Wall Reinforcement

Project: Hotel Project

The hotel features a multi-level underground structure, including a large underground parking garage and equipment rooms. During construction, structural testing and assessment revealed that the shear capacity and ductility of some underground shear walls needed reinforcement to meet the overall seismic resistance and operational safety requirements of the building.

Project Challenges

1. Complex Underground Environment

The reinforcement area is located in the underground level, with numerous electromechanical facilities such as fire sprinkler systems, ventilation ducts, and lighting cable trays beneath the roof slab. Limited construction space necessitates a high degree of flexibility and adaptability to the site conditions in the reinforcement plan.

2. Tight Schedule

The overall construction schedule of the hotel project is tight. The reinforcement work needs to be completed and handed over to the work site within a short period without affecting the normal progress of subsequent decoration, electromechanical installation, and other processes.

3. High Structural Safety Requirements

As a densely populated hotel building, the underground structure must not only meet normal operating loads but also possess excellent seismic performance to ensure overall structural safety in the event of earthquakes or other emergencies.

4. Clearance and Usable Space Constraints

Underground parking areas and other functional areas have specific requirements for clearance height. The reinforcement scheme cannot significantly reduce usable space, nor can it increase the structural self-weight excessively.

CFRP Reinforcement Scheme

Considering the dense electromechanical pipelines in the underground level, limited clearance, and tight construction schedule, after technical and economic comparison, an external carbon fiber reinforced polymer (CFRP) reinforcement scheme was ultimately adopted to strengthen the shear wall and improve its ductility.

The carbon fiber reinforced polymer (CFRP) fabric is fully laid along the wall surface, forming a complete load-bearing reinforcement system, effectively improving the wall's shear capacity, ductility, and overall seismic performance.

Wall Strengthening Materials

• Carbon Fiber Reinforced Polymer Fabric: HM-30 high-strength unidirectional carbon fiber fabric was selected as the main load-bearing material for reinforcement. Its high strength and high elastic modulus ensure reinforcement efficiency, while its single-sheet thickness of only about 0.167mm (300g/m² specification) means it occupies almost no building space.Impregnating

• Adhesive: HM-180C3P epoxy resin impregnating adhesive is used to impregnate and bond the carbon fiber cloth to the concrete surface. This adhesive must possess good permeability, bonding strength, and aging resistance to ensure effective stress transfer between the carbon fiber and the concrete.

• Primer and Leveling Materials: HM-180 primer is used for concrete substrate treatment, and HM-180CE leveling and repair adhesive ensures a smooth and dense bonding surface, providing a reliable bonding base for the carbon fiber cloth.

After reinforcement with carbon fiber cloth in this project, the shear capacity and ductility of the shear wall were effectively improved, meeting the design requirements. From the on-site results, the reinforced layer bonded tightly to the original concrete wall, with a smooth surface, without altering the building's appearance or usable space, and the construction process had almost no interference with surrounding electromechanical pipelines and other construction processes.