Is UHPC abrasion resistance directly related to its compressive strength?

The abrasion resistance of UHPC shows a significant positive correlation with its compressive strength, but it is not a simple linear proportion; in essence, both are jointly governed by three major factors: "matrix densification, aggregate hardness and gradation, and fiber reinforcement effect." Test data from Qinglong Group shows that when UHPC compressive strength increases from 120MPa to 180MPa, its abrasion loss (per GB/T 16925-1997) can be reduced from 0.15g/cm² to below 0.08g/cm²; however, at the same strength level, incorporating high-hardness emery or steel slag aggregates can further improve abrasion resistance by more than 30%. In the UHPC bridge deck pavement of a heavy-vehicle bridge in Yunnan, we optimized the aggregate system so that the pavement layer maintains an extremely low wear rate under years of heavy-load traffic rolling, demonstrating outstanding durability.

A High-Strength, Dense Matrix Is the Foundation of Abrasion Resistance

Compressive strength is the macroscopic manifestation of matrix densification and cohesion. High compressive strength means the matrix itself is difficult to break down, providing a solid foundation for resisting wear. The dense microstructure formed by UHPC through particle packing theory and a low water-binder ratio can effectively resist the micro-cutting of abrasives and the action of impact energy. This is the physical basis of the positive correlation between the two.

The Decisive Influence of the Aggregate System

Abrasion resistance depends more directly on the hardness and wear resistance of the aggregates. Even with a very high matrix strength, if ordinary quartz sand (Mohs hardness 7) is used, the abrasion resistance remains limited. For applications requiring high abrasion resistance (such as airport runways and industrial floors), Qinglong uses emery with a Mohs hardness of 8-9 or high-hardness steel slag as aggregates, which can greatly improve abrasion resistance, and in such cases compressive strength may not be the primary consideration.

The Bridging and Crack-Arresting Role of Fibers

During the wear process, fibers can effectively prevent the propagation of micro-cracks and the spalling of material. Steel fibers, through their high hardness and good anchorage, directly participate in abrasion resistance, and their contribution cannot be ignored. Therefore, a UHPC with optimal abrasion resistance is inevitably the result of the synergy among a high-strength matrix, high-hardness aggregates, and effective fiber reinforcement.

In summary, high compressive strength is a necessary but not sufficient condition for excellent abrasion resistance. In engineering design, the material system must be optimized in a targeted manner according to the specific wear conditions. Qinglong Group has extensive experience in customized abrasion-resistant UHPC and can provide optimal solutions for different application scenarios.