About Concrete Peeling and Concrete Cancer Concrete Peeling describes the state in which concrete begins to degrade or peel off. Common signs include cracking, crumbling or peeling of concrete, rust stains or bubbles on concrete or cement plaster, and leaks in the ceiling and walls. Chipping is a term used to describe areas of concrete that have cracked and delaminated from the substrate. There are several reasons why husking occurs, including freeze-thaw cycles, the expansive effects of the alkaline silica reaction, or exposure to fire.
However, the most common cause of chipping is corrosion of embedded steel reinforcing bars or steel sections. Corrosive steel can expand up to ten times its original volume, putting stress on the surrounding concrete. There are also serious business considerations. If a structure is allowed to deteriorate, the value of the asset will decrease and, in addition, maintenance costs will tend to increase as corrosion and scaling become more widespread.
For some structures, such as car parks, customers will stay away if the environment is unattractive and potentially dangerous. Concrete chipping occurs when steel reinforcement within a concrete slab begins to rust. Rusty steel increases to approximately five times its original size, which displaces concrete and causes it to flake. Once the concrete flakes, more and more damage occurs, as more water can enter the affected area and cause more rust, speeding up the process and increasing the affected area.
The descaling of concrete is usually caused by corrosion of steel reinforcing bars embedded in the concrete matrix, but can be caused by other ferrous elements, either fully or partially embedded in the structure. Steel-framed window systems, handrails, structural I-beams, metal pipes and ducts are among the most common damage-causing building components. However, corrosion of reinforcing steel is by far the most common cause of chipping and splitting in older concrete structures. Concrete cancer occurs when steel reinforcement inside a concrete slab begins to rust.
As steel rusts, it expands and displaces surrounding concrete, causing it to become brittle and crack, exacerbating the problem. Adequate mixing of sand, cement and aggregates must be achieved, since insufficient aggregate can result in a weak and prone top layer to chipping. And, if you have chipping, have it treated as soon as possible to maintain the structural integrity of the concrete as much as possible. One of the most common causes of chipping in old solid-walled buildings is the use of targeted cement on soft-lime mortar joints.
If peeling has already occurred, damaged bricks can be replaced, but the cause of moisture must also be properly identified and treated. Usually, homeowners only become aware of the peeling of concrete once the symptoms of the problem are visible to the naked eye or when delaminated concrete begins to fall to the ground, however, visible defects of concrete are usually only the indicator of major problems. Chipping is often caused by poor installation, poor maintenance, poor repairs, or environmental factors. The descaling of the concrete normally begins when the steel reinforcement embedded within the concrete element is oxidized.
In addition, delamination and descaling require greater maintenance, subsequently higher maintenance costs, and may result in decreased service life of the concrete member (s). Delamination and chipping of a concrete member are undesirable conditions; they not only represent a potential impact hazard in the scenario in which chipped concrete falls and hits a person, but also reduces the cross-sectional area of the concrete member and decreases its load-bearing capacity securely imposed. Concrete peeling affects a wide variety of structures, including concrete framed buildings, multi-storey car parks, bridges, jetties, tanks and ponds. An additional consideration is that both delamination and descaling offer greater air and water access to the reinforcing steel within that member; thus creating a corrosion cycle and increased access of corrosive elements, which exacerbates the process with each subsequent cycle.
In construction, “peeling” refers to the flaking, cracking, peeling, crumbling or chipping of concrete or brick, particularly when parts of the surface can be said to have “peeled off”. . .
