What are Pop-outs?
Pop-outs in concrete structures refer to small, conical pieces that break away from the concrete surface, resulting in shallow holes or pits.
This phenomenon occurs due to the expansion of near surface concrete, causing cracks and displacement of the surrounding concrete cover.
Pop-outs are often caused by the absorption of water and freeze / thaw within certain types of aggregates, such as cherts with low specific gravity or limestone containing clay and shale materials. High temperatures can also cause explosive popouts as the pore water boils, turns to steam, increases in volume and forces off the cover concrete.
How do Pop-outs damage concrete structures?
Pop-outs can damage concrete structures by compromising the integrity of the surface and exposing underlying layers to environmental factors. These small pits and holes weaken the concrete, making it more susceptible to further deterioration from moisture ingress, chemical exposure, and freeze-thaw cycles.
Additionally, pop-outs can create aesthetic issues and increase maintenance needs. Preventive measures, such as using suitable aggregates and proper curing techniques, are crucial to mitigate the risk of pop-outs and ensure the durability of concrete structures.
What causes Pop-outs?
Fire.
Reactive aggregates.
Lack of air entrainment.
Poor mix design.
How can I identify Pop-outs in concrete structures?
Visual survey | Non-destructive testing | Destructive testing |
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How can I repair Pop-outs in concrete structures?
The combination of this method with Concrete Impregnation or Concrete Coating can be used to mitigate the progress of some underlying deterioration process.