Enhancement of early age cementitious properties of yellow phosphorus slag via CO2 aqueous carbonation
Document Type
Article
Publication Date
10-1-2022
Abstract
Yellow phosphorus slag (YPS) is an industrial waste by-product and has pozzolanic characteristics. Due to its poor early-age reactivity, this study aims to overcome this limitation via CO2 activation of raw YPS (RYPS) and use as a cement substitute. The experimental results showed that carbonation of RYPS under optimal conditions (liquid to solid ratio of 8 ml/g, temperature of 80 degrees C, pressure of 0.1 MPa, and for 9 h) can form rich amorphous silica gel and hydro calcite-type CaCO3. As a result, carbonated YPS (CYPS) was utilized as a supplementary cementitious material to improve the early age of pozzolanic characteristics in cement paste. This is because the formation of hemi-and mono-carboaluminates and amorphous silica gel played the important role in early-age strength development in CYPS incorporated cement pastes. Moreover, the presence of CYPS can accelerate the hydration rate of cement clinker, together with the intensification of the alite reaction. The microstructure of composite cement paste containing CYPS was denser compared to that of corresponding samples with RYPS.
Keywords
Yellow phosphorus slag, Early age cementitious properties, Composite cement paste, Supplementary cementitious material, Strength activity index, Microstructure
Divisions
fac_eng
Publication Title
Cement and Concrete Composites
Volume
133
Publisher
Elsevier
Publisher Location
THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND