CRL K Road Station – Adaptive Mould Makes Curved GRC Panels in Complex Freeform Architecture
Adaptive Mould Technology Brings Freeform Architecture to Life
From London to Auckland? The Karangahape Road Station (K Road Station) is a design twin from award winning Elizabeth line in London, UK. Project forms a central architectural moment in Auckland’s transformative City Rail Link (CRL) — New Zealand’s largest-ever public infrastructure project. The interior of the station is defined by sinuous, freeform tunnel linings, composed of large-scale Glassfibre Reinforced Concrete (GRC) panels.
These panels—many of which feature double-curved, parabolic geometries—could not be produced efficiently using traditional concrete formwork methods. Instead, ADAPA’s adaptive mould technology played a central role in shaping the station’s iconic forms, enabling rapid, sustainable, and precise fabrication of hundreds of custom panels.
This project sets a new standard for digitally fabricated architectural concrete, and shows what’s possible when computational design meets reconfigurable moulding systems.
Solving Complexity in GRC Fabrication
The tunnel lining’s flowing design was derived from a detailed digital twin model of the station interior. This geometry was directly translated to the adaptive mould via parametric design tools, ensuring millimetre-precise surface control and fidelity to the architect’s vision. Architectural projects that feature complex geometry, especially those with non-repetitive double-curved surfaces, face significant challenges during fabrication. Standard moulding techniques—whether timber formwork or CNC-cut foam—are labour-intensive, expensive, wasteful, and rigid.
ADAPA’s solution is different. Our adaptive mould system replaces the need for hundreds of unique moulds by using a single, digitally controlled, reconfigurable surface. Adjusting curvature takes minutes instead of days, and all shape data comes directly from 3D design files, eliminating translation errors and speeding up the entire production cycle.
This was a game-changer for the K Road Station project, where:
- 360 unique and repeating curved GRC panels were needed
- Many panels had two-way curvature, with no flat surface to reference
- Surface texture, color, and mounting systems had to meet tight tolerances
- Pandemic-related constraints demanded efficiency and flexibility
A Smarter Way to Make Moulds: From CNC Foam to Adaptive Reuse
For certain panels—particularly repetitive & larger ones that exceeded the mould’s physical limits—the fabrication team used ADAPA’s adaptive mould to shape precise, reusable composite moulds (GRP). These GRP moulds were then used to cast the final GRC panels. This approach allowed fabricator to preserve the precise geometry and surface quality enabled by the adaptive mould, while overcoming size limitations and enabling repeated use of the GRP moulds for identical or similar panels. By using the adaptive mould to generate these intermediate moulds, the fabrication process remained flexible and efficient, even for panels with complex double-curved forms without relying on labor-intensive manual formwork.
The station’s interior lining required over 360 uniquely curved panels, some featuring two-way curvature or continuous freeform transitions. Traditionally, each of these would have required a unique CNC-cut foam mould—often discarded after a single use.
This shift in method brought a host of benefits:
- ✅ No CNC-milled polystyrene moulds were required
- ✅ Shorter lead times—moulds were reconfigured digitally in minutes
- ✅ Increased repeatability without loss of curvature accuracy
- ✅ High surface quality and geometric precision for complex forms
This approach eliminated the long setup times and cost of foam-based moulding while delivering high-performance, form-accurate GRP moulds ready for repetitive GRC casting.
High-Performance GRC Panels with Architectural Finish
The GRC panels produced using this adaptive moulding approach achieved a high level of surface quality and geometric precision, meeting the demanding architectural specifications of the CRL K Road Station project. Fabricated using GRC Grade 18x, a high-performance mix known for its durability and structural performance, the panels featured an off-white colour complemented by a custom surface texture developed specifically for the project. By utilizing adaptive mould system, the fabrication team ensured a smooth, defect-free surface finish across even the most complex double-curved panels—without the inconsistencies often associated with CNC-cut or hand-crafted foam moulds. This process delivered architectural-grade results at scale, with no compromise in visual or structural integrity.
The success of this process was largely due to the flexibility and precision of the adaptive mould, which proved to be particularly well-suited for the demands of complex geometry and freeform surface fabrication. Unlike traditional moulding methods, the adaptive mould could be rapidly reconfigured to suit each unique shape, allowing the team to produce a wide variety of panels with speed and accuracy—while eliminating the need for one-off CNC-milled foam moulds.
The adaptive mould system was particularly advantageous in this context due to its ability to:
- Accurately produce double-curved and non-repetitive geometries
- Support rapid shape changes for efficient production
- Deliver high-fidelity surfaces directly from digital models
- Enable mass customization with minimal material waste
Project Summary
Location: Auckland, New Zealand
Client: Liquidstone
Architect: Grimshaw
Main Contractor: Link Alliance / Thermosash
Technology: ADAPA Adaptive Mould System
Panels Produced: 360 GRC Panels
Panel Type: Single and Double Curved, Freeform GRC
Project Scope: Digital Fabrication & Formwork Innovation
Get in touch with our team to learn how adaptive moulding can bring efficiency, precision, and flexibility to your next GRC project.