ABSTRACT
This chapter outlines the many and various uses of shotcrete in infrastructure repair and rehabilitation/strengthening. Examples of useful guide specifications for such applications are provided. Information is provided on the proper means for preparation of the substrate surface prior to shotcrete application. In addition, this chapter stresses the importance of understanding the factors/mechanisms which gave rise to the need for repair/rehabilitation, so that appropriate remedial interventions can be implemented. Factors which could give rise to the need for repair/rehabilitation could include: restrained drying shrinkage cracking; damage from freezing and thawing, with or without exposure to deicing chemicals; sulphate attack; chloride or carbonation induced corrosion of reinforcing steel; impact and abrasion, and cavitation erosion in hydraulic structures; differential thermal stresses, and fire damage; structural overload and fatigue-induced damage, and alkali-aggregate reactivity. The authors have been involved in shotcrete repairs for all of the above types of damage to infrastructure and case history examples are provided for some projects, including bridges and highway infrastructure; marine structures (shipping berth faces, piers, seawalls and light stations); dams, aqueducts, spillways and other hydraulic structures; grain silos and historic high-rise buildings.
