Evaluation of Vibra-Tension for Inspection of Tension of Prestressing Strands.

摘要

Vibra-Tension,an instrument developed by Vemco Industries,Inc.,was evaluated as a means of measuring tension in prestressing strands for prestressed concrete. Vibra-Tension works on the principle of the 'vibrating string'formula T = 4M(L squared)(F squared) where T is the strand tension, M is mass per unit length of strand, L is the length of the vibrating strand,and F is the strand frequency of vibration. When certain settings peculiar to the size of the strand and the length of the vibrating strand are made on the Vibra-Tension,the strand tension is a function of the frequency of vibration of the strand. Vibra-Tension measurements were compared with strand tensions computed from strand elongation.