How to Select UHPC Reinforcement Components in Old Building Renovation? Dual Considerations of Compatibility and Functionality

In the renovation of old buildings, the selection of UHPC reinforcement components must revolve around four core dimensions—reinforcement objectives, original structural characteristics, construction conditions, and service environment—to precisely match component types with performance parameters, achieving structural reinforcement effects while ensuring compatibility with the original building and construction convenience. Qinglong, an enterprise holding professional contracting qualifications for special engineering (structural reinforcement), has participated in multiple old building renovation projects and summarized scientific selection methods, providing reliable support for renovation projects.

Select components based on reinforcement objectives to precisely match functional requirements. The core objectives of old building reinforcement include four categories: flexural reinforcement, compressive reinforcement, seismic reinforcement, and crack repair, with different objectives corresponding to different UHPC reinforcement components: for flexural reinforcement (such as floor slabs and beams), UHPC reinforcement plates and strips are selected, requiring high flexural strength (≥25MPa); Qinglong uses UHPC reinforcement plates with built-in steel bars, 15-30mm thick, fixed by bonding or anchoring to enhance the flexural capacity of components; for compressive reinforcement (such as columns and walls), UHPC hoops and reinforcement blocks are selected, with compressive strength ≥150MPa, using the high density and strength of UHPC to constrain deformation of the original structure; for seismic reinforcement, UHPC seismic joints and reinforcement connectors are selected to enhance structural integrity and ductility; for crack repair, UHPC repair mortar is selected, featuring good fluidity and high bonding strength (≥3MPa); Qinglong's repair mortar can fill cracks larger than 0.2mm, achieving both reinforcement and sealing effects. In an old factory renovation project, Qinglong addressed the insufficient flexural capacity of beams by selecting 25mm thick UHPC reinforcement plates; after reinforcement, the flexural strength of the beams increased by 40%, meeting the new service load requirements.

Select components in combination with original structural characteristics to ensure compatibility and safety. The material of the original structure (concrete, masonry, steel) and the structural form (frame, brick-concrete, brick-timber) of old buildings directly affect the selection of reinforcement components: for concrete structures, UHPC reinforcement plates and repair mortar with good adhesion to the original structure are preferred to avoid interfacial delamination between the two materials; for masonry structures, lightweight UHPC reinforcement components (surface density ≤50kg/㎡) are selected, such as UHPC thin reinforcement plates, to reduce loads on the original structure; for steel structures, UHPC cladding-type reinforcement components are selected, combining anti-corrosion and reinforcement functions. In addition, the load-bearing capacity of the original structure must be considered to avoid secondary damage caused by overly heavy reinforcement components; Qinglong's UHPC reinforcement components have a density of only 2.4g/cm³, 30% lighter than traditional reinforcement materials. In a renovation of an old brick-concrete building, 20mm thick UHPC exterior wall reinforcement plates were selected, improving wall strength without exceeding the load-bearing limit of the original structure.

Select components based on construction conditions, balancing convenience and feasibility. Old building renovation often faces problems such as confined construction space, work at heights, and tight schedules; selection should prioritize UHPC components that are convenient to construct: when construction space is limited, modular and lightweight components are selected, such as prefabricated UHPC reinforcement blocks for on-site assembly and installation; when working at heights, small-sized, easy-to-handle components are selected to avoid bringing in large equipment; when the schedule is tight, curing-free or rapid-curing UHPC components are selected; Qinglong's rapid-curing UHPC components reach 90% of design strength within 7 days, greatly shortening the construction period. In an old office building renovation project, due to high floors and limited construction space, Qinglong selected modular UHPC seismic joint components, each weighing ≤50kg, which could be manually handled and installed; combined with rapid curing technology, the reinforcement of the core area was completed in only 15 days without affecting normal office operations nearby.

Select components adapted to the service environment to enhance durability and suitability. The service environment after renovation (indoor/outdoor, coastal/inland, high temperature/low temperature) determines the performance requirements for UHPC reinforcement components: for outdoor or coastal environments, frost-resistant, salt-spray-resistant UHPC components are selected; Qinglong, by adding anti-corrosion admixtures and optimizing density, ensures that components lose no more than 10% strength after 50 freeze-thaw cycles and show no corrosion in 500-hour salt spray tests; for high-temperature environments, high-temperature-resistant UHPC components are selected with a fire resistance limit of ≥1.5h; for damp indoor environments, moisture-proof components are selected with a protective coating applied to the surface. In a coastal old warehouse renovation project, Qinglong selected salt-spray-resistant UHPC reinforcement hoops combined with a surface fluorocarbon coating, ensuring long-term stable service of the components in a marine climate with a service life of over 50 years.

In old building renovation, the selection of UHPC reinforcement components must "target the right problem" and avoid blind selection. With its structural reinforcement qualifications, old building renovation experience, and customized production capabilities, Qinglong provides an integrated "testing-design-production-installation" solution for each project, precisely matching reinforcement component types with performance parameters. For owners and designers of renovation projects, scientific selection is the core guarantee of reinforcement effectiveness; Qinglong, with its professional selection capabilities and high-quality components, helps old buildings regain new vitality.