| 摘要 |
PROBLEM TO BE SOLVED: To facilitate installation of a filling state detection device.SOLUTION: A filling state detection device 10 comprises a rubber sheet 1, an optical fiber 2, a waterproof sheet 3 and an OTDR 4. The rubber sheet 1 is configured by disposing first rubber layers 1a and second rubber layers 1b alternately in an X-axis direction. Hardness of the first rubber layer 1a is greater than that of the rubber layer 1b. The optical fiber 2 is connected to the OTDR 4. When a concrete filling object space is filled with concrete, pressure in a direction of an arrow P is applied from the concrete. Since the second rubber layers 1b are relatively soft, the second rubber layer are crushed by this pressure and the volume thereof is reduced. Since the first rubber layers 1a are harder in comparison with the second rubber layers 1b, a rate for the first rubber layers to be crushed by this pressure is smaller than that of the second rubber layers 1b, and a degree of the volume thereof being reduced is also smaller in comparison with that of the second rubber layers 1b. The optical fiber 2 is bent in the vicinity of a boundary between the first rubber layers 1a and the second rubber layers 1b. |
