Many standardised durability testing methods have been developed for Portland cement-based concretes, but require validation to determine whether they are also applicable to alkali-activated materials. To address this question, RILEM TC 247-DTA ‘Durability Testing of Alkali-Activated Materials’ carried out round robin testing of carbonation and chloride penetration test methods, applied to five different alkali-activated concretes based on fly ash, blast furnace slag or metakaolin. The methods appeared overall to demonstrate an intrinsic precision comparable to their precision when applied to conventional concretes. The ranking of test outcomes for pairs of concretes of similar binder chemistry was satisfactory, but rankings were not always reliable when comparing alkali-activated concretes based on different precursors. Accelerated carbonation testing gave similar results for fly ash-based and blast furnace slag-based alkali-activated concretes, whereas natural carbonation testing did not. Carbonation of concrete specimens was observed to have occurred already during curing, which has implications for extrapolation of carbonation testing results to longer service life periods. Accelerated chloride penetration testing according to NT BUILD 443 ranked the tested concretes consistently, while this was not the case for the rapid chloride migration test. Both of these chloride penetration testing methods exhibited comparatively low precision when applied to blast furnace slag-based concretes which are more resistant to chloride ingress than the other materials tested.
|Journal||Materials and Structures/Materiaux et Constructions|
|Publication status||Published (in print/issue) - 13 Feb 2020|
Bibliographical noteFunding Information:
The participation of J. L. Provis and S. A. Bernal in this research was sponsored by the Engineering and Physical Sciences Research Council (EPSRC; UK) under grant number EP/M003272/1. The participation of A. Castel in this research was funded by the Cooperative Research Centre (CRC) for Low Carbon Living Ltd supported by the Cooperative Research Centres, an Australian Government initiative. Participation of V. Ducman was financially supported by the Slovenian Research Agency Programme Group P2-0273. The work and research of K. Dombrowski-Daube in RILEM TC-247 DTA was supported by ZIM—Central Innovation Program, German Federal Ministry of Economic Affairs and Energy (BMWi) by order of the German Bundestag. The contribution of the team at TU Delft led by G. Ye was supported by the Materials innovation institute M2i/Netherlands Organisation for Scientific Research (STW/M2i project 13361). The contributions of K. Arbi were also supported by Delta Concrete Consult BV. Acknowledgements
The authors would like to thank all members of RILEM TC 247-DTA for the valuable discussions in planning the activities for the round robin. Particularly we would like to acknowledge the immense contribution of A. Buchwald (ASCEM, Netherlands), W. Rickard and A. van Riessen (Curtin University, Australia), G. Gluth (BAM, Germany), R. Pouhet and M. Cyr (Toulouse University, France) in developing the concrete mix designs evaluated; and for arranging the donations of raw materials, and the logistics for their distribution to all the round robin participants. The participation of Dr Andrew Dunster (BRE, United Kingdom) in the round-robin testing and enriching the associated discussions is very gratefully acknowledged. We greatly appreciate the help of colleagues, laboratory assistants and students in the participating laboratories, including Rajetharan Krishnakumar, Zhijun Tan, Maria Criado and Oday Hussein at the University of Sheffield. Special thanks are also due to Ecocem (France), BauMineral (Germany) and Argeco (France) for the generous donation of several tonnes of slag, fly ash and flash-calcined metakaolin to the members of this technical committee; and to PQ Corporation and Grupo IQE for the donation of activator constituents to some of the participating laboratories.
© 2020, The Author(s).
Copyright 2020 Elsevier B.V., All rights reserved.
- Alkali-activated concrete
- Blast furnace slag
- Chloride penetration
- Durability testing
- Fly ash
- Round robin