Abstract

Self Sensing Concrete is artificially created concrete that has inbuilt ability to sense damage without any human intervention. Generally normal concrete does not conduct current to pass through it. Hence in order to conduct current in the concrete carbon fibres are added to the concrete matrix. Effective monitoring permits the control of working conditions of materials in the infrastructure and identification of behavioural parameters due to damages by application of load. Hence we can sense the amount of crack formed in the concrete structure through increase in electrical resistivity created within the concrete. The self sensing ability is achieved by correlating the variation of external stress or strain with the variation of electrical properties such as electrical resistance and conductivity.
This paper aims at the investigation of M30 concrete’s sensitivity at 7 and 28 days. Cubes were casted with the proportion of 0.24%, 0.4%, 15% of carbon fibre, methyl cellulose and silica fumes respectively and the cracking patterns were sensed at 7 and 28 days with circuit connections consisting of Ammeter, Voltmeter and Regulated Power Supply (DC). The measurement of the electrical characteristics is completely monitored. The values of resistivity is compared with the conventional M30 concrete and the sensing characteristics are enhanced by wounding three layers of copper wires over the concrete cubes painted with nickel conductivity paints. Structural application of this project can be used in the power plants and also industrial plants in which structural health monitoring is essential.

Key words: Self Sensing Concrete