| 摘要 |
<p>The invention relates to a filter device for use with impermeable sand bag liners or concrete placement bags 5, to allow the placement of dry powdered cement containing bags below water. The device can be attached with a simple snap or threaded fit and forms a fixed filtration device that will allow the controlled movement of water into the bag and also if necessary the controlled movement of air outside, from inside the bag, such that sufficient water for hydration can be absorbed by the dry powdered cementitious material to ensure the concrete hardens. It also allows the trapped air inside the bag to escape without flushing cement fines out of the bag as it escapes, into the surrounding water. The control of cement fines is possible in the device by the incorporation of a filter media 1 or permeable passageway that allows the passage of air and water, whilst assuring the entrapment and non-migration of cement fines.</p> |
