SELF-SENSING CEMENT-BASED COMPOSITE FOR STRAIN MEASUREMENT AND DAMAGE DETECTION

摘要

This article shows that carbon fiber added into concrete becomes carbon fiber reinforced concrete (CFRC) and with the functionality similar to piezoresistivity material can be used as a self-sensing material for strain measurement and damage detection. It is based on the reversible effect of strain on the volume electrical resistivity and the irreversible effect of damage on the resistivity. The strain sensing behavior is such that the resistivity decreases reversibly upon compression due to the slight push-in of crack-bridging fibers and the consequent decrease of the contact electrical resistivity of the fiber-cement interface. Similarly, the resistivity increases reversibly upon tension due to the slight pull-out of crack-bridging fibers and the consequent decrease of the contact resistivity. The self-sensing ability of CFRC cement-based composite has been well demonstrated under compression and under flexure. With the use of CFRC's electrical resistance change and appearance of structural cracks, we are able to derive an integration of sensors, and which also possesses material smartness quotient of self-sensing, stability and repetitiveness.