Is the UHPC Production Process Complex? Precision Manufacturing and Qinglong Group's Industry 4.0 Production Line

The UHPC production process is significantly more complex than that of ordinary concrete. Its core difficulty lies in achieving the fourfold goals of "high workability at an extremely low water-binder ratio, uniform fiber distribution, high-density molding, and precisely controlled curing." It is a systematic engineering task involving "precision batching, efficient mixing, uniform molding, and scientific curing." Based on 28 years of UHPC/GRC manufacturing experience, Qinglong Group has built a fully automated integrated "batching-mixing-molding-curing" production line: a German BHS high-speed planetary mixer (mixing time 5-8 minutes) ensures three-dimensional random fiber distribution; dense molding is achieved through robotic spraying or high-pressure casting processes; and a standard curing regime (80°C steam curing for 12 hours) is executed in intelligent curing kilns (temperature control accuracy ±2°C). In the Hainan International Convention and Exhibition Center project, we used this process to stably produce 120,000 square meters of double-curved roof panels with a strength variation coefficient ≤5%. The complexity of the process is the inevitable price of high performance.

Precision Batching and Efficient Mixing Come First

A fully automatic batching system precisely measures cement, silica fume, aggregates, fibers, admixtures, and water (error ≤±0.5%). The feeding sequence is strictly specified: first dry-mix the aggregates and binders, then add water in two additions, with fibers added midway. High-speed mixing (100-150 rpm) ensures uniform fiber dispersion and prevents segregation or bleeding of the slurry. The central control room of the Qinglong production line monitors mixing torque in real time and automatically determines the mixing endpoint.

Diverse Molding Processes for Different Products

For flat panels and standard components, the "casting + high-frequency vibration + vacuum dewatering" process is used, with a vacuum level of -0.08 MPa to remove excess water and increase density. For double-curved and irregularly shaped components, robotic spraying is used: the robot moves along preset paths while spraying fibers and slurry simultaneously, forming complex curved surfaces in one pass. In the Wuhan Hanxiu Theater project, robotic spraying ensured uniform thickness of the red double-curved panels (20±1 mm).

Scientific Curing Regimes Determine Final Performance

Immediately after molding, plastic film is applied to retain moisture and prevent plastic cracking. After 24 hours of curing in the mold, components are demolded and transferred to intelligent curing kilns for steam curing (80°C × 12 h) to promote rapid strength development. Temperature and humidity inside the kiln are programmatically controlled, with heating and cooling rates ≤15°C/h to avoid thermal stress cracking. After curing, components are moved to the storage yard for continued water curing until 28 days. Through extensive testing, we customize optimal curing curves for different mix proportions.

Full-Process Quality Testing and Traceability

Samples are retained from each batch for compressive and flexural strength testing. All factory-shipped components undergo full inspection of dimensions, appearance, and flatness. An MES system assigns a unique code to each panel and records data from raw materials to finished products, enabling full quality traceability. Our factory pass rate is consistently above 99.8%.

Therefore, the "complexity" of UHPC production is reflected in the fine control of every step. Qinglong Group uses automation and digitalization to transform complex processes into stable, reliable product quality.