How to Select UHPC Reinforcement Components for Old Building Retrofit: Analysis of Key Influencing Factors and Practical Strategies

Amid the wave of urban renewal and old building renovation, Ultra-High Performance Concrete (UHPC) has become an innovative choice in the field of structural reinforcement thanks to its outstanding mechanical properties and design flexibility. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group draws on its full-chain technical experience to provide designers and owners with scientifically sound reinforcement component selection solutions from three dimensions—material properties, structural requirements, and construction conditions—helping historic buildings gain new life.

1. Analysis of Key Factors in UHPC Reinforcement Component Selection

Reinforcing old buildings requires balancing safety, economy, and the preservation of architectural character, and component selection should focus on three key dimensions. First, structural load-bearing requirements: UHPC has a compressive strength of over 150MPa and a flexural strength exceeding 20MPa—3 to 5 times that of conventional concrete—making it suitable for reinforcing key load-bearing components such as beams and columns. Second, space constraints: where interior headroom in old buildings is limited, UHPC thin panels just 5-10cm thick can be used, achieving “minimally invasive reinforcement” through bonding or bolt anchoring to avoid excessive occupation of usable space. Finally, durability requirements: UHPC's dense microstructure improves impermeability by more than 10 times, extending structural life to over 50 years in harsh environments such as humid or corrosive settings (e.g., coastal buildings and industrial plants).

Take the renovation of a Republic of China-era building as an example: its brick-timber structural beams were suffering from cracking. Qinglong's technical team adopted a UHPC composite beam reinforcement solution: a 30mm-thick precast UHPC panel was added to the bottom of the beams and connected to the original structure via embedded rebar to form an integrated load-bearing system, meeting the requirement of a 40% increase in load capacity while preserving the original decorative texture of the timber beams. This case demonstrates UHPC's balancing advantage between “reinforcement strength” and “heritage preservation.”

2. Practical Strategies and Scenario Adaptation for UHPC Reinforcement Components

Differentiated selection strategies should be developed for different building types and reinforcement objectives: in heritage-protected buildings, decorative UHPC reinforcement components are recommended, such as antique-style carved column casings and curved string courses, leveraging UHPC's moldability to achieve integrated “reinforcement + decoration.” In the renovation of one provincial-level cultural heritage site, Qinglong replicated traditional brick carving patterns in UHPC, allowing the reinforcement components to blend seamlessly with the original architectural style. In industrial heritage renovations, UHPC hollow-core trusses or special-shaped supports are preferred, as their lightweight, high-strength properties meet the demands of large-span space renovation. In one project converting an old factory into an art center, UHPC cantilevered components created an 8-meter column-free space with a self-weight 30% lower than a steel structure.

Notably, the combined application of UHPC with materials such as GRC and GRP can further optimize solutions: UHPC is used for base reinforcement to ensure structural safety, while GRC antique-style finishes or GRP light-transmitting components are chosen for surface decoration, forming a “function-aesthetics” composite system. In one commercial street renovation, Qinglong used combined UHPC+GRC components to resolve the floor slab reinforcement problem while enhancing the visual quality of the commercial district through GRC's stone-like texture.

3. Full-Chain Service Support: Technical Backing from Selection to Implementation

As a national high-tech enterprise and a participant in setting UHPC industry standards, Qinglong Group has built a full-chain service system of “detailed design – digital production – precise construction”: in the design phase, BIM technology is used for parametric component modeling to simulate reinforcement effects and load conditions; in production, automated production lines keep UHPC component tolerances within ±2mm; during construction, 3D scanning positioning technology ensures precise alignment between old building structures and new components. To date, Qinglong has completed more than 300 old building reinforcement projects, including benchmark cases such as the renovation of Guangzhou's Qilou arcade districts and the renewal of Shanghai's Shikumen neighborhoods, accumulating extensive hands-on experience.

Selecting UHPC reinforcement components in old building renovation is, in essence, a unification of technical logic and humanistic value. Building on 28 years of professional expertise, Qinglong Group delivers safe, reliable, and aesthetically compatible customized solutions for every renovation project through material innovation and full-chain services. Going forward, as UHPC material costs are optimized and application technologies mature, its use in urban renewal will become increasingly widespread, enabling more old buildings to achieve sustainable development through both “reinforcement” and “renewal.”