Effect of Particle Size of Fly Ash Microspheres (FAMs) on the Selected Properties of Concrete

This paper presents the investigations of selected properties concrete containing two fractions fly ash microspheres (FAMs) with grain size up to 200 µm and 500 µm. Concrete mixtures ordinary Portland cement three substitution rates by FAMs, 1.3%, 2.0%, 2.6%, were investigated. For all mixes, constant water–binder ratio (w/b) equal 0.50 was used. The research program included determination chemical composition, particle distribution, pozzolanic activity FAMs. analysis showed that consist main elements: silicon, aluminum, iron, whose oxides constitute about 89% material. total content air pores, measured in at 28 days, ranges from 1.3 3.1% for sizes below 1.4% 3.9% FAMs a diameter < have relatively high level days. SEM proved use reduces gaps increases CSH phase. compression test addition long-term strength.