The aim of research reported in this paper is to quantify fracture parameters of selected mortars prepared with an alkali-activated binder and hemp fibres. The alkali-activated materials are environmental friendly building materials, which can be used as an alternative to…
The aim of research reported in this paper is to quantify fracture parameters of selected mortars prepared with an alkali-activated binder and hemp fibres. The alkali-activated materials are environmental friendly building materials, which can be used as an alternative to ordinary Portland cement-based composites. Just like cement-based composites, these materials can be classified as quasi-brittle materials with low energy absorption capacity under tensile load. To enhance the energy absorption capacity, different types of fibres are used in cement-based materials. In this experiment, the hemp fibres were chosen as environmental friendly alternative to the commonly used steel and synthetic materials. The main attention was focused on the evaluation of three-point bending fracture tests of prism specimens, with an initial central edge notch, made of alkali-activated fly ash mortar with different amount of hemp fibres. The load versus crack mouth opening displacement diagrams were recorded during the fracture tests and 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 effect of softening function type and their input parameters on resulting fracture parameters was investigated.