타원구를 사용한 중공형 슬래브의 진동실험

In this study, free vibration tests by applying the impact loading of 29.4kN of a sand bag were performed on the hollow core slabs with elliptical balls to investigate their stiffness. Eight specimens were manufactured: Four specimens were tested for caparison with the hollow core slab; two deck slab were tested to investigate the to their applicability to hollow core slabs, and two half PC slab were tested to investigate the to their applicability to hollow core slabs. The slabs were simply supported at two ends, and impact load was induced by free falling sand bag, and then vertical accelerations were measured at the middle and a forth of the span. Modal frequency and damping ratio were identified and those values were compared with the stiffness of gross cross section of the test specimens.