Düşük Dayanımlı Betonların Elastisite Modülünün Bulunması

Year 2020, , 1384 - 1397, 30.09.2020

B.ahmet Yaşar , Mehmet Metin Kose , Sila Avğın , Hüseyin Temiz

https://doi.org/10.31202/ecjse.720700

Cited By: 1

Abstract

Bu çalışma, düşük mukavemetli betonun esneklik modülünü deneysel olarak belirlemeyi ve yeni elastisite modülü denklemlerini önermeyi amaçlamaktadır. Elastisite modülü ile ilgili çalışmalar genellikle normal ve yüksek dayanımlı beton numuneleri için gerçekleştirilmiştir. Elastisite modülü, statik ve dinamik elastisite modülü olarak belirlenebilir. Bu çalışmada 64 beton test örneği hazırlanmıştır. Gerilme-birim şekil değiştirme çerçevesi üzerine 38 numune yerleştirilmiş ve statik elastisite modülünü belirlemek için basınç testine tabi tutulmuştur. Karakteristik beton basınç dayanımlarının %40, %45 ve%50'si TS-500, ACI 318-11 ve CEB 2004'e göre düşük mukavemetli betonun statik elastisite modülünü belirlemek için gerilim-gerinim eğrisinde ikinci bir nokta olarak kullanılmıştır. Statik elastisite modülü değerleri standart denklemleri ile karşılaştırılmış ve üç standardın düşük dayanımlı beton için daha yüksek esneklik modülü değerleri verdiği görülmüştür. 26 beton numunesinin dinamik elastisite modülleri ultrasonik test cihazı kullanılarak belirlenmiştir. Dinamik elastisite modülü değerleri Hermit fonksiyonu ile karşılaştırılmıştır. Hermit fonksiyonunun daha yüksek elastisite modülü değerleri verdiği gözlenmiştir. Bu nedenle, yapılan deney sonuçlarına göre düşük dayanımlı betonun statik ve dinamik elastisite modülü için regresyon analizi kullanılarak yeni denklemler, önerilmiştir.

Keywords

Düşük dayanımlı beton, Statik elastisite modülü, Dinamik elastisite modülü

Determination of Elasticity Modulus For Low Strength Concrete

Abstract

This study aims to experimentally determine the elasticity modulus of low strength concrete and propose new elasticity modulus equations. Studies on elasticity modulus have been generally carried out for normal and high strength concrete samples. The elasticity modulus can be determined as static and dynamic elasticity modulus. 64 concrete test samples were prepared in this study. 38 samples were placed on the stress-strain frame and subjected to the compression test to determine static elasticity modulus. 40%, 45% and 50% of the characteristic concrete compressive strengths were used as a second point on the stress-strain curve to determine the static elasticity modulus of low strength concrete according to TS 500, ACI 318-11 and CEB 2004, respectively. Static elasticity modulus values were compared with three code equations and it was observed that three codes yield higher elasticity modulus values for low strength concrete. Dynamic elasticity modules of 26 concrete samples were determined using an ultrasonic test device. Dynamic elasticity modulus values were compared with Hermit function. It was observed that Hermit function also gives higher elasticity modulus values. Therefore, new equations for static and dynamic elasticity modulus of low strength concrete were proposed based on the experiment results using regression analysis.

Keywords

Low strength concrete, Static elasticity modulus, Dynamic elasticity modulus

References

• [1] Topcu İ.B and Uzunomeroğlu A. (2019) “Statistical Analysis of Ready Mixed Concrete in Ankara’ Journal of Quantitative Sciences / Volume: 1, Issue: 1, pp. 16-42. (In Turkish)
• [2] Turkel E. B. (2002) “The Relation Between Compressive Strength and Modulus of Elasticity in Concrete” MSc. Thesis. Istanbul Technical University, Graduate School of Natural and Applied Sciences, Istanbul. (In Turkish)
• [3] Emiroglu M., Yıldız S., Ozgan E. (2009) “Experimental and Theoretical Study of Modulus of Elasticity on Rubberized Concrete” Fac. Eng. Arch. Gazi Univ. Vol 24, No 3, pp. 469-476, (In Turkish)
• [4] ACI 318 (2011) Building Code Requirements for Structural Concrete, American Concrete Institute USA.
• [5] Pekgokgoz R.K., Izol G., Avcil F., Gurel M.A. (2018) “Determination of the Elastic Modulus of the Building Stone of Sanliurfa Grand Mosque Minaret by of Using Ultrasonic Testing Machine”, Harran University Journal of Engineering. 01 (2018) p.35-45 (In Turkish)
• [6] Buyuktas K., Alagoz T., Kumova Y. (2005) “Determination of the Compressive Strength and Elasticity Modules of Concrete Produced Using Different Cement Kinds in Field Conditions” Mediterranean Agricultural Sciences, 18(3),365-376 (In Turkish)
• [7] TS500 (2005). Requirements for design and construction of reinforced concrete structures (in Turkish). Turkish Standardization Institute, Ankara.
• [8] Şaman R. (2018) “Comparison of dynamic and static elastic modulus for sample created by using different concrete types and fiber ratio” MSc. Thesis, Bozok University, Graduate School of Natural and Applied Sciences, Yozgat (In Turkish)
• [9] Abdullah A., Saeed V. (2016) “Determining Young Modulusof Concrete with Ultrasonic Wave Velocity Measurement”, Msc Thesis, Dicle University, Institute Of Natural And Applied Sciences (In Turkish)
• [10] Ozden A. (2010) “A Research on The Relationship Between Compressive and Tensile Strength of Concrete wth Modulus of Elasticity”, MSc. Thesis, Namık Kemal University Graduate School of Natural and Applied Sciences (In Turkish)
• [11] Sideris, K.K., Manita, P., and Sideris, K. (2004), “Estimation of ultimate modulus of elasticity and Poisson ratio of normal concrete” Cement & Concrete Composites. Vol. 26, pp.623-631.
• [12] Demir F. (2005). “A new way of prediction elastic modulus of normal and high strength concrete-fuzzy logic” Cement and Concrete Research. Vol. 35, pp. 1531-1538.
• [13] Aydin, A.C., Tortum A., and Yavuz, M. (2006). “Prediction of concrete elastic modulus using adaptive neuro-fuzzy inference system” Civil Engineering and Environmental Systems. Vol.23(4),pp.295-309.
• [14] Yan, K., and Shi, C. (2010). “Prediction of elastic modulus of normal and high strength concrete by using support vector machine” Construction and Building Materials.
• [15] Ispir M., Dalgıc K.D., Sengul C., Kuram F., İlki A., Tasdemir M.A., (2010) Modulus of elasticity of low strength concrete 9th International Congress on Advances in Civil Engineering, Karadeniz Technical University, Trabzon, Turkey
• [16] Ahmad S., Pilakoutas K.,Khan Q.Z., Neocleous K.,(2014) “Stress-Strain Model for Low Strength Concrete in Uni-axial Compression”, Arabian Journal for Science and Engineering, 40(2), 313-328.
• [17]TS 802 (1985) Design Concrete Mixes, (in Turkish), Turkish Standardization Institute, 19s, Ankara.
• [18] TS EN 12390-2 (2002) Testing hardened concrete - Part 2: Making and curing specimens for strength tests (in Turkish), Turkish Standardization Institute, Ankara.
• [19] TS EN 12390-3 (2003). Testing hardened concrete-Part 3: Compressive strength of test specimens (in Turkish), Turkish Standardization Institute, Ankara.
• [20] Akman Ms. (1990) Building Materials, İ.T.Ü. Construction Faculty Printing House, 162 p. Istanbul. (In Turkish)
• [21] Lord, J. D. ve Morrell, R. M., (2010), “Elastic modulus measurement; obtaining reliable data from the tensile test”, Metrologia, (47), 41–49
• [22] Committee Euro-International du Beton, CEB-FIB Model Code for Concrete Structures, 1990.