Characterization of ferrocement slab panels containing lightweight expanded clay aggregate using digital image correlation technique

Ferrocement slab panels (FSPs) are thin-walled elements with appropriate strength, hardness, durability and lightness. The flexural behavior of FSPs has been investigated in this study. Specifically, 12 FSPs containing three expanded rib lath layers (i.e. one, two and three) and four volume contents of lightweight expanded clay aggregate (leca) (40, 20, 10 and 0 vol%) were constructed and exposed to three-point flexural test. Digital image correlation (DIC) technique as a full-field approach was used for measuring displacements and strains of the FSPs and the results were compared with those obtained from the displacement sensors. The cracking behavior of the FSPs was also evaluated using the DIC technique. The microstructure of the mortar of FSPs was finally investigated using scanning electron microscopy (SEM) imaging along with energy dispersive spectroscopy (EDS) analysis. The DIC results show that as the mesh volume fraction increases, the flexural capacity (about 14-70%), ductility index (about 9-24%), energy absorption (about 16-107%) and number of cracks increase but the length and width of cracks decrease. The DIC results also indicate that incorporating 10% leca leads to the highest increase of energy absorption (about 48%), ductility index (about 26%) and crack width (about 106%) of the FSPs. The results of microstructural analysis show that incorporating super-plasticizer admixture can decrease the total porosity of mixtures (by about 29-79%).