Increasing Mechanical Strength of Ignimbrite Rocks

Öz

Ignimbrite is a type of pyroclastic rock that is formed by the volcanic lava. With the explosion of the Nemrut crater in the city of Bitlis, the lava sprawling around it has cooled down. Because of these cooling, pyroclastic rocks, known as Ahlat stones (AS), were formed in the region. The compressive and bending strength of natural Ahlat stone is very low. In this study, the compressive and bending strength of natural Ahlat stone has been increased by the applications of drying oven curing and combined curing. Natural AS samples were cut into sizes of 150×150×150 mm for compressive test and of 100×100×400 mm for bending test. No cure was applied to some of the natural Ahlat stone samples brought from the quarry, which were selected as reference samples. 10 different cure types were applied to other natural Ahlat stones with the same characteristics as Reference Ahlat stone. These 10 different curing types included air curing, standard water curing, 4 drying oven curing types and 4 combined curing types. After curing, all samples were subjected to compressive and bending tests. Average compressive strength of the reference samples was found to be 9.8 MPa, and its bending strength was found to be 1.6 MPa. The highest average compressive strength of Ahlat stone was found to be 19.2 MPa after 3 days of drying oven curing at 200oC. The highest average bending strength of Ahlat stone was found to be 3.2 MPa after 3 days of drying oven curing at 200oC. The results of the study showed that the compressive and bending strength of the natural Ahlat stone can be increased to approximately 2 times after 3 days of drying oven curing at 200oC.

Anahtar Kelimeler

• Ignimbrite rocks,Heat treatments,Drying oven curing,Combined curing,Compressive strength,Bending strength

Teşekkür

We would like to thank the Rector of Bitlis Eren University who provided all his support in our studies and the Van lake Building Quality Control Laboratory Construction Industry Trade Limited Company.

İgnimbirit Kayaçlarının Mekanik Dayanımının Artırılması

Öz

İgnimbirit, volkanik lavlar tarafından oluşturulan piroklastik bir kayaç türüdür. Bitlis ilinde Nemrut kraterinin patlamasıyla etrafa yayılan lavlar soğumuştur. Bu soğuma nedeniyle bölgede Ahlat taşı (AT) olarak bilinen piroklastik kayaçlar oluşmuştur. Doğal Ahlat taşının basınç ve eğilme dayanımı çok düşüktür. Bu çalışmada, etüv kürü ve kombine kür uygulamalarıyla doğal Ahlat taşının basınç ve eğilme dayanımı arttırılmıştır. Doğal AT numuneleri basınç deneyi için 150×150×150 mm ve eğilme deneyi için 100×100×400 mm boyutlarında kesilmiştir. Taş ocağından getirilen ve referans örnekleri olarak seçilen doğal Ahlat taşı numunelerinin hiçbirine kür uygulanmamıştır. Referans Ahlat taşı ile aynı özelliklere sahip diğer doğal Ahlat taşlarına ise 10 farklı kür tipi uygulandı. Bu 10 farklı kür tipi; hava kürü, standart su kürü, 4 tip etüv kürü ve 4 tip kombine kürü içermektedir. Kür sonrası tüm numunelere basınç ve eğilme deneyi uygulandı. Referans numunelerinin ortalama basınç dayanımı 9,8 MPa ve ortalama eğilme dayanımı 1,6 MPa olarak bulundu. Ahlat taşının en yüksek ortalama basınç dayanımı, 200oC' de 3 günlük etüv küründen sonra 19,2 MPa olarak bulundu. Ahlat taşının en yüksek ortalama eğilme dayanımı, 200oC' de 3 günlük etüv küründen sonra 3,2 MPa olarak bulundu. Çalışma sonuçları, doğal Ahlat taşının basınç ve eğilme dayanımının, 200oC' de 3 günlük etüv küründen sonra yaklaşık iki katına çıkarılabileceğini gösterdi.

Anahtar Kelimeler

• İgnimbirit kayaç,Isıl işlemler,Etüv kürü,Kombine kür,Basınç dayanımı,Eğilme dayanımı

Kaynakça

1. Akin, M., Ozvan, A., Dincer, I., Topal, T. (2017). Evaluation of the physico-mechanical parameters affecting the deterioration rate of Ahlat ignimbrites (Bitlis, Turkey), Environmental earth sciences, 76(24), pp. 827. https://doi.org/10.1007/s12665-017-7175-7
2. Akkaya, I., Ozvan, A., Tapan, M., Bor, M., Ozvan, E. E. (2017). Determination of the Relationship between Poisson’s Ratio and Physical, Mechanical and Chemical Properties of Different Type Rocks, National Symposium on Engineering Geology and Geotechnics, Cukurova University, Adana, pp. 208–215.
3. Akkopru, E., Christol, A. (2019). Lake Van, Landscapes and Landforms of Turkey, pp. 369–382, https://doi.org/10.1007/978-3-030-03515-0_18
4. Aydar, E., Gourgaud, A., Ulusoy, I., Digonnet, F., Labazuy, P., Sen, E. (2003). Morphological Analysis of Active Mount Nemrut Stratovolcano, Eastern Turkey: Evidences and Possible Impact Areas of Future Eruption, Journal of Volcanology and Geothermal Research, 123, pp. 301–312, https://doi.org/10.1016/S0377-0273(03)00002-7
5. Aygun, Z., Aygun, M. (2016). Spectroscopic analysis of Ahlat stone (ignimbrite) and pumice formed by volcanic activity, Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 166, pp. 73–78. https://doi.org/10.1016/j.saa.2016.05.018
6. Bakis, A. (2019). Determination of Water Absorption of Natural Ahlat Stone, International Engineering and Science Symposium, Siirt University, Siirt, pp. 335–337. Baykara, T., Isik, M. C. (2016). Physical characterization, microstructural evaluation, and condition assessment of Ancient Ahlat Tombstones in the Seljukian Cemetery of Ahlat (Turkey), International Journal of Architectural Heritage, 10(8), pp. 1025–1040. https://doi.org/10.1080/15583058.2016.1181227
7. Boran, A. (1997). Ahlat Stone (Andesite Tuff) (in Turkish), Vakiflar Journal, 26, pp. 363–373.
8. Cengiz, M. S., Cengiz, C. (2018). Numerical Analysis of Tunnel LED Lighting Maintenance Factor. IIUM Engineering Journal, vol. 19(2), pp. 154–163.

9. Cengiz, M. S. (2019). The Relationship Between Maintenance Factor and Lighting Level in Tunnel Lighting. Light & Engineering, vol. 27. 3, pp. 154–163.
10. Eren, M., Kaynaklı, M., Yapici, I., Gencer, G., Yurci, Y., Cengiz, M. S., Cengiz, C. (2017). Numerical Analysis of Maintanance Factor for Tunnel and Road in Solid State Lighting. International Conference on Multidisciplinary, Science, Engineering and Technology 2017, Bitlis, October 27–29, Turkey.
11. Eric, M. (1982). Materials Science and Structural Physics Problems. 1st Edition, Maket Publishing house, Istanbul.
12. Ertugral, H., Gunay, V. (2019). Conservation of Ahlat tombstones by using nanotechnology, FEB-Fresenius Environmental Bulletin, 28(2), pp. 941.
13. Gevrek, A. I., Kazanci, N. (1994). Ignimbrite: Occurrence and properties (in Turkish), Geological Engineering, 38 (1991), pp. 39–42.
14. Hattatoglu, F., Bakis, A. (2017). Usability of ignimbrite powder in reactive powder concrete road pavement, Road Materials and Pavement Design, 18(6), pp. 1448–1459, https://doi.org/10.1080/14680629.2016.1213182
15. Karaman, E. M., Kibici, Y. (2008). Basic Principles of Geology, 2nd Edition, Belen Publishing and Printing, Ankara.
16. Kuluozturk, M. F., Buyuksarac, A., Ozbey, F., Yalcin, S., Dogru, M. (2018). Determination of indoor radon gas levels in some buildings constructed with Ahlat stone in Ahlat/Bitlis, International Journal of Environmental Science and Technology, 16(9), pp. 5033–5038, https://doi.org/10.1007/s13762-018-1692-0
17. Simsek, O., Erdal, M. (2004). Investigation of some mechanical and physical properties of the Ahlat stone (ignimbrite), G.U. Journal of Science, 17(4), pp. 71–78.
18. Ozvan, A., Dincer, I. , Akin, M., Oyan, V., Tapan, M. (2015). Experimental studies on ignimbrite and the effect of lichens and capillarity on the deterioration of Seljuk Gravestones, Engineering geology, 185, pp. 81–95, https://doi.org/10.1016/j.enggeo.2014.12.001
19. TS 500. (2000) Requirements for design and construction of reinforced concrete structures, Turkish Standards Institute, Ankara.
20. TS EN 12390-3. (2010) Testing hardened concrete-Part 3: Compressive strength of test specimens, Turkish Standards Institute, Ankara.
21. TS EN 12390-5. (2010). Testing hardened concrete - Part 5: Flexural strength of test specimens, Turkish Standards Institute, Ankara.
22. TS 25/T1. (2011). Natural pozzolan (Trass) for use in cement and concrete - Definitions, requirements and conformity criteria, Turkish Standards Institute, Ankara.
23. TS EN 1097-6. (2013). Tests for mechanical and physical properties of aggregates - Part 6: Determination of particle density and water absorption, Turkish Standards Institute, Ankara.
24. TS EN 1097-2. (2015). Tests for mechanical and physical properties of aggregates- Part 2: Methods for the determination of resistance to fragmentation, Turkish Standards Institute, Ankara.
25. Tunc, A. (2007) Road Materials and Applications. 2nd Edition, Nobel publishing, Istanbul.
26. Ulusoy, I., Cubukcu, H. E., Mouralis, D., Aydar, E. (2019). Nemrut Caldera and Eastern Anatolian Volcanoes: Fire in the Highlands, Landscapes and Landforms of Turkey, pp. 589–599, https://doi.org/10.1007/978-3-030-03515-0_35
27. Unsal, A., Sen, H. (2008). Concrete paving blocks - Requirements and test methods TS 2824 EN 1338, Concrete and Concrete Materials Laboratory Experiments, Department of Technical Research Materials Lab. Branch Office, Ankara.