ACI 506.5R

Abstract

This guide is intended for owner, designer, specifier, and inspection and testing personnel interested in or in need of information and background on the application of underground shotcrete. The guide briefly discusses the concept of composite ground support&#8212;the combination of shotcrete and other support elements used to provide early and effective tunnel support. The guide is not a comprehensive treatise on the design of these systems, but is intended to provide sufficient information to understand how the combination and sequencing of ground support elements can influence the performance, application, inspection, and testing of shotcrete. <br>The general format of the document is such that each section provides a brief introductory overview followed by a table that contains points considered important to specifications (Example Specifications) and brief notes to the specifier where necessary. The reader should, however, recognize that each underground project is unique, and that the example specifications and notes to the specifier provided need to be considered in that context. <br>Although this guide is written to those users typically involved with civil projects involving shotcrete, it is equally applicable to users involved with shotcrete in the underground mining industry. Whereas terms such as owner, specifier, and contractor are ubiquitous for civil projects, these key players are nonetheless involved in mining; however, they are typically one or more individuals, groups, or entities within the mining company, and may be referred to as engineering, production, or quality control. <br>Measurements in this document are presented in inchpound units (followed by SI units in parentheses). Table 1.1 contains the constants that were used to convert inch-pound units to SI and vice versa. Due to issues of rounding, significant figures, and the dimensions of locally available products, the values resulting from conversion may be misleadingly precise.