Understanding the hydration of dolomite in cementitious systems with reactive aluminosilicates such as calcined clay

Journal Article · Fri Jun 15 04:00:00 EDT 2018 · Cement and Concrete Research

DOI:https://doi.org/10.1016/J.CEMCONRES.2018.03.010· OSTI ID:22806495

Krishnan, Sreejith; Bishnoi, Shashank ^[1]

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1. Department of Civil Engineering, Indian Institute of Technology Delhi, 110016 (India)

This study investigates the hydration of dolomite, CaMg(CO{sub 3}){sub 2}, with calcined clay in presence of calcium hydroxide and ordinary Portland cement. The hydration products as well as the microstructure at various ages were characterized using X-ray diffraction (XRD), thermogravimetric analysis (TGA), and mercury intrusion porosimetry (MIP). Isothermal calorimetry was used to understand the reaction kinetics. The systems with dolomite were compared against control systems with limestone and quartz. It was seen that, the formation of carbonate – AFm phases takes place in the dolomite systems similar to limestone systems. No formation of brucite (Mg(OH){sub 2}) was observed till 90 days of hydration, with Mg{sup 2+} ions most likely being incorporated into hydrotalcite phase (Mg{sub 4}Al{sub 2}(OH){sub 14}). The synergetic effect observed in the Portland cement – calcined clay – dolomite system was found to result in a refined pore structure at early ages and improvement in the mechanical properties such as compressive strength.

• OSTI ID: 22806495
• Journal Information: Cement and Concrete Research, Journal Name: Cement and Concrete Research Vol. 108; ISSN 0008-8846; ISSN CCNRAI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ALUMINIUM SILICATES
CALCIUM HYDROXIDES
CALORIMETRY
CARBONATES
CLAYS
COMPRESSION STRENGTH
DOLOMITE
HYDRATION
LIMESTONE
MAGNESIUM HYDROXIDES
MAGNESIUM IONS
MERCURY
PORE STRUCTURE
PORTLAND CEMENT
QUARTZ
REACTION KINETICS
THERMAL GRAVIMETRIC ANALYSIS
X-RAY DIFFRACTION