Self-monitoring, pseudo-ductile, hybrid FRP reinforcement rods for concrete applications

The feasibility of hybrid -fiber-reinforced-polymer rods that demonstrate t he important safety features of self-monitoring capability and pseudo-ducti lity is demonstrated. The rods are intended to be the basis of improved pul truded reinforcements for concrete or other civil applications where safety is of critical importance. The lowest elongation fiber in the seven rods i nvestigated is carbon, which by virtue of its piezoresistivity allows the m onitoring of deformation and fracture throughout an entire rod with simple electronic equipment. Resistance measurements obtained during quasi-static tests clearly reveal failure of the carbon fibers. Following this easily de tected event, higher loads can be safely sustained by the remaining high-el ongation fibers if the carbon tows are dispersed in the cross-section rathe r than concentrated in one location. (C) 2001 Elsevier Science Ltd. All rig hts reserved.