Crystal transformation of calcium silicate minerals synthesized by calcium silicate slag and silica fume with increase of C/S molar ratio

Calcium silicate slag (CSS) is waste slag and it contains a large amount of beta-dicalcium silicate. This study is mainly focused on the effect of CSS on the hydration of cementitious pastes. CSS was used to partly replace cement, and composite pastes containing CSS and cement were prepared. The mineral composition and particle size distribution of CSS were characterized. The chemically combined water of the paste sample was measured at a given test age. Based on the value of chemically combined water, the hydration degree and the hydration rate of composite pastes were analyzed. The flexural strength of the samples was established. The pore structure and micromorphology of the sample were also observed. The results indicate the chemically combined water decreased, the hydration degree decreased, the hydration rate declined, and the spherical micromorphology of the calcium silicate hydrate gel was reduced after more cement was replaced by CSS in the composite pastes. Besides, the amount of pores increased, its size was bigger, and air content in the pore was higher. However, flexural strength was lower. CSS has a significant impact on the hydration of cementitious pastes, and it is thus suitable to regulate hydration.

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CALCIUM SILICATE SLAG AS A GROWTH STIMULANT FOR SUGARCANE ON LOW-SILICON SOILS

Soil Science ◽

10.1097/00010694-196603000-00009 ◽

1966 ◽

Vol 101 (3) ◽

pp. 216-227 ◽

Cited By ~ 54

Author(s):

A. S. AYRES

Keyword(s):

Calcium Silicate ◽

Silicate Slag ◽

Calcium Silicate Slag ◽

Growth Stimulant

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Economics of calcium silicate slag application in a rice-sugarcane rotation in the Everglades

Agricultural Systems ◽

10.1016/0308-521x(88)90050-9 ◽

1988 ◽

Vol 28 (3) ◽

pp. 179-188 ◽

Cited By ~ 11

Author(s):

J. Alvarez ◽

G.H. Snyder ◽

D.L. Anderson ◽

D.B. Jones

Keyword(s):

Calcium Silicate ◽

Silicate Slag ◽

Calcium Silicate Slag

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Liquidus Surface of Newly Defined "Ferrous Calcium Silicate Slag" and its Metallurgical Implications

High Temperature Materials and Processes ◽

10.1515/htmp.2001.20.3-4.201 ◽

2001 ◽

Vol 20 (3-4) ◽

pp. 201-208 ◽

Cited By ~ 7

Author(s):

Akira Yazawa, ◽

Florian Kongoli,

Keyword(s):

Calcium Silicate ◽

Liquidus Surface ◽

Silicate Slag ◽

Calcium Silicate Slag

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Preparation and Characterization of Calcium Silicate Slag Based Lightweight Wall Materials

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.512-515.110 ◽

2012 ◽

Vol 512-515 ◽

pp. 110-114 ◽

Cited By ~ 1

Author(s):

Lei Hou ◽

Jin Hong Li ◽

Ling Xin Tong

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Calcium Silicate ◽

Raw Materials ◽

Xrd Analysis ◽

Potassium Feldspar ◽

Water Soluble ◽

Silicate Slag ◽

Calcium Silicate Slag ◽

Wall Materials

Potassium feldspar (KAlSi3O8) can be used to extract potassium to solve the shortage of water soluble potash resources in China, but it will produce large amount of calcium silicate slag. Resource recycling from calcium silicate slag can be realized by synthesising wall materials. In this research， calcium silicate slag based lightweight wall materials have been successfully prepared by calcium silicate hydrates (CSH), lime and fly ash through autoklave process. Furthermore, the wall materials are charactered by strength determination, X-ray diffraction (XRD) analysis, and Scanning electron microscopy (SEM) analysis. The results show that the compressive strength is mainly influenced by the lime/fly ash mass ratio (L/F), CSH content and water/solid ratio (W/S). The compressive strength of 21.1-23.9 MPa and density of 0.87-0.91 g/cm3 are achieved respectively with the L/F value of 0.82-1.00, CSH content of 70 % and W/S of 0.9. The main hydrate product of wall materials is 11Å tobermorite [Ca5(OH)2Si6O16•4H2O], which is partly formed from the phase transformation of CSH, and partly produced by the reaction among raw materials during the process of autoclaving. The tobermorite is easy formed at low L/F value and it has a contribution to the low density for its flake-like structure that make the materials porous.

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