Design is always shaped by real-world constraints: cost, schedule, and constructability among them. But new materials are expanding what’s possible with facades, giving architects more freedom to bring bold ideas to life.

Ultra high performance concrete (UHPC), a European invention introduced to North America more than 20 years ago, is finally gaining traction for its super-strong mix, giving it the ability to articulate never-before-possible facade designs in prefabricated panels as thin as 1 inch.

Architects are limited only by their imaginations when designing with UHPC. This can take shape in deeply sculpted facades, intricate surface textures, sharp returns and reveals, or open, perforated panels that filter light and air. From smooth monolithic forms to highly articulated geometries, UHPC allows architects to achieve levels of detail and complexity that would be difficult or impossible with traditional materials.

It’s all made possible by science; 500 microns marks the size of the largest component in the premix. All other elements are chosen for their gradation size, roundness and ability to compact with each other. This significantly reduces the amount of water necessary to create the precast mix and provides a higher-strength formation.

Strength, Durability, and Performance of UHPC

The dense matrix in UHPC allows architects to design incredibly thin cross-sections without the need for structural support. UHPC is internally reinforced with small fibers made from steel, stainless steel, plastic or other materials that act as “micro rebars” in the mix and provide the flexural strength architectural panels require. The panels can simply be clipped to a building or incorporated into open, perforated types of designs with little to no visible structural supports, since they’re significantly stronger than traditional concrete applications.

Additionally, the UHPC mix is extremely dense with smaller pores than traditional architectural precast mixes, so water can’t ingress into the panel matrix. That gives the system a superior freeze-thaw capacity, and with no reinforcing steel in the panel, there’s nothing that can corrode. As a result, UHPC can often achieve 10 times the life expectancy of traditional concrete when installed in an unsuitable environment (such as near saltwater or in high humidity).

While UHPC panels have a similar weight per square foot to traditional architectural concrete, their significantly reduced thickness means far less material is required overall. The result is a much lighter facade system, opening the door to concrete applications that were previously only feasible with metal, enabling architects to imagine wildly outside-the-box designs.

From Concept to Constructability

DEX®, Wells’ designer concrete system, is historically known for its interior applications but has recently gained traction as an exterior facade system because of its enhanced flexibility and aesthetic range. On a typical UHPC project, Wells becomes involved early in a design-assist capacity, providing architects with suggestions in terms of panel thickness, cost-saving measures, and constructability.

In the process, opportunities are identified to introduce panel repetition, aiming to optimize the number of molds required while maintaining the design intent. This is often achieved through small, typically unnoticeable design adjustments.

Design assist is an iterative process in which the prefabricator suggests changes or tweaks that will work better in the fabrication process, with the overriding goals of reducing costs, reducing failure points and accelerating the timeline.

During manufacturing, molds made from materials such as rubber, wood, or plexiglass can be fabricated efficiently using CNC equipment. Once cast, panels are transported on A-frames, like glass, to protect them during handling, when the greatest stresses often occur.

A New Era of Facades

But it’s the system’s equal parts flexibility and strength that excite architects the most. Despite its thinness, UHPC can handle wind loads comparable to traditional concrete and provide architects with an unlimited number of options in their exterior facade designs.

Put simply, UHPC is creating revolutionary systems that are providing architects with opportunities that simply weren’t available in the past. With systems like DEX, designers can now let their imaginations run wild.

We’d love to be a part of your next exploratory design journey. Contact us today for more information about our innovative facade solutions.