稻壳灰替代硅灰对超高性能混凝土性能影响的试验研究

通过对单/双掺活性稻壳灰(RHA)与硅灰(SF)以及RHA的粒径对超高性能混凝土(UHPC)的抗压强度和孔结构影响的研究,得出活性RHA粒径是取代SF的关键.研究结果表明,平均粒径为5.9 μm的R HA能够部分取代SF并应用于UHPC中;在相同总掺量的情况下,复掺RHA与SF的UHPC抗压强度要高于单掺RHA或单掺SF的,并且最佳取代水泥的复掺量为10％RHA与10％SF;在UHPC中掺入RHA能够减少孔体积以及平均孔径,优化孔结构,从而提高UHPC的抗压强度.

Experimental Research of Rice Husk Ash(RHA) Replacing Silica Fume (SF) on Performance Effects of Ultra-high Performance Concrete(UHPC)

The influences of single/double-doped rice husk ash(RHA) & silica fume(SF) and the particle size of RHA on the compressive strength and pore structure of ultra-high performance concrete(UHPC)are studied.The research reveals that the active RHA’s particle size is the key to replace the SF in UHPC and its average particle size of 5.9μm is the rational one used to partially replace the SF in UHPC.With the same total blend dosage of RHA and SF,the concrete with double-doped RHA & SF has higher compressive strength than the ones of single-doped(RHA or SF) concrete.Furthermore,it is found that the best blend dosage is 10% RHA & 10% SF replacing the cement.The mixing of RHA into UHPC can reduce the concrete pore volume and average pore size and also improve the compressive strength of UHPC by optimizing its pore structure.