A high performance multifunctional cementitious nanocomposite material is made by adding a nano admixture to the water used in a conventional cementitious material manufacturing process. The nano admixture is made by dispersing nanomaterials in a solvent and sonicating the mixture, adding a hydrophilic emulsifier, thickener, additive or cellulose derived compound to hot water, where it separates and expands, cooling the water, causing the compound to dissolve, and then adding the solvent and nanomaterial mixture to the water and mechanically mixing. The contact between the nanomaterials and the surrounding matrix changes with applied stress, affecting the volume electrical response of the finished nanocomposite material. By measuring the electrical resistance of the material, its structural health, as well as the stress applied to it, can be monitored. A bridge made with the material is monitored for structural integrity and for the weight, speed, and location of traffic over the bridge.