Poured concrete lining

Concrete nuclear reactor vessels, of the order of magnitude of 15-m (50-ft) inside diameter and length, have inner linings of steel which confine the pressure. After fabrication of the liner, the tubes for the cables or wires are put in place and the concrete is poured. High-strength reinforcing steel is used. Because there are thousands of reinforcing tendons in the concrete vessel, there is a statistical factor of safety. The failure of 1 or even 10 tendons would have little effec t on the overall structure. 

Liner Plate and Tile In addition to the above mentioned brick there is also liner tile, smooth faced with dove tailed or grooved backs. These are used to line concrete pipe and trenches. They are set into the forms, joints filled with corrosion resistant mortar, then concrete of the pipe or trench walls poured. Similarly, half round tile known as channel tile is available. This may be installed in... 

The Rubber Manufacturers Association (see Bibliography) has prepared a Protective Linings Technical Bulletin which provides specific standards for welded steel structures to receive such sheet linings. No such standard has been prepared for concrete, but the engineer who plans to design such a vessel will find that if the principles enunciated in this steel standard are followed, and the above four points observed, and if he consults a competent applicator before he starts to pour the concrete, he should be able to produce a satisfactory vessel. 

Tile construction is not used to any great extent for very aggressive liquid corrosives because the tile and the mortar joints are relatively thin approximately V2 in. deep) and are somewhat porous. These structures, therefore, have a tendency to weep or leak. Other factors which contribute to this tendency are the lack of a membrane and the susceptibility of the Portland cement core to attack by acidic media. Also, because the tiles are essentially the forms for the concrete and are not removed after the concrete cures, controlling the quality of the concrete wall by visually identifying stone pockets, pour lines, etc., is impossible. Structural tile vessels are, therefore, used in stock tanks, pulp storage tanks, washers, etc., where some leakage can be tolerated or the solids in the contained media will plug leaks. 

Deep shafts are generally lined with eonerete as excavation proceeds. In zones where freezing was done, this results in concrete being poured against a frozen surface. The result is poor quality and often porous concrete. When the ground thaws groundwater will find open fissures and seep into the shaft. Grouting is done to seal sueh fissures if the total water inflow is a nuisance. 

San Angeles spaceport was situated on the southern rim of the metropolis. A square ten kilometres to a side, a miniature city chiselled from machinery. Vast barren swathes of carbon concrete had been poured over the levelled earth and then divided up into roads, taxi aprons, and landing pads. Hundreds of line company hangars and cargo terminals hosted a business which accounted for a fifth of the entire planet s ground-toorbit traffic movements. 

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