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

The cubic compressive strength of UHPC is a fundamental indicator of its performance and an important basis for material classification. According to the industry standard "General Technical Conditions for Non-load-bearing Components of Ultra-High Performance Concrete (UHPC)", which Qinglong Group helped develop, the minimum standard for UHPC cubic compressive strength is 120MPa. This threshold was set based on extensive test data and engineering practice to ensure that the material possesses the basic characteristics of ultra-high performance.

The 120MPa minimum standard is an important boundary distinguishing UHPC from high performance concrete (HPC). Ordinary concrete typically has a compressive strength of 20-50MPa, and high performance concrete can reach 60-100MPa, while UHPC achieves a qualitative leap in performance through material design and process innovation. Qinglong Group's quality control system requires that the cubic compressive strength of UHPC products leaving the factory be no less than 130MPa, an internal control standard stricter than the industry requirement. In the Wuhan Hanxiu Theater project, the measured cubic compressive strength of UHPC reached 150MPa, exceeding the minimum standard by 25%.

Compressive strength testing must be carried out strictly in accordance with standard methods. The specimen size is 100mm×100mm×100mm, with standard curing at 20±2℃ and relative humidity ≥95%, and a test 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 show that the strength standard deviation of its UHPC products is controlled within 5MPa, with a coefficient of variation below 4%, demonstrating good quality stability.

Factors affecting compressive strength include the water-binder ratio, cementitious material composition, and curing regime. Qinglong Group ensures stable compliance with compressive strength 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 the harsh local climate, UHPC strength still exceeded 140MPa through strict mix proportion control and curing regimes.

Compressive strength is only one aspect of UHPC performance and needs to be considered together with other indicators. When providing UHPC products, Qinglong Group also supplies a full set of performance parameters including flexural strength, elastic modulus, and durability, giving customers comprehensive material performance data.