| 摘要 |
<p>A sensor for use during the construction of a concrete structure is provided to enable an assessment to be made of whether or not a pour of fresh concrete has settled uniformly throughout the placement area. One (2b) of two main electrodes (2a, 2b) is fitted with an auxiliary electrode (2c) in parallel such that the polarity of the electrodes (2a, 2b, 2c) is reversed when they are immersed in water and when they are immersed in fresh concrete. By monitoring this function, it is possible to detect the presence or absence of fresh concrete in accordance with the polarity. In the case of a sensor without an auxiliary electrode (2c), it is still possible to monitor changes in the voltage level when the electrodes (2a, 2b) are immersed in water and in fresh concrete, thereby providing access to a similar mode of assessment. <IMAGE></p> |
