What is Spalling?
Spalling of concrete refers to the detachment of the concrete cover from a structure's surface due to internal forces such as reinforcement corrosion, impact, fire, or overload.
The primary cause of spalling is often identified as reinforcement corrosion within the concrete. When steel reinforcement corrodes, it produces corrosion products that have a larger volume than the original metal, leading to significant tensile stresses in the concrete cover. This stress can result in cracking, delamination, and ultimately, spalling
How does Spalling damage concrete structures?
Spalling damages concrete structures by compromising the integrity of the concrete cover and exposing underlying components to environmental factors. The detachment of the concrete cover weakens the structure locally and exposes the reinforcement to further corrosion, leading to steel loss and exacerbating deterioration.
Spalling also creates pathways for moisture ingress, chemical exposure, and freeze-thaw cycles, further compromising the durability and longevity of the concrete. Preventive measures, such as corrosion protection and maintenance, are essential to mitigate spalling and preserve the structural integrity of concrete.
What causes Spalling?
Fire.
Impact.
Over loading.
High porosity.
High water to cement ratio.
Inadequate cover for aggressive environments.
Congested reinforcements.
How can I identify Spalling in concrete structures?
Visual survey | Non-destructive testing | Destructive testing |
How can I repair Spalling in concrete structures?
Corrosion inhibitors can be used in conjunction with localized Concrete replacement depending on the deterioration process underlying the cause of spalling.