AN INVESTIGATION ON THE MECHANICAL PROPERTIES OF STANDARD CURED ALKALI ACTIVATED MORTARS UNDER STATIC AND DYNAMIC LOADINGS

Öz

In this study, the effects of partial replacement of ground granulated blast furnace slag (YFC) with fly ash (FA), metakaolin (MK) and silica fume (SD) and the silicate modulus of the activator solution on the compressive strength and flexural performance under static and impact loading conditions have been investigated. The reaction forces were recorded by an data acqusision system which is Test results showed that the MK incorporation influenced the mechanical properties negatively while the SD incorporation affected positively. Increasing the Ms ratio of the activator significantly improved the mechanical properties of MK incorporated mixtures. It has been shown that the flexural strength and fracture energy of standard water cured alkali activated mortars under impact loading were 2.54 – 4.89 and 14.20 – 26.93 times more than that of static loading conditions, respectively

Anahtar Kelimeler

• Alkali activated cement, low-velocity impact, Ductility index

ALKALİLERLE AKTİVE EDİLMİŞ STANDARD KÜRLÜ HARÇLARIN STATİK VE DİNAMİK YÜKLEME ALTINDAKİ MEKANİK ÖZELİKLERİNİN İNCELENMESİ

Öz

Bu çalışmada, alkalilerle aktive edilmiş bağlayıcıların ana hammaddesi olan yüksek fırın cürufu (YFC) yerine uçucu kül (UK), metakaolin (MK) ve silis dumanı (SD) ikamesinin ve aktivatörün Ms oranının (SiO2/Na2O) alkalilerle aktive edilmiş standart kürlü harçların (AAH), basınç dayanımları, statik ve düşük hızlı darbe yüklemeleri altındaki eğilme performansları üzerindeki etkileri incelenmiştir. Sonuçlar, YFC yerine MK ikamesinin mekanik özellikleri olumsuz yönde, SD ikamesinin ise olumlu yönde etkilediğini göstermiştir. Ms oranındaki artış, MK ikamesi ile üretilen harçların mekanik özelliklerini önemli ölçüde geliştirmiştir. Darbe yükleri altında, standart su kürüne maruz AAH’lerin eğilme dayanımı ve kırılma enerjisinin statik yüklemedekine kıyasla sırasıyla 2,54 – 4,89 ve 14,20 – 26,93 kat daha yüksek olduğunu ortaya konmuştur

Anahtar Kelimeler

• Alkalilerle aktive edilmiş bağlayıcılar, Düşük hızlı darbe, Düktilite indeksi

Kaynakça

1. Roy DM. Alkali-activated cements: Opportunities and challenges, Cement and Concrete Research, Cilt. 29, 1999, No. 2, s. 249-254.
2. Palomo A, Grutzeck MW, Blanco MT. Alkali-activated fly ashes: A cement for the future, Cement and Concrete Composites, Cilt. 29, 1999, Sayı: 8, s. 1323-9.
3. Bakharev T, Sanjayan JG, Cheng YB. Alkali activation of Australian slag cements, Cement and Concrete Research, Cilt. 29, 1999, s. 113-120.
4. Fernandez-Jimenez A, Palomo JG, Puertas F. Alkali-activated slag mortars-Mechanical strength behavior, Cement and Concrete Research, Cilt. 29, 1999, s.1313-1321.
5. Shi C, Krivenko PV, Roy D. Alkali-Activated Cements and Concretes. 2006, USA and Canada: Taylor and Francis.
6. Bakharev T, Sanjayan JG, Cheng YB. Sulfate attack on alkali-activated slag concrete, Cement and Concrete Research, Cilt.32, 2002, s. 211-216.
7. Bakharev T, Sanjayan JG, Cheng,YB. Resistance of alkali-activated slag concrete to acid attack, Cement and Concrete Research, Cilt. 33, 2003, s. 1607-1611.
8. Puertas F, Amat T, Fernandez-Jimenez A, Vazquez T. Mechanical and durable behaviour of alkalin cement mortars reinforced with polypropylene fibres, Cement and Concrete Research, Cil.33, 2003, s. 2031-2036.

9. Shi C, Xie P. Interface between cement paste and quartz sand in alkali-activated slag mortars, Cement and Concrete Research, Cilt. 28, 1998, s. 887-896.
10. Zivica, V. Effects of type and dosage of alkalin activator and temperature on the properties of alkali-activated slag mixtures, Construction and Building Materials, Cilt. , 2007, s. 1463-9.
11. Collins FG, Sanjayan JG. Workability and mechanical properties of alkali activated slag concrete, Cement and Concrete Research, Cilt. 29, 1999, s. 455-458.
12. Atış CD, Bilim C, Çelik Ö, Karahan O. Influence of activator on the strength and drying shrinkage of alkali-activated slag mortar, Construction and Building Materials, Cilt. 23, , s. 548-555. Zivica V. Effectiveness of new silica fume alkali activator, Cement and Concrete Composites, Cilt. 28, 2006, Sayı. 1, s. 21-25.
13. Ramachandran VS. (Ed.) Concrete Admixtures Handbook (2nd ed.), 1995, Noyes publications.
14. Yang KH, Song JK, Ashour AF, Lee ET. Properties of cementless mortars activated by sodium silicate", Construction and Building Materials, Cilt. 22, 2007, Sayı. 9, s. 1981
15. Pacheco-Torgal F, Castro-Gomes J, Jalali S. Alkali-activated binders: A review. Part 2. About materials and binders manufacture, Construction and Building Materials, Cilt. , 2008, Sayı. 7, s. 1315-1322.
16. Aydın S. Alkalilerle aktive edilmiş yüksek fırın cürufu bağlayıcılı lifli kompozit geliştirilmesi. Dokuz Eylül Üniversitesi, Fen Bilimleri Enstitüsü, 2010, Doktora tezi.
17. Ong KCG, Basheerkhan M, Paramasivam P. Resistance of fibre concrete slabs to low velocity projectile impact, Cement & Concrete Composites, Cilt. 21, 1999, s. 391-401.
18. Almansa EM, Canovas MF. Behaviour of normal and steel fiber-reinforced concrete under impact of small projectiles, Cement and Concrete Research, Cilt. 29, 1999, s. 1814.
19. Luo X, Sun W, Chan SYN. Characteristics of high-performance steel fiber-reinforced concrete subject to high velocity impact, Cement and Concrete Research, 30, 2000, s. 914.
20. Banthia N, Mindess S, Bentur A, Pigeon M. Impact testing of concrete using a drop- weight impact machine, Experimental Mechanics, Cilt. 29, 1988, Sayı. 1, s. 63-69.
21. Wang N, Mindess S, Ko K. Fibre reinforced concrete beams under impact loading, Cement and Concrete Research, Cilt. 26, 1996, Sayı. 3, s. 363-376.
22. Zhang XX, Ruiz G, Yu RC. A new drop weight impact machine for studying fracture process in structural concrete, Anales de Mecanica de la Fractura Cilt. 25, 2008, Sayı.2, s. 655-659.
23. Dancygier A, Katz A, Yardımcı MY, Yankelevsky D. On the behavior of high ductility concrete under low impact, Proceedings of Seventh International Symposium on Impact Engineering (ISIE 2010), Chmielewski, R & Kruszka, L editors, s. 197-203, , Warsaw, Poland.
24. Banthia N, Mani M. Toughness indices of steel fiber reinforced concrete at subzero temperatures, Cement and Concrete Research, Cilt. 23, 1993, s. 863-873.
25. Hillerborg, A. The theoretical basis of a method to determine the fracture energy of concrete, Materials and Structures, Cilt. 18, Sayı. 106, 1985, s. 291-296.
26. RILEM Technical Committee 50-FMC. Draft Recommendation: Determination of the fracture energy of mortar and concrete by means of three point bend test on notched beams, Materials and Structures, 18, (106), 1985, s. 287-291.
27. Beygi MHA, Kazemi MT, Nikbin IM, Amiri JV. The effect of water to cement ratio on fracture parameters and brittleness of self-compacting concrete, Materials and Design, Cilt. 50, 2013, s. 267-276.
28. Chiaia B, Van Mier JGM, Vervuurt A. Crack growth mechanisms in four different concretes: microscopic observations and fractal analysis", Cement and Concrete Research, Cilt. 28, Sayı. 1, 1998, s. 103-114.
29. Mindess S, Banthia N, Yan C. Fracture toughness of concrete under impact loading, Cement and Concrete Research, Cilt. 17, Sayı 2, 1987, s. 231-241.
30. Bindiganavile V, Banthia N, Aarup B. Impact response of ultra-high-strength fiber- reinforced cement composite, ACI Materials Journal, Cilt. 99, Sayı 6, 2002, s. 543-548.
31. Zhang XX, Ruiz G, Yu RC, Tarifa M. Fracture behavior of high-strength concrete at a wide range of loading rates, Int. J. Impact. Eng., Cilt. 36 Sayı 10-11, 2009, s. 1204
32. Chakradhara RM, Bhattacharyya SK, Barai SV. Behaviour of recycled aggregate concrete under drop weight impact load, Construction and Building Materials, Cilt. 25, Sayı 1, 2011, s. 69-80.
33. Dancygier A, Katz A, Yardımcı MY, and Yankelevsky DZ. Behavior of high ductility cement composite beams under low impact, International Journal of Protective Structures, Cilt. 3 Sayı 2, 2012, s. 177-191.
34. Malvar LJ, and Ross CA. Review of strain rate effects for concrete in tension, ACI Materials Journal, Cilt. 95, 1998, s. 735-739.
35. CEB (Comité Euro-International du Béton). Concrete structures under impact and impulsive loading, CEB Bulletin 187, Lausanne, 1988.
36. Cadoni E. Fracture behavior of concrete at high strain rate. In: Proceedings of VIII International Conference on Fracture Mechanics of Concrete and Concrete Structures (FraMCoS-8), J.G.M. Van Mier, G. Ruiz, C. Andrade, R.C. Yu and X.X. Zhang (Eds), University of Castilla La-Mancha, Toledo, Spain, 2013