What standard should the impact resistance of GRC panels meet?

The impact resistance of GRC panels must comply with the "Glass Fibre Reinforced Cement (GRC) Decorative Products" (JC/T940-2022) standard. The core indicators are impact strength ≥3kJ/m² (thin panels ≤15mm), ≥5kJ/m² (standard panels 15-30mm), and ≥8kJ/m² (thick panels >30mm). Through fibre optimization and process upgrades, Qinglong has enabled GRC panel impact strength to consistently exceed the standard by more than 20%, with no impact damage issues in projects such as Hainan Poly Peninsula No. 1 and Shanghai Xinghewan.

1. Core Impact Indicators: Graded by Thickness

Thickness determines the baseline impact strength requirement. Thin panels (≤15mm): impact strength ≥3kJ/m², suitable for interior decoration and lightweight exterior walls — Qinglong's 15mm-thick GRC panels achieve an impact strength of 3.8kJ/m², far exceeding the standard; standard panels (15-30mm): impact strength ≥5kJ/m², suitable for exterior wall cladding panels and landscape components — Qinglong's 25mm-thick GRC panels achieve an impact strength of 6.5kJ/m², with excellent collision resistance; thick panels (>30mm): impact strength ≥8kJ/m², suitable for load-bearing components and large sculptures — Qinglong's 40mm-thick GRC panels achieve an impact strength of 9.8kJ/m², meeting heavy-duty application requirements.

2. Key Factors Affecting Impact Resistance

Materials and processes determine the upper limit of impact resistance. Fibre content and distribution: alkali-resistant glass fibre content ≥2.2%, evenly distributed to form a three-dimensional reinforcement network — Qinglong precisely controls fibre content at 2.2-2.5%, with a distribution uniformity of 98%; panel density: high-pressure vibration (pressure ≥0.5MPa) achieves a density of ≥2.2g/cm³, reducing pores and improving impact transfer efficiency — Qinglong's density compliance rate is 100%; aggregate gradation: continuously graded quartz sand of 0.15-0.6mm is selected to enhance inter-particle bonding — Qinglong's aggregate clay content is ≤0.3%, with bonding strength improved by 20%; curing process: constant-temperature, constant-humidity curing (≥14 days) ensures full hydration and stable strength — Qinglong's impact strength after curing is 15% higher than with standard curing.

3. Qinglong's Testing and Project Practice: Verifying Performance Reliability

Full-process testing ensures stable impact resistance. Factory testing: 3 specimens are drawn from each batch and tested for impact per the GB/T 15231 standard, and Qinglong's factory testing pass rate reaches 99.8%; on-site sampling: random sampling before project installation ensures no performance degradation during transport and storage, with a 100% sampling pass rate for Qinglong's Hainan Poly Peninsula No. 1 project; project cases: Shanghai Xinghewan GRC exterior wall panels (20mm thick) achieve an impact strength of 5.8kJ/m², with no damage from daily impacts; Hainan Poly Peninsula No. 1 double-curved GRC panels (25mm thick) achieve an impact strength of 6.8kJ/m², with no cracking or damage during installation and use, meeting the requirements of high-end real estate projects.