Estimation method, estimation device, and program

Patent metadata

Field	Value
Publication number	US-12025608-B2
Application number	US-201917776265-A
Country	US
Kind code	B2
Filing date	Nov 13, 2019
Priority date	Nov 13, 2019
Publication date	Jul 2, 2024
Grant date	Jul 2, 2024

Abstract

An estimation method includes: an acquisition step (S 101 ) of acquiring deflection stress information that indicates a relationship between a deflection and a tensile stress of a specimen ( 200 ) of a reinforced concrete structure; and a derivation step (S 102 ) of deriving an estimation formula for estimating a depth of a crack generated in the reinforced concrete structure when a deflection of the reinforced concrete structure is no less than a first deflection of the specimen at a start of a generation of the crack, and is no greater than a second deflection of the specimen at an end of the generation of the crack.

First claim

The invention claimed is:

1. An estimation method, performed by an estimation device, the estimation method comprising:
determining, based on measuring a reinforced concrete structure, thickness data of the reinforced concrete structure, wherein the reinforced concrete structure includes a reinforced concrete material;
acquiring deflection stress data of a specimen of the reinforced concrete material by measuring deflections while applying tensile stresses and bending the specimen of the reinforced concrete material, wherein the deflection stress data indicate a relationship between a deflection and a tensile stress of the specimen of the reinforced concrete material;
determining, based on the deflection stress data, a first deflection of the specimen at a first tensile stress and a second deflection of the specimen at a second tensile stress, wherein the first deflection of the specimen represent a beginning of generating a crack on the specimen, and the second deflection of the specimen represent an end of generating the crack on the specimen;
acquiring, based on image data of an external appearance of the reinforced concrete structure, deflection information of the reinforced concrete structure;
determining, based at least on the first second deflections of the specimen and the acquired deflection information of the reinforced concrete structure, a set of operations for estimating a depth of a crack being generated in the reinforced concrete structure, wherein a deflection of the reinforced concrete structure is no less than the first deflection of the specimen, and the deflection information of the reinforced concrete structure is no greater than a second deflection of the specimen at an end of the generation of the crack, and the set of operations indicates an estimation formula for the depth of the crack;
determining, based on the determined set of operations for estimating the crack being generated in the reinforced concrete structure, depth information of the crack in the reinforced concrete structure, wherein the depth information indicates an estimated depth of the crack being generated in the reinforced concrete structure; and
transmitting the depth information to an application configured to output an estimation of the crack being generated in the reinforced concrete structure.

2. The estimation method according to claim 1 , further comprising:
in response to determination that the crack has been generated in the reinforced concrete structure, estimating the depth of the crack based on the estimation formula;
determining that the crack has reached a reinforcing steel bar of the reinforced concrete structure if the depth of the crack is no less than a cover thickness of the reinforced concrete structure; and
determining that the crack has not reached the reinforcing steel bar of the reinforced concrete structure if the depth of the crack is less than the cover thickness of the reinforced concrete structure.

3. The estimation method according to claim 2 ,
wherein the determining the depth information of the crack further includes determining the crack having been generated when the deflection information of the reinforced concrete structure obtained from an external appearance no less than the first deflection.

4. The estimation method according to claim 2 ,
wherein the determining the set of operations further includes determining the estimation formula based on a rate of change of a slope of a graph indicating the deflection stress information obtained through a bending test performed on the specimen.

5. The estimation method according to claim 2 ,
wherein the estimation formula includes:
d=D ×{( x−x 1)/( x 2− x 1)},

where D denotes the thickness of the reinforced concrete structure, x denotes the deflection information of the reinforced concrete structure, x1 denotes the first deflection, x2 denotes the second deflection, and d denotes the depth of the crack in the reinforced concrete structure.

6. The estimation method according to claim 1 ,
wherein the determining the set of operations further includes determining the estimation formula based on a rate of change of a slope of a graph indicating the deflection stress data obtained through a bending test performed on the specimen.

7. The estimation method according to claim 1 ,
wherein the estimation formula includes:
d=D×{ ( x−x 1)/( x 2− x 1)},

where D denotes the thickness of the reinforced concrete structure, x denotes the deflection information of the reinforced concrete structure, x1 denotes the first deflection, x2 denotes the second deflection, and d denotes the depth of the crack in the reinforced concrete structure.

8. An estimation device comprising a processor configured to execute operations comprising:
determining, based on measuring a reinforced concrete structure, thickness data of the reinforced concrete structure, wherein the reinforced concrete structure includes a reinforced concrete material;
acquiring deflection stress data of a specimen of the reinforced concrete material by measuring deflections while applying tensile stresses and bending the specimen of the reinforced concrete material, wherein the deflection stress data indicate a relationship between a deflection and a tensile stress of the specimen of the reinforced concrete material;
determining, based on the deflection stress data, a first deflection of the specimen at a first tensile stress and a second deflection of the specimen at a second tensile stress, wherein the first deflection of the specimen represent a beginning of generating a crack on the specimen, and the second deflection of the specimen represent an end of generating the crack on the specimen;
acquiring, based on image data of an external appearance of the reinforced concrete structure, deflection information of the reinforced concrete structure;
determining, based at least on the first second deflections of the specimen and the acquired deflection of the reinforced concrete structure, a set of operations for estimating a depth of a crack being generated in the reinforced concrete structure, wherein a deflection of the reinforced concrete structure is no less than the first deflection of the specimen, and the deflection information of the reinforced concrete structure is no greater than a second deflection of the specimen at an end of the generation of the crack, and the set of operations indicates an estimation formula for the depth of the crack;
determining, based on the determined set of operations for estimating the crack being generated in the reinforced concrete structure, depth information of the crack in the reinforced concrete structure, wherein the depth information indicates an estimated depth of the crack being generated in the reinforced concrete structure; and
transmitting the depth information to an application configured to output an estimation of the crack being generated in the reinforced concrete structure.

9. The estimation device according to claim 8 , the processor further configured to execute a method comprising:
in response to determination that the crack has been generated in the reinforced concrete structure, estimating the depth of the crack based on the estimation formula;
determining that the crack has reached the reinforcing steel bar of the reinforced concrete structure if the depth of the crack is no less than a cover thickness of the reinforced concrete structure; and
determining that the crack has not reached a reinforcing steel bar of the reinforced concrete structure if the depth of the crack is less than the cover thickness of the reinforced concrete structure.

10. The estimation device according to claim 9 ,
wherein the dete

Assignees

• Nippon Telegraph & Telephone

Inventors

• Takeuchi Yosuke
• Okamura Yosuke
• Tamamatsu Junichiro

Classifications

• G01M99/007

  by applying a load, e.g. for resistance or wear testing (G01M99/001 takes precedence; testing the elasticity of structures G01M5/00) · CPC title

• G01M5/0058

  of elongated objects, e.g. pipes, masts, towers or railways · CPC title

• G01M5/0033

  by determining damage, crack or wear · CPC title

• G01N33/38

  Concrete; Lime; Mortar; Gypsum; Bricks; Ceramics; Glass · CPC title

• G01N33/383 Primary

  Concrete or cement · CPC title