The proposed work aims to develop innovative nano-modified cement, and concrete, which will be used as components in multi-functional, smart structural elements. For this purpose conventional materials (cement, plasticizer, concrete) will be appropriately modified with carbon-based nanofibers (carbon nanotubes - CNTs, carbon nanofibers - CNFs and chopped carbon fibers - CF), in order to achieve multi-functional properties. In addition, we will determine and verify the different functionalities of the modified materials.

A detailed investigation will be conducted to determine the type and the volume fraction (percolation threshold) of the nanoscale fibers for which the resistivity of the matrix decreases sharply by several orders of magnitude. The electrical and piezoresistive properties of the nano-modified materials will be investigated using the four-probe method with both AC and DC current. Additionally, we will study the mechanical behavior and monitor in real time the structural integrity of the modified material in simulated operational conditions (mechanical and/or environmental loading), using the intrinsic multi-functional properties of the material as damage and stress/strain sensors.

Finally, in order to demonstrate the possibility of integrating the new nano-modified materials into practice for full-scale application in concrete, the effect of the nano-reinforcement on the performance and the multi-functionality of modified lab scale material, as well as of structural components, will be assessed by means of advanced electrical, thermal, acoustic and optical non-destructive techniques. The nano-modified materials developed in this work, will be directly applicable as, high-performance materials, thermal actuators and sensors for self-diagnosing the structural integrity of civil engineering structures such as dams, bridges and highways.