Project Overview:

The reinforcement work for this project primarily includes the connection of new and old concrete with rebars, strengthening of beam-columns with encased steel frame columns, repair of cracks in the original structure beams and columns, and restoration of damaged concrete. Additionally, new reinforced concrete reinforcement, increased cross-sectional reinforcement of beams and columns, and reinforcement of prefabricated floor slabs with cast-in-place concrete overlay layers are implemented.

Technical Requirements:

Before reinforcing the components, the original structural elements must be unloaded, excluding their self-weight. If unloading is not possible, the design unit must be reported, and construction can only proceed with their approval.

During the reinforcement process, should structural cracks, corrosion, aging, or discrepancies with the drawings be found, document the extent of damage to the structure and report it to the design unit. Reinforcement work on the affected structure may only continue with the approval of the design personnel.

3. During the construction process, ensure proper treatment of the interface between new and old concrete, including chiseling, moistening, and applying bonding agent to guarantee the quality and reliability of the connection surface.

4. During reinforcement construction, pay attention to the temperature and humidity requirements of the reinforcement materials. Follow the instructions in the product manual, and ensure safety during storage and use of the materials, taking appropriate measures.

Reinforcement Grouting

(1) Technical Preparation

1) Prior to reinforcement installation, familiarize yourself with the blueprints, locate and lay out the lines, and confirm the quantity and specifications of the steel bars before proceeding with the construction.

2) During the reinforcement grouting process, it is mandatory to clean off any deteriorated concrete, such as spalling, loose, or corroded areas, from the surface of the components to be reinforced. Remove the protective layer until the new structural surface is exposed.

3) The drilling diameter was performed according to design and specification requirements, utilizing Grade A anchor bolt adhesive.

4) The bonding adhesive used is a type with excellent weldability.

5) Prevent any interference during the curing period of the bonding adhesive.

(II) Construction Method

1.定位: Confirm the placement of steel bars and bolts according to the design drawings.

2. Drilling: Drilling according to design drawings, construction specifications, and the specified hole diameter and depth requirements provided by the supplier for the reinforcing bolts. Drill to the required depth.

3. Cleaning Holes: After drilling, use an air blower to clean the dust inside the holes.

4. Rebar Bolt Treatment: The surface of the rebar bolts to be implanted must be thoroughly cleaned.

5. Injection: After drilling and cleaning the hole, inject the rebar bonding adhesive upon passing inspection.

6. Reinforcement and bolt insertion: Inject the adhesive into the holes, insert the steel bars, and a small amount of adhesive oozing out on the surface is preferred.

(3) Construction Requirements

1. The positioning of reinforcement and bolt anchoring must be in accordance with design specifications. The center distance between the anchoring points should not be less than 4d, and the distance from the component edge should not be less than 2.5d. During positioning, it is essential to inspect the original component's steel reinforcement layout, avoid the original reinforcement, and meet the requirements of the design drawing.

2. Drilling: Use electric hammers and drill bits for rebar drilling, ensuring no damage to the original structure's steel reinforcement. Before drilling, the construction supervisor must brief the workers on the technical requirements. The hole diameter and depth (which vary for this project) must be carefully checked against the construction drawings, with clear instructions for each location.

3. Drilling Cleaning: The cleaning process should be repeated until the hole is free of dust, debris, and water stains. If rebar is not planted immediately after cleaning, protective measures for the hole should be taken. Cotton yarn can be used to tightly block the hole opening to prevent debris and water from falling into the hole. Repeat the cleaning process before inserting rebars or bolts.

4. Rebar and Bolt Treatment: Before the rebar and bolt insertion, the insertion area should be cleaned thoroughly, ensuring there are no debris, water stains, or oil spots. Place them in a proper storage location for use.

5. Gel Injection, Tube-Installed Anchor Gel: Before inserting rebars or bolts, the process must be inspected and appropriate records must be kept. Rebars and bolts can only be inserted after confirming that the holes meet the requirements. The inspection of the holes should include the location of the rebars, hole diameter, depth, and cleanliness. The gel should be injected into the hole quickly, and the portion extruded from the front should be discarded until the gel is evenly mixed. The gel injected into the hole should meet the insertion requirements for the rebars.

6. Reinforcement Insertion: Insert the steel bar immediately after injecting the anchoring adhesive, ensuring proper depth; the adhesive within the hole should be full, with a slight overflow on the hole's surface. The verticality of the inserted steel bar should not exceed 5 degrees.

7. Bolt Insertion: After applying the tube anchor adhesive, attach the sleeve to an electric drill, install the bolt, tighten it, and ensure the insertion depth. The verticality of the inserted bolt should not exceed 5 degrees.

8. Steel bars and bolts must not be disturbed before the adhesive material cures; a dedicated person must be on-site to supervise the construction area.

9. Waste holes from rebars and bolt insertion drilling must be filled with rebonding adhesive. The cleaning method for waste holes should be handled in the same manner as that for rebonding cleaning.

Beam and column outsourcing for steel reinforcement

The engineering framework columns and beams are reinforced using the package steel grouting method. The columns are reinforced with corner angle steel at all four corners and with additional plates for strength; the bottom sides of the beams are wrapped with corner steel, with steel plates bonded to the beams and complemented by closed additional plates for reinforcement.

(1) Technical Requirements

All steel sections and plates are made of Q235B steel, and the welding rods must meet the corresponding design requirements.

All beam and column corner steel components in the bonding zone are filled with structural adhesive to ensure compactness. All components are assembled with welding followed by filling, and it is strictly prohibited to use electric welding or any other fire-related measures after filling.

All structural adhesives used are of Grade A quality.

4. Other sections are filled with self-leveling grout material.

All beam and column reinforcement is done from the ground floor upwards, strictly adhering to the bottom-up reinforcement process.

(1) Construction Procedures

Surface Treatment, Assembly of Parts, Installation of Molding Nozzle Exhaust Ports, Sealing Joints

Seal Inspection | Compound Mixing | Pressure Filling | Sealing | Quality Inspection

(II) Construction Method

Surface Treatment: Remove loose dust, dirt, and grime from the old concrete bonding surface. If there are honeycombs or cracks, they should be repaired to expose the structural integrity and cleaned thoroughly. The bonding surface of the steel plate must be de-rusted, and after sanding, it should reveal a metallic luster.

2. Assembly of Components: Assemble the components of the reinforced concrete surface according to the design requirements.

3. Installation of Grouting Nozzle Vent Holes: Vent holes for grouting nozzles are installed on the assembled parts.

4. Sealing: Apply structural adhesive around the assembled component.

5. Seal Inspection: After assembling the components, use compressed air to input from the grout nozzle for a seal inspection.

6. Mixing the Adhesive Mixture: After thoroughly mixing the cement mortar in proportion, pour it into the grouting container.

7. Pressure Inflation: Use 0.5～0.8Mpa compressed air to force the rubber material into the product through the feed port. Seal each exhaust hole as the rubber overflows until the product is completely filled with rubber material.

8. Sealing: After the pressure-injection molding material inside the component is completed, seal the inlet.

9. Inspection: After the pressure infusion of the components is completed and cured, check the tightness of the glue at all parts, and supplement the infusion for any locally loose areas.