Destruction of a surface by frost, heat, corrosion, or mechanical causes. Concrete exposed to intense heat may spall explosively. Expansion and contraction of the concrete as well as vaporising moisture contained in the concrete contribute to this effect. It does not necessarily mean an accelerant was used.
Spalling is the breaking down of concrete usually due to corroding reinforcement, which has expanded in the concrete, forcing chunks of the member to crack and separate. Many older concrete house stumps spall leaving the stump with huge cracks that eventually open up and release large sections of concrete from the face of the stump. Such stumps should be replaced for structural reasons.
Hard outer surface of brick separates and falls off exposing brick's soft interior. This occurs when water freezes and expands after it has penetrated a porous or cracked brick wall, forcing the brick' surface to pull away. Exposure of the brick's soft interior accelerates the deterioration of the brick.
Uneven chipping or flaking. Occurs in stone, brick and terra cotta from pressure of salts and freeze-thaw cycle as well as improper laying, repointing or cleaning. Also caused by water infiltration, which rusts metal anchors and causes increased uneven pressure on the masonry.
When poured concrete chips, fragments or breaks apart. This problem is usually caused when the reinforcement bar (rebar) is located too close to surface or edges. It can also result from improper or inconsistent concrete mixture or a combination of excessive moisture and temperature change.
A breaking away of concrete at joints in floors or slabs. Typically occurs at joints that are installed improperly or don't adequately support the loads applied to them. (Also see raveling.) spray-down system – A decorative overlay applied as a splatter coat or a knock-down finish to a thickness of about 1/8 inch. Often used in conjunction with paper or adhesive stencils. Available precolored or can be integrally colored during mixing.
Stress induced failure of the rock mass that results in small, thin, curved, sharp edged pieces of rock ejected or falling from the backs or walls of an excavation. Generally accompanied by rock noise, usually associated with high rock stress.