To enable detection as to whether or not concrete has been uniformly placed and filled, during placement of the concrete, without affecting the quality of a concrete structure.
A plurality of through holes 11a are formed in a concrete form 11, which are then blocked with stopper members 12 each formed of an elastic material. Each stopper member 12 is pierced with two needle terminals 23 which are exposed to the interior of the concrete form 11. Then, a change in electric resistance across the needle terminals 23 is measured by a resistance detecting means such as a resistance measuring instrument or an ammeter, to thereby detect whether or not the concrete has been filled. Holes perforated by the needle terminals 23 are blocked due to the elasticity of the stopper member 12, and therefore the needle terminals can be pulled out after the measurement. The resistance detecting means may include a power source for supplying voltage between the needle terminals 23, and a light-emitting diode and a buzzer which are serially connected to the power source via the needle terminals 23, which may facilitate recognition as to whether or not the concrete has been filled.
TAGUCHI TAKESHI
MIYASHITA TAKESHI
KANEKAWA MOTOI
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