The delivery acceptance of granite components is centered on complete documentation, qualified appearance, precise dimensions, compliant ormance, and stable installation. Quality control spans the entire process from factory release, site entry, installation to finished products, strictly adhering to national standards and design requirements.
I. Core Cofor Delivery Acceptance (Mandatory for Factory Release / Site Entry)
- Documentation Acceptance (Veto Power)
Factory certificate of conformity, product manual, batch quality assurance certif
Third-party authoritative test reports: physical and mechanical properties, water absorption rate, radioactivity (Class A), gloss, wear resistance / acid-alkali resistance / frost resis.
Processing drawings, dimensional deviation records, factory inspection records, packing lists.
Certificates of conformity and test reports for auxiliary materials (dry hanging adhesive, hangers, sealant).
2ance Quality Acceptance (100% Inspection)
Color and Texture: Color difference within the same batch ΔE ≤ 5 (≤ 3 color grades), consistent with, no obvious color spots, color lines, or mixed colors.
Surface Defects (Front Face):
No through-cracks; non-through cracks ≤ 1 2 per piece.
Chipped edges ≤ 5mm, chipped corners ≤ 5mm², ≤ 2 per piece.
Pits/holes ≤ m, ≤ 3 per m² and not concentrated.
Polished Surface: Gloss ≥ 80GU, no scratches, chipped edges, water marks, or oil stains.
Flamed/Lichi Surface: Uniform texture, no local over-burning or missing surfaces.
- Dimensional and Geometric Precision Acceptance (Sampling / Full Inspection) Item Permissible Dviation (mm) Applicable Scenario Inspection Method Length / Width ≤1m: ±1; >1m: ±2 Contional slabs Steel tape measure Thickness Thin slab: ±0.5; Thick slab: ±1 As designed Vernier caliper Diagonal Diffrence ≤1m: ±2; >1m: ±3 Square / Rectangular Diagonal measurement Flatness Polished: ≤0.5/m;ough: ≤1/m All surfaces 2m straightedge feeler gauge Perpendicularity (Dry Hanging) ≤2/2m Wall surfaces Perpendicularityint Straightness Precision components (e.g., platforms, gauges) shall coly with GB/T 20428-2006, with precision reaching Grade 00 (≤0.02mm/m).
- Physical and Mechanical Property tance (Third-party Testing)
Density: ≥2.5g/cm³.
Water Absorption Rate: Polished ≤0.6%, Rough ≤1.0%.
Compressitrength: Dry ≥100MPa, Water-saturated ≥80MPa; Curtain wall / Load-bearing ≥130MPa.
Flexural Strengh: Dry ≥8MPa, Water-saturated ≥7MPa.
Wear Resistance: Wear pit length ≤20mm (500g/1000 revolutions).
FrostResistance: 25 freeze-thaw cycles at -20℃, no cracks or spalling, mass loss ≤1.0%, strength loss ≤10%.
Radioactiviomplies with GB 6566 Class A (suitable for indoor and outdoor use). - Packaging and Marking Acceptance
Marking: Clearly labeled with model, spation, batch, production date, processing number, and traceable.
Packaging: Complies with GB/T 191, moisture-proof, shock-proof, and collision-proof; precisioents require three-layer protection of rust prevention EPE wooden pallets.
II. Full Process Quality Control Standards (Factory Release → Site Entry → Installation → Finished)
- On-site Quality Control (Responsibility of the Purchaser / Supervisor)
Verification of Documents: Certificates, reports, and batch consisty; reject if documents are incomplete.
Visual Sampling Inspection: Sample 5%-10% per batch; reject the entire batch if defects exceed standards.
Dimensional Re-meaurement: 100% verification of critical components; reject if deviations exceed standards.
Performance Re-inspection: For key projects, conduct sampling re-inspection on compressive strength, flexural strr absorption, and radioactivity. - Installation Construction Quality Control (Responsibility of the Contractor)
Base Layer: Firm, flat, and clean; meets design load-bearing c
Dry Hanging / Laying:
Dry Hanging: Hanger material/specification meets standards; welding/bolting is secure with no looseness.
Laying: Mortar/adhesive is hollow drum rate ≤1% (floor), 0 hollow drums on walls.
Joints: Joint filling is compact; sealant has no bubbles, sagging, or cracking; woofing meets standards.
Protection of Finished Products: Cover and protect after installation to avoid scratches, contamination, and impact. - Finished Product Acceptance (Comprehensive Evaluation)
Physiuality: Full inspection of appearance, flatness, plumbness, joints, hollow drums, and gloss.
Document Archiving: Complete acceptance records, test reports, concealed work recand as-built drawings.
Judgment: Sign acceptance certificate if all items meet standards; rectify non-conforming items within a time limit, and delivery is permitted only after re-inspectiis passed.
III. Key Acceptance References (National Standards)
GB/T 18601-2009 “Natural Granite Building Slab”.
GB/T 9966 Series “Test Methods for Natural Stone” (strength, water absorption, wear resistance, etc.).
GB 6566 “Limit of Radionuclidesng Materials”.
GB/T 20428-2006 “Granite Platform” (precision components).
Project design drawings, technical requirements, and contract
