The Effect of Homogenization Procedure on Mechanical Properties of High-Performance Concrete with Partial Replacement of Cement by Supplementary Cementitious Materials

Abstract:

High-performance concrete is a very specific type of concrete. Its production is sensitive to both the quality of compounds used and the order of addition of particular compounds during the homogenization process. The mechanical properties were observed for four dosing procedures of each of the three tested concrete mixtures. The four dosing procedures were identical for the three mixes. The three mixes varied only in the type of supplementary cementitious material used and in water content. The water content difference was caused by variable k-value of particular additives. The water-to-binder ratio was kept constant for all the concretes. The additives used were metakaolin, fly ash and microsilica. The comparison of particular dosing procedures was carried out on the values of basic mechanical properties of concrete. The paper compares compressive strength and depth of penetration of water under pressure. Besides the comparsion of macro-mechanical properties, the effect of microsilica and fly ash additives on micro-mechanical properties was observed with the use of scanning electron microscopy (SEM) and nanoindentation data analysis. Nanoindentation was used to determine the thickness and strength of interfacial transition zone (ITZ) for different sequence of addition of cement, additive and aggregate. The thickness obtained by nanoindentation was further investigated by SEM EDS line scanning.

• Periodical: Solid State Phenomena (Volume 292)
• Pages: 102-107
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.292.102
• Online since: June 2019
• Authors: Josef Fladr, Petr Bily*, Karel Šeps, Roman Chylík, Vladimír Hrbek
• Keywords: Fly Ash, High-Performance Concrete, Interfacial Transition Zone, Metakaolin, Microsilica

References

[1] ČSN EN 12390-3 Testing hardened concrete – Part 3: Compressive strength of test specimens, ČNI, Prague (2012).

[2] M. Ťažký, R. Hela, T. Ťažký, Vývoj konstrukčních betonů s elektrárenskými popílky, Beton TKS 2 (2015).

[3] ČSN EN 12390-8 Testing hardened concrete – Part 8: Depth of penetration of water under pressure, ČNI, Prague (2009).

[4] ČSN EN 12390-5 Testing hardened concrete – Part 5: Flexural strength of test specimens, ČNI, Prague (2009).

[5] A. Podstawka, M. Foglar, V. Křístek, Statistical evaluation of three and four-point bending tests of FRC, Engineering mechanics 2015, Institute of Theoret. and Applied Mechanics, Prague, (2015).

[6] R. Chylík, K. Šeps, Influence of cement replacement by admixture on mechanical properties of concrete, Proceedings of the 12th fib International PhD Symposium in Civil Engineering, pp.1267-1274, Czech Technical University, Prague, (2018).

[7] W. Oliver, G. M. Pharrr, An Improved Technique for Determining Hardness and Elastic Modulus Using Load and Displacement Sensing Indentation Measurements, Journal of Material Research 7 (1992), 1564 – 1583.

DOI: 10.1557/jmr.1992.1564

[8] G. M. Pharrr, A. Bolshakov, Understanding Nanoindentation Unloading Curves, Journal of Material Research 17 (2002), 2660 – 2671.

DOI: 10.1557/jmr.2002.0386

[9] W. Oliver, G. M. Pharrr, Measuring of Hardness and Elastic Modulus by Instrumented Indentation: Advances in Understanding and Refinement of Methodology, Journal of Material Research 19 (2004), 3 – 20.

DOI: 10.1557/jmr.2004.19.1.3

[10] G. Constantinides, K.S. Ravi Chandran, F.-J. Ulm, K.J. Van Vliet, Grid Indentation Analysis of Composite Microstructure and Mechanics: Principles and Validation, Journal of Material Science and Engineering 430 (2006), 189 – 202.

DOI: 10.1016/j.msea.2006.05.125

[11] L. Sorelli, G. Constantinides, F.-J. Ulm, F. Toutlemonde, The nano-mechanical signature of Ultra High Performance Concrete by statistical nanoindentation techniques, Cement and Concrete Research 38 (2008), 1447 – 1456.

DOI: 10.1016/j.cemconres.2008.09.002