How Long Does UHPC Mixing Take: Key Points of UHPC Mixing Process and Time Control

In the field of building materials, UHPC (Ultra-High Performance Concrete) has become the ideal choice for high-end buildings such as grand theaters and commercial complexes, thanks to its outstanding mechanical properties and durability. As an industry leader with 28 years of experience in detailed design, production, and manufacturing of UHPC/GRC/GRG/GRP materials, Qinglong Group deeply understands the decisive impact of the mixing process on UHPC performance. Drawing on full-chain practical experience, this article analyzes the core points of UHPC mixing time control and provides professional solutions for designers and owners.

### I. Scientific Basis and Industry Standards for UHPC Mixing Time
The UHPC mixing process requires uniform material dispersion and microstructure optimization, and its time control is far more demanding than that of ordinary concrete. According to the industry standard "General Technical Requirements for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)" (Plan No. 2024-0232T-JC), which Qinglong participated in formulating, the standard mixing procedure is typically divided into two stages: dry mixing and wet mixing. The dry mixing stage (3-5 minutes) ensures uniform distribution of steel fibers and mineral admixtures, while the wet mixing stage (5-8 minutes) promotes full hydration of the cementitious materials. In actual production, adjustments must be made dynamically according to mixer type (e.g., twin-shaft forced mixer) and material proportions. Over-mixing may cause steel fiber breakage, while insufficient mixing leads to strength loss.

### II. Four Elements of the Mixing Process: Equipment, Proportions, Temperature, and Quality Monitoring
Qinglong's practice at its production base in Nanning, Guangxi shows that mixing time control must be coordinated with four key elements: 1) Equipment selection: use a dedicated mixer with a rotation speed of ≥30r/min to ensure adequate shear force; 2) Material proportions: the addition of silica fume and ultrafine mineral powder requires extending the wet mixing time by 1-2 minutes; 3) Ambient temperature: in winter construction, mixing time can be increased by 20% by preheating the aggregates; 4) Real-time monitoring: use torque sensors to feed back material viscosity, and stop mixing when torque stabilizes at 35-45N·m. This refined control system enables Qinglong UHPC components to achieve compressive strength consistently exceeding 150MPa and flexural strength above 25MPa.

### III. Common Mixing Problems and Qinglong's Solutions
Industry research shows that approximately 30% of UHPC quality problems stem from mixing process defects. In response to customer feedback on issues such as "excessive surface bubbles" and "high strength variability," Qinglong provides customized solutions: for complex-shaped components (such as translucent concrete curtain walls), a "step-by-step feeding method" is adopted—first dry mixing the cementitious materials with steel fibers for 4 minutes, then adding the water reducer and wet mixing for 6 minutes, effectively reducing bubbles; for the production of large-volume components, BIM technology is used to simulate the mixing flow field and optimize blade angles, shortening mixing time by 15%. These technical achievements represent the core competitiveness that has made Qinglong a national Specialized, Refined, Distinctive, and Innovative (SRDI) enterprise and a participant in formulating multiple industry standards.

### IV. Full-Chain Services Ensure Implementation of the Mixing Process
As a national high-tech enterprise integrating detailed design, production manufacturing, and construction installation, Qinglong emphasizes the connection between the mixing process and subsequent stages: mixing parameters are determined through parametric models at the design stage, RFID chips are used in production to trace the mixing records of each batch of materials, and specialized transport equipment is provided during construction to ensure pouring is completed before the initial setting of the mixture. This whole-process control model has been successfully applied to benchmark projects such as the Nanjing East Road Century Plaza renovation project, where translucent UHPC components achieved 0.1mm-level precision control. For more industry information: WeChat qlfsbl123

UHPC mixing time control is a systematic discipline that combines materials science with engineering practice. Built on 28 years of industry experience, Qinglong Group has transformed the mixing process into a replicable, standardized workflow through a four-dimensional control system of "equipment–proportions–environment–monitoring." In the future, as UHPC sees wider application in municipal engineering, bridges, and other fields, scientific mixing time control will become a key prerequisite for project success. Qinglong will continue to pursue its mission of "creating beautiful architecture" and provide better UHPC solutions for customers worldwide.