Alkali-activated mortars: porosity and capillary absorption

Abstract

Studies conducted on alkali-activated materials in late years attested that they could be a replacement to ordinary Portland cement (OPC). Nevertheless, their performances in aggressive conditions require profound investigations to evaluate the ability to the fluid transfer. This article assesses the pore structure of alkali-activated mortars produced using one-part metakaolin combined with ground granulated blast furnace slag and other-part using only alkali-activated ground granulated blast furnace slag. The pore characteristics of alkali-activated mortars were compared to those of OPC as a reference. Tests consist in the measurement of the porosity accessible to water, water absorption and sorptivity. The results revealed that the alkali-activated based metakaolin combined with ground granulated blast furnace slag have greater porosity, water absorption, sorptivity and rate of water saturated porosity than alkali-activated based ground granulated blast furnace slag and Portland cement mortars.

Keywords:

• Alkali-activated mortar
• ground granulated blast furnace slag
• metakaolin
• porosity
• sorptivity

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors are grateful to the Investment Program PIA3 of the French State for the grant awarded. We also are grateful the Scientific Program H2020 for Research and Innovation by the European Commission. The authors would also like to acknowledge the Institute of Rennes Chemical Science (ISCR-UMR CNRS 6226) particularly Stephane Freslon from the laboratory Solid Chemistry and Materials of INSA Rennes for provided facilities available.