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2015SummerShotcreteEMag

Published by WaterShapes.com, 20 May 2015, the first installment of a three-part series. Reprinted with permission. Beginnings By Lily Samuels and Bill Drakeley Flong been the preferred material of construc- Institute formed in 1904, with both emerging inFirst came the Lehigh Portland Cement Co.,founded in 1897, and then the American Concreterom mine shafts to subway tunnels, fromfountains to swimming pools, shotcrete has tion for major projects worldwide. This process, response to the growing interest in using concrete which involves the spraying of concrete material as the foundation of modern construction. at a high velocity onto a receiving surface to In the 2000 years from the Roman Empire achieve compaction, offers substantial advantages through to the early twentieth century, concrete over alternative approaches with respect to dura- was primarily cast-in-place—that is, liquid con- bility, versatility, integrity, and sustainability. crete was placed into tightly constructed molds This has been the case ever since the technique of dense forming. While time-honored, this was invented at the turn of the twentieth century, method limited the use of concrete to applications yet only now are watershapers—professionals in which forming was possible. who have made concrete such a crucial part of This severely restricted concrete’s use in tun- their livelihoods—truly coming to understand and nels, for example, and in other underground set- appreciate shotcrete for what it is. tings—which is ironic, given the fact that the Lehigh Valley’s cement was a byproduct of iron- Emergence mining operations. The need for a different Shotcrete was born in the heart of a different approach was clear. Happily, an inventor came world. In the late 1800s, the vast mining opera- tions in the Lehigh Valley of Pennsylvania turned out huge quantities of iron ore, but the digging also extracted limestone, chalk, clay, and shale— the basic components used to manufacture port- land cement, which, when mixed with water and aggregate, becomes concrete. Fig. 2: Figure accompanying Akeley’s patent Fig. 1: Carl E. Akeley, father of shotcrete application 22 Shotcrete • Summer 2015


2015SummerShotcreteEMag
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