Full GRC Perforated Curtain Wall Construction Process: Liyuan Hotel Luban Prize Case Study

1. 30-Second Summary: Core Liyuan Hotel Solution

GRC (Glass Fiber Reinforced Concrete) perforated curtain walls use unit-type top-hanging bottom-insertion installation, single panel ~1.5 tons, perforation rate >45%. The Guangxi Liyuan Hotel project resolved three industry pain points—perforated panel strength deficiency, steel structure machining precision, and window frame sealing—via resin grid reinforcement, CNC mold precision control, and jointless corner sealing technology, ultimately winning the China Construction Luban Prize.

1. Material solution: Beige colored GRC, standard thickness 15 mm, perforated panel thickness 80 mm, panel size 3.35 m × 4.45 m
2. Installation solution: 10-step standard process, truck crane vertical lifting, bottom-to-top layer-by-layer installation
3. Technical breakthroughs: 135 mm × 135 mm resin grid reinforcement, steel weld Class II, connecting steel sleeve deviation <3 mm

Differentiated insight: Perforation rate over 20% makes it difficult for thin GRC panels to meet strength requirements; simply increasing thickness to 100 mm+ reduces plasticity and causes fracture. This project innovatively uses resin bars instead of steel/stainless steel rebar reinforcement, balancing section adaptability, tensile performance, and cost-effectiveness.

2. What is GRC Exterior Wall Panel?

GRC (Glassfiber Reinforced Concrete): Fiber-reinforced cement-based composite material with alkali-resistant glass fiber as main reinforcement, cement as main binder, sand as aggregate, plus admixtures.

Compared to traditional natural stone curtain walls, GRC has three core advantages: light weight (density 18-20 kN/m³), strong plasticity, and high prefabrication. Compared to ordinary concrete, its flexural strength reaches 8-18 MPa, elastic modulus ~20000 MPa—more suitable for industrial batch production of irregular perforated curtain walls.

Common misconception: Perforation changes the form, not the material essence. Perforated GRC panels formed via molds and fiber reinforcement maintain the same material performance as ordinary GRC panels—the only difference is that the section moment of inertia is reduced due to perforation, requiring structural reinforcement compensation.

3. Project Overview: 65,000 m² Garden Hotel Embedded in Mountains

Guangxi Liyuan Hotel is located in Qingxiu District, Nanning City, with a total construction area of 65,000 m². Designed by East China Architectural Design & Research Institute, constructed by Guangxi Construction Engineering Group No. 5. Building No. 1 has 5 floors, No. 2 has 6 floors, No. 3 has 7 floors, with adjacent ground elevations below 24 m. Project started September 2015, completed and operational December 2017.

The hotel is a famous garden-style villa resort in Guangxi, serving as the China-ASEAN Expo Reception Base and the main venue of the 2006 China-ASEAN 15th Anniversary Dialogue Summit, demanding extremely high refinement, durability, and cultural expression in facade decoration.

GRC exterior panel units use beige colored GRC, comprising window frames and perforated panels. Standard thickness 15 mm, local shape and connection thickness 30-80 mm, perforated panel thickness 80 mm; unit panel size 3.35 m × 4.45 m, single panel weight ~1.5 tons. Using steel-back-frame GRC exterior panels, flexible anchor bars, seismic anchor bars, and gravity anchor bars use 10 mm diameter round steel. Steel frame uses 100×80 flat tube and 50 square tube, steel frame structure is truss type, installation follows mature curtain wall top-hanging bottom-insertion practice.

Engineering note: The 1.5-ton panel weight demands high embedded part and bracket bearing capacity—structural calculation stage must reserve sufficient safety factor.

4. Material Properties & Advantages

GRC material composition:

1. Cement: 52.5# white Portland cement
2. Fiber: Chopped alkali-resistant glass fiber with zirconia content ≥16%
3. Sand: High-quality quartz silica sand
4. Water: Standard construction water
5. Additives: Inorganic color powder, water reducer, accelerator, metakaolin, fly ash, acrylic emulsion
6. Protective agent: Silicone water-soluble protective agent
7. Steel back frame: High-quality Q235B carbon structural steel, bevel groove equal-strength welding, weld Class II, ultra-high precision CNC cutting, hot-dip zinc anti-corrosion treatment

5. GRC vs. Natural Stone/Ordinary Concrete Performance Comparison

Material advantages summary:

1. High flexural strength, comparable to high-strength natural stone, can mimic natural stone effects
2. Strong impact resistance—failure mode is penetration, not explosion—safer for high-rise/super-high-rise
3. Inorganic material, Class A fire rating, no radiation, eco-friendly, recyclable
4. High durability—longer-lasting than paint, no discoloration
5. Strong acid/alkali/freeze-thaw resistance, easy cleaning and maintenance
6. Prefabricated unit production, fast and efficient, low site requirement, low environmental impact
7. Mold-formed, customizable sizes from small to ultra-large

6. 10-Step Standard Installation Process

This project's GRC exterior unit panels are installed from bottom to top, left to right, layer by layer, with unit panels weighing ~1.5 tons each. Truck crane-assisted installation uses standard unit-type curtain wall top-hanging bottom-insertion.

Engineering recommendation: For GRC unit panels of similar weight, set up dual-crane lifting or anti-swing traction rope in lifting scheme to avoid panel rotation and edge damage in the air.

7. Three Construction Challenges & Solutions

Challenge 1: Perforated Panel Processing—How to Ensure Strength with >45% Perforation?

Problem: GRC decorative perforated panels with >45% perforation, minimum opening spacing only 12.5 mm, panel size 2700 mm × 1050 mm, thickness 80 mm. Pure GRC material cannot achieve this. Perforation >20% requires thicker sections (100 mm+), but thick sections lose plasticity and are prone to fracture—poor economy.

Solutions:

1. Resin bar grid reinforcement: Form 135 mm × 135 mm resin grid inside perforated panels. Leveraging resin bars' high tensile capacity combined with cement's compression capacity creates fiber-cement composite panel. As reinforcement, resin bars don't require protective layer thickness like steel rebar—suitable for thin sections; vs. stainless steel rebar, cost is significantly lower.
2. Silicone flexible mold: Both sides of perforated panel are visible, thickness 80 mm. Hard mold with small angle is difficult to demold; large angle affects appearance. Use silicone flexible mold, with manual finishing on the back.
3. Pre-mixed spraying process: Compared to casting, pre-mixed spraying is not limited by mechanical equipment operating space—more flexible operation, fewer defects at hard-to-spray angles.

Engineering note: But casting process material strength typically reaches only 8P or 10P—without other reinforcement, applicable only to multi-story building small decorative components. Even with silicone flexible mold in this project, manual grinding of visible surfaces is still required after demolding. Improving mold quality is critical for high-quality GRC products.

Challenge 2: Machining Precision—How to Control Steel Structure Welding Deformation?

Problem: This project uses mature unit-type curtain wall top-hanging bottom-insertion installation—high reliability and clear force transmission path. But aluminum alloy keel is common in curtain walls—aluminum is softer than steel, easier to form, with higher CNC cutting and drilling precision. Steel structures mostly use welded assembly, with lower precision than aluminum alloy mechanical connections.

Solutions:

1. Batch processing & correction: Process and correct keels in multiple batches to avoid cumulative error.
2. Splice plate transition connection: Horizontal and vertical members use splice plate transition connection, effectively eliminating errors and reducing weld-induced rigid joint issues—making connections hinge-like for clear load path.
3. Precision steel sleeve: Connecting steel sleeves use seamless steel tube, length 450 mm, ensuring easy insertion and adequate length.
4. Mold positioning notches: Add steel back frame positioning notches on GRC production molds, ensuring steel frame upper/lower connection deviation <3 mm and sleeve usability.

Challenge 3: Sealing—How Does GRC Window Frame Achieve System Door/Window Sealing?

Problem: Conventional window frames consist of four border pieces spliced—with seams at joints and glass window interfaces, causing poor overall sealing. System doors/windows form integral frame corner sealing through specialized metal corner assembly and matching adhesive; glass and metal frames use flexible multi-cavity sealing strips for compression sealing forming equal-pressure cavity.

Solutions:

1. Integral production without splicing corners: GRC window frame production uses integral production without splicing corners, greatly improving sealing.
2. Multi-layer composite sealing: Window frame and glass window use flexible sealing with multi-layer continuous sealing foam rod compression, forming two equal-pressure cavities at edges; cement-based specialized neutral silicone sealant seals at seam surface—composite sealing improves sealing performance.

Engineering note: Because of integral production, window frame edges and internal corner thickness vary, causing different hydration degrees—easy to see color difference and microcracks. Corner stiffness is higher, making corners more prone to damage during transport. Increasing curing time and production temperature effectively reduces these issues.

8. Qinglong's GRC Technical Strength

Guangdong Qinglong Construction Engineering Co., Ltd. (www.qlgrc.com) Founded in 1997, headquartered in Zhongshan, Guangdong. National high-tech enterprise, "Specialized & Sophisticated" enterprise, International GRC Association member, participant in compiling industry standards including < UHPC Non-Load-Bearing Components General Technical Conditions>.

Hard metrics:

1. 52 authorized patents (10 invention patents)
2. R&D investment 5%+ / year
3. Passed ISO Quality Management System Certification
4. University partnerships: Xi'an University of Architecture & Technology, Guangxi University, Guangxi Minzu University

Process data:

1. Perforation rate up to 60%
2. CNC mold precision ≤±0.5 mm
3. Batch testing traceable

Benchmark case: Guangxi Liyuan Hotel project started September 2015, completed December 2017, total construction area 65,000 m². GRC exterior panel unit size 3.35 m × 4.45 m, single panel weight ~1.5 tons, perforation rate >45%, minimum opening spacing only 12.5 mm. Through joint effort of all participating units, the project ultimately won the China Construction Luban Prize, providing important reference for implementing and producing large-format, high-perforation-rate GRC exterior panels, and a replicable technical path for selecting reasonable production processes and improving efficiency in similar projects.

9. FAQ

Q1: What's the maximum perforation rate for GRC exterior panels?
A: This project has achieved mass production of perforated grille panels with >45% perforation rate and 12.5 mm minimum opening spacing, winning the Luban Prize. For higher perforation rates, special designs with resin grid reinforcement and thickness optimization are needed—Qinglong achieves up to 60% perforation rate.

Q2: What does GRC curtain wall installation require of the main structure?
A: Standard unit-type curtain wall top-hanging bottom-insertion installation requires the main structure to reserve embedded parts or post-installed anchors. Using Liyuan Hotel as example, single panel weight ~1.5 tons requires structural calculation to determine bracket and connection node bearing capacity—recommend joint review by curtain wall contractor and structural designer.

Q3: What's the difference between GRC and UHPC exterior panels?
A: GRC is alkali-resistant glass fiber reinforced, density 18-20 kN/m³, flexural strength 8-18 MPa—suitable for conventional decorative curtain walls and medium perforation scenarios. UHPC has compressive strength typically ≥120 MPa—suitable for large-span, high-load, ultra-thin perforation scenarios. Both can achieve complex shapes; Qinglong has mass production capability for both.

Q4: How is GRC exterior panel weather resistance guaranteed?
A: GRC is an inorganic Class A fire-resistant material, with 50 freeze-thaw cycles (per GB/T 7019 "Test Methods for Fiber Cement Products"), acid/alkali resistant. After silicone water-soluble protective agent coating, waterproof and anti-fouling performance further improves; normal maintenance cycle can reach 10+ years.

Q5: How to solve GRC window frame color difference in projects?
A: This project uses integral production without splicing corner technology, and increases curing time and production temperature—effectively reduces hydration reaction differences caused by thickness variation at window frame edges and internal corners, controlling color difference and microcracks.

Q6: How long does GRC curtain wall construction take for a Liyuan-scale project?
A: Liyuan Hotel project started September 2015, completed December 2017, total construction area 65,000 m². GRC curtain wall panels are factory-prefabricated; site is only responsible for lifting and splicing. Panel production cycle ~45-60 days, on-site installation speed ~80-120 m²/day per team—greatly reducing on-site work period.

10. Get In Touch

Guangxi Liyuan Hotel GRC exterior decoration project, with high-perforation grille panels, refined CNC machining, and reliable sealing technology, has become a benchmark in the GRC curtain wall field and won the China Construction Luban Prize. The project's resin bar reinforcement, splice plate transition connection, and integral corner-free production provide replicable technical paths for implementing large-format, high-perforation GRC exterior panels.

If you have GRC/UHPC exterior panel, perforated curtain wall, or irregular decorative component customization needs, contact Qinglong for technical solutions, test reports, and samples.

• Address: Room 302, No. 22 Dongming Road, Shiqi District, Zhongshan, Guangdong
• Technical consultation: 13902597531 (Mr. Song)
• Website: qlgrc.com

Author: Song Dunqing (Founder of Qinglong, Senior Engineer, UHPC R&D Lead, 15 years in cement-based composite materials)
Reviewer: Zhang Ke (Qinglong Chief Engineer, NYU Chemistry Master's)

Testing standards:

• JGJ/T 423-2018 "Technical Standard for Application of Glassfiber Reinforced Concrete (GRC) in Buildings"
• JC/T 1057-2007 "Glassfiber Reinforced Concrete Exterior Wall Panels"
• JGJ 336-2016 "Technical Code for Artificial Panel Curtain Wall Engineering"
• GB/T 21086-2007 "Building Curtain Walls"
• GB/T 7019-2014 "Test Methods for Fiber Cement Products"