Development of low cost and innovative smart materials for highways and civil engineering structures

With the increasing cost of infrastructure monitoring and maintenance and the limited funding for these activities the engineering community is looking towards the development of smart materials. Today there are several examples of innovative smart materials requiring however a) increased high-tech knowledge for their installation monitoring and interpretation of data, and b) significant expense for their installation in large scale projects, such as highways and bridges. This paper presents the result of a project undertaken for investigating the development of simple and low cost sensor for concrete and asphalt mixtures. Several configurations of metallic grids were imbedded into concrete and asphalt beams that were exposed to different stress and strain levels, and temperature differentials. The input and output voltage of these grid sensors were monitored in relation to the applied external stimuli. The results indicated that such a simple and low cost sensing devices can be used with the conventional asphalt and concrete mixtures for developing smart civil engineering materials and structures. In addition to the advantages related to smart materials, (real time monitoring, ability to identify current condition of materials and structures; possibility of predicting future conditions; examining behavior and response; and cognitive interpretation of the external excitation factors), such sensors are low cost, easy to install and could be combined with the current reinforcement of the structural elements for additional savings and monitoring capabilities. The methodology of this study can be used in developing simple and low cost materials for other engineering materials and applications.