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Pool & Recreational Shotcrete Corner pool shells. In fact, such applications became a new “norm.” But those applications should be unnecessary: as we will discuss in the final part of this series, good shotcrete materials, properly mixed, placed, and cured, will be watertight on their own. Through it all, however, those fortunate engineers who managed to have positive experiences with reputable, knowledgeable shotcrete contractors continued to specify shotcrete as a method of concrete placement and effectively kept it alive. But many more engineers had negative experiences and studiously specified other methods and materials or—and this became the rule rather than the exception—demanded provision of an encapsulating waterproofing membrane over the oftensubstandard shotcrete material. Shotcrete Rebirth Fortunately—and at the same time as the reputation of the shotcrete industry was being profoundly compromised (largely by the misdeeds of pool contractors)—key developments in other areas of the industry were paving the way for redemption. The emergence of the wet-mix process and development of new pumps and nozzles developed to support the wet-mix approach made shotcrete the ideal method for working in underground environments. In fact, the use of shotcrete in tunnels, mines, and underground infrastructure exploded in the 1970s, giving engineers a different and beneficial set of exposures to the method and lending the process a level of credibility it hadn’t seen since the early 1950s. Test data and documentation began to emerge, and ACI, along with ASA (formed in 1998), began taking the steps needed to produce standards on what it takes to make good shotcrete. This reinvention of the process laid the foundation for the current reputable state of the shotcrete industry— and in the nick of time. In our next and final article in this series, we’ll discuss the current state of the shotcrete industry, some of the challenges it faces, and its future as one of the most versatile construction methods currently available. References ACI Committee 506, “Guide to Shotcrete (ACI 506R-05),” American Concrete Institute, Farmington Hills, MI, 2005, 40 pp. ACI CP-60, “Craftsman Workbook for ACI Certification of Shotcrete Nozzleman,” American Concrete Institute, Farmington Hills, MI, 2015, 124 pp. American Shotcrete Association Pool and Recreational Shotcrete Committee, “Position Statement #1: Compressive Strength Values of Pool Shotcrete,” Shotcrete, Winter 2012, p. 37. American Shotcrete Association Pool and Recreational Shotcrete Committee, “Position Statement #2: Definitions of Key Shotcrete Terminology,” Shotcrete, Summer 2012, pp. 27-29. American Shotcrete Association Pool and Recreational Shotcrete Committee, “Position Statement #4; Watertight Shotcrete for Swimming Pools,” Shotcrete, Winter 2015, pp. 69-70. Yoggy, G. D., “The History of Shotcrete, Part I,” Shotcrete, V. 2, No. 4, Fall 2000, pp. 28-29. Yoggy, G. D., “The History of Shotcrete, Part II,” Shotcrete, V. 3, No. 2, Spring 2001, pp. 22-23. Yoggy, G. D., “The History of Shotcrete, Part III,” Shotcrete, V. 4, No. 1, Winter 2002, pp. 20-23. Lily Samuels is Vice President of Drakeley Industries, a design and structural shotcrete consulting firm for swimming pools, water tanks, tunneling, mining, and other infrastructural shotcrete applications; and Vice President of Sales and Marketing at Drakeley Pool Company, a specialty watershape design, construction, and service firm—both located in Bethlehem, CT. She has partnered with Bill Drakeley to develop educational materials on the history and science of the shotcrete process since 2009. Samuels received her bachelor’s degree from Smith College, Northampton, MA, and her master’s degree from Columbia University, New York, NY. Bill Drakeley is Principal and Owner of Drakeley Industries and Drakeley Pool Company. Drakeley holds the distinction of being the first and only member of American Concrete Institute (ACI) Committee 506, Shotcrete, from the pool industry. He is also an approved Examiner for the ACI Certified Nozzlemen program on behalf of the American Shotcrete Association (ASA), 2016 President of ASA, an ASA Technical Adviser, a Genesis 3 Platinum member, and a member of the Society of Watershape Designers as well as Chairman of its Advisory Board. Drakeley teaches courses on shotcrete applications at the Genesis 3 Construction School, World of Concrete, and numerous other trade shows. He is a contributor to Shotcrete magazine and other industry publications. Shotcrete • Spring 2016 45


2016SpringShotcreteEMag
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