Effect of pigments on bond strength between coloured concrete and steel reinforcement


  • Joseph J. Assaad University of Balamand, Department of Civil and Environmental Engineering, Balamand, PO Box 100, Al Kourah, Lebanon
  • Matthew Mata University of Balamand, Department of Civil and Environmental Engineering, Balamand, PO Box 100, Al Kourah, Lebanon
  • Jad Saade University of Balamand, Department of Civil and Environmental Engineering, Balamand, PO Box 100, Al Kourah, Lebanon




coloured concrete, iron oxide pigment, carbon black, titanium dioxide, durability, bond strength


The effect of pigments on mechanical properties of coloured concrete intended for structural applications, including the bond stress-slip behaviour to embedded steel bars, is not well understood. Series of concrete mixtures containing different types and  oncentrations of iron oxide (red and grey colour), carbon black, and titanium dioxide (TiO2) pigments are investigated in this study. Regardless of the colour, mixtures incorporating increased pigment additions exhibited higher compressive and splitting tensile strengths. This was attributed to the micro-filler effect that enhances the packing density of the cementitious matrix and leads to a denser microstructure. Also, the bond to steel bars increased with the pigment additions, revealing their beneficial role for improving the development of bond stresses in reinforced concrete members. The highest increase in bond strength was recorded for mixtures containing TiO2, which was ascribed to formation of nucleus sites that promote hydration reactions and strengthen the interfacial concrete-steel transition zone. The experimental data were compared to design bond strengths proposed by ACI 318-19, European Code EC2, and CEB-FIP Model Code.


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P. Bartos. Fresh concrete properties and test. Elsevier, Amsterdam, 1992.

L. Popelová. The symbolic-aesthetic dimension of industrial architecture as a method of classification and evaluation: the example of bridge structures in the Czech republic. Acta Polytechnica 47(1):23–31, 2007. https://doi.org/10.14311/912.

ASTM C979. Standard specification for pigments for integrally colored concrete. Annual book of ASTM standards. Farmington Hills, USA, 4(2), 2007.

V. Hospodarova, J. Junak, N. Stevulova. Color pigments in concrete and their properties. Pollack Periodica 10(3):143–151, 2015. https://doi.org/10.1556/606.2015.10.3.15.

S. R. Naganna, H. A. Ibrahim, S. P. Yap, et al. Insights into the multifaceted applications of architectural concrete: A state-of-the-art review. Arabian Journal for Science and Engineering 46:4213–4223, 2021. https://doi.org/10.1007/s13369-020-05033-0.

Y.-M. Gao, H.-S. Shim, R. H. Hurt, et al. Effects of carbon on air entrainment in fly ash concrete: The role of soot and carbon black. Energy Fuels 11(2):457–462, 1997. https://doi.org/10.1021/ef960113x.

K. Loh, C. C. Gaylarde, M. A. Shirakawa. Photocatalytic activity of ZnO and TiO2 ‘nanoparticles’ for use in cement mixes. Construction and Building Materials 167:853–859, 2018. https://doi.org/10.1016/j.conbuildmat.2018.02.103.

S. S. Lucas, V. M. Ferreira, J. L. Barroso de Aguiar. Incorporation of titanium dioxide nanoparticles in mortars – Influence of microstructure in the hardened state properties and photocatalytic activity. Cement and Concrete Research 43:112–120, 2013. https://doi.org/10.1016/j.cemconres.2012.09.007.

H.-S. Jang, H.-S. Kang, S.-Y. So. Color expression characteristics and physical properties of colored mortar using ground granulated blast furnace slag and White Portland cement. KSCE Journal of Civil Engineering 18(4):1125–1132, 2014. https://doi.org/10.1007/s12205-014-0452-z.

R. Alves, P. Faria, A. Brás. Brita Lavada – An eco-efficient decorative mortar from Madeira Island. Journal of Building Engineering 24:100756, 2019. https://doi.org/10.1016/j.jobe.2019.100756.

J. J. Assaad, D. Nasr, S. Chwaifaty, T. Tawk. Parametric study on polymer-modified pigmented cementitious overlays for colored applications. Journal of Building Engineering 27:101009, 2020. https://doi.org/10.1016/j.jobe.2019.101009.

J. J. Assaad. Disposing waste latex paints in cementbased materials – effect on flow and rheological properties. Journal of Building Engineering 6:75–85, 2016. https://doi.org/10.1016/j.jobe.2016.02.009.

H.-S. Lee, J.-Y. Lee, M.-Y. Yu. Influence of inorganic pigments on the fluidity of cement mortars. Cement and Concrete Research 35(4):703–710, 2005. https://doi.org/10.1016/j.cemconres.2004.06.010.

A. Woods, J. Y. Lee, L. J. Struble. Effect of material parameters on color of cementitious pastes. Journal of ASTM International 4(8):1–18, 2007. https://doi.org/10.1520/JAI100783.

T. Meng, Y. Yu, X. Qian, et al. Effect of nano-TiO2 on the mechanical properties of cement mortar. Construction and Building Materials 29:241–245, 2012. https://doi.org/10.1016/j.conbuildmat.2011.10.047.

A. Mohammed, N. T. K. Al-Saadi, J. Sanjayan. Inclusion of graphene oxide in cementitious composites: state-of-the-art review. Australian Journal of Civil Engineering 16(2):81–95, 2018. https://doi.org/10.1080/14488353.2018.1450699.

A. López, J. M. Tobes, G. Giaccio, R. Zerbino. Advantages of mortar-based design for coloured self-compacting concrete. Cement and Concrete Composites 31(10):754–761, 2009. https://doi.org/10.1016/j.cemconcomp.2009.07.005.

L. Hatami, M. Jamshidi. Application of SBRincluded pre-milled colored paste as a new approach for coloring self-consolidating mortars (SCMs). Cement and Concrete Composites 65:110–117, 2016. https://doi.org/10.1016/j.cemconcomp.2015.10.015.

P. Weber, E. Imhof, B. Olhaut. Coloring pigments in concrete: Remedies for fluctuations in raw materials and concrete recipes. Tech. Report, Harold Scholz & Co GmbH, 2009.

J. J. Assaad, M. Vachon. Valorizing the use of recycled fine aggregates in masonry cement production. Construction and Building Materials 310:125263, 2021. https://doi.org/10.1016/j.conbuildmat.2021.125263.

M. J. Positieri, P. Helene. Physicomechanical properties and durability of structural colored concrete. In ACI Symposium Publication, vol. 253, pp. 183–200. 2013. https://doi.org/10.14359/20175.

S. A. Yıldızel, G. Kaplan, A. U. Öztürk. Cost optimization of mortars containing different pigments and their freeze-thaw resistance properties. Advances in Materials Science and Engineering 2016:5346213, 2016. https://doi.org/10.1155/2016/5346213.

S. Masadeh. The effect of added carbon black to concrete mix on corrosion of steel in concrete. Journal of Minerals and Materials Characterization and Engineering 3(4):271–276, 2015. https://doi.org/10.4236/jmmce.2015.34029.

D. Inoue, H. Sakurai, M. Wake, T. Ikeshima. Carbon black for coloring cement and method for coloring molded cement article. European patent, WO 01/046322, 10 p, 1999.

J. Topič, Z. Prošek, K. Indrová, et al. Effect of pva modification on properties of cement composites. Acta Polytechnica 55(1):64–75, 2015. https://doi.org/10.14311/AP.2015.55.0064.

A. Nazari, S. Riahi. The effect of TiO2 nanoparticles on water permeability and thermal and mechanical properties of high strength self-compacting concrete. Materials Science and Engineering: A 528(2):756–763, 2010. https://doi.org/10.1016/j.msea.2010.09.074.

J. Chen, S.-C. Kou, C.-S. Poon. Hydration and properties of nano-TiO2 blended cement composites. Cement and Concrete Composites 34(5):642–649, 2012. https://doi.org/10.1016/j.cemconcomp.2012.02.009.

R. Zhang, X. Cheng, P. Hou, Z. Ye. Influences of nano-TiO2 on the properties of cement-based materials: Hydration and drying shrinkage. Construction and Building Materials 81:35–41, 2015. https://doi.org/10.1016/j.conbuildmat.2015.02.003.

A. Folli, C. Pade, T. B. Hansen, et al. TiO2 photocatalysis in cementitious systems: Insights into self-cleaning and depollution chemistry. Cement and Concrete Research 42(3):539–548, 2012. https://doi.org/10.1016/j.cemconres.2011.12.001.

M. Konrad, R. Chudoba. The influence of disorder in multifilament yarns on the bond performance in textile reinforced concrete. Acta Polytechnica 44(5-6):186–193, 2004. https://doi.org/10.14311/654.

J. J. Assaad, P. Matar, A. Gergess. Effect of quality of recycled aggregates on bond strength between concrete and embedded steel reinforcement. Journal of Sustainable Cement-Based Materials 9(2):94–111, 2020. https://doi.org/10.1080/21650373.2019.1692315.

ACI 408R-03. Bond and development of straight reinforcing bars in tension, 2003.

ACI 318-19. Building code requirements for reinforced concrete, 2019.

EN 1992-1-1. Eurocode 2: design of concrete structures – part 1-1: general rules and rules for buildings, 2004.

FIB (International Federation for Structural Concrete). Model Code for Concrete Structures. Ernst & Sohn, Berlin, 2013.

ASTM C642-13. Standard test method for density, absorption, and voids in hardened concrete. Annual book of ASTM standards. West Conshohocken, PA, 2013, USA.

ASTM C39/C39 M-05. Standard test method for compressive strength of cylindrical concrete specimens. Annual book of ASTM standards. West Conshohocken, PA, 2005, USA.

ASTM C496/C496 M-04. Standard test method for splitting tensile strength of cylindrical concrete specimens. Annual book of ASTM standards. West Conshohocken, PA, 2004, USA.

ASTM C 597-16. Standard test method for pulse velocity through concrete. Annual book of ASTM standards. West Conshohocken, PA, 2016, USA.

G. Teichmann. The use of colorimetric methods in the concrete industry. Betonwerk Fertigteil-Technik 11:58–73, 1990.

RILEM/CEB/FIB. Bond test for reinforcing steel: 2, pullout test. Materials and Structures 3:175–178, 1970.

J. Němeček, P. Padevět, Z. Bittnar. Effect of stirrups on behavior of normal and high strength concrete columns. Acta Polytechnica 44(5-6):158–164, 2004. https://doi.org/10.14311/648.

A. AlArab, B. Hamad, J. J. Assaad. Strength and durability of concrete containing ceramic waste powder and blast furnace slag. Journal of Materials in Civil Engineering 34(1):04021392, 2022. https://doi.org/10.1061/(ASCE)MT.1943-5533.0004031.

J. Machovec, P. Reiterman. Influence of aggressive environment on the tensile properties of textile reinforced concrete. Acta Polytechnica 58(4):245–252, 2018. https://doi.org/10.14311/AP.2018.58.0245.