Title:
Durability Issues of One-Part Alkali-Activated Mortars in Aggressive Environments
Author(s):
Luigi Coppola, Denny Coffetti, Elena Crotti and Gabriele Gazzaniga
Publication:
Symposium Paper
Volume:
349
Issue:
Appears on pages(s):
550-562
Keywords:
Alkali activated materials; Ground granulated blast furnace slag; Sustainability; Durability
DOI:
10.14359/51732772
Date:
4/22/2021
Abstract:
This paper presents an experimental study carried out to investigate the durability of one-part alkaliactivated slag (AAS) mortars in different aggressive environments, such as chloride- and sulphate-rich solutions or in presence of freezing-thawing cycles. The mixtures were manufactured at equal water content and were activated by using sodium silicate, potassium hydroxide and sodium carbonate in powder form. In particular, the behavior of AAS mortars with different alkali content was compared with that of mixtures based on Portland cement and blast-furnace cement. Results show that the alkali content is a key-parameter for the durability of these innovative binders. In fact, in mortars manufactured with an alkali content higher than 0.06 by binder
mass, the strength loss is similar to those of mixtures based on blast furnace cement after 150 freeze/thaw cycles. On the contrary, the sulphate-rich solution promotes a stronger degradation of the slag-based mortars respect to that shown by cement-based mixtures, regardless of the alkali content. Finally, the strong deterioration of cement matrix promoted by the formation of oxychloride in CaCl2-rich environment is negligible in AAS mortars due to the lack of calcium hydroxide in the slag matrix.
Related References:
1. L. Coppola, D. Coffetti, E. Crotti, G. Gazzaniga, T. Pastore, An Empathetic Added Sustainability Index (EASI) for cementitious based construction materials, J. Clean. Prod. 220 (2019) 475–482. doi: 10.1016/j.jclepro.2019.02.160
2. A. Kashani, J.L. Provis, G.G. Qiao, J.S.J. Van Deventer, The interrelationship between surface chemistry and rheology in alkali activated slag paste, Constr. Build. Mater. 65 (2014) 583–591. doi: 10.1016/j.conbuildmat.2014.04.127
3. P.F.G.B. Marta Palacios and Francisca Puertas, Rheology and Setting of Alkali-Activated Slag Pastes and Mortars: Effect of Organic Admixture, Mater. J. 105 (n.d.). doi: 10.14359/19754
4. M. Palacios, Y.F. Houst, P. Bowen, F. Puertas, Adsorption of superplasticizer admixtures on alkaliactivated slag pastes, Cem. Concr. Res. 39 (2009) 670–677. doi: 10.1016/j.cemconres.2009.05.005.
5. A. Fernandez-Jimenez, F. Puertas, Effect of activator mix on the hydration and strength behaviour of alkali-activated slag cements, Adv. Cem. Res. 15 (2003) 129–136.
6. D. Bondar, Q. Ma, M. Soutsos, M. Basheer, J.L. Provis, S. Nanukuttan, Alkali activated slag concretes designed for a desired slump, strength and chloride diffusivity, Constr. Build. Mater. (2018). doi: 10.1016/j.conbuildmat.2018.09.124
7. W.-J. Long, J.-J. Wei, Y.-C. Gu, F. Xing, Research on dynamic mechanical properties of alkali activated slag concrete under temperature-loads coupling effects, Constr. Build. Mater. 154 (2017) 687–696.
8. D.E. Angulo-Ramírez, R. Mejía de Gutiérrez, F. Puertas, Alkali-activated Portland blast-furnace slag cement: Mechanical properties and hydration, Constr. Build. Mater. 140 (2017) 119–128.
9. L. Coppola, D. Coffetti, E. Crotti, One-Part Alkali-Activated Slag Cement for Conservation of Existing Structures, ACI Spec. Publ. 330 (2018) 107–122. Proceedings of 14th International conference on Recent Advances in Concrete Technology and Sustainability Issues, Beijing (China), 30 october 2018 – 2 November 2018.
10. S. Bernal, R. San Nicolas, J. Provis, J.S.J. van Deventer, Alkali-activated slag cements produced with a blended sodium carbonate / sodium silicate activator, Adv. Cem. Res. 28 (2015) 1–12.
11. C. Shi, P. V. Krivenko, D.M. Roy, Alkali-activated cements and concretes, Taylor & Francis, 2006.
12. S. Aydin, B. Baradan, Effect of activator type and content on properties of alkali-activated slag mortars, Compos. Part B Eng. 57 (2014) 166–172. doi: 10.1016/j.compositesb.2013.10.001
13. D.W. Law, A.A. Adam, T.K. Molyneaux, I. Patnaikuni, Durability assessment of alkali activated slag (AAS) concrete, Mater. Struct. Constr. 45 (2012) 1425–1437. doi: 10.1617/s11527-012-9842-1
14. M. Palacios, F. Puertas, Effect of carbonation on alkali-activated slag paste, J. Am. Ceram. Soc. 89 (2006) 3211–3221. doi: 10.1111/j.1551-2916.2006.01214.x.
15. R.R. Lloyd, J.L. Provis, J.S.J. Van Deventer, Microscopy and microanalysis of inorganic polymer cements. 2: The gel binder, J. Mater. Sci. 44 (2009) 620–631. doi: 10.1007/s10853-008-3078-z
16. Y. Fu, L. Cai, W. Yonggen, Freeze-thaw cycle test and damage mechanics models of alkali-activated slag concrete, Constr. Build. Mater. (2011). doi: 10.1016/j.conbuildmat.2010.12.006
17. L. Cai, H. Wang, Y. Fu, Freeze-thaw resistance of alkali-slag concrete based on response surface methodology, Constr. Build. Mater. 49 (2013) 70–76. doi: 10.1016/j.conbuildmat.2013.07.045
18. Q. Li, L. Cai, Y. Fu, H. Wang, Y. Zou, Fracture properties and response surface methodology model of alkali-slag concrete under freeze-thaw cycles, Constr. Build. Mater. 93 (2015) 620–626. doi: 10.1016/j.conbuildmat.2015.06.037
19. F. Shahrajabian, K. Behfarnia, The effects of nano particles on freeze and thaw resistance of alkaliactivated slag concrete, Constr. Build. Mater. 176 (2018) 172–178. doi: 10.1016/j.conbuildmat.2018.05.033
20. T. Bakharev, J.G. Sanjayan, Y.B. Cheng, Sulfate attack on alkali-activated slag concrete, Cem. Concr. Res. 32 (2002) 211–216. doi: 10.1016/S0008-8846(01)00659-7
21. M. Komljenovic, Z. Bascarevic, N. Marjanovic, V. Nikolic, External sulfate attack on alkali-activated slag, Constr. Build. Mater. 49 (2013) 31–39. doi: 10.1016/j.conbuildmat.2013.08.013
22. A.M. Neville, Properties of concrete, Longman London, 1995.
23. I. Ismail, S.A. Bernal, J.L. Provis, S. Hamdan, J.S.J. Van Deventer, Microstructural changes in alkali activated fly ash/slag geopolymers with sulfate exposure, Mater. Struct. Constr. 46 (2013) 361–373. doi: 10.1617/s11527-012-9906-2
24. L. Coppola, D. Coffetti, E. Crotti, A. Marini, C. Passoni, T. Pastore, Lightweight cement-free alkaliactivated slag plaster for the structural retrofit and energy upgrading of poor quality masonry walls, Cem. Concr. Compos. 104 (2019) 103341. doi: 10.1016/j.cemconcomp.2019.103341
25. L. Coppola, D. Coffetti, E. Crotti, Pre-packed alkali activated cement-free mortars for repair of existing masonry buildings and concrete structures, Constr. Build. Mater. 173 (2018) 111–117. doi: 10.1016/j.conbuildmat.2018.04.034
26. S.-D. Wang, K.L. Scrivener, Hydration products of alkali activated slag cement, Cem. Concr. Res. 25 (1995) 561–571.
27. S.D. Wang, K.L. Scrivener, P.L. Pratt, Factors affecting the strength of alkali-activated slag, Cem. Concr. Res. 24 (1994) 1033–1043.
28. L. Coppola, A. Buoso, S. Lorenzi, Compatibility issues of NSF-PCE superplasticizers with several lots of different cement types (long-term results), Kuei Suan Jen Hsueh Pao/Journal Chinese Ceram. Soc. 38 (2010).
29. A. Allahverdi, E. Najafi Kani, S. Esmaeilpoor, Effects of Silica Modulus and Alkali Concentration on Activation of Blast-Furnace Slag, Iran. J. Mater. Sci. Eng. 5 (2008) 32–35.
http://ijmse.iust.ac.ir/browse.php?a_code=A-10-3-26&slc_lang=en&sid=1.
30. R. Bayuaji, A.K. Yasin, T.E. Susanto, M.S. Darmawan, S. Darmawan, A review in geopolymer binder with dry mixing method (geopolymer cement), AIP Conf. Proc. 1887 (2017) 20042.
doi: 10.1063/1.5003513
31. C. Qiao, P. Suraneni, J. Weiss, Phase diagram and volume change of the Ca(OH) 2 -CaCl 2 -H 2 O system for varying Ca(OH) 2 /CaCl 2 molar ratios, J. Mater. Civ. Eng. 30 (2018).
doi: 10.1061/(ASCE)MT.1943-5533.0002145
32. D. Coffetti, Alternative binders as milestone of 3R strategy for sustainable construction materials, PhD Thesis, University of Bergamo, 2009. doi: 10.13140/RG.2.2.26173.31201
33. H. Ye, C. Cartwright, F. Rajabipour, A. Radli?ska, Understanding the drying shrinkage performance of alkali-activated slag mortars, Cem. Concr. Compos. 76 (2017) 13–24.
34. H. Ye, A. Radlińska, Shrinkage mechanisms of alkali-activated slag, Cem. Concr. Res. 88 (2016) 126–135.
35. Y. Fu, L. Cai, W. Yonggen, Freeze-thaw cycle test and damage mechanics models of alkali-activated slag concrete, Constr. Build. Mater. 25 (2011) 3144–3148. doi: 10.1016/j.conbuildmat.2010.12.006
36. I. Galan, L. Perron, F.P. Glasser, Impact of chloride-rich environments on cement paste mineralogy, Cem. Concr. Res. 68 (2015) 174–183. doi: 10.1016/j.cemconres.2014.10.017
37. R.J. Myers, S.A. Bernal, J.L. Provis, Phase diagrams for alkali-activated slag binders, Cem. Concr. Res. 95 (2017) 30–38. doi: 10.1016/j.cemconres.2017.02.006.
38. R.J. Myers, B. Lothenbach, S.A. Bernal, J.L. Provis, Thermodynamic modelling of alkali-activated slag cements, Appl. Geochemistry. 61 (2015) 233–247. doi: 10.1016/j.apgeochem.2015.06.006