JP-7857120-B2 - Method for evaluating the water absorption of concrete

Inventors

• ▲高▼橋 直希
• 井手 一雄
• 平野 勝識

Assignees

• 株式会社フジタ

Dates

Publication Date

20260512

Application Date

20220311

Claims (6)

1. The mass of a viscoelastic, water-containing substance that is fluid and does not have a fixed shape is measured. A viscoelastic, water-containing substance that is fluid and does not retain its shape is brought into contact with the surface of the concrete. After a certain period of time has elapsed , the viscoelastic water-containing substance that is fluid and does not retain its shape is removed from the surface of the concrete. The weight of the viscoelastic water-containing substance that is fluid and has no fixed shape after removal is measured. A method for evaluating the water absorption of a concrete surface, characterized by comparing the weight of the aforementioned fluid and non-shape-retaining viscoelastic water-containing substance before and after contact with the concrete surface.
2. The method for evaluating the water absorption of a concrete surface according to claim 1, wherein when the viscoelastic water-containing substance having fluidity and not being shaped is brought into contact with the surface of the concrete, the viscoelastic water-containing substance having fluidity and not being shaped is covered with a water-impermeable coating material.
3. A method for evaluating the water absorption of a concrete surface according to claim 1, comprising filling a non-permeable measuring container having an opening with the fluid and non -shape-retaining viscoelastic water-containing substance, and bringing the opening into contact with the surface of the concrete, thereby bringing the fluid and non-shape-retaining viscoelastic water -containing substance into contact with the surface of the concrete.
4. A method for evaluating the water absorption of a concrete surface according to claim 1 or 2, wherein when the viscoelastic water-containing substance having fluidity and not being shaped is brought into contact with the surface of the concrete, a frame material is placed on the surface of the concrete and the viscoelastic water-containing substance having fluidity and not being shaped is filled into the frame material.
5. The method for evaluating the water absorption of a concrete surface according to any one of claims 1 to 4, wherein the viscoelastic water-containing substance having fluidity and not being morphologically fixed is a water-absorbing polymer.
6. The method for evaluating the water absorption of a concrete surface according to claim 5, wherein the water-absorbing polymer is a polyacrylate-based, starch-acrylate graft polymer, vinyl acetate copolymer, maleic anhydride copolymer, polyvinyl alcohol-based, or carboxymethylcellulose (CMC)-based polymer.

Description

One embodiment of the present invention relates to a method for evaluating the water absorption of concrete. Compared to natural stone, concrete is known to have a higher water absorption rate. The degree of water absorption is considered an indicator of concrete's durability, particularly its loss of alkalinity, and various methods for measuring it have been proposed. One method for evaluating the water absorption of a concrete surface involves contacting water or a water-containing sponge with the concrete surface and measuring the change (decrease) in moisture content (see, for example, Patent Documents 1 and 2). Utility Model Registration No. 3172025 PublicationUtility Model Registration No. 3172498 Gazette This figure illustrates a method for evaluating the water absorption of concrete according to one embodiment of the present invention, where (A) is a plan view when a substance having viscosity, elasticity, and water content is brought into contact with the surface of concrete, and (B) is a cross-sectional view corresponding to the space between A1 and B1.This figure illustrates a method for evaluating the water absorption of concrete according to one embodiment of the present invention, where (A) is a plan view when a substance having viscosity and elasticity and water content is brought into contact with the surface of concrete, (B) is a cross-sectional view corresponding to the space between A2 and B2, and (C) shows a configuration in which an injection port is provided in the measuring container.This figure illustrates a method for evaluating the water absorption of concrete according to one embodiment of the present invention, where (A) is a plan view when a substance having viscosity, elasticity, and water content is brought into contact with the surface of concrete, and (B) is a cross-sectional view corresponding to the area between A3 and B3. The embodiments of the present invention will be described below with reference to the drawings. However, the present invention can be implemented in many different forms, and is not limited to the embodiments described below. The drawings may schematically represent the width, thickness, shape, etc., of each part compared to the actual embodiments in order to clarify the explanation, but these are merely examples and do not limit the interpretation of the present invention. Furthermore, in this specification and each drawing, elements similar to those described above in previously shown drawings are denoted by the same reference numerals, and detailed explanations may be omitted as appropriate. In addition, the words "first," "second," etc., appended to each element are convenient indicators used to distinguish each element and have no further meaning unless specifically explained. A method for evaluating the water absorption of a concrete surface according to one embodiment of the present invention can be used to evaluate the water absorption of the surface of a concrete structure, or of crack repair portions or cross-sectional repair portions of a concrete structure. The details will be described below with reference to the drawings. To evaluate the water absorption of a concrete surface, a fluid, water-containing substance is used. In other words, to evaluate the water absorption of a concrete surface, a viscoelastic substance possessing both the viscosity of a liquid and the elasticity of a solid, and being both fluid and water-containing, is used. Such a substance is sometimes called "slime," but in this embodiment, it will be referred to as a "viscoelastic water-containing substance." Viscoelastic water-containing substances are not form-specific, and when evaluating the water absorption of concrete, a certain amount is spread and adhered to the concrete surface. Figures 1(A) and (B) show the state when a viscoelastic water-containing substance 102 is brought into contact with the surface of concrete 200 to test the water absorption of the concrete. In Figure 1, (A) is a plan view, and (B) is a cross-sectional view corresponding to the section between A1 and B1. As shown in Figures 1(A) and (B), the viscoelastic water-containing substance 102 does not have a fixed shape, but when evaluating its water absorption, it can be spread over a certain area on the surface of the concrete 200. Because the viscoelastic water-containing substance 102 is fluid, it can be spread and brought into contact with any area on the surface of the concrete 200. Furthermore, due to its fluidity, as shown in the inset in Figure 1(B), even if there are depressions such as fine surface bubbles on the surface of the concrete 200, the viscoelastic water-containing substance 102 can adhere to them by conforming to their shape. Although not shown, even if the surface of the concrete 200 has a stepped shape, the viscoelastic water-containing substance 102 can adhere to the stepped portion. When the viscoelastic water-containing substance 102 is brought into contact with the surf