Title: Effect of the Combined Use of Ultra-Fine Fly Ash and Silica Fume on Strength of HPC

Author(s): Sun Wei, Pan Ganghua and Ding Dajun

Publication: Symposium Paper

Volume: 172

Issue:

Appears on pages(s): 299-312

Keywords: Admixtures; fly ash; high-performance concretes; silica fume

DOI: 10.14359/6138

Date: 12/1/1999

Abstract:
In this paper, a technic of both adding ultra-fine fly ash(UFFA) and silica fume(SF) for preparing high performance concrete(HPC) of C150~200 is presented. Under the condition of replacing 15% cement with UFFA or SF or their composite respectively, the strength characters of HPC with the same proportion of both UFFA and SF were systematically studied by comparing adding-both UFFA and SF sample(HPFASFC--- high performance’ fly ash and silica fume concrete) with adding only UFFA sample(HPFAC---high performence fly ash concrete) and adding only SF sample(HPSFC---high performence silica fume concrete). The experimental results showed that the strength of HPFASFC may be higher than that of HPSFC or HPFAC because of existence of effects of promoting and making up each other in strengthening of mineral admixture. The results of micro tests and analysis for the mechanism of composite effects proved the conclusion. It follows that there is a possibility for preparing high performance concrete with UFFA.