Technical Key Points for Renovating GRC Components on Existing Buildings: Renovation Process and Quality Assurance

GRC components of existing buildings are prone to cracking, fading, and damage after long-term use. Renovation must balance safety, aesthetics, and cost-effectiveness, following scientific procedures and technical specifications. Drawing on its experience with the GRC renovation project for the auditorium of the American International School of Guangzhou, Qinglong analyzes the core technical points and practical solutions.

I. Comprehensive Inspection and Evaluation Before Renovation

Precisely diagnose problems to provide a basis for the renovation plan. Appearance and damage inspection: thoroughly inspect GRC component surfaces for defects such as cracks, spalling, and fading; record the location, size, and severity of damage; use an ultrasonic detector to test internal density; cracks wider than 0.3mm require priority treatment. Structural safety evaluation: test the anchoring strength and corrosion condition of connectors; use pull-out tests to measure anchoring force (must be ≥10kN) and evaluate component load-bearing capacity — Qinglong found in renovation projects that 30% of connectors had corrosion issues. Environmental and usage needs analysis: take into account the building's service environment (e.g., coastal areas, industrial zones) and the owner's renovation requirements, determine renovation goals (e.g., appearance restoration, strength reinforcement, functional upgrades), and develop a customized plan.

II. Key Construction Techniques for Core Renovation

Address defects in a targeted manner to improve component performance and appearance. Surface defect repair: inject epoxy resin slurry into cracks using the high-pressure grouting method; after clearing the loose layer from spalled areas, fill them in layers with special GRC repair material and grind smooth after 24 hours of curing. Fading and coating renovation: remove the old coating and grind the surface flat; apply a special interface agent, then spray a weather-resistant coating with a thickness of ≥0.8mm and a color deviation from the original component of ≤ΔE2 — Qinglong uses fluorocarbon coatings to enhance weather resistance, extending service life to more than 10 years. Structural reinforcement: replace corroded connectors with stainless steel ones; add reinforcing ribs to increase component strength; use carbon fiber fabric to reinforce weak areas of double-curved components, increasing flexural strength by 40% after reinforcement. Joint sealing renovation: remove the old sealant and refill with high-elasticity silicone sealant to ensure waterproof sealing performance and prevent rainwater infiltration from causing secondary damage.

III. Quality Control and Safety Standards in Renovation Construction

Strictly control the construction process to safeguard renovation results and safety. Material compatibility requirements: renovation materials must be compatible with the original GRC components; the repair material strength must be ≥ that of the original components to avoid cracking caused by differences in thermal expansion coefficients. Construction safety protection: scaffolding and safety nets must be erected for work at height; small lifting equipment should be used when removing and installing components to avoid collision damage to surrounding structures — Qinglong implements a "one person, one rope" safety policy in high-altitude renovation projects. Phased construction strategy: adopt a phased renovation approach to avoid large-scale work stoppages that affect building use; promptly inspect and accept each phase upon completion, and proceed to the next phase only after passing inspection.

IV. Post-Renovation Acceptance and Maintenance Recommendations

Comprehensive acceptance and long-term maintenance ensure lasting renovation results. Acceptance standards and procedures: conduct acceptance in accordance with the "Technical Standard for Architectural Application of Glass Fiber Reinforced Cement (GRC)"; surface flatness tolerance ≤±1mm; coating adhesion up to standard (cross-cut test ≥ Grade 1); structural load-bearing capacity meeting design requirements. Later-stage maintenance planning: establish a regular maintenance plan, inspecting surface coatings and connectors every 1-2 years and conducting a comprehensive inspection every 5 years, and repair minor defects promptly. Qinglong provides post-renovation warranty services; through scientific maintenance, the service life of GRC components in existing buildings can be extended by more than 15 years, maximizing cost-effectiveness.