Effects of temperature and stress on the interface between concrete and its carbon fiber epoxy-matrix composite retrofit, studied by electrical resistance measurement

DC electrical resistance measurement was used to investigate the effects of temperature and stress on the interface between a concrete substrate and i ts carbon fiber epoxy-matrix composite retrofit. The apparent resistance of the retrofit in the fiber direction was increased by bond degradation, whe ther the degradation was due to heat or stress. The degradation was reversi ble. Irreversible disturbance in the fiber arrangement occurred slightly as thermal or load cycling occurred, as indicated by the resistance decreasin g cycle by cycle. (C) 2000 Elsevier Science Ltd. All rights reserved.