EVALUATION OF THE DEPENDENCY OF THE COMPRESSIVE STRENGTH OF CONCRETE ON THE CORE DRILLING DIRECTION THROUGH ANOVA TEST

Yıl 2020, Cilt: 38 Sayı: 4, 1879 - 1895, 05.10.2021

Şakir Erdoğdu Safa Nayır Ufuk Kandıl Şirin Kurbetcı Kurbetcı Memduh Nas

Öz

Determination of the compressive strength of concrete in existing reinforced concrete structures is important, particularly in some cases. Destructive and non-destructive test methods are used to determine the compressive strength in such structures. Amongst these, coring is the most widely used method as a destructive method in determining the compressive strength in existing reinforced concrete structures. However, even though numerous studies have been carried out on the variation of the determined compressive strength depending on the coring direction, the discussions continue. In this study, concrete blocks containing fly ash (FA) and silica fume (SF) and aggregates of different maximum sizes were produced. In the mixtures, cement was replaced by fly ash at ratios of 20%, 40%, and 60% and silica fume at ratios of 5%, 10%, and 15%, respectively. Two aggregates with the maximum aggregate sizes of 16 mm and 31.5 mm were used in the production of the concrete blocks. The concrete blocks were kept in a laboratory by covering them with burlaps moistened intermittently for 28 days and then cores of 10 cm diameter were taken and cut to have 20 cm height then capped and tested to determine compressive strength. Core drilling was carried out parallel and perpendicular to the casting direction and then the compressive strengths were determined. Cubes of 15 cm were also prepared and tested to determine the compressive strength level of concrete and to make comparisons accordingly. The compressive strength of mineral-added core samples taken parallel to the casting direction is higher than those of taken perpendicular to the casting direction, in all mixtures. The ANOVA test applied on the results obtained, it was found that the maximum aggregate size (Dmax) and the core drilling direction with respect to casting direction is statistically significant in terms of the compressive strength of concrete produced using fly ash and silica fume at certain substitution ratios.

Anahtar Kelimeler

Core, coring direction, fly ash, silica fume, aggregate size, compressive strength, anova test.

Kaynakça

• [1] Shaikh FUA., Taweel M., (2015) Compressive strength and failure behaviour of fibre reinforced concrete at elevated temperatures. Advance in Concrete Construction 3 (4), 283- 293. doi.org/10.12989/acc.2015.3.4.283.
• [2] Allahverdi A., Mahinroosta M., Pilehvar S., (2017) A temperature–age model for prediction of compressive strength of chemically activated high phosphorus slag content cement. International Journal of Civil Engineering 15, 839-847. doi.org/10. 1007/s40999-017-0196-5.
• [3] ASTM C42-90, (1992) Standard test method for obtaining and testing drilled cores and sawed beams of concretes. ASTM International, West Conshohocken, PA, USA.
• [4] Sullivan PJE., (1991) Testing and evaluation of concrete strength in structures. ACI Materials Journal 88 (5), 530-535.
• [5] Price WF., Hynes FP., (1996) In-situ strength testing of high strength concrete. Magazine of Concrete Research,48 (176),189-197. doi.org/10.1680/macr.1996.48.176.189.
• [6] Kot P., Shaw A., Riley M., Ali AS., Cotgrave A., (2017) The feasibility of using electromagnetic waves in determining membrane failure through concrete. International Journal of Civil Engineering 15, 355-362. doi.org/10. 1007/s40999-016-0074-6.
• [7] Meininger RC., Wagner FT., Hall KW., (1977) Concrete core strength-The effect of length to diameter ratio. Journal of Testing and Evaluation 5 (3), 147-153. doi.org/10.1520/JTE11631J.
• [8] Bartlett FM., MacGregor JG., (1994) Cores from high-performance concrete beams. ACI Materials Journal 91, 567-576.
• [9] Durmuş A., Öztürk HT., Durmuş A., (2013) A reliable approach for determining concrete strength in structures by using cores. Computers and Concrete 11 (5), 463-473. doi.org/10.12989/cac.2013.11.5.463.
• [10] Kabay N., Aköz F., (2020) Investigation of factors affecting core compressive strength and non-destructive testing of concrete. Sigma Journal of Engineering and Natural Sciences 38 (1), 171-182.
• [11] Ergün A., Kürklü G., (2012) Assessing the relationship between the compressive strength of concrete cores and molded specimens. Gazi University Journal of Science 25 (3), 737-750.
• [12] Khoury S., Aliabdo AAH., Ghazy A. (2014) Reliability of core test – Critical assessment and proposed new approach. Alexandria Engineering Journal 53, 169-184. doi.org/10.1016/j.aej.2013.12.005.
• [13] Bungery JH., (1979) Determining concrete strength by using small-diameter cores. Magazine of Concrete Research 31 (107), 91–98. doi.org/10.1680/macr.1979.31.107.91.
• [14] Swamy RN., Al-Hamed AH., (1984) Evaluation of small diameter core tests to determine in situ strength of concrete. American Concrete Institute 82, 411–440.
• [15] Tuncan M., Ariöz Ö., Ramyar K., Karasu B., (2008) Assessing concrete strength by means of small diameter cores. Construction and Building Materials 22; 981-988. doi.org/10.1016/j.conbuildmat.2006.11.020.
• [16] BS EN 12350-2, (2019) Testing fresh concrete. Slump test. British Standards Institution, London.
• [17] BS EN 12350-6, (2019) Testing fresh concrete. Density. British Standards Institution, London.
• [18] BS EN 12390-3, (2019) Testing hardened concrete. Compressive strength of test specimens. British Standards Institution, London.
• [19] Mehta PK., Monteiro PJM., (2014) Concrete: Microstructure Properties, and Materials. 4th Ed. The McGraw Hill Companies, Inc., New York, USA.
• [20] Neville AM., (1997) Properties of Concrete. John Wiley&Sons, New York, USA.
• [21] Neville AM., (2001) Core tests: easy to perform, not easy to interpret. Concrete International, 59-68.
• [22] Johnston CD., (1973) Anisotropy of Concrete and its Practical Implications, Highway Research Record. No. 423:11-16.
• [23] Bartlett FM., MacGregor JG., (1994) Effect of core diameter on concrete core strengths. ACI Materials Journal 91, 460-470.
• [24] Sanga CM., Dhir RK., (1976) Core-Cube Relationships of Plain Concrete. Advanced in Ready Mixed Concrete Technology. Pergamon Press, Oxford, 193-292.
• [25] Carroll AC., Grubbs, AR., Schindler AK., Barnes RW., (2016) Effect of core geometry and size on concrete compressive strength, Highway Research Center, Research Report No.1 for Aldot Project 930-828.
• [26] Peng SS., Wang EH., Wang, HY. Chou YT., (2012) Quality assessment of high-performance concrete using digitized image elements. Computers and Concrete 10 (4), 409-417. doi.org/10.12989/cac.2012.10.4.409.
• [27] Hinton P.R., McMurray I., Brownlow C. (2014) SPSS Explained. Taylor and Francis, New York, 157-167.
• [28] Walpole R.E., Myers R.H., (1989) Probability and Statistics for Engineers and Scientits. Collier Macmillan Publishers, New York, 463-527.
• [29] Abubakar A.U., Akçaoğlu T., Marar K., (2018) P-value Significance Level Test for High-Performance Steel Fiber Concrete (HPSFC). Computers and Concrete 21 (5), 485-493. doi.org/10.12989/cac.2018.21.5.485.
• [30] Mendenhall W., Sincich T., (1988) Statistics for the Engineering and Computer Sciences. 2nd Ed. Dellen Publishing Company, San Francisco, California, USA.