foundation system of burj al arab

Surface Preparation for Commencing Concrete Repair Work (Part-3)

Here we have provided a figure showing the removal of defective concrete and making exposed the full perimeter of reinforcing bars in reinforced concrete, that are corroded. Normally a disc type mechanical cutter is used to expose bar without reducing or cutting the remaining reinforcing bars.

In the previous post we have learned some requirements of concrete removal around reinforcement. Here we will provide the remaining task to be done for removing loose concrete around reinforcing bars. We have learned the conditions when the reinforcing bars have to expose to its full depth.

Concrete repair: Corroded reinforcement, sectional reduction more than 15%

When fully exposing is concerned, a question arises how much gap between reinforcement and prepared concrete should be kept. The clearance is

Average clearance=25 m

Average clearance= (Maximum aggregate size+5) mm

Greater of the two are provided as a clearance between reinforcement and concrete surrounding it.

So far we learned about removing loose concrete and making clearance between them. Now we have to observe the condition of reinforcing bars. The things to be noticed that

a. For individual bar, cross-sectional area must not reduced ≥15%

b. For adjacent two bars, cross-sectional area must not reduced ≥10%

c. Loose reinforcement and its location in out of plane should rearrange and relocated.


For the above cases a structural engineer should be appointed to justify the further progress can be carried out. 

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