CIFICEN   24414
CENTRO DE INVESTIGACIONES EN FISICA E INGENIERIA DEL CENTRO DE LA PROVINCIA DE BUENOS AIRES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Portland limestone cements with metakaolin addition
Autor/es:
IRASSAR, E.F.; TREZZA, M. A.; TROCHEZ-SERNA, J.J.; RAHHAL, V. F.; MEJÍA DE GUTIÉRREZ, R.
Lugar:
La Plata
Reunión:
Congreso; Conferencia Internacional sobre Hormigón Estructural Sostenible; 2015
Institución organizadora:
RILEM
Resumen:
The hydration of ternary cements based on Portland cement with limestone filler (PLC) and metakaolin (MK) is investigated. PLCs exhibit good initial strength, but the mechanical and durable properties are limited by the dilution effect. The addition of MK can compensate this shortcoming. Three PLCs (0, 11 and 22% LF) combined with MK (7.5 and 15% by weight) were studied on pastes (w/cm = 0.50, 20 ºC): The mini-slump, the heat of hydration and the compressive strength were determined. Hydration was followed by XRD and the CH-content was determined by TG. The results show that incorporation of MK decreases mini-slump increases the heat release rate and initial strength. Finally, the 28-day strength increases with MK content regardless of the filler - content in PLC. The XRD analyses show that the products of hydration are CH and ettringite for all cements, the calcium hemicarboaluminate appears in cements with high LF or MK at 7 days and later becomes it is transformed in monocarboaluminate. For cements with MK, the relative content of CH increases to 2 days and decreased after 28 days. We can conclude that the dilution effect of the LF cannot be fully compensate by high fineness of clinker, and the incorporation of MK cause a stimulating effect on the fraction of clinker. The pozzolanic reaction improves the later compressive strength.