AU2017101577A4

AU2017101577A4 - Seawater corrosion-preventing reinforced concrete pile structure based on semipermeable membrane

Info

Publication number: AU2017101577A4
Application number: AU2017101577A
Authority: AU
Inventors: Yongyi LI; Qixian Lu; Guoxiong Mei; Wenbing Wu; Meijuan XU; Yanlin Zhao
Original assignee: Guangxi University
Current assignee: Guangxi University
Priority date: 2016-11-08
Filing date: 2017-11-08
Publication date: 2017-12-14
Anticipated expiration: 2025-11-08
Also published as: CN106677174A

Abstract

Abstract Disclosed is a seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane. The pile structure includes: a pile body, along 5 which main reinforcing steel bars are arranged in the longitudinal direction; a semipermeable membrane, which covers the outer surface of the pile body and is used for filtering chloride ions in seawater; a protective layer, which covers the outer surface of the semipermeable membrane; and end plates, which are arranged at two ends of the pile body. The pile structure is simply provided with a semipermeable 10 membrane, and the surface of the semipermeable membrane is covered by a protective layer. Thus, the anti-corrosion ability of a concrete pile to chloride ions in the seawater environment is improved, and seawater is blocked from reaching the inner area of the pile structure via microcracks in concrete, thereby enhancing the oxidation resistance and corrosion resistance of the concrete of the pile body and prolonging the 15 service life of the reinforcing steel bars. Hence, the concrete of the pile body can work for a long time without damage, thereby improving the durability of a marine structure. Besides, it is convenient for construction, and working procedures and construction costs are reduced. Fig. 1 Fig. 2

Description

SEAWATER CORROSION-PREVENTING REINFORCED CONCRETE PILE STRUCTURE BASED ON SEMIPERMEABLE MEMBRANE

Field of the Invention

The present utility model relates to the technical field of concrete anti-corrosion engineering, and in particular, to a seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane.

Background of the Invention

Traditional reinforced concrete piles are widely used in pile foundation engineering, and especially for offshore engineering, a pile is always chosen for making a foundation. However, mediums in the seawater environment will corrode the traditional reinforced concrete piles. Specifically, corrosion forms include: Dissolving and Leaching: solid components in hardened cement slurry dissolve gradually, resulting in dissolving-loss damage; Ion Exchange: the ion exchange reaction occurs between corrosive mediums and the components in the hardened cement slurry to produce a product that easily dissolves or has no cementing ability, thereby destroying the original slurry structure; and Forming of Intumescent Components: under the action of the corrosive mediums, the volume of formed salt increases as the crystal is growing, thereby producing harmful internal stresses and resulting in intumescent damage. Corrosive mediums in seawater not only have an effect on the concrete, but also penetrate into the concrete and act on reinforcing steel bars. Thus, once the reinforcing steel bars are corroded, the performance and service lives of the reinforcing steel bars are reduced. Since piles in offshore engineering are in the sea for during the service life, they suffer stronger corrosion attack than piles in the earth in onshore engineering. Therefore, the service life of the traditional reinforced concrete piles in offshore engineering is greatly shortened, which affects the normal use of offshore building facilities.

Summary of the Invention

The present utility model is to provide a seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane, so as to eliminate defects of a reinforced concrete pile structure in the prior art, i.e., complicated procedures in corrosion protection construction and difficulties in ensuring the quality of a project.

In order to achieve the above objective, the present utility model provides a seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane. The pile structure comprises a pile body, along which main reinforcing steel bars are arranged in the longitudinal direction; a semipermeable membrane, which covers the outer surface of the pile body and is used for filtering chloride ions in seawater; a protective layer, which covers the outer surface of the semipermeable membrane; and end plates, which are arranged at two ends of the pile body.

Preferably, in the above technical solution, the main reinforcing steel bars are wound up by a stirrup.

Preferably, in the above technical solution, the protective layer is made of a concrete material.

Preferably, in the above technical solution, the protective layer has a thickness in a range from 5 cm to 15 cm.

Preferably, in the above technical solution, the protective layer only allows water molecules to pass through, and is made of a special polymer material. A polymer has hydrophilicity and only allows water to pass through, thereby having a filtering effect on chloride ions. Thus, chloride ions in seawater are blocked from penetrating into the inner area of the pile body via microcracks in concrete.

Preferably, in the above technical solution, the semipermeable membrane is an asymmetric cellulose membrane.

Compared with the prior art, the present utility model has beneficial effects as follows. In the seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane of the present utility model, the pile structure is simply provided with a semipermeable membrane which is covered by a protective layer made of concrete with a thickness of 10 cm, and then end plates with a certain thickness are provided. In this way, an anti-corrosion ability of the concrete pile to chloride ions in the seawater environment is improved, and sea water is blocked from reaching the inner area of the pile structure via microcracks in concrete, thereby enhancing the oxidation resistance and corrosion resistance of the concrete of the pile body and prolonging the service life of reinforcing steel bars. Thus, the concrete of the pile body can work for a long time without damage, thereby improving the durability of a marine structure. Besides, it is convenient for construction, and working procedures and construction costs are reduced.

Brief Description of the Drawings

Fig. 1 schematically shows the structure of a seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane according to the present utility model, and

Fig. 2 is the cross-section view of the seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane according to the present utility model.

Detailed Description of the Embodiments

Embodiments of the present utility model will be explained in detail hereinafter with reference to accompanying drawings, but it should be understood that the protection scope of the present utility model is not limited to the embodiments.

In the whole description and the claims, the term “comprise”, or its changing form “include”, or “contain” will be understood as “all elements or components mentioned herein are included, but other elements or components not mentioned are not excluded”, unless the context clearly indicates otherwise.

As shown in Figs. 1 and 2, according to the seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane of one embodiment of the present utility model, the seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane is mainly used in the seawater environment.

The seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane comprises a pile body 1, along which main reinforcing steel bars 2 are arranged in the longitudinal direction. The main reinforcing steel bars 2 are wound up by a stirrup 3. The stirrup 3 is used for enhancing the stability of the pile body. A semipermeable membrane 4 covers the outer surface of the pile body 1 and is used for filtering chloride ions in seawater. Preferably, the semipermeable membrane 4 only allows water molecules to pass through, and is used for preventing chloride ions in seawater from reaching the inner area of the pile structure via microcracks in concrete. A protective layer 5 covers the outer surface of the semipermeable membrane 4. The protective layer 5 is made of a concrete material, and has a thickness of 10 cm. The protective layer 5 having the thickness of 10 cm is provided around the outer surface of the semipermeable membrane 4, such that the semipermeable membrane will not be damaged due to exposure to water for a long time. End plates 6 are arranged at two ends of the pile body 1.

Preferably, the semipermeable membrane is an asymmetric cellulose membrane which is most widely used in reverse osmosis technology at present. The semipermeable membrane comprises a compact surface layer (a pore size thereof is less than 1 nm) and a porous supporting layer, which form a bell mouth having a dense upper part and a sparse lower part. Because it can be regarded that cellulose used herein is formed by polycondensation of a lot of glucose molecules, a structure of the cellulose comprises many hydroxyl functional groups. Hydroxyl has very strong hydrophilicity and can attract water by hydrogen bonding, which has water permeability. At the same time, since a membrane surface contains only bonded water which has lost the hydration ability, salt substances of a solution cannot be dissolved further. Therefore, separation of salt and water is achieved, and thus isolation of chloride ions by the semipermeable membrane is achieved. Hence, the semipermeable membrane can improve the anti-permeability and crack resistance of reinforced concrete in the seawater environment, thereby improving the durability of a structure.

The above description of the specific exemplary embodiments of the present utility model is for the purpose of illustration. The purpose of selecting and describing the exemplary embodiments is to explain specific principles and practical applications of the present utility model, so that those skilled in the art will be able to realize and utilize various exemplary embodiments of the present utility model as well as different alternatives and variations. The scope of the present utility model is limited by the claims and equivalents thereof.

Claims

Claims

1. A seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane, wherein the pile structure comprises: a pile body, along which main reinforcing steel bars are arranged in the longitudinal direction; a semipermeable membrane, which covers the outer surface of the pile body and is used for fdtering chloride ions in seawater; a protective layer, which covers the outer surface of the semipermeable membrane; and end plates, which are arranged at two ends of the pile body.
2. The seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane according to claim 1, wherein the main reinforcing steel bars are wound up by a stirrup.
3. The seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane according to claim 1, wherein the protective layer is made of a concrete material.
4. The seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane according to claim 1, wherein the protective layer has a thickness in a range from 5 cm to 15 cm.
5. The seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane according to claim 1, wherein the semipermeable membrane has a filtering action on chloride ions, and only allows water molecules to pass through.
6. The seawater corrosion-preventing reinforced concrete pile structure based on a semipermeable membrane according to claim 1, wherein the semipermeable membrane is an asymmetric cellulose membrane.