Strength of AAAS Composites with Ceramic Precursor over Time

Abstract:

The paper deals with the approximation of the time evolution of the strengths of selected alkali-activated aluminosilicate (AAAS) composites based on ceramic precursors. Composites made of brick dust as a precursor and an alkaline activator with a silicate modulus of M_s = 0.8, 1.0, 1.2, 1.4, and 1.6 were investigated. The filler consisted of standard quartz sand in one case, and crushed brick in the other. The test specimens had nominal dimensions of 40 × 40 × 160 mm and were tested in three-point bending after 7, 28, 90, and 300 days of maturation. From each composite, 3 specimens were tested and the compressive strength was determined from the 6 specimen parts that remained after the bending tests. The obtained flexural and compressive strength values for the abovementioned 4 composite ages were approximated by the exponential function , where the coefficient a represents a horizontal asymptote to the approximation curve, i.e. the theoretical strength of the composite at time t = ∞; the exponential term of the approximation with the coefficients b and c expresses the degree of the time-dependent change of the respective compressive strength in the interval t = (0, ∞). The approximation was performed with the least squares method using genetic algorithms implemented in the Java GA package with open source code.

• Periodical: Solid State Phenomena (Volume 322)
• Pages: 60-65
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.322.60
• Online since: August 2021
• Authors: Petr Frantík, Pavla Rovnaníková, Zbyněk Keršner*
• Keywords: Alkali-Activated Aluminosilicate, Ceramic Precursor, Compressive Strength, Flexure Strength, Time Approximation

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