The effect of different volumes of continuous elements on the mechanical properties of concrete panels

Abstract

The scope of this dissertation was to analyse the effect that the volume of continuous elements has on the mechanical properties of a concrete mix used for concrete panels. The question that it sought to answer was whether concrete with an increase in volume of continuous elements loses some its mechanical properties and whether there are any differences between concrete panels containing monofilament fishing line and those containing optical fibres as continuous elements. This was carried out by fabricating panels with different volumes of continuous elements, namely monofilament fishing line (MFFL) that were investigated at 0%, 1 %, 1.5% and 2% respectively and optical fibres which were investigated at 0% and 2%. They were tested under flexure, impact loading and pull-through testing. This allowed for a thorough analysis of the strength of the concrete mixture by observing any effects that the volume of the continuous elements had on the mechanical properties of the concrete. From the results, it was found that the extent to which the continuous elements affect the concrete's mechanical property is not easily evident. However, it was ascertained that the inclusion of polypropylene fibres (as opposed to their exclusion) in the mix significantly increased the concrete's strength. Furthermore, it was confirmed that continuous elements can contribute to the propagation of cracks and also slightly decrease the stability of the concrete, even though the failure of the concrete could not be attributed to them. Moreover, no discernable difference in behaviour was noticed when using either monofilament fishing-line or optical fibres as continuous elements.