CN111042568A - Precast beam crack repairing construction process - Google Patents

Abstract

The invention discloses a precast beam crack repairing construction process, which comprises the steps of dipping an anti-corrosion coating by adding silane twice on the surface of a precast beam crack which is less than or equal to 0.2 mm; for the surface with the crack of 0.2mm < 1mm, cutting and slotting along the length direction of the crack, sealing and repairing by using high-strength grouting material, and sticking 1 layer of carbon fiber cloth. The precast beam crack repairing scheme provided by the invention can be used for efficiently and high-quality repairing of the precast beam crack, and can effectively overcome the problems in the prior art.

Description

Precast beam crack repairing construction process

Technical Field

The invention relates to a precast member beam pouring technology, in particular to a crack repairing technology of a precast member beam.

Background

In recent years, port engineering has been continuously developed, and high pile cap type bank protection structures are increasingly adopted. For some high pile bearing platform type revetment structures, the upper structure of a platform adopts a beam plate structure type, a beam adopts a cast-in-place inverted T-shaped beam, a middle longitudinal beam, an edge beam and a prefabricated pipe trench are placed on a lower beam, a prefabricated electric pipe trench beam is arranged on the rear edge of the platform, and the platform surface is a laminated slab.

In the actual pouring process, cracks sometimes appear at the flange of the prefabricated member beam after the prefabricated member beam of the platform is poured, but the repairing quality of the existing crack repairing scheme cannot meet the requirements.

Therefore, the crack repairing scheme capable of effectively improving the repairing quality is an urgent problem to be solved in the field.

Disclosure of Invention

Aiming at the problems of the existing crack repairing scheme of the platform precast member beam, a new precast beam crack repairing scheme is needed.

Therefore, the invention aims to provide a precast beam crack repairing construction process to realize efficient and high-quality repair of precast beam cracks.

In order to achieve the aim, the precast beam crack repairing construction process provided by the invention comprises the following steps of

For the surface with the crack of the precast beam less than or equal to 0.2mm, silane is added for dipping the anticorrosive paint twice;

for the surface with the crack of 0.2mm < 1mm, cutting and slotting along the length direction of the crack, sealing and repairing by using high-strength grouting material, and sticking 1 layer of carbon fiber cloth.

Further, in the repair construction process, when the silane dipping anticorrosive paint is added twice on the surface with the crack less than or equal to 0.2mm, the dosage of each layer is 250-350ml/m²。

Further, in the repair construction process, the repair process for the surface with 0.2mm < crack < 1mm sequentially comprises the following steps:

cleaning the surface of the crack;

cutting V-shaped grooves obliquely downwards on two sides of the crack, and cleaning;

sealing the high-strength grouting material;

and adhering a layer of carbon cloth at the crack on the side surface of the bracket of the precast beam.

Further, the construction process of the repair construction process comprises the following steps:

three types of cracks on the same prefabricated beam are firstly repaired, wherein the crack is smaller than 0.5mm and smaller than or equal to 1mm, then the crack is smaller than 0.2mm and smaller than or equal to 0.5mm, and finally the crack is repaired, wherein the width of the crack is smaller than or equal to 0.2 mm.

The precast beam crack repairing scheme provided by the invention can be used for efficiently and high-quality repairing of the precast beam crack, and can effectively overcome the problems in the prior art.

Drawings

The invention is further described below in conjunction with the appended drawings and the detailed description.

Fig. 1 is an exemplary view of a bonded carbon cloth according to an embodiment of the present invention.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further explained below by combining the specific drawings.

Aiming at cracks appearing at the flange of the prefabricated beam after the platform prefabricated beam is poured, the corresponding repairing scheme is provided according to the size of the cracks.

When the width of the crack of the precast beam is less than or equal to 0.2mm, the precast beam is coated and sealed twice by adopting silane dipping anticorrosive paint, and the dosage of each layer is 250-350ml/m²Preferably 300ml/m²。

For the crack with the thickness of 0.2mm and the thickness of less than or equal to 1mm, cutting and slotting along the length direction of the crack, sealing and repairing by using high-strength grouting material, and adhering 1 layer of carbon fiber cloth. The basic repair process is as follows: cleaning the surface of the crack → cutting a V-shaped groove downwards and obliquely in the range of 4cm at two sides of the crack → cleaning → sealing the high-strength grouting material → adhering a layer of carbon cloth at the crack on the side surface of the bracket of the precast beam.

According to the restoration scheme, the construction process comprises the following steps:

three types of cracks on the same prefabricated beam are firstly repaired, wherein the crack is smaller than 0.5mm and smaller than or equal to 1mm, then the crack is smaller than 0.2mm and smaller than or equal to 0.5mm, and finally the crack is repaired, wherein the width of the crack is smaller than or equal to 0.2 mm.

For the above scheme, the following implementation processes are exemplified as follows:

firstly, grouting material enters a field;

the crack repair in the embodiment preferably adopts high-strength grouting material repair, the strength is more than or equal to 60mpa, and the crack repair can be used after passing the supervision and acceptance after entering the field.

And (4) manufacturing grouting material test blocks on site, and sending the grouting material test blocks to a third party for detection after the maintenance period is up.

(II) cleaning cracks;

and polishing the periphery of the crack, cleaning impurities such as dust and mud on the surface, and removing floating dust in the crack by using a blower.

Thirdly, cutting and grooving at two sides of the crack;

after the surface of the crack is cleaned, cutting and grooving downwards and obliquely within the range of 4cm at two sides of the crack, wherein the grooving depth is 4 cm-5 cm, and washing and cleaning the crack. The depth of the grooves here must not exceed the thickness of the protective layer.

(IV) sealing treatment;

and (4) carrying out crack sealing along the groove by using the prepared high-strength grouting material. Before sealing, the surface of the concrete is ensured to be dry and clean and can not contain water, oil stain, scum and the like;

and supporting the formwork at the side face of the groove, fixing and sealing the formwork by using a steel bar clamp and a grout-stopping adhesive tape, pouring grout into the formwork after the grout is prepared, ensuring fullness and compactness, sending a specially-assigned person for later observation, and preventing the formwork from leaking grout, if leakage is found, remedying.

Fifthly, pasting carbon cloth;

after the high-strength grouting material is sewn, carbon fiber cloth (shown in figure 1) is adhered to the side face of the bracket, the width of the carbon fiber cloth is preferably 200mm, and the two sides of a crack are respectively ultra-adhered by 300 mm. And (3) laying along the side surface of the bracket of the precast beam, if a plurality of cracks continuously appear, carrying out common laying, wherein the direction of the carbon fiber is orthogonal to the direction of the cracks. The performance of the carbon fiber and the matched glue can meet the design and standard requirements.

The basic scheme for pasting the carbon fiber cloth in the step is as follows:

(1) carbon fiber cloth parameter requirements

The carbon fiber cloth used for repairing the precast beam adopts PAN-based single-item carbon fiber cloth, the material grade is first grade, and the specification is 300g/m²。

(2) The surface should be kept dry prior to consolidation, the component dried with a blower applied to the component with the wet surface, and the relative humidity of the component surface is maintained at no greater than 70%.

(3) And (3) treating the surface of the member, namely polishing and flattening the surface of the adhered concrete, and removing impurities such as surface coating paste, oil stains and the like until a new surface of the concrete structure is completely exposed.

(4) And (4) brushing the bottom resin, and uniformly smearing the bottom resin on the surface of the concrete member by adopting a roller brush after the surface of the member is treated.

(5) The carbon fiber sheet is adhered by putting the carbon fiber cloth cut according to the required size into resin prepared according to the process specification for soaking, and uniformly smearing on the adhered part. When the carbon fiber cloth is pasted, the carbon fiber cloth is lightly pressed to the position needing pasting by hand, a special roller is adopted to roll for multiple times along the fiber direction, air bubbles are squeezed out, so that the impregnating resin fully permeates the carbon fiber cloth, the carbon fiber cloth cannot be damaged during rolling, and the direction of the unidirectional carbon fiber is orthogonal to the crack. The above steps should be repeated when the multiple layers are pasted, and the next layer of pasting is preferably carried out on the impregnating resin on the surface of the carbon fiber cloth, and then the impregnating resin is uniformly smeared on the surface of the last layer of carbon fiber cloth.

(VI) surface protection; and performing antiseptic treatment according to requirements.

(VII) checking and accepting;

before construction, product qualification certificates and product quality delivery inspection reports of carbon fiber sheets and prepared resin adhesive materials are confirmed, and various performance indexes meet the requirements of technical Specification for repair and reinforcement of harbor hydraulic structures JTS 311-2011. The actual pasting area of the carbon fiber sheet is not smaller than the design area, and the position deviation is not larger than 10 mm. The bonding quality between the carbon fiber sheet and the concrete can be checked by lightly knocking or pressing the surface of the carbon fiber sheet by hand with a small hammer, and the total effective bonding area is not less than 95%. When the carbon fiber isThe hollowing area is not more than 10000mm²In time, the needle tube can be repaired by a method of injecting glue into the needle tube. When the hollowing area is more than 10000mm²When in use, the carbon fiber sheets at the hollowing part are cut off, and the same amount of carbon fiber sheets are attached in a lap joint mode again, wherein the lap joint length is not less than 100 mm.

According to the embodiment, the precast beam crack repairing scheme provided by the embodiment can be used for efficiently and high-quality repairing of the precast beam crack; meanwhile, the whole implementation process is simple, the construction period is short, and the cost is low.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (4)

1. The precast beam crack repairing construction process is characterized by comprising the following steps

For the surface with the crack of the precast beam less than or equal to 0.2mm, silane is added for dipping the anticorrosive paint twice;

for the surface with the crack of 0.2mm < 1mm, cutting and slotting along the length direction of the crack, sealing and repairing by using high-strength grouting material, and sticking 1 layer of carbon fiber cloth.

2. The precast beam crack repairing construction process according to claim 1, wherein in the repairing construction process, when silane dipping anticorrosive paint is added twice to the surface with crack smaller than or equal to 0.2mm, the dosage of each layer is 250 ml/m-²。

3. The precast beam crack repair construction process according to claim 1, wherein the repair construction process for the surface with 0.2mm < crack ≦ 1mm comprises the following steps in sequence

Cleaning the surface of the crack;

cutting V-shaped grooves obliquely downwards on two sides of the crack, and cleaning;

sealing the high-strength grouting material;

and adhering a layer of carbon cloth at the crack on the side surface of the bracket of the precast beam.

4. The precast beam crack repairing construction process according to any one of claims 1 to 3, wherein the repairing construction process comprises the following construction procedures:

three types of cracks on the same prefabricated beam are firstly repaired, wherein the crack is smaller than 0.5mm and smaller than or equal to 1mm, then the crack is smaller than 0.2mm and smaller than or equal to 0.5mm, and finally the crack is repaired, wherein the width of the crack is smaller than or equal to 0.2 mm.

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