颗粒级配对高掺量粉煤灰干混砂浆性能影响的研究

依据颗粒紧密堆积理论,一般采用Andreasen方程计算粉体紧密堆积用于表征粉体颗粒的级配作用.通过研究不同粒径粉煤灰对高粉煤灰掺量干混砂浆的性能影响,研究得出:颗粒太细的粉煤灰,会更加偏离原来的紧密堆积状态,不但不能充分发挥其微观填充的补强作用,反而大大降低强度.因此,使用粉煤灰与水泥复合掺配时,特别是高粉煤灰掺量,需要考虑颗粒与颗粒之间的相互补充作用,使胶凝材料的颗粒粒径分布更趋近于紧密堆积,从而提高基体材料的密实度,保持较高干混砂浆性能.

Effect of the Particle Size Distribution on the Performance of Dry-mixed Mortar with High Loading Fly Ash

Based on particle dense packing theory, the Andreasen equation is generally used to calculate powder packing for evaluating the grading of powder particles.By studying the effect of the same fly ash with different particle sizes on the performance of high loading fly ash dry-mixed mortar, the result shows that the packing curve using ultrafine fly ash significantly deviates from the original dense packing state. This micro-filling cannot achieve the reinforcing effect but also greatly reduce the strength.Therefore, using fly ash to replace cement in dry-mixed mortar, particularly for high loading fly ash, the complementary role of all particles should be considered for the better dense packing to increase the density and maintain the performance of dry mortar.