Abstract：Four kinds of ash with the same particle size and quality were separated from the primary ash with different particle size ranges by air flow separation technology, with the particle size from small to large as the separation ash Ⅰ, Ⅱ, Ⅲ and Ⅳ. 30% cement was replaced by separated ash Ⅰ, Ⅱ, Ⅲ and raw ash, and its compressive strength was compared with that of pure cement at 3 d, 7 d and 28 d. The results show that the 3d strength of raw ash and separated ash is lower than that of cement, while the 7d compressive strength of separated ash Ⅰ and separated ash Ⅱ is close to that of pure cement, and the 28d compressive strength is higher than that of pure cement. The particle size distribution of separated ash Ⅲ and raw ash is close to that of cement, and the 28d compressive strength is close to that of pure cement, but the 7d compressive strength is lower than that of pure cement. The separation ash Ⅱ, Ⅲ and its combination were used to replace 50% cement, and the complex ratio was 4:1, 3:2, 1:1, 2:3, 4:1, and the compressive strength was compared with that of pure cement for 3 d, 7 d and 28 d. The results showed that the strength of separation ash Ⅱ, Ⅲ and its compound at 3 d and 7 d was lower than that of cement. The 28 d strength of separation ash Ⅱ and Ⅲ is lower than that of pure cement, but the 28 d compressive strength of compound separation ash can exceed that of pure cement when the complex ratio of separation ash Ⅱ: sorted ash Ⅲ was 3:2 or 1:1, and the strength of compound separation ash with other compound ratios is close to that of pure cement. It can be seen that under the replacement of 50% cement, in addition to the fineness of fly ash, the combination of different particle sizes can further improve the28 d strength, which is due to the particle accumulation effect
2024, Vol. 0 
