Matters needing attention in the selection of micro-silica fume impact-resistant and wear-resistant concrete

As we all know, once the cavitation of high-speed water flow occurs, any material will generally be damaged. Therefore, as for how to choose engineering measures to reduce cavitation damage, generally speaking, the first thing is to prevent cavitation, that is, to prevent the occurrence of cavitation through engineering measures, such as adopting Engineering measures to aerate high-speed water flow to reduce cavitation erosion, make the structure streamlined and limit the flatness of the flow surface, etc.; the second is resistance, that is, to choose materials with good anti-wear and anti-cavitation performance. When cavitation occurs, Reduce the speed and harm of destruction as much as possible. Then the matters that should be paid attention to when selecting materials should also obey the relationship between prevention and resistance, that is, the prevention of cavitation is the main focus, and the selection of materials to resist cavitation damage is supplemented. Specifically, when selecting anti-wear and anti-cavitation materials, it should first be required that the selected materials cannot cause cavitation conditions:

Concrete protection surface should be easy to make the surface to meet the flatness required by the design, which requires that the selected concrete has good workability;

The surface protection material is required to be relatively homogeneous macroscopically, which requires that the selected concrete must meet the requirements of simple construction and easy quality control, so as to ensure that the mean square deviation of the strength of the concrete is small, and it will not be damaged under the erosion of water flow and the abrasion of sandy water flow. Produces a non-uniform uneven surface capable of cavitation erosion, i.e. the regenerative unevenness should meet the requirements;

The surface of the selected concrete after construction should not produce large cracks, so as to avoid cavitation damage, that is, the selected materials should not produce cracks as much as possible.

In addition, the selected materials should meet the characteristics of high-speed water flow. Specifically, the surface protection after construction can withstand the pulsating pressure of high-speed water flow and the effect of high dynamic water pressure, and can maintain stability under the long-term action of high-speed water flow. Especially when cavitation occurs and potholes are formed, there will be no fracture erosion damage along the cracks.

In recent years, a new type of anti-impact and wear-resistant material, HF high-strength wear-resistant fly ash concrete (HF concrete), has the same impact and wear resistance and cavitation resistance as silica fume concrete, and overcomes the silica fume at the same time. Concrete is easy to crack and construction is difficult, and it has achieved great success in engineering applications. It has been proved that it is a kind of anti-wear and anti-cavitation performance that meets the requirements of high-speed water flow pulsation pressure and dynamic water pressure. Facing material that keeps itself stable.