Cement substitution by a combination of metakaolin and limestone

Journal Article · Sat Dec 15 00:00:00 EST 2012 · Cement and Concrete Research

DOI:https://doi.org/10.1016/J.CEMCONRES.2012.09.006· OSTI ID:22149358

Rossen, J. ^[1]; Martirena, F. ^[2]; Scrivener, K. ^[1]

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1. EPFL-STI-IMX-Laboratoires des Materiaux de Construction, Station12, CH-1015 Lausanne (Switzerland)
2. CIDEM-UCLV, Universidad Las Villas, Santa Clara (Cuba)

This study investigates the coupled substitution of metakaolin and limestone in Portland cement (PC). The mechanical properties were studied in mortars and the microstructural development in pastes by X-ray diffraction, thermogravimetry analysis, mercury intrusion porosimetry and isothermal calorimetry. We show that 45% of substitution by 30% of metakaolin and 15% of limestone gives better mechanical properties at 7 and 28 days than the 100% PC reference. Our results show that calcium carbonate reacts with alumina from the metakaolin, forming supplementary AFm phases and stabilizing ettringite. Using simple mass balance calculations derived from thermogravimetry results, we also present the thermodynamic simulation for the system, which agrees fairly well with the experimental observations. It is shown that gypsum addition should be carefully balanced when using calcined clays because it considerably influences the early age strength by controlling the very rapid reaction of aluminates.

• OSTI ID: 22149358
• Journal Information: Cement and Concrete Research, Vol. 42, Issue 12; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0008-8846
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINATES
ALUMINIUM OXIDES
ATOMIC FORCE MICROSCOPY
BIOINTRUSION
CALCIUM CARBONATES
CALORIMETRY
CLAYS
GYPSUM
HYDRATION
LIMESTONE
MECHANICAL PROPERTIES
MERCURY
MICROSTRUCTURE
MORTARS
PLUTONIC ROCKS
PORTLAND CEMENT
SIMULATION
THERMAL GRAVIMETRIC ANALYSIS
WATER INFLUX
X-RAY DIFFRACTION