A theory is presented which describes the mechanisms involved in concrete pressures on formwork in wide sections. The main value of the theory is in providing a framework for analysing site data and indicating areas in which potential economies in design might be made. The horizontal pressure of concrete on formwork comprises two components whose magnitude depends -on the proportion of the vertical load taken by the particle structure and the pore water pressure. In normal formwork, the pore water pressure provides the major contribution to the maximum horizontal pressure and therefore any factor which increases the rate of load transfer from the pore water pressure onto the particle structure, will decrease the maximum pressure. For example, porous formwork will give lower horizontal pressures than impermeable formwork and the re-analysis of existing site data supports this prediction. Normal internal vibration does not have such a significant' affect on the maximum horizontal pressure as previously reported, but it can fluidify concrete to the depth of poker immersion. The elements of the theory are supported by an experimental programme, re-analysis of existing site data and new site measurements. These site measurements have shown that during underwater concreting a rapidly falling tide can cause the horizontal pressure to exceed the vertical pressure.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:458389 |
| Date | January 1979 |
| Creators | Harrison, T. A. |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1349338/ |
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