Prediction of Corner Columns’ Load Capacity Using Composite Material Analogy

A. Ali, Z. Soomro, S. Iqbal, N. Bhatti, A. F. Abro


There are numerous reasons for which concrete has become the most widely used construction material in buildings, one of them being its availability in different types, such as fiber-reinforced, lightweight, high strength, conventional and self-compacting concrete. This advantage is specially realized in high-rise building construction, where common construction practice is to use concretes of different types or strength classes in slabs and columns. Columns in such structures are generally made from concrete which is higher in compressive strength than the one used in floors or slabs. This raises issue of selection of concrete strength that should be used for estimating column capacity. Current paper tries to address this issue by testing nine (09) sandwich column specimens under axial loading. The floor concrete portion of the sandwich column was made of normal strength concrete, whereas column portions from comparatively higher strength concrete. Test results show that aspect ratio (h/b) influences the effective concrete strength of such columns. A previously adopted methodology of composite material analogy with some modifications has been found to predict well the capacity of columns where variation in floor and concrete strength is significant.


composite material analogy; sandwich columns; corner columns; axial loading

Full Text:



ACI Committee 363, “Report on High-Strength Concrete (ACI 363R-10)”, in: ACI Manual of Concrete Practice, American Concrete Institute, 2013

ACI 318-14, Building Code Requirements for Structural Concrete and Commentary, American Concrete Institute, 2014

A. C. Bianchini, R. E. Woods, C. E. Kesler, “Effect of Floor Concrete Strength on Column Strength,” ACI Journal, Vol. 31, No. 11, pp. 1149–1169, 1960

J. K. Wight, Reinforced concrete : mechanics and design,Pearson, 2016

M. K. Kayani, “Load Transfer from High-Strength Concrete Columns through Lower Strength Concrete Slabs”, University of Illinois, 1992

J. H. Lee, Y. S. Yoon, W. D. Cook, D. Mitchell, “Benefits of using puddled HSC with fibers in slabs to transmit HSC column loads”, Journal of Structural Engineering, Vol. 133, No. 12, pp. 1843–1847, 2007

S. C. Lee, P. Mendis, “Behavior of high-strength concrete corner columns intersected by weaker slabs with different thicknesses”, ACI Structural Journal, Vol. 101, No. 1, pp. 11–18, 2004

A. A. Shah, Y. Ribakov, “Estimation of RC slab-column joints effective strength using neural networks”, Latin American Journal of Solids and Structures, Vol. 8, No. 4, pp. 393–411, 2011

I. Shahid, S. H. Farooq, N. A. Qureshi, K. R. Kayani, H. Mumtaz, “Effective Concrete Strength within Slab- Column Joint”, International Journal of Engineering and Technology Vol. 7, No. 3, pp. 965–972, 2015

J.-H. Lee, Y.-S. Yoon, “Prediction of effective compressive strength of corner columns comprising weaker slab–column joint”, Magazine of Concrete Research, Vol. 64, No. 12, pp. 1113–1121, 2012

C.-C. Shu, N. M. Hawkins, “Behavior of Columns Continuous through Concrete Floors”, ACI Structural Journal,Vol. 89, No. 4, pp. 405–414, 1993

A. A. Shah, J. Dietz, N. V Tue, G. Koenig, “Experimental investigation of column-slab joints”, ACI Structural Journal, Vol. 102, No. 1, pp. 103–113, 2005

R. F. Gibson, Principles of composite material mechanics, McGraw-Hill, 1994

P. J. McHarg, W. D. Cook, D. Mitchell, Y. S. Yoon, “Improved transmission of high-strength concrete column loads through normal strength concrete slabs”, Structural Journal,Vol. 97, No. 1, pp. 157–165, 2000

eISSN: 1792-8036     pISSN: 2241-4487