Chipping is a term used to describe areas of concrete that have cracked and delaminated from the substrate. This deterioration of steel-reinforced concrete is characterized by the appearance of cracks and red rust, and in severe cases, the concrete sections are completely detached from the reinforcing steel bar (known as “rebar”), exposing it to the elements. 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.
The descaling of concrete describes the state in which the concrete begins to degrade or peel off. Common signs include cracking, crumbling or peeling of concrete, rust stains or bubbles in concrete or cement plaster, and leaks in the ceiling and walls. Peeling concrete is a common problem where part of the surface flakes off, breaks or splinters. Also known as flaking, it is the result of a weak surface that is susceptible to damage. Concrete chipping occurs when steel reinforcement inside 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 is flaking, 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. Magnesite floors should always be removed for your safety, as they can contain asbestos and often cause chipping of concrete. The descaling of the concrete leaves the surface uneven and pitted while exposing the aggregate underneath. As soon as peeling of concrete is detected, it must be properly repaired, otherwise it compromises the integrity of the surface and endangers the final capacity of the member. Chipping can have far-reaching consequences in terms of health and safety, structural integrity and asset value.
Beyond the obvious aesthetic problems, a reduction in cross-sectional area due to flaking and delamination is synonymous with a weakened concrete section. If left unchecked, the husking will tend to accelerate and spread, so that eventually the structure could become unstable. Fortunately, most cases of concrete chipping can be prevented by sealing to ensure moisture penetration is prevented. In addition to living near the ocean with “common area windows open” leaving corridors with carpet and magnesite underneath exposed to elements that led to entire unit block having concrete chipping, peeling can also occur when ends of reinforcing beams are too close to surface. We specialize in providing concrete chip repair solutions to residential, commercial, industrial and civil sectors throughout Sydney. If left unchecked, chipping will tend to accelerate and spread so that eventually structure could become unstable.
Concrete Spalling Sydney offers free inspection of slab to inspect any chips.