The two types of spalling, direct spalling and scabbing, occur during the ductile mode of behavior. Because direct spalling is dependent upon the transmission of shockpressures, fragments formed from this type of spalling are produced immediately afterthe blast pressures strike the wall. Scabbing, on the other hand, occurs during the laterstages of the flexural (ductile mode) action of the element. Both types of spalls affectthe capacity of the element to resist the applied blast load.