand, by making it equal to or less than the above upper limit, it becomes easy to remove the mortar panel 10 after the measurement period has elapsed.

3A and 3B are schematic diagrams of a modification of the degradation diagnostic tool 100, where (a) is a side view of the degradation diagnostic tool 100 and (b) is a top view of the back side.

The deterioration diagnostic tool 100 may include a peelable peeling layer 50 on the back surface 24 of the adhesion layer 20 .
By peeling off the release layer 50 (cover film) from the adhesion layer 20 (double-sided tape) on the back surface 24 side, the deterioration diagnosis tool 100 can be installed. Therefore, the workability of the deterioration diagnosis tool 100 can be improved.
The back surface 24 of the adhesion layer 20 is a surface located on the opposite side of the main surface 22 that is in close contact with the back surface of the mortar panel 10 . In addition, by protecting the adhesive surface of the adhesion layer 20 with the release layer 50, it is possible to prevent the adhesive surface (back surface 24) from being contaminated before use.

The release layer 50 is made of a known material, but may be made of, for example, silicone-treated plain paper (release paper), polyester, or the like.

Further, in the degradation diagnostic tool 100, the main surface 12 of the degradation diagnostic tool 100, which is the exposed surface, may be exposed, and the shielding layer 30 may be provided on other surfaces, for example, the side surface 16 of the degradation diagnostic tool 100. good.
For example, all four sides 16 of the mortar panel 10 having a substantially square or cuboid shape may be coated with the shielding layer 30 .

The shielding layer 30 may shield chloride ions or carbon dioxide, and may be a metal seal tape in which an adhesive layer is laminated on a metal layer, such as an aluminum tape. The entire side surface 16 may be covered with aluminum tape. As a result, the degradation diagnosis tool 100 capable of stable evaluation can be realized by using one surface (main surface 12) exposed to the environment.

A label 40 may be formed on the shielding layer 30 as shown in FIG. The label 40 may be printed or written, or may be stamped. The imprinted label 40 is highly recognizable even after long measurement periods. For example, the shielding layer 30 can be an aluminum tape with a stamp.

The label 40 may indicate various information such as lot number and date of manufacture. Alternatively, initial information such as the initial mass of the mortar panel 10 prior to installation may be included. As a result, the deterioration diagnosis tool 100 is excellent in traceability.

The mortar panel 10 may be composed of a hardened mortar composition containing cement and fine aggregate.

The raw materials and additives for the mortar composition are described below.
The mortar composition according to the present embodiment contains cement, fine aggregate, and water as raw materials.

As cement, known ordinary cement, blast furnace cement, etc. can be used.

As fine aggregates, silica-based fine aggregates (silica sand, standard sand for cement strength, etc.), alumina fine aggregates, and the like can be used. Silica-based aggregates and alumina-based aggregates hardly react with cement and chloride ions. Therefore, deterioration diagnosis stability using a mortar panel can be improved.

The fine aggregate may be configured not to contain limestone-based aggregate. When limestone-based aggregates are used, calcium aluminate monocarbonate hydrate and calcium aluminate hemicarbonate hydrate are produced, and there is a possibility that deterioration diagnosis stability using mortar panels may be lowered.

Water is not particularly limited, but may be tap water, industrial water, or the like.

The water/cement ratio (W/C ratio) may be appropriately adjusted, and may be, for example, 30% to 70%. By making it equal to or higher than the above lower limit, the density of the mortar panel becomes moderate, and by making it equal to or lower than the above upper limit, excessive porosity can be suppressed.

The ratio of cement to fine aggregate may be, for example, 1:0.5 to 1:4 in mass ratio. A uniform mortar panel can be manufactured by setting the ratio of the fine aggregate to 0.5 or more. In addition, the denseness of the mortar panel can be moderately adjusted. On the other hand, by setting the ratio of fine aggregate to 4 or less, uniform mortar panels can be manufactured, and deterioration diagnostic stability using mortar panels can be improved.

The mortar composition may contain additives such as a water reducing agent, a thickening agent, and an antifoaming agent, if necessary. These may be used alone or in combination of two or more. Further, other additives such as a dispersant, a curing accelerator, and a retarder may be included as long as the object of the present invention is not impaired.

The water reducing agent is not particularly limited, but polyalkylallylsulfonate water reducing agents, aromatic aminosulfonate water reducing agents, melamine formalin resin sulfonate water reducing agents, and the like can be used.
Examples of polyalkylallylsulfonate-based water reducing agents include salts of methylnaphthalenesulfonic acid formalin condensates, naphthalenesulfonic acid formalin condensates, and anthracene sulfonic acid formalin condensates.
In addition, general water reducing agents such as ligninsulfonate water reducing agents, polyol water reducing agents, and oxycarboxylate water reducing agents may be used. These may be used alone or in combination of two or more.

The water reducing agent may be contained, for example, in an amount of 0.05 to 2.0 parts by mass with respect to 100 parts by mass of cement. By adding a water reducing agent, it is possible to suppress the deterioration of the mortar and the formation of a highly irregular porous structure.

The thickener is not particularly limited, but includes methylcellulose-based, polyethylene glycol and ethylene oxide-based, acrylic-based such as polyacrylamide, and polyvinyl alcohol-based thickeners. You can use whatever you have. The thickener may be contained, for example, in an amount of 0.05 to 2.0 parts by mass with respect to 100 parts by mass of cement.

Antifoaming agents are not particularly limited, but oxyalkylene antifoaming agents (polyether antifoaming agents), silicone antifoaming agents, alcohol antifoaming agents, mineral oil antifoaming agents, fatty acid antifoaming agents, fatty acid antifoaming agents An ester antifoaming agent or the like can be used. The antifoaming agent may be contained, for example, in an amount of 0.05 to 2.0 parts by mass with respect to 100 parts by mass of cement.

By appropriately controlling the blending ratio of the water reducing agent, the thickening agent and the antifoaming agent, it is possible to realize a mortar panel in which variations in the porous structure are suppressed.

By adjusting the raw materials (cement, water, fine aggregate), additives, and W/C ratio, it is possible to realize a mortar panel with a chloride ion diffusion coefficient higher than that of concrete. As a result, it becomes possible to efficiently capture airborne salt content, enabling analysis and deterioration diagnosis in a short period of time.

A mortar composition can be obtained by a method of mixing the above materials (raw materials and additives). The mixing method is not particularly limited, but the respective materials may be mixed at the time of construction, or a part or all of them may be mixed in advance. A mixing device may be used for kneading the materials. The rotational speed and kneading time during kneading, and the order of adding materials are appropriately set.

As a mixing device, a known device can be used, and examples thereof include a tilting mixer, an omnimixer, a proshare mixer, a Henschel mixer, a V-type mixer, and a Nauta mixer.

<Method for manufacturing mortar panel>
The mortar panel 10 according to this embodiment is obtained by curing the mortar composition.
A method for manufacturing a mortar panel is not particularly limited, but may include, for example, a step of pouring a mortar composition into a mold and a step of hardening and curing the mortar composition.

FIG. 4 is a perspective view schematically showing an example of a mold 60 used for manufacturing a mortar panel.

The mold 60 in FIG. 4 is a mold for molding a mortar panel, and a mortar composition is filled in a molding space 66 in the mold 60 to form a mortar panel 10 having a main surface 12, a back surface 14 and side surfaces 16. can be molded. The molding space 66 may have a structure that matches the three-dimensional shape of the mortar panel 10, and may be configured with, for example, a substantially square shape or a substantially rectangular parallelepiped shape.

The molding space 66 of the formwork 60 may be configured with the volume of one mortar panel, or may be configured with the volume of a plurality of mortar panels. The molding space 66 may be partitioned by a plurality of partition plates 64 . Each partitioned molding space 66 has a volume equivalent to one mortar panel.

The mold 60 may be made of a metal material, and steel may be used as the metal material from the viewpoint of durability during repeated use and manufacturing stability.

Formwork 60 may be constructed of one or more metal members. A plurality of metal members are fixed by a fixing jig to form the formwork 60 . Since the mold can be removed by removing the fixing jig, the mold can be easily removed.

The partition plate 64 may be fixed to the formwork 60, may be provided integrally with the formwork 60, or may be a removable movable plate. Forming the mold 60 with a movable plate facilitates demolding.

The mold 60 is used to pour the mortar composition. A mortar composition is poured into the molding space 66 from the top opening of the frameless mold 60 corresponding to one side of the side surface 16 of the mortar panel 10 to fill the molding space 66 . Any material protruding from the top opening may be removed using an instrument such as a squeegee. Further, the mortar composition in the upper opening portion may be subjected to a smoothing treatment.

A vibration device may be used to vibrate the mold 60 . The mold 60 may be vibrated during or after pouring the mortar composition. As a result, lot-to-lot variations can be suppressed.

Next, the mold 60 filled with the mortar composition is cured. As a curing method, steam curing is performed.
Appropriately adjust the heating time and the rate of temperature increase/decrease in steam curing. This hardens and cures the mortar composition.

By appropriately selecting the conditions for steam curing, it is possible to sufficiently promote the hydration reaction and suppress changes in the mineral composition during use. Therefore, the pores are made more uniform, and the deterioration diagnostic tool 100 capable of stable measurement can be realized.

After that, the formwork 60 is demolded to obtain one or a plurality of mortar panels 10 .

A plurality of mortar panels 10 may be obtained by cutting from one mortar bar with a diamond cutter. From the viewpoint of suppressing lot-to-lot variations in the mortar panels 10, a method of forming a plurality of mortar panels 10 from one formwork 60 using a partition plate 64 is preferable.

The adhesion layer 20 is attached to the obtained mortar panel 10 to obtain the deterioration diagnostic tool 100 .
The deterioration diagnosis tool 100 may be stored in a packaging bag. A plurality of mortar panels 10 having little variation in properties may be selected and accommodated in the same packaging bag.

FIG. 5 shows a schematic diagram of a package 300 containing the deterioration diagnosis tool 100 in a packaging bag 310. As shown in FIG.

A package 300 in FIG. 5 includes one or more deterioration diagnostic tools 100 and a packaging bag 310 that accommodates the deterioration diagnostic tools 100 .

The packaging bag 310 may accommodate, for example, three degradation diagnostic tools 100 . A plurality of deterioration diagnosis tools 100 may be accommodated in the packaging bag 310 in a stacked state. A release layer 50 provided on the back surface 24 of the adhesion layer 20 between the mortar panels 10 can function as a cushioning material. By laminating the mortar panels 10, it is possible to prevent the mortar panels 10 from coming into contact with each other and being damaged.

The packaging bag 310 may be an aluminum pouch made of an aluminum laminate film. The aluminum laminate film may be a laminate film in which an aluminum layer and a resin layer are laminated. In addition to aluminum and resin, packaging bag 310 may contain other materials for the purpose of enhancing gas barrier properties and lowering water vapor permeability.

The thickness of packaging bag 310 is not particularly limited, but is 50 μm or more and 300 μm or less, more preferably 80 μm or more and 250 μm or less, and still more preferably 100 μm or more and 200 μm or less. The mechanical strength and gas barrier properties of the packaging bag 310 can be improved by making it equal to or greater than the above lower limit. The handleability of the packaging bag 310 is improved by making it equal to or less than the above upper limit.

As the form of the packaging bag 310, for example, a standing pouch, a two-side seal, a three-side seal, a four-side seal, or the like is used.

The inside of packaging bag 310 may be degassed or kept in an inert gas atmosphere.

The packaging bag 310 may be provided with a zipper 320 that can be freely opened and closed. The deterioration diagnostic tool 100 taken out of the packaging bag 310 can be put back into the packaging bag 310 after the measurement period has elapsed.

In addition, packaging bag 310 with zipper 320 may be provided with a writable sticker (label) on its surface. This makes it easy to identify the deterioration diagnosis tool 100 even when it is collected.

The package 300 is packed in a box such as a cardboard box or a plastic case. That is, the packing box includes a plurality of packages 300 and a box that accommodates them. Thereby, the transportation efficiency of the package 300 can be improved.

At least part of the periphery of the package 300 may be covered with a cushioning material in the packing box. As the cushioning material, a known cushioning material such as a bubble cushioning sheet or paper can be used.

The details of the concrete structure deterioration diagnosis tool 100 of the present embodiment will be described.

According to the findings of the present inventors, the pore diameter having the maximum peak in the differential pore volume distribution, its differential pore volume, and the pore diameter at 10% cumulative pore volume in the cumulative pore volume distribution are used as indices. It was found that the adsorption property of the mortar panel can be evaluated stably, and that the dispersion of the adsorption property of the mortar panel can be suppressed by setting the index within an appropriate range.
By suppressing the variation in the adsorption properties of the mortar panel, when the mortar panel is used as a tool for diagnosing deterioration, it is possible to measure the amount of ionized substances permeated and the initial mass of the saturated water content, which can be used as a basis for evaluating the deterioration of concrete structures. It is possible to stably measure the value. That is, it becomes possible to stabilize deterioration measurement.

For the mortar panel 10, the pore size distribution can be measured by mercury porosimetry.
Based on the obtained pore size distribution, the differential pore volume distribution (dV / d (log D)) was calculated, and the maximum peak pore size, maximum peak differential pore volume, maximum peak half-value width, 5 μm or more fine Calculate the ratio of the accumulated pore volume corresponding to the pore diameter.
Also, the cumulative pore volume distribution is calculated based on the pore size distribution, and the pore size at 10% cumulative pore volume and the pore size at 90% cumulative pore volume are determined.

In the mortar panel 10, the pore diameter having the maximum peak, the differential pore volume at the maximum peak, and the pore diameter at 10% cumulative pore volume satisfy the following conditions.

The lower limit of the pore diameter having the maximum peak of the mortar panel 10 is 1.0×10 ⁻² μm or more, preferably 7.0×10 ⁻² μm or more, more preferably 9.0×10 ⁻² μm or more. . On the other hand, the upper limit of the pore diameter with the maximum peak is 5.0 μm or less, preferably 2.0 μm or less, more preferably 2.0×10 ⁻¹ μm or less. By setting it within such a range, the mortar panel 10 can exhibit suitable adsorption characteristics.

The lower limit of the maximum peak differential pore volume of the mortar panel 10 is 5.0×10 ⁻² ml/g or more, preferably 7.0×10 ⁻² ml/g or more, more preferably 9.0×10 ^{− 2} ml/g or more. On the other hand, the upper limit of the maximum peak differential pore volume is 2.0 ml/g or less, preferably 1.0 ml/g or less, more preferably 1.4×10 ⁻¹ ml/g or less. By setting it within such a range, the mortar panel 10 can exhibit suitable adsorption characteristics.

The lower limit of the pore diameter at 10% cumulative pore volume of the mortar panel 10 is 1.0×10 ⁻¹ μm or more, preferably 2.0×10 ⁻¹ μm or more, more preferably 3.0×10 ⁻¹ μm. That's it. On the other hand, the upper limit of the pore diameter at 10% cumulative pore volume is 3.0 μm or less, preferably 2.5 μm or less, more preferably 2.0 μm or less. As a result, variations in the adsorption characteristics of the mortar panel 10 can be suppressed.

The lower limit of the half width of the maximum peak of the mortar panel 10 is, for example, 7.0×10 ⁻² μm or more, preferably 9.0×10 ⁻² μm or more, more preferably 1.0×10 ⁻¹ μm or more. be. As a result, the mortar panel 10 can exhibit suitable adsorption properties. On the other hand, the upper limit of the half width of the maximum peak is, for example, 7.0×10 ⁻¹ μm or less, preferably 3.0×10 ⁻¹ μm or less, more preferably 2.0×10 ⁻¹ μm or less. As a result, variations in the adsorption characteristics of the mortar panel 10 can be suppressed.

The lower limit of the pore diameter at 90% cumulative pore volume of the mortar panel 10 is, for example, 7.0×10 ⁻³ μm or more, preferably 8.0×10 ⁻³ μm or more, more preferably 1.2×10 ^{− 2} μm or more. As a result, the mortar panel 10 can exhibit suitable adsorption properties. On the other hand, the upper limit of the pore diameter at 90% cumulative pore volume is, for example, 3.0×10 ⁻¹ μm or less, preferably 2.0×10 ⁻¹ μm or less, more preferably 1.5×10 ⁻¹ μm. It can be below.

The upper limit of the ratio of the accumulated pore volume corresponding to the pore diameter of 5 μm or more to the total accumulated pore volume of the mortar panel 10 is, for example, 10.0% or less, preferably 9.0% or less, more preferably 7.0% or less. As a result, variations in the adsorption characteristics of the mortar panel 10 can be suppressed. On the other hand, the lower limit of the ratio of the cumulative pore volume corresponding to pore diameters of 5 μm or more is not particularly limited, but may be 0% or more or 0.1% or more.

The total pore volume of the mortar panel 10 measured by mercury porosimetry is, for example, 0.05 ml/g or more and 0.23 ml/g or less, preferably 0.09 ml/g or more and 0.20 ml/g. As a result, the mortar panel 10 can exhibit suitable adsorption properties.

The total pore specific surface area of the mortar panel 10 measured by mercury porosimetry is, for example, 9.0 m ² /g or more and 22.0 m ² /g or less, preferably 10.0 m ² /g or more and 16.0 m ² /g. It is below. As a result, the mortar panel 10 can exhibit suitable adsorption properties.

The porosity of the mortar panel 10 measured by the mercury intrusion method is, for example, 15.0% or more and 30.0% or less, preferably 16.0% or more and 29.0% or less, more preferably 17.0% or more and 28%. .0% or less. As a result, variations in the adsorption characteristics of the mortar panel 10 can be suppressed.

In the present embodiment, for example, by appropriately selecting the type and amount of each component contained in the mortar composition, the method of preparing the mortar composition, the method of manufacturing the mortar panel, etc., the above dimensions, density, compressive strength, Maximum peak pore diameter, maximum peak differential pore volume, maximum peak half width, ratio of cumulative pore volume corresponding to pore diameters of 5 μm or more, pore diameter at 10% cumulative pore volume, and 90% cumulative fineness It is possible to control the pore size in the pore volume. Among these, for example, the use of water reducing agents, kneading conditions, vibration conditions, curing conditions, use of molds with movable partitions, etc. Pore diameter, differential pore volume of maximum peak, half width of maximum peak, ratio of cumulative pore volume corresponding to pore diameter of 5 μm or more, pore diameter at 10% cumulative pore volume, and at 90% cumulative pore volume It is mentioned as a factor for setting the pore diameter within a desired numerical range.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than those described above can be adopted. Moreover, the present invention is not limited to the above-described embodiments, and includes modifications, improvements, etc. within the scope of achieving the object of the present invention.
1. A concrete structure composed of a plate-like mortar panel having a main surface exposed to the environment in which the concrete structure is placed and a back surface serving as an attachment surface for the concrete structure or a structure existing in the vicinity thereof. A tool for diagnosing deterioration of objects,
In the mortar panel, when the differential pore volume distribution and the cumulative pore volume are calculated based on the pore size distribution measured by the mercury intrusion method,
The pore diameter having the maximum peak in the differential pore volume distribution is in the range of 1.0 × 10 ^-2 μm or more and 5.0 μm or less.
The maximum peak differential pore volume in the differential pore volume distribution is 5.0×10 ⁻² ml/g or more and 2.0 ml/g or less,
Pore diameter at 10% cumulative pore volume is in the range of 1.0 × 10 ^-1 μm or more and 3.0 μm or less,
Deterioration diagnosis tool for concrete structures.
2. 1. A deterioration diagnostic tool for a concrete structure according to
The half width of the maximum peak in the differential pore volume distribution is in the range of 7.0 × 10 ^-2 μm or more and 7.0 × 10 ^-1 μm or less.
Deterioration diagnosis tool for concrete structures.
3. 1. or 2. A deterioration diagnostic tool for a concrete structure according to
The pore diameter at 90% cumulative pore volume is in the range of 7.0 × 10 ^-3 μm or more and 3.0 × 10 ^-1 μm or less,
Deterioration diagnosis tool for concrete structures.
4. 1. ~3. A deterioration diagnosis tool for a concrete structure according to any one of
The ratio of the cumulative pore volume corresponding to pore diameters of 5 μm or more to the total cumulative pore volume is 10.0% or less.
Deterioration diagnosis tool for concrete structures.
5. 1. ~ 4. A deterioration diagnosis tool for a concrete structure according to any one of
The total pore volume measured by mercury porosimetry is 0.05 ml / g or more and 0.23 ml / g or less,
Deterioration diagnosis tool for concrete structures.
6. 1. ~ 5. A deterioration diagnosis tool for a concrete structure according to any one of
The total pore specific surface area measured by mercury porosimetry is 9.0 m ² /g or more and 22.0 m ² /g or less,
Deterioration diagnosis tool for concrete structures.
7. 1. ~6. A deterioration diagnosis tool for a concrete structure according to any one of
The apparent diffusion coefficient of chloride ions in the mortar panel measured in accordance with JSCE-G 572-2018 is 10 cm ² /year or more and 50 cm ² /year or less.
Deterioration diagnosis tool for concrete structures.
8. 1. ~7. A deterioration diagnosis tool for a concrete structure according to any one of
The mortar panel has a porosity of 15.0% or more and 30.0% or less.
Deterioration diagnosis tool for concrete structures.
9. 1. ~8. A deterioration diagnosis tool for a concrete structure according to any one of
The thickness of the mortar panel is 3 mm or more and 20 mm or less.
Deterioration diagnosis tool for concrete structures.
10. 1. ~ 9. A deterioration diagnosis tool for a concrete structure according to any one of
A shielding layer that shields chloride ions or carbon dioxide is provided on the side surface of the mortar panel,
Deterioration diagnosis tool for concrete structures.
11. 1. ~ 10. A deterioration diagnosis tool for a concrete structure according to any one of
The mortar panel is composed of a hardened mortar composition containing cement and fine aggregate,
Deterioration diagnosis tool for concrete structures.

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited to the description of these Examples.

<Adjustment of mortar composition>
(Test example 1)
Cement (manufactured by Denka Co., Ltd., ordinary cement) 628.0 g, water reducing agent (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Celluflow 110P, polyalkylallylsulfonate water reducing agent) 2.4 g, thickener (manufactured by Shin-Etsu Chemical Co., Ltd., MH4000P2, methyl cellulose-based thickener) 3.4 g and antifoaming agent (manufactured by San Nopco, SN Deformer 14HP, polyether anti-foaming agent) 3.4 g were weighed and mixed. To this mixture, 1350.0 g of standard sand (standard sand for cement strength test, (one company) Cement Association) and 376.8 g of water (tap water) (water/cement ratio: 60%) were added and mixed using a mixer. Then, kneading was carried out while changing the rotation conditions in the order of low speed, stop, and low speed, and a mortar composition A was obtained.

(Test example 2)
A mortar composition B was obtained in the same manner as in Test Example 1 above, except that no water reducing agent was used and the rotation conditions were changed in the order of low speed and high speed.

<Preparation of mortar panel>
(Example 1)
A mold 60 shown in FIG. 4 having a plurality of molding spaces 66 partitioned by movable partition plates 64 is prepared.
Using a table vibrator, the obtained mortar composition A was poured into each of the molding spaces 66 of the mold 60 while vibrating the mold 60 under the following conditions.
Vibration condition of table vibrator:
・Time: 6 minutes ・Rotation speed of vibration motor: 2800±50 rpm
・Vibration table: Total amplitude 0.8±0.05mm

The formwork 60 was placed in a constant temperature and humidity room at 20° C. and a relative humidity of 80%, and steam curing was performed under the following conditions.
Steam curing conditions:
・The temperature is raised from 20°C to 85°C over 6 hours.
- Hold at 85°C for 3 hours.
・The temperature is lowered to 20°C by natural cooling.
- Allow to stand at 20°C for 1 hour.

After the steam curing, the fixing jig for the formwork 60 was removed, the formwork 60 was demoulded, and three plate-like mortar panels A1 were obtained. Each mortar panel A1 had a substantially rectangular parallelepiped shape with a thickness of about 5 mm, a length of about 4 cm, and a width of about 4 cm.

(Example 2)
Three plate-like mortar panels A2 were obtained in the same manner as in Example 1, except that the steam curing conditions were changed to the following conditions. Each mortar panel A12 had a substantially rectangular parallelepiped shape with a thickness of about 5 mm, a length of about 4 cm, and a width of about 4 cm.
Steam curing conditions:
The formwork 60 was placed in a constant temperature and humidity room at 20° C. and a relative humidity of 80%, and steam curing was performed under the following conditions.
・The temperature is raised from 20°C to 60°C over 4 hours.
- Hold at 60°C for 3 hours.
・The temperature is lowered to 20°C by natural cooling.
- Allow to stand at 20°C for 1 hour.

(Comparative example 1)
A mold with one molding space without partitions is prepared.
The obtained mortar composition B was poured into the molding space of the mold without vibrating.

The formwork was placed in a constant temperature and humidity room at 20° C. and a relative humidity of 80%, and subjected to steam curing under the following conditions.
Steam curing conditions:
- Hold at 20°C for 4 hours.
・The temperature is raised from 20°C to 80°C over 4 hours.
- Hold at 80°C for 4 hours.
・The temperature is lowered to 20°C by natural cooling.

After the steam curing, the fixing jig of the formwork was removed and the formwork was demolded to obtain a mortar bar.
The obtained mortar bar was cut into a predetermined thickness with a diamond cutter to obtain three plate-like mortar panels B.
Each mortar panel B had a substantially rectangular parallelepiped shape with a thickness of about 5 mm, a length of about 4 cm, and a width of about 4 cm.

<Production of concrete panel>
(Comparative example 2)
100 parts of cement (ordinary Portland cement), 230 parts of fine aggregate and 345 parts of coarse aggregate were put into a mixer and kneaded, and 60 parts of water was added and kneaded to obtain a concrete composition.
Three plate-like concrete panels were obtained in the same manner as in Comparative Example 1, except that a concrete composition was used instead of the mortar composition B.
Each concrete panel had a substantially rectangular parallelepiped shape with a thickness of about 5 mm, a length of about 4 cm, and a width of about 4 cm.

The pores, dimensions and mass of one of the obtained mortar panels A1, A2 and B and the concrete panel were measured. Table 1 shows the results.

[pore]
The pore size distribution, pore volume, specific surface area, and porosity were determined by a mercury intrusion method using a mercury porosimeter (manufactured by Shimadzu Corporation, Autopore IV9520) as a measuring device.
First, the obtained panel was pulverized using a jaw crusher so as to have a sieve gap of 2.5 to 5.0 mm to prepare a sample for measurement.
A sample of about 2.5 g was sealed in the cell and set in the measuring device. Then, it was measured after evacuation processing to 100 μmHg in the measuring device.
The measurement was performed under the conditions of maximum mercury pressure of 44500 psia and equilibrium time of 5 seconds. Mercury surface tension: 480 dynes/cm, Mercury contact: 140°, Mercury density: 13.5462 g/ml, Measurement particle size range: 0.0020 μm to 100.0000 μm.

A differential pore volume distribution (dV/d (log D)) was calculated based on the obtained pore size distribution, and the maximum peak pore size, the maximum peak differential pore volume, and the maximum peak half width were determined.

Calculate the cumulative pore volume distribution based on the pore size distribution, the pore size at 10% cumulative pore volume, the pore size at 90% cumulative pore volume, and the ratio of the cumulative pore volume corresponding to the pore size of 5 μm or more. asked for

The differential pore volume distribution and integrated pore volume distribution obtained using the panels of Example 1, Comparative Example 1, and Comparative Example 2 are shown in FIGS. 6 to 8, respectively.

[Dimensions, mass]
The dimensions (thickness, length, width) of the obtained panel were measured using vernier calipers, and the mass (g) was measured using a precision balance. The density (g/cm ³ ) of the panel was calculated by dividing the measured mass by volume.

The amount of chloride ion permeation and the initial mass in a saturated water content state were measured for each of the three mortar panels A1, A2 and B and the concrete panel thus obtained.

Amount of Chloride Ion Penetration The obtained panel was dried at 105° C. for 24 hours, and the dry mass (g) was determined. Unit volume mass (g/cm ³ ) was calculated from dry mass/volume of panel.
Next, the obtained panel was immersed in a 3% sodium chloride aqueous solution for 28 days, and then pulverized to 150 μm or less to prepare a powdery sample. The sample was measured for the total chloride ion concentration (wt%) in accordance with JIS A 1154:2012.
Concentration in unit volume mass (kg/m ³ ) = measured value of total chloride ion concentration (wt%) x unit volume mass (g/cm ³ ) x 1000
The concentration per unit volume mass (kg/m ³ ) calculated by the above formula was used as an indicator of the amount of chloride ion permeation.

- Initial mass in a state of saturated water content The obtained panel is immersed in pure water for 24 hours. After that, the surface was wiped off with a Kimtowel, and before it dried, the mass of the panel in a state of saturated water content (after immersion in water for 24 hours) was measured using a precision balance.

All of the mortar panel B of Comparative Example 1, the chloride ion permeation amount, and the initial mass in the saturated water-containing state showed large variations in values and large standard deviations. Three of the concrete panels of Comparative Example 2 showed no or low chloride ion penetration values.
On the other hand, in the three mortar panels A1 and A2 of Examples 1 and 2, compared to Comparative Examples 1 and 2, both the amount of chloride ion permeation and the initial mass in the saturated water content state have variations in value. was reduced and the standard deviation was small.

<Preparation of deterioration diagnosis tool>
Using the mortar panels A1 and A2 of Examples 1 and 2, deterioration diagnosis tools were produced.
First, an acrylic adhesive double-sided tape (manufactured by 3M, 4485, tape thickness: 0.5 mm, with release paper on one side) was cut into a length of 3.8 cm and a width of 3.8 cm. The adhesive surface of the cut tape was attached to the back surface of the mortar panel as shown in FIG. 1(a).
Subsequently, the adhesive surface of the aluminum seal was attached to the entire four sides of the mortar panel as shown in FIG. 3(b). As described above, deterioration diagnosis tools A1 and A2 are obtained.

The release paper was peeled off from the double-sided tape of the deterioration diagnosis tool A1 obtained, and the adhesive surface was adhered to the flat surface of the outdoor concrete structure. Three deterioration diagnosis tools A1 were exposed for several months (1 month or more, less than 1 year), then collected and analyzed to analyze the total amount of chloride ions contained in each mortar panel A1. bottom. Variation in the total chloride ion content in the three mortar panels A1 was suppressed. Similar results were also obtained using the deterioration diagnosis tool A2.
Therefore, by using the deterioration diagnostic tool of the embodiment, it is possible to stably estimate the condition of the concrete near which the deterioration diagnostic tool is fixed.

10 Mortar panel 12 Main surface 14 Back surface 16 Side surface 20 Adhesion layer 22 Main surface 24 Back surface 30 Shielding layer 40 Label 50 Peeling layer 60 Formwork 64 Partition plate 66 Molding space 100 Deterioration diagnostic tool 200 Concrete structure 202 Girder 204 Bridge pier floor plate 210 Structure body 300 package 310 packaging bag 320 chuck

Claims (7)

A concrete structure composed of a plate-like mortar panel having a main surface exposed to the environment in which the concrete structure is placed and a back surface serving as an attachment surface for the concrete structure or a structure existing in the vicinity thereof. A tool for diagnosing deterioration of objects,
In the mortar panel, when the differential pore volume distribution and cumulative pore volume were calculated based on the pore size distribution measured by the mercury porosimetry,
The pore diameter having the maximum peak in the differential pore volume distribution is 1.0 × 10 ^-2 μm or more and 5.0 μm or less ,
The half width of the maximum peak in the differential pore volume distribution is 7.0 × 10 ^-2 μm or more and 7.0 × 10 ^-1 μm or less,
the maximum peak differential pore volume in the differential pore volume distribution is 5.0×10 ⁻² ml/g or more and 2.0 ml/g or less;
Pore diameter at 10% cumulative pore volume is 1.0 × 10 ^-1 μm or more and 3.0 μm or less ,
Pore diameter at 90% cumulative pore volume is 7.0 × 10 ^-3 μm or more and 3.0 × 10 ^-1 μm or less,
The ratio of the cumulative pore volume corresponding to the pore diameter of 5 μm or more to the total cumulative pore volume is 10.0% or less,
The total pore volume of the mortar panel measured by mercury porosimetry is 0.05 ml/g or more and 0.23 ml/g or less,
The total pore specific surface area of the mortar panel measured by mercury porosimetry is 9.0 m ² /g or more and 22.0 m ² /g or less, and
The porosity of the mortar panel measured by mercury porosimetry is 15.0% or more and 30.0% or less.
Deterioration diagnosis tool for concrete structures. A deterioration diagnosis tool for a concrete structure according to claim 1 ,
The apparent diffusion coefficient of chloride ions in the mortar panel measured in accordance with JSCE-G 572-2018 is 10 cm ² /year or more and 50 cm ² /year or less.
Deterioration diagnosis tool for concrete structures. The deterioration diagnostic tool for concrete structures according to claim 1 or 2 ,
The thickness of the mortar panel is 3 mm or more and 20 mm or less.
Deterioration diagnosis tool for concrete structures. A degradation diagnosis tool for concrete structures according to any one of claims 1 to 3 ,
A shielding layer that shields chloride ions or carbon dioxide is provided on the side surface of the mortar panel,
Deterioration diagnosis tool for concrete structures. A deterioration diagnosis tool for concrete structures according to any one of claims 1 to 4,
The compressive strength of the mortar panel measured in accordance with JIS A 1108 is 15 N/mm ² ~30N/mm ² A tool for diagnosing the deterioration of concrete structures. A deterioration diagnosis tool for a concrete structure according to any one of claims 1 to 5,
An adhesion layer provided on the back surface of the mortar panel,
A tool for diagnosing deterioration of a concrete structure, wherein the adhesion layer is composed of a double-sided tape having adhesive surfaces that can be adhered on both sides. A deterioration diagnosis tool for concrete structures according to any one of claims 1 to 6 ,
The mortar panel is composed of a hardened mortar composition containing cement and fine aggregate,
Deterioration diagnosis tool for concrete structures.

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