How Long Should UHPC Be Mixed? Qinglong's Precisely Controlled UHPC Mixing Process

The mixing time of UHPC requires precise control; too long or too short will affect material performance. According to Qinglong's 28 years of process data, the optimal mixing time is typically between 5-8 minutes, depending on the mix proportion and equipment type.

In terms of mixing technology, Qinglong adopts a staged feeding process: dry materials are mixed first for 2 minutes, most of the water is added and mixed for 1 minute, and finally the water reducer and remaining water are added and mixed for another 2-3 minutes. In a precision engineering project in Shenzhen, the mixing time was shortened to 4 minutes using a high-speed mixer (linear speed 3m/s), but fibers must be added in the last 30 seconds to prevent excessive breakage. This precise control achieves fiber distribution uniformity of over 95% and keeps the product strength variation coefficient within 5%.

Dry Mixing Time Control

Dry mixing of cementitious materials and aggregates for 2-3 minutes ensures uniform mixing. Too short a time results in uneven mixing, while too long causes segregation.

Wet Mixing Time Control

After adding water, mix for 2-3 minutes to ensure the cement is fully moistened. The mixing speed increases gradually from low to high.

Fiber Addition Timing

Fibers are added in the later stage of mixing, with the time controlled at 1-2 minutes. Adding them in batches avoids clumping and ensures uniform dispersion.

Total Time Control

The total mixing time is 5-8 minutes, adjusted according to the mix proportion. Too short a time leads to insufficient reaction, while too long affects workability.

Precise mixing control requires accumulated experience. Qinglong UHPC determines the optimal process parameters through extensive experiments to ensure stable product quality.