How to Select UHPC Strengthening Components for Old Building Renovation? Applicable Scenarios and Technical Solutions

In old building renovation, UHPC has become the preferred reinforcement material thanks to its high strength, high durability, and ease of construction, but the selection of reinforcement components must be precisely matched to the building's defect types, structural load requirements, and renovation goals. With 28 years of experience in UHPC/GRC/GRG/GRP reinforcement engineering, Qinglong Group has participated in the development of multiple standards for old building renovation and has developed a full-process selection system of "defect diagnosis - load analysis - component selection - construction adaptation," successfully completing projects including the auditorium of the American International School of Guangzhou and the renovation of an old factory building in Shanghai.

1. Selection by Reinforcement Goal: Targeted Solutions to Core Problems

For load-bearing capacity improvement, "UHPC reinforcement panels/reinforcement beams" are suitable: when the beams and slabs of an old building suffer insufficient load-bearing capacity due to aging or overloading, UHPC reinforcement panels 20-40mm thick (compressive strength ≥150MPa) are selected and bonded or mechanically connected to the original components. When Qinglong renovated a 1970s office building, it used 30mm-thick UHPC reinforcement panels to strengthen the floor slabs, increasing load-bearing capacity by 60%. For seismic performance enhancement, "UHPC seismic jackets/reinforced joints" are suitable: to address the seismic weakness of frame joints, customized UHPC seismic jackets are used to wrap the original joints with built-in steel bars. In the renovation of an old building in a seismic fortification zone, Qinglong adopted UHPC joint reinforcement jackets, increasing the shear capacity of the joints by 80%. For durability repair, "UHPC repair layers/integrated decorative reinforcement panels" are suitable: when the facade of an old building is weathered or corroded, 15-25mm-thick UHPC decorative reinforcement panels are selected, which both repair damaged areas and enhance the decorative effect. In the renovation of the auditorium of the American International School of Guangzhou, Qinglong used 20mm-thick UHPC panels to repair the exterior walls while achieving an appearance makeover.

2. Selection by Component Type: Adapting to Different Structural Parts

Beam reinforcement: the combination of "UHPC bottom reinforcement strips + side reinforcement panels" is selected, with bottom strips 30-50mm thick (for tension zone strengthening) and side panels 20-30mm thick (for shear strengthening). When Qinglong reinforced the crane beams of an old factory, this combination increased the beam's load-bearing capacity by 75%. Column reinforcement: "UHPC circular reinforcement jackets" are used, customized according to the column's cross-sectional dimensions, 25-40mm thick, with built-in longitudinal bars and stirrups. In the column reinforcement of an old office building, Qinglong selected a 35mm-thick UHPC circular jacket, increasing the column's axial compressive capacity by 55%. Floor slab reinforcement: large-area slabs use "cast-in-place UHPC reinforcement layers" (20-30mm thick), while localized damage uses "precast UHPC reinforcement patches." When Qinglong reinforced the floor slabs of an old shopping mall, it used a cast-in-place UHPC reinforcement layer, increasing overall load-bearing capacity by 40% and shortening the construction period by 30%. Wall reinforcement: non-load-bearing walls use "lightweight UHPC reinforcement panels" (15-20mm thick), while load-bearing walls use "composite UHPC reinforcement panels" (with built-in steel mesh). In the renovation of an old residence, Qinglong used 18mm-thick lightweight UHPC reinforcement panels, increasing the wall's crack resistance by 3 times.

3. Selection by Construction Conditions: Balancing Convenience and Feasibility

Confined space construction: "modular precast UHPC reinforcement components" are selected, prefabricated in the factory and assembled on site. When Qinglong renovated the underground garage of an old building, it used modular UHPC reinforcement beams, with on-site installation completed in just 3 days. Renovation without suspending operations: "formwork-free UHPC reinforcement components" are selected, installed by self-bonding or dry hanging without large-scale formwork. When Qinglong renovated an operating shopping mall, it used formwork-free UHPC reinforcement panels, and the mall remained open during construction. Work at height: "lightweight UHPC reinforcement components" (surface density ≤60kg/㎡) are selected to reduce lifting difficulty. In the exterior wall renovation of a high-rise old building, Qinglong used 25mm-thick lightweight UHPC panels, each weighing ≤30kg, improving installation efficiency at height by 50%.

4. Qinglong's Selection Advantages and Engineering Practice

Qinglong possesses full-chain service capabilities covering "detailed design - customized production - construction and installation." Before selection, it precisely diagnoses defects in old buildings through non-destructive testing and load tests, combined with BIM technology to simulate reinforcement effects. In the renovation of an old factory building in Shanghai, Qinglong selected a combined solution of UHPC reinforcement beams and panels based on defect diagnosis, enabling the building to meet modern industrial use requirements. In the renovation of an old hotel in Nanning, UHPC integrated decorative reinforcement panels were used, solving the exterior wall weathering problem while achieving a high-end makeover. As a national "specialized, refined, distinctive, and innovative" enterprise, Qinglong holds 58 related patents, including the patented technology "Modular UHPC Reinforcement Components for Old Buildings," which enables standardized and customized production of reinforcement components, improving selection adaptability by 40%. Relying on its nationwide office network, Qinglong can quickly respond to old building renovation needs and provide localized selection and construction services.

The selection of UHPC reinforcement components in old building renovation requires "prescribing the right remedy for the condition," with comprehensive consideration of reinforcement goals, component types, and construction conditions. Qinglong Group always adheres to the philosophy of "professional innovation, environmental protection, and efficiency." With extensive engineering experience and technological innovation, it provides precise UHPC reinforcement component selection solutions for various types of old building renovations, addressing structural safety issues while balancing economy and aesthetics, giving old buildings renewed vitality.