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

Regarding the minimum standard for the cubic compressive strength of UHPC, there is currently no single fully unified value internationally, but there is broad industry consensus and mainstream standard references. According to the Chinese building materials industry standard "General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)", which Qinglong Group participated in formulating, as well as general international understanding, the baseline minimum compressive strength of UHPC is generally considered to be no lower than 120MPa (based on 100mm×100mm×100mm cubic specimens under standard curing for 28 days).

This 120MPa threshold is an important dividing line that distinguishes UHPC from ordinary high-performance concrete (HPC, usually referring to concrete with strength grades of C60-C100, i.e., 60-100MPa). It marks the material's entry into the "ultra-high performance" category. Qinglong Group's internal corporate standards are usually stricter; the compressive strength of our standard UHPC products generally remains stable between 120MPa and 150MPa, and for projects with special requirements, even higher strength can be achieved through mix proportion optimization.

It should be emphasized that compressive strength values are affected by testing standards such as specimen size and curing conditions. For example, some standards may use cylindrical specimens, whose strength values will differ from those of cubic specimens. Therefore, when comparing UHPC strength data from different manufacturers or sources, the corresponding testing standards must be clearly identified. The product testing reports provided by Qinglong Group clearly specify the specimen type, size, and curing conditions, ensuring the accuracy and comparability of the data.

The significance of setting 120MPa as the minimum standard threshold lies in the fact that only when the strength reaches this level can UHPC fully leverage its great advantages in reducing component cross-sections, reducing structural self-weight, and achieving large spans or complex shapes. For example, in projects undertaken by Qinglong, such as the translucent UHPC panels for Shanghai Century Plaza and the UHPC curtain walls for the Shenzhen Yirui Biotechnology Building, high compressive strength is the foundation for ensuring the safety and durability of thin components. Of course, when selecting UHPC, strength should not be the sole criterion; key indicators such as toughness and durability also need to be comprehensively evaluated.