Crack Initiation of Alkali-activated Slag Based Composites with Graphite Filler

Crack Initiation of Alkali-activated Slag Based Composites with Graphite Filler

Paper in proceedings (conference paper)

The alkali-activated slag is an alternative building material to ordinary Portland cement based materials. This type of material is effective in reducing CO2 emissions and energy consumption. Addition of graphite powder increases its electric conductivity, hence, introducing new functionality to building materials such as self-sensing and self-heating properties. In this study, the effect of graphite filler on the crack initiation of alkali-activated slag composite is investigated. The graphite powder was added in the amount of 5, 10 and 15% with respect to the slag mass. Beam specimens with an initial stress concentrator were tested in three-point bending at the age of 28 days. The load versus crack mouth crack opening displacement (F–CMOD) diagrams were recorded during the fracture tests and subsequently evaluated using the Double-K fracture model. This model allows the quantification of two different levels of crack propagation: initiation, which corresponds to the beginning of stable crack growth, and the level of unstable crack propagation. The course of fracture tests was also monitored by acoustic emission (AE) method.

The alkali-activated slag is an alternative building material to ordinary Portland cement based materials. This type of material is effective in reducing CO2 emissions and energy consumption. Addition of graphite powder increases its electric conductivity, hence, introducing new functionality to building materials such as self-sensing and self-heating properties. In this study, the effect of graphite filler on the crack initiation of alkali-activated slag composite is investigated. The graphite powder was added in the amount of 5, 10 and 15% with respect to the slag mass. Beam specimens with an initial stress concentrator were tested in three-point bending at the age of 28 days. The load versus crack mouth crack opening displacement (F–CMOD) diagrams were recorded during the fracture tests and subsequently evaluated using the Double-K fracture model. This model allows the quantification of two different levels of crack propagation: initiation, which corresponds to the beginning of stable crack growth, and the level of unstable crack propagation. The course of fracture tests was also monitored by acoustic emission (AE) method.

Fracture test, crack initiation, double-K model, alkali-activation, slag, graphite, acoustic emission

Fracture test, crack initiation, double-K model, alkali-activation, slag, graphite, acoustic emission

ŠIMONOVÁ, H.; TOPOLÁŘ, L.; ROVNANÍK, P.; SCHMID, P.; KERŠNER, Z.

2019

22.01.2018

Trans Tech Publications

Switzerland

978-3-0357-1096-0

Key Engineering Materials: Non-Traditional Cement and Concrete

1013-9826

Key Engineering Materials (print)

761

Swiss Confederation

57

60

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