Title: Shotcrete in the United States--A Brief History
Author(s): I. Leon Glassgold
Publication: Symposium Paper
Appears on pages(s): 289-306
Keywords: concrete construction; fibers; history; shotcrete; tests; General
Gunite (dry-mix shotcrete) was introduced to the construction industry in the early days of concrete technology (1911) when many new ideas and concepts were just developing. The literature indicates that what we know as wet-mix shotcrete had its start about the same time but did not receive positive acceptance until 1950. The evolution of the shotcrete process to its present status in the construction industry is tracked by definitions of the process from Gunite in 1912 to the American Railway Engineers Association (AREA) definitions of Shotcrete in early the 1930s. By 1951, the adopted the term shotcrete, making it the official generic name of the process. The definitions by ACI from that time on reflect the introduction of new ideas and equipment into the market place. The author questions whether some low velocity shotcretes are truly shotcrete or just an extension of the concrete pumping process. A brief description and evaluation, from the past to present, of shotcrete materials, applications, and testing is presented. The future of the process is discussed and two major problems posed: the improvement of applicator workmanship and the development of a rational design for most shotcrete applications.