Naslov
Durability of the hydrated limestones-silica fume PC mortars under sulphate attack

Autori
Zelić, Jelica ; Krstulović, Ruža ; Tkalčec, Emilija ; Krolo, Petar

Izvornik
Cement and concrete research (0008-8846) 29 (1999), 6; 819-826

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
durability; sulphate attack; CaCO3; silica fume; mortar

Sažetak
The effect of silica fume, emerging as a by-product in production of ferrosilicon, on corrosion resistance to sulphate attack of Na2SO4 and MgSO4 solutions has been studied in Portland cement mortars containing limestone and mortars containing no limestone. Expansion and the changes in the elasticity modulus of mortars as a function of silica fume content have been investigated. The phases formed and the microstructural changes in the mortar exposed to sulphate corrosion have been determined by differential thermal analysis (DTA), X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The presence of monocarbonate and the absence of monosulphate were detected in the mortars containing limestone. The addition of silica fume results in less CH formed by hydration process and consequently less gypsum and ettringite during the sulphate immersion of mortars. Mortars containing more than 5 mass % of SiO2, or simultaneously limestone and more than 2 mass % of SiO2, are characterised by a good sulphate resistance and show lower expansion than a control, the sulphate-resisting mortars independent of the type of the sulphate solution.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo

POVEZANOST RADA