What later-stage maintenance do UHPC components require?

Post-installation maintenance of UHPC components is key to ensuring long-term performance and requires a systematic maintenance system. Based on 28 years of project tracking data, Qinglong Group divides UHPC maintenance into three levels: routine inspection, periodic testing, and professional maintenance. Maintenance intervals are dynamically adjusted according to environmental conditions; generally, routine inspection is recommended once per quarter, comprehensive testing once per year, and professional maintenance once every 5-8 years.

Routine inspection is the foundation of maintenance, focusing on surface contamination, micro-cracks, and joint sealing. In the Hainan International Convention and Exhibition Center project, Qinglong Group uses drones equipped with high-definition cameras for inspections, achieving 10 times the efficiency of manual methods. Inspection items include color difference changes (ΔE≤3), surface chalking (≤Grade 1), and crack width (≤0.2mm). Minor issues found are addressed promptly to prevent escalation. Inspection records are digitized and archived to establish component health files.

Periodic testing evaluates the performance status of components, including non-destructive testing (rebound method for strength, ultrasonic flaw detection) and sampling tests (core drilling for strength). Qinglong Group conducts full testing of critical components every year; a maintenance procedure is initiated when strength loss exceeds 10% or carbonation depth exceeds one-third of the protective cover. In coastal areas, chloride ion content testing is added to ensure effective reinforcement protection. Testing data is used to predict remaining service life and guide maintenance decisions.

Professional maintenance restores component performance, including surface cleaning (neutral detergent, pressure ≤50Bar), crack grouting (epoxy resin slurry), and protective coating renewal (fluorocarbon coating, dry film thickness ≥30μm). In old building maintenance, Qinglong Group uses profile-matching repair technology, ensuring no color difference between maintained components and original sections. Performance verification is carried out after maintenance to ensure design standards are restored. Through scientific maintenance, UHPC components can remain in optimal condition for more than 50 years.