An An Analysis of Crystalline Admixtures in Terms of Their Influence on the Resistance of Cementitious Composites to Aggressive Environments

Authors

  • Ámos Dufka
    Affiliation

    Department of Technology of Building Materials and Components , Faculty of Civil Engineering, Brno University of Technology, Veveří 95, 602 00 Brno, Czech Republic

  • Nikol Žižková
    Affiliation

    Department of Technology of Building Materials and Components , Faculty of Civil Engineering, Brno University of Technology, Veveří 95, 602 00 Brno, Czech Republic

  • Jiří Brožovský
    Affiliation

    Department of Structural Mechanics, Faculty of Civil Engineering, VSB - Technical University of Ostrava, Ludvika Podeste 1875/17, 708 33 Ostrava-Poruba, Czech Republic

https://doi.org/10.3311/PPci.14514

Abstract

This paper describes the influence of crystalline admixtures on the chemical resistance of cement composites exposed to aggressive environments. The effect of the crystalline admixtures was determined by a series of physical-mechanical and innovative physical-chemical methods. Specifically, this concerned the measurement of flexural strength, compressive strength, determination of the dynamic modulus of elasticity by the ultrasonic pulse velocity test, and an analysis of the internal structure by mercury intrusion porosimetry and x-ray computed tomography. Physical-chemical analyses were also performed; namely an x-ray diffraction analysis to determine the mineralogical composition and electron microscopy to examine the microstructure. The use of non-destructive testing methods (ultrasonic pulse velocity test and computed tomography) made it possible to compare the properties of the same specimens for 16 months. The specimens were stored in reference laboratory conditions, a sodium sulphate solution and an ammonium chloride solution. The physical-mechanical tests and physical-chemical analyses clearly showed the benefit that crystalline admixtures have for the resistance of cementitious composites attacked by chemically aggressive solutions without affecting the fresh-mixture rheology or decreasing the strength of the composites.

Keywords:

cementitious composites, crystalline admixtures, aggressive environment, resistance, modern diagnostic methods

Published Online

2020-11-23

How to Cite

Dufka, Ámos, Žižková, N., Brožovský, J. “An An Analysis of Crystalline Admixtures in Terms of Their Influence on the Resistance of Cementitious Composites to Aggressive Environments”, Periodica Polytechnica Civil Engineering, 65(1), pp. 344–352, 2021. https://doi.org/10.3311/PPci.14514

Issue

Section

Research Article