ICE - Institution of Civil Engineers - Virtual Library

Existing literature on pre-stressed concrete failed to provide sufficient information on certain points which, basically, me dependent on the bond in pre-stressed concrete.

Experiments were carried out, therefore, to investigate those points by further examination of the subject of the pre-stressed-concrete bond; those experiments are described in this Paper.

The Paper enumerates the points which were investigated and, after dealing briefly with the variables concerned in the pre-stressed-concrete bond, describes the materials and apparatus used in the experiments, the methods of carrying out the tests and, finally, the experiments carried out, first on the materials and then on the test specimens and beams.

A summary of the main conclusions reached is given at the end of the Paper.

Works for the intake of water from rivers in India for waterworks, power stations, and textile factories have to be designed to cope with the extreme variations in the flow conditions in such rivers; in fact, during the dry season it is often exceedingly difficult to obtain an adequate supply without sustaining heavy recurring expenditure.

Several types of intake in general use are mentioned in the Paper, and it is shown that some are very inefficient when judged by their ability to admit the cleanest water during the monsoon and sand-free water during the dry season. These factors have to be considered in addition to head losses between river-level and the pumps, since, apart from the additional wear and tear in the pumping plant, the disposal of great quantities of silt and sand from the settling tanks at a large works over period of years can become quite a serious problem.

In the latter part of the Paper a new type of intake is described, and it is claimed that, when used under suitable conditions, it has a much higher efficiency, judged by the standards laid down above, than many other types.