Evaluation of lightweight Concrete Core Test Including Steel Bars

Document Type : Original Article

Authors

1 Department of Civil Engineering, Wasit University, Wasit, Iraq

2 Department of Materials Engineering, Mustansiriyah University, Baghdad, Iraq

Abstract

In many steel reinforced concrete members, steel bars are not avoidable during concrete core drilling and the presence of these steel bars have a direct impact on the results of this test. This study aims to examine the effect of steel bars presence on the test results of recycled aggregate lightweight concrete (LWC) cores. For the purpose, one lightweight concrete mix was made with a total number of 48 concrete cores were taken from a slab having the dimensions of 1 m width, 1.5 m length and 0.15m thickness. Each core has the dimensions of 90 mm in diameter and 150 mm in height. Three different sizes of steel bars (12, 16 and 20 mm) were used in six different locations (25, 45 and 65 mm) from the base of the core and (15 and 30 mm) from the center line of the core. A recycled crashed clay brick (CCB) was used as an alternative to the coarse aggregate. Compare to the density of the normal concrete (2400 kg/m3), the LWC was able to achieve nearly 20% reduction of the total weight by fully replacing of normal aggregate with CCB. It has been found that the presence of the steel increases the compressive strength of the LWC cores. This effect is more noticeable when the location of the steel bar is near to the mid-height or the centerline of the concrete core. Also, the influence of the steel bar diameter has increased by increasing the size of the steel bar.

Keywords

Main Subjects


  1. Weigler, H. and Karl, S., "Structural lightweight aggregate concrete with reduced density—lightweight aggregate foamed concrete", International Journal of Cement Composites and Lightweight Concrete, Vol. 2, No. 2, (1980), 101-104. doi: 10.1016/0262-5075(80)90029-9.
  2. Amran, Y.M., Farzadnia, N. and Ali, A.A., "Properties and applications of foamed concrete; a review", Construction and Building Materials, Vol. 101, (2015), 990-1005. doi: 10.1016/j.conbuildmat.2015.10.1112.
  3. Lu, Y., Hu, X., Yang, X. and Xiao, Y., "Comprehensive tests and quasi-brittle fracture modeling of light-weight foam concrete with expanded clay aggregates", Cement and Concrete Composites, Vol. 115, (2021), 103822. doi: 10.1016/j.cemconcomp.2020.103822.
  4. Neville, A., "Properties of concrete, john wiley & sons inc., new york, 1996", Vol., No. doi.
  5. Akers, D.J., Gruber, R.D., Ramme, B.W., Boyle, M.J., Grygar, J.G., Rowe, S.K., Bremner, T.W., Kluckowski, E.S., Sheetz, S.R. and Burg, R.G., "Guide for structural lightweight-aggregate concrete", ACI 213R-03. American Concrete Institute (ACI), Michigan, (2003).
  6. Cui, H., Lo, T.Y., Memon, S.A. and Xu, W., "Effect of lightweight aggregates on the mechanical properties and brittleness of lightweight aggregate concrete", Construction and Building Materials, Vol. 35, (2012), 149-158.
  7. Del Rey Castillo, E., Almesfer, N., Saggi, O. and Ingham, J.M., "Light-weight concrete with artificial aggregate manufactured from plastic waste", Construction and Building Materials, Vol. 265, (2020), 120199. doi: 10.1016/j.conbuildmat.2020.120199.
  8. Vakhshouri, B. and Nejadi, S., "Mix design of light-weight self-compacting concrete", Case Studies in Construction Materials, Vol. 4, (2016), 1-14.
  9. Wei, H., Wu, T., Liu, X. and Zhang, R., "Investigation of stress-strain relationship for confined lightweight aggregate concrete", Construction and Building Materials, Vol. 256, (2020), 119432. doi: 10.1016/j.conbuildmat.2020.119432.
  10. Yang, Y., Ge, Z., Li, Y., Xiong, Y. and Yuan, Q., "Study on impact resistance of precast light-weight concrete sandwich panels", in Structures, Elsevier. Vol. 47, (2023), 966-975.
  11. Aarthi, K., Jeyshankaran, E. and Aranganathan, N., "Comparative study on longitudinal shear resistance of light weight concrete composite slabs with profiled sheets", Engineering Structures, Vol. 200, (2019), 109738. doi: 10.1016/j.engstruct.2019.109738.
  12. Martins, R., Carmo, R., Costa, H., Júlio, E., Cordeiro, T. and Almeida, V., "Interface role in composite rc beams with a light-weight concrete core and an ultra high-durability concrete skin", Engineering Structures, Vol. 228, (2021), 111524. doi: 10.1016/j.engstruct.2020.111524.
  13. Ghanbari, M., Kohnehpooshi, O. and Tohidi, M., "Experimental study of the combined use of fiber and nano silica particles on the properties of lightweight self compacting concrete", International Journal of Engineering, Transactions B: Applications, Vol. 33, No. 8, (2020), 1499-1511. doi: 10.5829/IJE.2020.33.08B.08.
  14. Kulkarni, P. and Muthadhi, A., "Improving thermal and mechanical property of lightweight concrete using n-butyl stearate/expanded clay aggregate with alccofine1203", International Journal of Engineering, Transactions A: Basics, Vol. 33, No. 10, (2020), 1842-1851. doi: 10.5829/ije.2020.33.10a.03.
  15. Mohammed, T. and Kadhim, H., "Static and dynamic behavior of high-strength lightweight reinforced concrete one-way ribbed slabs", International Journal of Engineering, Transactions A: Basics, Vol. 35, No. 4, (2022), 732-739. doi: 10.5829/ije.2022.35.04a.13.
  16. International, A., Astm c42/c42m—16 standard test method for obtaining and testing drilled cores and sawed beams of concrete. 2016, ASTM International West Conshohocken, PA, USA.
  17. BSI, B., "Testing concrete: Part 120-method for determination of compressive strength of concrete cores", British Standards Institution, London, (1983).
  18. 11, C.S.T.R., Concrete core testing for strength, in Technical Report No.11, The Concrete Society, London. 1976.
  19. Tuncan, M., Arioz, O., Ramyar, K. and Karasu, B., "Assessing concrete strength by means of small diameter cores", Construction and Building Materials, Vol. 22, No. 5, (2008), 981-988. doi: 10.1016/j.conbuildmat.2006.11.020.
  20. Momeni, K., Madandoust, R. and Ranjbar, M.M., "Evaluating the application of reinforcement correction factor for concrete core testing", Journal of Rehabilitation in Civil Engineering, Vol. 7, No. 3, (2019), 166-182. doi: 10.22075/JRCE.2018.14724.1269.
  21. Lessly, S.H., Senthil, R. and Krishnakumar, B., "A study on the effect of reinforcement on the strength of concrete core", Materials Today: Proceedings, Vol. 45, (2021), 6476-6481. doi: 10.1016/j.matpr.2020.11.367.
  22. Reddy, B. and Wanjari, S., "A partially destructive method for testing in-situ strength of concrete", in IOP Conference Series: Materials Science and Engineering, IOP Publishing. Vol. 431, (2018), 052012.
  23. Haavisto, J., Husso, A. and Laaksonen, A., "Compressive strength of core specimens drilled from concrete test cylinders", Structural Concrete, Vol. 22, (2021), E683-E695. doi: 10.1002/suco.202000428.
  24. Reddy, B.S.K. and Wanjari, S., "Core strength of concrete using newly developed in situ compressive testing machine", Magazine of Concrete Research, Vol. 70, No. 22, (2018), 1149-1156. doi: 10.1088/1757-899X/431/5/052012.
  25. No, I.S., "For aggregates of natural resources used for concrete and construction", Baghdad, Iraq, (1984).
  26. ASTM, American standard for testing materials. C143-03, standard test method for slump of hydraulic cement concrete in ASTM International. 2003.
  27. BSI., "Bs en 12390-3: 2019: Testing hardened concrete. Part 3: Compressive strength of test specimens, BSI British Standards Institution, (2022).