Belite

– Etymology:
– Named by Törnebohm in 1897
– Belite is common in the cement industry
– Derived from Larne, Northern Ireland
– Occurs naturally as larnite
– Discovered near Scawt Hill

– Composition and Structure:
– Belite in Portland cement differs from pure dicalcium silicate
– Contains minor amounts of other oxides
– Typical composition includes CaO and SiO
– Formula expressed as Ca1.94Si0.02O5
– Composition varies with clinker bulk composition

– Polymorphs:
– Stable dicalcium silicate
– Low-temperature form is γ-belite
– Rapid reaction similar to natural hydration of forsterite
– Hydrate phase referred to as C-S-H phase
– Rapid cooling needed to avoid γ-form

– Detection:
– Minerals in Portland cement clinker observed by petrographic microscopy
– Clinker nodules cut and ground for observation
– Minerals made visible by etching the surface
– Belite appears as blue under optical microscopy
– X-ray diffraction preferred for accurate mineral quantification

– See Also:
– Hydration reaction of forsterite in serpentinisation
– CCN, cement chemist notation

– References:
– Jean-Pierre Bournazel et al., 1998, Concrete, from Material to Structure
– Deer et al., 1997, Larnite. Disilicates and ring silicates
– Taylor H.F.W., 1990, Cement Chemistryhttps://en.wikipedia.org/wiki/Belite