Assessing the potential of nano-reinforced blended lime-cement pastes as self-sensing materials for restoration applications

Abstract

Structural integrity and safety are among the most important criteria dictating the design of interventions and the selection of restoration materials for Cultural Heritage Monuments. After the interventions, continuous structural health monitoring of the restored structures is of crucial importance. In this direction, the classic approach is based on the use of suitable sensors, properly attached to strategic points of the restored structural elements. An alternative approach is the exploitation of restoration materials which exhibit piezo-resistive characteristics, i.e., their electrical resistance is changing with the application of mechanical load. In this context, an attempt is in progress to incorporate carbon-based nanomaterials (graphene, carbon nanotubes) into monument restoration materials. In the present study, two types of modified carbon nanotubes are incorporated in a lime-based binder. As a first step, the compressive strength and the electrical resistance of the pastes are evaluated, where an essential increase in the flexural strength is noticed due to the incorporation of the carbon nanotubes. Then, the piezoresistive behaviour of the composite materials is studied in the direction of assessing their potentials to be used as strain sensors.