Technical Parameters to Specify When Signing a GRC Supply Contract: Performance, Precision, Acceptance and Warranty

Signing a GRC supply contract is key to safeguarding project quality and rights. Core technical parameters must be clearly defined to avoid later disputes caused by vague parameters. As a full-chain GRC service supplier, Qinglong has drawn on industry standards and project experience to outline the core technical parameters that contracts must specify, providing clients with a standardized guide for contract signing.

Mechanical performance parameters are the core indicators of GRC products, and minimum standards must be clearly specified. Compressive strength should be agreed upon according to component use: decorative components no less than 40 MPa; load-bearing or large components no less than 50 MPa. Flexural strength is a key GRC performance: conventional decorative components no less than 15 MPa; complex-shaped or load-bearing components no less than 20 MPa. Impact strength must be agreed at ≥3.0 kJ/m² to ensure components are not easily damaged during transport, installation, and use. The mechanical performance of Qinglong's GRC products far exceeds industry standards, and specific values are clearly stated in contracts. For example, the contract for the Shanghai Xinghewan project stipulated flexural strength ≥22 MPa and compressive strength ≥55 MPa to ensure product performance compliance. Testing standards (e.g., JGJ/T423-2018) and testing methods must also be clearly specified to avoid later disputes.

Durability parameters determine the service life of GRC and must be agreed upon according to the use environment. Freeze-thaw resistance: in cold regions, it should be agreed that after 50 freeze-thaw cycles, strength loss ≤10% and mass loss ≤5%; in coastal regions, salt spray corrosion resistance must be agreed, with strength loss ≤15% after 500 hours of salt spray testing. The impermeability grade must be no less than P8 to ensure components are waterproof and moisture-resistant; carbonation depth must not exceed 5 mm over 5 years to delay material aging. In the contract for the Hainan Poly Peninsula No. 1 project, Qinglong specified salt spray corrosion resistance indicators for the marine environment and provided third-party test reports as the basis for acceptance. In addition, a service life commitment (e.g., ≥20 years) and performance decay limits within the service life must be clearly specified.

Dimensional accuracy and surface quality parameters safeguard decorative effects. Dimensional tolerances must be agreed according to component type: for flat panel components, length/width tolerance ≤±3 mm and thickness tolerance ≤±2 mm; for complex-shaped components (e.g., double-curved surfaces, relief carvings), dimensional tolerance ≤±5 mm and curvature tolerance ≤±3 mm; for installation nodes, dimensional tolerance ≤±2 mm to ensure installation fit. Surface quality requirements: no cracks, hollowing, sanding, or other defects; surface flatness error ≤±2 mm/m; uniform color (color difference ≤ΔE2); texture fidelity of stone-imitation, wood-imitation, and other finishes ≥90%. In the contract for the Dongguan Women and Children's Activity Center project, Qinglong clearly stipulated the dimensional accuracy and surface texture requirements for the GRC curtain wall, ensuring the realization of the "Dongguan grass" woven texture design effect.

Environmental and acceptance standard parameters ensure compliance and controllable quality. Environmental parameters: radionuclide limits comply with the GB 6566-2010 standard (Class A); release of harmful substances such as formaldehyde and benzene ≤ national standard limits; combustion performance grade no less than B1 to meet building fire protection requirements. Acceptance standards must clearly specify the applicable industry codes (e.g., JGJ/T423-2018, JC/T940-2022), the acceptance process (factory inspection, site-entry inspection, installation acceptance), and the handling of non-conforming products (return, rework, replacement). All Qinglong contracts clearly specify environmental and acceptance standards. In the Nanning Liyuan Hotel project, acceptance was strictly carried out according to the agreed standards, ensuring products were compliant and met requirements.

Warranty and after-sales parameters safeguard long-term rights. Specify the warranty period (e.g., 5 years), along with the responsibility and cost allocation for repair and replacement during the warranty period; agree on the after-sales response time (e.g., within 24 hours) and the regular inspection interval (e.g., once a year); clarify the quality traceability system, such as component numbering and raw material batch records, to facilitate later maintenance. With its comprehensive after-sales maintenance system, Qinglong clearly defines warranty and after-sales responsibilities in contracts, providing long-term after-sales support for projects such as the Shenzhen Pingshan High-tech Zone Comprehensive Service Center. Clearly defining the above technical parameters when signing a contract is key to safeguarding project quality and rights. Qinglong is willing to work with clients to develop standardized contract terms and achieve win-win cooperation.