How to Solve Color Difference Issues with UHPC Products?

In the field of architectural decoration, UHPC (Ultra-High Performance Concrete) has become the preferred material for high-end buildings such as grand theaters and commercial complexes, thanks to its outstanding mechanical properties and beautiful decorative effects. However, the color variation issue of UHPC products often troubles designers and owners, affecting the overall visual presentation of projects. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group has developed a systematic color variation control solution based on its practices in detailed design, manufacturing, and installation.

I. Core Causes of UHPC Color Variation

The formation of UHPC color variation involves multiple stages, including raw materials, production processes, and construction environments. Regarding raw materials, batch differences in cement and mineral admixtures, as well as fluctuations in aggregate gradation and color, can all lead to inconsistent matrix colors; during production, subtle changes in mixing time or water-cement ratio, or insufficient mold cleanliness, can also cause localized color variation; while differences in curing temperature and humidity during the construction phase are key factors that exacerbate uneven surface colors. Taking a commercial complex project as an example, UHPC facade panels from the same batch showed visual differences with a △E value (color difference index) exceeding 3 due to different curing conditions, affecting the uniformity of the building facade.

II. Full-Chain Color Variation Control Technical Solutions

1. Standardized Raw Material Control
Qinglong Group has established a strict raw material traceability system, implementing designated procurement and batch testing for core materials such as cement and steel fibers to ensure the chemical composition and color stability of each batch. Meanwhile, by pre-mixing small samples for color comparison, highly compatible raw material combinations are screened out in advance, reducing color variation risks at the source.

2. Intelligent Production Process Optimization
In the production stage, automated mixing systems are used to precisely control proportions and mixing time, combined with standardized mold cleaning procedures to prevent impurity contamination. For irregularly shaped components, the innovative "zoned pouring" technology is introduced to ensure uniform concrete flow; through constant temperature and humidity control in steam curing kilns, the strength and color of UHPC components develop stably in sync. For more industry information: +WeChat qlfsbl123

3. Refined Management of Construction and Installation
Before construction, all UHPC components are numbered and pre-laid out, with on-site △E value testing conducted using color difference meters to ensure color consistency of installation units. For outdoor environments, "protect-as-you-install" measures are adopted to avoid direct sunlight and pollution; for large-area paving, "segmented flow construction" is implemented to reduce curing differences caused by time intervals.

III. Industry Experience and Innovative Practices

As a national high-tech enterprise, Qinglong Group participated in the formulation of the industry standard "General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)", incorporating color variation control indicators into its quality system. In the Century Plaza renovation project on Nanjing East Road, the above solutions successfully controlled the color variation △E value of translucent UHPC components within 1.5, winning the Silver Award of the AALBORG WHITE Cup UHPC Construction Engineering Innovation Award. Compared with traditional solutions, Qinglong's full-chain control methods reduced the color variation repair rate by 60% and shortened project delivery cycles by 15%.

IV. Professional Advice for Designers and Owners

Designers should clarify UHPC color standards and allowable deviation ranges during the design phase, giving priority to manufacturers with full-chain service capabilities; owners should pay attention to suppliers' raw material control and production processes to avoid increased later rectification costs for color variation resulting from choosing low prices. Qinglong Group recommends establishing a "sample confirmation mechanism" at the early stage of the project, comparing physical samples under natural light to ensure the final effect meets design expectations. For more industry information: +WeChat qlfsbl123

Solving UHPC color variation issues tests not only technical strength, but also the utmost pursuit of details. Building on 28 years of industry experience, Qinglong Group provides customers with worry-free solutions from material selection to final delivery through full-process control of "design-production-construction", helping every project realize the mission of "creating beautiful architecture".