Is UHPC Abrasion Resistance Directly Related to Compressive Strength? Correlation Mechanisms and Improvement Solutions

The abrasion resistance of UHPC is significantly correlated with its compressive strength, but not in a simple linear relationship; both are jointly influenced by material composition and microstructure. Clarifying the correlation mechanism and optimizing abrasion resistance in combination with compressive strength is key to applying UHPC in wear-resistant scenarios. Based on extensive testing and project practice, Qinglong analyzes the correlation characteristics of the two and the paths for optimization.

1. Positive Correlation Mechanism Between Abrasion Resistance and Compressive Strength

Compressive strength is the foundation of abrasion resistance, and the two show a clear positive correlation. UHPC with high compressive strength typically has a denser microstructure, low porosity, and fewer internal defects, making it less prone to particle detachment and surface damage during wear, which naturally results in better abrasion resistance. Qinglong's test data show that when compressive strength increases from 120MPa to 160MPa, the abrasion resistance of UHPC (the reciprocal of wear amount) improves by more than 40%, fully demonstrating the supporting role of strength in wear resistance. This correlation stems from a shared microstructural foundation: both rely on the full formation of cement hydration products, tight packing of aggregates, and the reinforcing effect of fibers. A dense structure not only enhances compressive capacity but also reduces erosion of the material surface by wear media.

2. Other Key Factors Affecting Abrasion Resistance

Besides compressive strength, aggregate properties, fiber type, and surface treatment also significantly affect abrasion resistance. Aggregate hardness is the core influencing factor: replacing ordinary river sand with quartz sand (Mohs hardness 7) can improve abrasion resistance by 30%, and Qinglong uses high-hardness quartz sand in all wear-resistant projects. The addition of fibers can inhibit crack propagation during wear; steel fibers provide better abrasion enhancement than polypropylene fibers, improving abrasion resistance by 25% at a 2% dosage. Surface treatment processes such as polishing and applying wear-resistant coatings can further increase surface hardness. In a UHPC flooring project for an industrial plant, Qinglong achieved a surface hardness above Mohs 6 through surface polishing, improving abrasion resistance by 50% compared with untreated products. Even with the same compressive strength, surface treatment can significantly optimize abrasion resistance.

3. Non-Absolute Correspondence Between Compressive Strength and Abrasion Resistance

Compressive strength is not the sole determinant of abrasion resistance; UHPC mixes with the same compressive strength may show markedly different abrasion resistance due to compositional differences. For example, when compressive strength is increased by adding an excessive amount of silica fume, the improvement in abrasion resistance is limited if aggregate hardness is insufficient. Conversely, by appropriately reducing the silica fume content and increasing the proportion of high-hardness aggregates, abrasion resistance may still improve even if compressive strength drops slightly. Qinglong's tests showed that, of two UHPC mixes both with a compressive strength of 140MPa—one using quartz sand + steel fibers and the other using river sand + polypropylene fibers—the former had 35% higher abrasion resistance than the latter, demonstrating the importance of compositional optimization for wear resistance. Therefore, abrasion resistance cannot be judged by compressive strength alone; the overall material composition must be considered comprehensively.

4. Qinglong's Practice in Optimizing UHPC Abrasion Resistance

Qinglong adopts a trinity approach of "strength foundation + compositional optimization + surface strengthening" to improve the abrasion resistance of UHPC. By precisely controlling the water-binder ratio and optimizing the steam curing process, a compressive strength of ≥150MPa is ensured; high-hardness quartz sand combined with steel fibers provides composite reinforcement, enhancing the material's inherent wear resistance; for wear-demand scenarios such as industrial floors and bridge decks, surface polishing or wear-resistant coating treatments are added. In a UHPC bridge deck project for a municipal bridge, Qinglong's approach achieved a deck abrasion resistance more than 8 times that of ordinary concrete and extended the service life to more than 15 years; in a UHPC flooring project for a high-end commercial complex in Shanghai, the solution balanced high strength with high abrasion resistance to meet the demands of high foot traffic, fully demonstrating the practical value of performance optimization.