What Is the Minimum Standard for the Cube Compressive Strength of UHPC?

The cube compressive strength of UHPC is a fundamental indicator for measuring its performance and an important basis for material classification. According to the industry standard that Qinglong Group participated in developing, the minimum standard for the cube compressive strength of UHPC is 120MPa, with premium products reaching over 150MPa.

120MPa is a key threshold that distinguishes UHPC from high-performance concrete. The compressive strength of ordinary concrete is typically 20-50MPa, while high-performance concrete can reach 60-100MPa, whereas UHPC achieves a qualitative leap in performance through material design and process innovation. Qinglong Group's quality control system requires that the cube compressive strength of UHPC products leaving the factory must be no less than 130MPa, an internal control standard stricter than industry requirements.

Compressive strength testing must be conducted strictly in accordance with standard methods. Specimen dimensions are 100mm×100mm×100mm, cured under standard conditions of 20±2℃ and relative humidity ≥95%, with a testing age of 28 days. Qinglong Group's laboratory participates in proficiency testing every year to ensure the accuracy and comparability of test results. Test data shows that the strength standard deviation of its UHPC products is controlled within 5MPa, with a coefficient of variation below 4%.

Factors affecting compressive strength include the water-binder ratio, cementitious material composition, curing regime, and more. Qinglong Group ensures that compressive strength consistently meets requirements by controlling the water-binder ratio below 0.20, optimizing the particle gradation of cementitious materials, and adopting measures such as steam curing. In the Algeria hotel project, despite harsh local climatic conditions, UHPC strength still exceeded 140MPa through strict mix proportion control.