Nueva Centinela Expansion Project | Sierra Gorda, Calama, Antofagasta, Chile

EFCO Formwork Powers Chile’s Largest Mining Investment

Sierra Gorda, Calama, Antofagasta

Maximum Productivity at Scale

The Nueva Centinela Expansion Project represents Chile’s largest mining investment in the past five years. Owned by Antofagasta Minerals, the $4.4 billion expansion will double processing capacity and add 170,000+ tons of annual copper production over a projected 36-year mine life.

The Challenge: Scale Meets Complexity

Empresa Constructora Fluor Salfa Ltda., under Site Manager Oscar Labarca, faced a demanding 15-month schedule to install more than 30,000 m² (322,917 ft²) of formwork across structurally diverse applications. The project required formwork solutions that could adapt quickly to varied requirements while maintaining aggressive timelines and tight budgets.

The Solution: Engineered Versatility

As a long-term EFCO customer, Fluor Salfa selected EFCO based on its proven ability to efficiently solve complex formwork challenges. For Nueva Centinela, EFCO provided a range of products used in various applications across multiple structures throughout the project. This comprehensive formwork package was specifically engineered to handle the project’s structural diversity:

PLATE GIRDER® for straight walls in feeding buildings (1,695 m² / 18,244 ft²), bilge structures (3,326 m² / 35,790 ft²), and four tailings thickeners
REDI-RADIUS® for three material storage domes with radii from 39m to 53.5m (127’11” to 175’6”)
E-Z DECK® for elevated slabs, including 1.3-meter-thick (4’3”) secondary crusher slabs (360 m² / 3,875 ft²)
SUPER STUD® Traveler Box for the 600-meter-long (1,969’) tailings channel

Tailings Infrastructure: Sequential Thickener Construction

The four tailings thickener structures set the pace for the entire project. Each featured 7.5-meter-high (24’7”) walls with 1.2-meter (3’11”) thickness and 2-meter-thick (6’7”) slabs—totaling 1,380 m² (14,854 ft²) of vertical formwork and 530 m² (5,704 ft²) of slab area per structure.

Rather than using dedicated equipment for each thickener, PLATE GIRDER® enabled sequential construction with a single equipment package. Eight-person crews completed each structure on 10-day pour cycles—a 40% time reduction compared to original estimates for conventional formwork—then stripped and repositioned the same formwork to the next thickener. This approach delivered all four structures while using 60% less equipment than simultaneous construction would have required—directly reducing rental costs and site congestion.

The 600-meter tailings channel progressed concurrently using SUPER STUD® Traveler Box systems. As the channel’s wall profile varied in height and thickness, the system’s adjustability eliminated equipment changes, maintaining steady progress throughout the phase.

Material Handling: Storage Domes and Processing Buildings

With thickener formwork now available for reuse, crews cycled PLATE GIRDER® systems to the feeding buildings and bilge structures. Simultaneously, the three material storage domes required REDI-RADIUS® curved forms at three different radii: 39m, 46m, and 53.5m. The system’s adjustable design allowed the same base equipment to adapt across all three geometries.

To accelerate installation and improve safety, crews preassembled REDI-RADIUS® panels at ground level and positioned them with cranes—eliminating time-consuming assembly work at height.

Final Structures: Elevated Slabs and Specialized Forms

The secondary crusher slabs represented the project’s most challenging elevated work: 360 m² of 1.3-meter-thick concrete at height. E-Z DECK® shoring towers were preassembled at ground level, then craned into position. This strategy removed assembly work from the critical path while eliminating complex operations at elevation.

For unique applications like thickener entrances and service shafts, EFCO shipped specialized forms preassembled from the warehouse—converting potential field fabrication delays into straightforward installations.

Nueva Centinela Expansion Project | Sierra Gorda, Calama, Antofagasta, Chile

Why Empresa Constructora Fluor Salfa Ltda Chose EFCO

Fluor Salfa’s decision to partner with EFCO reflected confidence built through proven performance on previous collaborations. The contractor recognized that Nueva Centinela’s scale and structural diversity demanded more than commodity formwork—it required integrated systems, responsive engineering, and the capacity to support a fast-moving project in a remote location.

EFCO’s product range offered the versatility needed to handle the project’s varied applications—from heavy thickener walls to curved domes to elevated slabs—without requiring specialized equipment for each structure. The ability to cycle and reuse equipment across phases directly supported budget and schedule objectives. EFCO demonstrated its ability to provide the Lowest In-Place Concrete Costs by providing engineered solutions that reduced the equipment on-site by reusing systems from one structure to the next, improved safety and efficiency, and accelerated timelines despite the project’s challenging complexities.

Beyond equipment, EFCO delivered engineering support for challenging applications, detailed shop drawings, logistics coordination to meet tight timelines, and dedicated field service throughout construction.

The Nueva Centinela expansion met its 15-month timeline while installing 30,000+ m² of formwork—validating Fluor Salfa’s choice of a partner capable of delivering both Innovation and results on Chile’s largest mining investment in five years.

We are very pleased with the results and the solutions; the proactive approach to the designs has paid off. We are currently making significant progress, with high-quality concrete and excellent finishes. EFCO’s service, engineering, and logistics have been outstanding on this important project.

-Oscar Labarca, Site Manager