Can UHPC Shapes Achieve Gradient Color Effects? The Art of Color and Qinglong Group's Gradient Coloring Technology

The color of UHPC shapes can fully achieve natural, uniform gradient effects, primarily through four technical approaches—layered coloring, controlled penetration, digital inkjet, and surface coating—completely breaking the traditional impression of concrete as a material of monotonous color. In an art museum facade project in Shenzhen, Qinglong Group successfully achieved a vertical gradient from “dawn yellow” to “twilight purple”: by combining full-body matrix coloring with layered surface spray coloring, and precisely controlling the spray range, thickness, and layering method of the differently colored slurries, a seamless, smooth color transition was created on the 8-meter-high facade, with the ΔE color difference gradient controlled within 0.5/meter—visual effects rivaling ceramic glaze variations. Color gradients elevate UHPC from a building material into a medium of architectural art.

Full-Body Gradient Coloring of the Matrix

During casting, two or more UHPC slurries of different colors are injected into different positions of the mold through multiple metering and conveying systems, following preset ratios and timing. The natural blending of the slurries as they flow creates soft color transitions. This method delivers stable, durable, and consistent color throughout, but demands extremely precise control of slurry fluidity and setting time, making it suitable for components cast vertically or at an incline.

Layered Surface Spray Coloring (Dry-Shake Method)

In the spray-up molding process, dual-gun or multi-gun robotic arms are used, each loaded with slurries of different colors. By programming the robot’s motion trajectory and output volume, slurries of different or blended colors are sprayed onto different areas of the component surface, forming color gradients. This method is highly flexible and can achieve complex pattern gradients, making it the current mainstream technology.

Digital Inkjet Printing Technology

On fully cured, surface-treated plain-color UHPC panels, industrial-grade concrete-specific inkjet printers precisely print inorganic pigment inks onto the surface. Similar in principle to paper printing, it can reproduce any digital image, including photographic-grade gradient effects. As the color lies on the surface layer, an additional protective coating is required; it is suitable for flat or gently curved panels.

Surface Coating Gradients

Through manual or robotic spray application, topcoats such as fluorocarbon paints in different colors are applied to installed UHPC surfaces, with gradients achieved by controlling spray gun distance, movement speed, and coating overlap. This method offers flexible application and easy later modification, but color durability depends on the coating’s lifespan and requires regular maintenance.

Whichever technique is used, the key to achieving high-quality gradients lies in “precise control” and “artistic guidance.” Qinglong Group not only possesses the corresponding technology and equipment, but also works closely with color artists and architects, conducting extensive small-sample trials in the laboratory to ensure the intended color transitions can be perfectly reproduced in mass production—letting a building’s colors flow like a painted scroll.