90 % of the particles of this product are below 10 micron whereas the mean particle size is 3 microns. The high silica content and sum of oxides (SiO2 + Al2O3 + Fe2O3) are similar to what would be expected for a Class F Fly Ash as per EN 450 or ASTM C 618 designation. This makes DP 100 a substitute of silica fume in concrete whilst showing further advantages in durability, workability, sulphate and chloride resistance. DP 100 reduces the heat of hydration in concrete.
Advantages
- The Ultrafine Fly Ash branded as DIRKPhoenix DP 100 can produce concrete strength comparable with that produced with a highly reactive pozzolan such as Silica Fume (SF). To reach the performance levels of SF concrete at early age, generally the concentration of UFFA and SF are the same or must be slightly increasedand the total water in the concrete must be reduced by about 15-20 %;
- DP100 displays a strong tendency to reduce water demand. For comparable workability as SF concrete, a 15-20% reduction in total water content, together with as much as a 30% reduction in HRWR (= High Range Water Reducer), is possible;
- DP 100 concrete also displays a lower tendency towards cracking due to drying and autogenous shrinkage compared with SF concrete;
- Processing FA into an ultra-fine material like DP100 with a refined particle size distribution clearly improves its performance as a durability-enhancing admixture. The practical significance of the increased reactivity, from a concrete technology perspective, is that a given improvement in performance can be achieved at a lower level of replacement (that is, the ultra-fine material is more efficient) compared with an unprocessed FA and at an earlier age. As such, DP 100 offers a viable alternative to SF in certain applications.