[PO-E2] Poster Session 2

[P2-41] Comparison of different alkali activated mortars with hemp fibres response during fracture test by acoustic emission method

Libor Topolar¹, ^○Hana Simonova¹, Barbara Kucharczykova¹, Zbynek Kersner¹, Jelena Dragas², Ivan Ignjatovic², Miroslav Komljenovic³, Violeta Nikolic³ (1.Brno University of Technology, Faculty of Civil Engineering, Czech Republic, 2.University of Belgrade, Faculty of Civil Engineering, Serbia, 3.University of Belgrade, Institute for Multidisciplinary Research, Serbia)

In last decades, natural fibres are increasingly used as reinforcements for the production of low-cost composites in civil engineering. The benefits of natural fibers include non-abrasive nature, high specific properties, and biodegradability. However, their disadvantages are the bad moisture absorption, poor wettability and large scattering in mechanical properties. The aim of this paper is contribute to the better understanding of mechanical behaviour and failure modes of alkali activated materials reinforced by hemp fibers. Two different mortars based on alkali activated fly ash and slag were investigated. The paper includes the results of acoustic emission measurement captured during the three-point bending fracture test of specimens made of mentioned composites. Acoustic emission method is proving useful for the capability of real-time monitoring of materials over the whole volume and with high sensitivity to any processes generating stress waves. The effect of different mix composition and amount of hemp fibers on the acoustic signal features such as the energy, counting and amplitude is including in this research. The obtained acoustic emission results together with mechanical fracture parameters can serve as input values of material models used for modelling of structure response.

This outcome has been achieved with the financial support of the Czech Science Foundation, project No. 18-12289Y and the results obtained within the project DS-2016-0060, which belongs to Multilateral Scientific and Technological Cooperation Project in Danube Region between Technische Universität Wien, Brno University of Technology and University of Belgrade, are presented in this paper.