Microwave-assisted selective demolition of concrete - Microwave-Assisted Concrete Technology: Production, Demolition and Recycling - page 94

Figure 3.6 Concrete removal using hydrodemolition. (Reprinted, with permission, from
ACI RAP-14 report published by ACI Committee E706: American Concrete Institute,
Field Guide to Concrete Repair Application Procedures: Concrete Removal
Using Hydrodemolition. Farmington Hills, MI: ACI, 2010.)
to disposal through local sanitary systems. Furthermore, hydrodemolition
is not suitable for removing concrete in posttensioned structural elements
as water may enter the posttensioned tendon sheathing and cause long-
term durability problems. Apart from these issues, the biggest disadvantage
associated with hydrodemolition is the safety issues arising from the use of
this method. The water jet is dangerous and can cause serious injury and
even death. Water jets can propel debris at high velocity and may result in
injury or death as well as damage to property. The hydrodemolition tool
should only be operated by a highly experienced operator (Figure 3.6).
3.3.5 Abrasive jetting
Abrasive jetting (Figure 3.7) uses a high-speed stream of particles carried
in an air or gas jet to remove a thin layer (paint, concrete, rust) from the
Figure 3.7 Abrasive jetting.