Title: Shotcrete in Seismic Repair and Retrofit
Author(s): James Warnar
Publication: Symposium Paper
Appears on pages(s): 299-314
Keywords: earthquake-resistant structures; reinforcing steels; renovating; repairs; shotcrete; Construction
Simply stated, shotcrete is sprayed concrete or mortar. Because of difficulty in obtaining good compaction and fully encasing large or closely spaced bars, it has traditionally been used in thin, relatively lightly reinforced sections. Unique to seismic repair and retrofit are heavily reinforced and often thick sections. Because of its ease of application in areas of poor access and the resulting reduction in construction time and cost, the process can be especially advantageous in seismic applications. Special procedures are required, however, to obtain good quality work under the common inherent constraints that often exist and overcome the limitations. Although not widely recognized, proven procedures are well established and have been successfully used in seismic repair and retrofit applications for nearly 50 years. Basic principles of the shotcrete process are reviewed in this paper; those special procedures required for proper placement in heavily reinforced and thick sections are discussed.