Investigation of factors affecting core compressive strength and non-destructive testing of concrete

Year 2020, Volume: 38 Issue: 1, 171 - 182, 27.03.2020

Nihat Kabay Fevziye Aköz

Abstract

This paper investigates several factors such as the effect of drilling, moisture content and presence of reinforcement on the compressive strength of core samples and the effect of reinforcement and concrete age on the rebound number and ultrasonic pulse velocity of concrete. Test results show that the effect of moisture on core strength was lower than the other factors. Due to the drilling effect, the core compressive strength was reduced by 11%. The presence and the number of reinforcement in core samples significantly affected the compressive strength. On average, the reduction in strength of cores that contain single and two bars was found as 12% and 16% respectively. The rebound number and ultrasonic pulse velocity values increased with the age of concrete. The reinforcement did not have a significant effect on the non destructive test results. However, direct and indirect ultrasonic pulse velocity results differed significantly and on average this ratio was found to be 1.16 and 1.17 for plain and reinforced concrete members, respectively.

Keywords

Core correction factors, compressive strength, non-destructive testing.

References

• [1] EN 13791, (2007) Assessment of in-situ compressive strength in structures and precast concrete components. European Standard, Brussels.
• [2] ASTM C42, (2018) Standard test method for obtaining and testing drilled cores and sawed beams of concrete. ASTM International, West Conshohocken, PA, USA.
• [3] EN 12504-1, (2009) Testing concrete in structures Part 1: Cored specimens-Taking, examining and testing in compression. European Standard, Brussels.
• [4] 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: 10.1520/JTE11631J.
• [5] Bartlett FM., MacGregor JG., (1994) Effect of core length-to-diameter ratio on concrete core strengths. Materials Journal 91 (4), 339-348.
• [6] Bartlett FM., MacGregor JG., (1994) Effect of core diameter on concrete core strengths. Materials Journal 91 (5), 460-470.
• [7] Bartlett FM., (1997) Precision of in-place concrete strengths predicted using core strength correction factors obtained by weighed regression analysis. Structural Safety 19, 397-410.
• [8] Yip WK., Tam CT., (1988) Concrete strength evaluation through of small diameter cores. Magazine of Concrete Research 40, 99-105. doi: 10.1680/macr.1988.40.143.99.
• [9] Masi A., Nigro D., Vona M., (2012) Effect of core drilling and subsequent restoration on RC column strength. 15th World conference on earthquake engineering, 24-28 September 2012, Portugal, Lisbon.
• [10] Pucinotti R., (2015) Reinforced concrete structure: Non destructive in situ strength assessment of concrete. Construction and Building Materials 75, 331-341. doi:10.1016/j.conbuildmat.2014.11.023.
• [11] Amini K., Jalalpour M., Delatte N., (2016) Advancing concrete strength prediction using non-destructive testing: Development and verification of a generalizable model. Construction and Building Materials 102:762-768. doi:10.1016/j.conbuildmat.2015.10.131.
• [12] Alwash M., Breysse D., Sbartaï ZM., (2015) Non-destructive strength evaluation of concrete: Analysis of some key factors using synthetic simulations. Construction and Building Materials 99, 235-245. doi:10.1016/j.conbuildmat.2015.09.023.
• [13] Bogas JA., Gomes MG., Gomes A., (2013) Compressive strength evaluation of structural lightweight concrete by non-destructive ultrasonic pulse velocity method. Ultrasonics 53, 962-972. doi:10.1016/j.ultras.2012.12.012.
• [14] Breysse D., (2012) Nondestructive evaluation of concrete strength: An historical review and a new perspective by combining NDT methods. Construction and Building Materials 33, 139-163. doi:10.1016/j.conbuildmat.2011.12.103.
• [15] Szilágyi K., Borosnyói A., Zsigovics I., (2011) Rebound surface hardness of concrete: Introduction of an empirical constitutive model. Construction and Building Materials 25, 2480-2487. doi:10.1016/j.conbuildmat.2010.11.070.
• [16] Malhotra VM., Carino NJ., (2004) Handbook on Nondestructive Testing of Concrete. CRC Press, second ed., London, UK.
• [17] Malhotra VM (2004) Surface hardness methods. Handbook on Nondestructive Testing of Concrete, second ed. CRC Press, London, UK, pp 13-27.
• [18] Naik TR., Malhotra VM., Popovics JS., (2004) The Ultrasonic Pulse Velocity Method. Handbook on Nondestructive Testing of Concrete, second ed. CRC Press, London, UK, pp. 181-199.
• [19] Khoury S., Aliabdo AAH., Ghazy A., (2014) Reliability of core test - Critical assessment and proposed new approach. Alexandria Engineering Journal 53, 169-184. doi:10.1016/j.aej.2013.12.005.
• [20] Masi A., Digrisolo A., Santarsiero G., (2013) Experimental evaluation of drilling damage on the strength of cores extracted from RC buildings. International Journal of Civil, Environmental, Structural, Construction and Architectural Engineering 7, 525-531.
• [21] Durmuş A., Öztürk HT., Durmuş A., (2013) A reliable approach for determining concrete strength in structures by using cores. Computers and Concrete 11, 463-473. doi: 10.12989/cac.2013.11.5.463.
• [22] ASTM C597, (2009) Standard test method for pulse velocity through concrete. ASTM International, West Conshohocken, PA, USA