Evaluate the optimum dosage of nano materials on self sensing properties of nano cement composites

Abstract

Health Monitoring is the process of identifying, locating and detecting the amount of damage that are occurring in the structure in early stage to prevent the unexpected failures. Structural health monitoring (SHM) using self-sensing material is emerging and it is preferred research area in structural engineering field. This self-sensing property for material is achieved by adding piezoresistive materials into them. These piezo resistivity makes the materials self-sensing by indicating a detectable change in their electrical resistivity with applied stress or strain and make them useful for health monitoring of structures. Many studies shows that nano materials possess greater conductivity properties which can be used as smart materials. A recent development shows cement matrix can be made self-sensing be by addition carbon fibre and nano materials such as graphene, multiwall carbon nanotubes (MWNCT), nano fibres. In the proposed work optimization of nano materials dosage to achieve conductivity property for cement matrix is carried out. The experimental study is carried out by preparing the cement nano composite sensor by adding different proposition of multiwall carbon nanotubes (MWCNT) and carbon fibre, which act as nano filler in the cement based nano composite sensor. Copper wire was used as electrode material in the sensor.The size of specimen sensor was fixed to 80 mm ×80 mm ×50 mm with three 10 mm diameter tube was the filler is filled with copper electrode. In the last step, electrotechnical test for nano sensor with the optimized dosage of carbon fibre and multiwall carbon nanotubes (MWNCT) were embedded in the beam and column of size 150 mm ×150 mm ×700 mm to evaluate the conductivity properties of the materials. The obtained results for optimum dosage of nano materials is then verified with full factorial method and two factorial method of design of experiment (DoE) which are the statistical methods of optimization.