Performance of Stainless Steel Rebar in Concrete

Corrosion mitigation of steel rebar in concrete can be achieved by  

The first mode of corrosion mitigation involves selection of material such as stainless steel rebar and the merits and demerits of this mode are detailed below. 

The mechanical and physical properties of some alloys chosen for rebar in concrete are relevant in the performance of the alloys. The mechanical properties of some reinforcing bar alloys are given in Table 7.11. All the steels except duplex steels were subjected to cold work in order to increase their strength. Duplex S31803 steel in the annealed state exhibits strength levels close to the values of the cold-worked alloys. 

Some physical properties such as coefficient of thermal expansion and modulus of elasticity of the alloys are given in Table 7.12. Other factors such as resistance to general and pitting corrosion, pitting resistance equivalent number (PREN) and the relative cost ratios are also given in Table 7.12. 

Pitting resistance equivalent number (PREN) is derived from a formula involving chromium, molybdenum and nitrogen contents of the alloys. These numbers are used as a qualitative indication of the pitting resistance of the alloys. The higher the PREN value the greater the resistance of the alloys to corrosion due to chloride. 

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Performance of Stainless Steel Rebar in Concrete Corrosion protection of steel rebar can be achieved by (i) selection of corrosion-resistant steel (ii) use of coatings (iii) addition of corrosion inhibitors such as calcium nitrite to concrete mix (iv) addition of concrete sealers (iv) use of membranes (v) use of thicker concrete overlay (vi) cathodic protection. 

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