Experimental evaluation of the effect of carbon fibres on acoustic emission parameters obtained during compressive strength tests of alkaliactivated slag composites

Abstract

The generation of acoustic emission signals is directly associated with formation of cracks in materials during loading. This paper deals with possibilities of acoustic emission method application as the tool for the identification of structural damage in alkali-activated composite materials during compressive strength test. In experimental part, the three piezoelectric sensors were occupied for the continuous record of emission signals of stressed material feedback on applied mechanical load in real time. Detection of specific acoustic emission signals in the course of deformation of the test samples indicates that irreversible structural changes occur in the composite. Four different mixtures of alkali-activated slag mortars were prepared, the first one was reference without the addition of carbon fibres. The others contain the carbon fibres in amount 0.5, 1.0 and 2.0 % from the weight of the slag.