The share of a gunning mix that ricochets off the target surface, mostly coarse aggregate, so the material that stays has a different makeup from what was in the bag. Dry gunning often loses 10 to 30 percent to rebound, shotcrete much less. Rebound must be cleared away and never shoveled back in or allowed to collect in corners, where it forms weak, porous pockets.
Rebound is piling up in the corner of the cone, stop and dig it out before you gun over it.
Also heard as
- rebound loss
Related terms
Gunning
Spraying refractory through a hose and nozzle with compressed air to build or repair a lining.
Shotcrete
Wet-mix gunning: castable pumped through a hose and set instantly by accelerator added at the nozzle.
Nozzleman
Operator who handles the gunning nozzle and controls water and placement on a gunning or shotcrete crew.
Fines
Smallest particle fraction of a refractory mix, which fills the gaps between coarse grains and forms the bond.