An investigation of self-sensing and mechanical properties of smart engineered cementitious composites reinforced with functional materials

In this study, hybrid functional fillers were used to create an electrical network that is used to develop self-damage sensing ability within conventional cementitious mixtures. This electrical network was used to examine the self-sensing properties of cementitious composites under different loading scenarios such as compression, splitting tensile, and cyclic loading for three ages, those are 7, 14, and 28. With the help of a single type of functional filler or fiber, the self-sensing capabilities of the majority of previous works are demonstrated. This study incorporates two types of functional fillers for sustainability and low cost: micro-scale carbon fibers (CF) and waste iron (Ir) powder in the form of microparticles. The purpose of the current work is to fill up the subject's gap using two different types of functional fillers as a hybrid form. Three hybrid proportions of a micro-scale CF (vol% of mixture) and waste iron powder (Ir) (wt% of cementitious materials) are utilized. These are (0.33, 15), (0.67, 10), and (1.00, 5), respectively. Unlike carbon-based materials, polyvinyl alcohol is used as a mechanical reinforcing fiber 2% by volume of the cementitious mixture. Additionally, a control combination without any fillers has been created. The electrical resistivity of the fabricated samples was monitored during various loading applications for every second to confirm their self-sensing capabilities. Regarding the fractional change in electrical resistivity, the self-sensing behavior was superior for mixes containing high dosages either of waste iron powder or CF in the same hybrid matrix. Quite the contrary to that, the piezoresistivity was modest in the middle hybrid ratio.