The Investigation of Seismic behaviour and structural hinge Characteristicsof HPFRCC Beams and Frames

Structural fuses are some points in structure which are exposed of destruction due to vast internal forces and plastic joints are summed up in them and possible destruction would start in these points, so the best way is substituting well-featured materials such as HPFRCC rather than conventional concrete against earthquake with rigidity behaviour of strain under tension and capability of high energy absorption before failure. The formation and features of plastic joints in HPFRCC beams and frames are investigated in this paper considering 12 concrete and HPFRCC beams and 12 columns with variables such as compressive strength, lateral load type, axial load in column. Results showed that in HPFRCC beams, increasing compressive strength leaded into increasing force and displacement, curve, plastic joint length. HPFRCC beams under concentrated loading had the more displacement and energy absorption, and beam under uniform loading had the maximum force and the beams under two-point loading had longer plastic hinge rather than beams under uniform loading. HPFRCC frames had lateral force and displacement of respectively 7% and 18% more than their relevant concrete frames and curvature, plastic joint length were increased up to 1.18 and 1.30 times of RC frames, respectively. Therefore the HPFRCC material is effective and appropriate for new concrete structures subjected cyclic loading.