Maintenance And Repair Of Concrete Structures In Railroad Construction
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Begins by outlining the basis of the selection of concrete as a structural material from the viewpoint of railroad management shortly after the turn of the century -that concrete requires no mainte- nance; and then makes a comparison of structures built on the D.L.&W. Railroad between that time and 1916, with their condition 20 years later (1936) to evaluate the soundness of such conception. The conclusion from this comparison indicates that, while in this climate concrete definitely requires protection or maintenance as evidenced by these structures, 25 years of exposure have not undermined their integrity and that with but minor expense they have a long life ahead of them. Traces the causes of deterioration between de- sign and construction. Under design, aside from provision against stresses due to loads and soil bear-ing, the details for drainage, sion and construction location of expanded joints to compensate for volume and temperature changes; under construction, proportioning of concrete mixtures, selection of materials, workmanship of mixing and placing, and curing. Causes of failures are discussed in the de-scription of the condition of the various structures. Second section discusses methods of repair, describing four types (a) patching, (b) coating, (c) encasement, and a whole member, (d) replacement of a part of or such work. and specifying the methods of Summarizes in conclusion the causes of cracks and deterioration, listing these between (a) structural and (b) installation - materials and methods; fol- lowed by a list of precautions to be taken when . ma king repairs. An appendix giving specifications for concrete repair work is included.