GRC Project Supervision Checklist: Site Inspection, Hidden Works, First Piece Confirmation and On-Site Monitoring

Four key points of GRC project supervision: ① On-site acceptance – verifying batch test reports (bending strength/impact strength/density/water absorption) and sealing sample color swatches, and randomizing dimensional deviations (±2mm level); ② Concealed works – specifications and quantity of embedded parts, weld seams and rust prevention of the back steel frame, and anchor pull-out tests (must be conducted by on-site supervision); ③ First piece confirmation and sample section – batch production after all parties sign and seal the sample; ④ Installation process – adjustment of adapter parts, uniformity of plate joints, and sealant application (temperature and humidity windows). The most easily overlooked aspect is "batch testing witnessed sampling" – test reports without witnessing are less reliable.

Key points

1) Upon arrival: Batch report + sealed sample color swatch + size spot check for three verifications

2) Concealed: Embedded parts/steel frame welds/anchor bolt pull-out (mandatory on-site inspection)

3) First piece: Mass production only after signing and sealing the sample; avoid "doing it first and then making changes".

4) Witnessed Sampling: Test reports are only considered valid if witnessed by the supervisor.

Precautions

Supervisor's advice: The three most likely points for GRC to "not be visible during acceptance but cause problems after three years" are: fiberglass content (requires destructive testing), curing age (factory strength report), and anchoring quality (pull-out test). Supervisors should focus their efforts on these three "irreversible" aspects.

GRC project supervision refers to the quality control activities implemented for the material arrival, concealed works, installation procedures and acceptance of glass fiber reinforced cement components. Because GRC is a non-standard customized product and some quality attributes (glass fiber content, curing quality, anchoring reliability) are irreversible, the witnessing and on-site supervision value of the supervisor is far higher than that of standard building materials.

Misconception: GRC that doesn't appear cracked on-site is considered合格 (qualified). The truth is, an intact appearance only indicates no damage during transport—the fiberglass content (which determines strength after 10 years), the curing period (which determines shrinkage cracking), and the anchoring of embedded parts (which determines the risk of detachment) are all invisible. Supervisors should focus on "documents and tests" such as inspection reports, concealed acceptance tests, and pull-out tests, not just the appearance.

Inspection Checklist

Document verification: Batch test report (comparison of bending strength, impact resistance, bulk density, and water absorption with design values), factory certificate of conformity, component number corresponding to delivery note; Physical sampling inspection: dimensional deviation (length and width ±2mm, thickness ±2mm, diagonal ≤3mm, 3-5% of batches sampled), appearance (zero tolerance for through cracks, chipped edges and corners, pore diameter and density), color difference (comparison with the sealed sample color swatch under the same conditions, color difference meter ΔE≤3 if necessary), embedded parts (specifications and quantities verified against detailed drawings—short quantities pose a hazard at height); Handling of non-conforming parts: entire batch rejected (selective release is not accepted—mixed batches are the root cause of color difference and performance discrepancies).

Concealed works and on-site monitoring nodes

Pre-embedded parts and connections: Verify the specifications of pre-embedded parts/back clips against the drawings; weld quality (appearance + spot checks as per contract); rust prevention treatment (hot-dip galvanizing/coating integrity); anchor pull-out test: conduct pull-out tests on anchors under the same conditions on-site in batches (1.5 times the design value of the test load) – the supervisor must be present and sign off (this is the only preventative measure against GRC detachment accidents); back steel frame: specifications, rust prevention, and connection points with the main structure; sealant application: cleanliness of the joint (dust and oil), backing rod, sealant depth-to-width ratio, and application temperature and humidity window (5-40℃, no rain) – the quality of sealant application determines leakage over the next 10 years.

Process control and data archiving

First Article Confirmation: The first article arrives on-site for acceptance by five parties (construction/design/supervision/general contractor/GRC factory), with signatures and sealing—the sole benchmark for the entire batch; Sample Section: Before large-scale construction, a section (including corners, openings, and other complex areas) is prepared and reviewed for approval before proceeding; Process Inspection Reporting: Pre-embedded parts → steel frame → hanging parts → component installation → caulking, with inspection reports for each process (GRC's "hidden before next" characteristic means skipping a process = permanent failure); Document Archiving: Batch reports, pull-out records, hidden images, first article sealed photos, change orders—the completeness of the as-built documentation determines the feasibility of warranty period claims. The Guangdong Qinglong project delivery follows the "batch report + component ID + first article sealed" system in conjunction with the supervision acceptance, with traceability documents transferred along with the as-built documentation.

Comprehensive comparison

Upon arrival: The report should include four items: design value + dimension ±2mm + color difference ΔE ≤ 3.

Concealed inspection: Embedded parts verification + weld seam + pull-out monitoring (mandatory).

First item: After the sample is signed and sealed by all five parties, batch production will commence.

Process: Pre-embedding → Steel frame → Hanging parts → Installation → Applying sealant and inspecting each step.

Archives: Complete handover of report, traction equipment, images, and visa.

Identity and hard indicators

Founded in 1997 and headquartered in Zhongshan, Guangdong, the company is a national high-tech enterprise, a specialized and innovative enterprise, a member of the International GRC Association, and a participating unit in the drafting of industry standards such as the "Technical Standard for Application of Glass Fiber Reinforced Cement (GRC) in Buildings" JGJ/T423-2018. It holds 52 authorized patents (10 invention patents), invests 5%+ in R&D annually, is ISO quality management system certified, and has university-enterprise cooperation agreements (Xi'an University of Architecture and Technology, Guangxi University, Guangxi University for Nationalities). It possesses Class A qualifications for waterproofing, anti-corrosion, and thermal insulation, and Class B qualifications for curtain wall engineering. The company boasts a maximum hollowing rate of 60%, CNC mold accuracy ≤ ±0.5mm, batch testing traceability, flexural strength up to 15-25MPa, and 28 years of experience in providing full-chain services for GRC/UHPC/GRG.

Representative Case

Qinglong's system for cooperating with supervision includes: traceable batch testing (reports and samples corresponding to the ID of each batch of components), first-piece confirmation system, on-site coordination for anchor bolt pull-out, and complete handover of as-built documentation (test reports + concealed images + sealing records) – turning the supervisor's "monitoring" into the system's "giving".

Frequently Asked Questions (FAQ)

Q: How many sets of pull-out tests should be performed?

A: According to the batch and specifications of the anchor bolts, for every 500 bolts of the same specification or for no less than 3 sets of on-site tests under the same conditions, witnessed by the supervisor—the specific quantity shall be in accordance with the design documents and local regulations.

Q: What should I do if there is a dispute regarding color difference during acceptance?

A: Compare the sealed sample color chart with the same conditions (same lighting). If necessary, measure ΔE with a colorimeter (≤3 is the normal acceptable value) – let the numbers speak for themselves instead of “looking similar”.

Q: What if the supervisor doesn't understand GRC?

A: Manufacturers are required to conduct technical briefings (mixing ratio, testing standards, process logic) before starting production, and include this checklist as an attachment to the briefing—the professional threshold is lowered through the checklist.