Aggregate water absorption

[malakin]

What are the main problems associated with using an aggregate in a marine environment with a water absorbtion of 4.5% say? Usually less than 3% is required. Can the concrete design be changed to accomodate for this poor quality in the aggregate? Thanks in advance.

 

[Ron]

Using aggregate with high absorption leads to greater permeation of chlorides into the concrete, which can lead to significant, premature corrosion of rebar and embeds.

There are mitigation techniques such as Nitrite additives to reduce the corrosion potential. Keeping a low water-cement ratio and making the quality of the concrete as high as practicable will also help mitigate the effect of aggregates of this type.