5 Conclusions
Based on the low-cycle repetitive loading test and theoretical analysis of the SRHC frame columns, the following conclusions can be generalized: (1) All seismic performance indexes of SRHC frame columns designed properly are adequate and can be applied in engineering practice. However, due to the natural brittleness of HSHPC, their ductility and energy dissipation capacity are inferior to those of ordinary SRC frame columns. Therefore, the axial compression ratio should be strictly limited, and some construction strengthening measures such as increasing stirrups should be adopted. (2) As the shear span ratio increases, the failure modes of the specimens subjected to the compound action of compression, bending and shearing are ordinal shearing compression failure, shearing splitting failure and fl exural failure, and the horizontal bearing capacity decreases gradually but the rate of deterioration slows down after the maximum horizontal load. The ductility and energy dissipation capacity is gradually enhanced. (3) As the concrete strength and axial compression ratio heighten, the horizontal bearing capacity increases gradually but the rate of decay increases after the maximum horizontal load. The ductility and energy dissipation capacity reduce gradually. (4) When the stirrup ratio and steel ratio grow, the horizontal bearing capacity increases gradually, and the rate of deterioration slows down. The ductility and energy dissipation capacity intensifi es gradually. (5) The calculation method proposed for shear bearing capacity of SRHC frame columns in different failure modes is reasonable and its corresponding expressions are accurate; hence, they can be applied to engineering design.
