Analysis of electrical and piezoresistive properties of mortar reinforced with carbon microfibers

Abstract Multifunctional mortars have been developed for applications in self-sensing systems, electromagnetic shielding, cathodic protection, and other areas. To achieve this, it is necessary to incorporate conductive materials, which often reduce mechanical properties, making their use challenging. Carbon microfiber can improve the durability of cementitious composites through its physical and mechanical properties. This research aims to find a reinforced mortar composition based on the limits of the NBR 11173 standard, balancing mechanical and electrical properties, such as conductivity and impedance, using carbon microfiber ~ 4 mm length. It was produced with a mix proportion of 1:2:0.45 (cement:sand:water/cement ratio) and the addition of 0.2 to 1.2% (by cement mass) of carbon microfiber. Compared to the reference mix, the results showed an increase of 30.17% in flexural strength and 11 times in electrical conductivity with the addition of 0.6% carbon microfiber. This demonstrates the potential of this mix for further research into the application of reinforced mortars with electrical properties. Therefore, it can be concluded that the studied mix proportion has potential for the development of further research aimed at the application of mortars with electrical properties.