The corrosion environments discussed in previous post are corrosive to both metal foundation and concrete foundation. We have learnt that concrete is usually resistant to corrosion, if there have no sulfate in ambient environment. In case of sulfate contamination, sulfate resistant concrete is necessary. Sometimes it is necessary to introduce air-entrainment in concrete to make concrete foundation corrosion resistant.
In our previous post we have preliminary idea about time-dependent corrosion. The salts of sulfate that affect concrete foundation elements are:
a. Magnesium sulfate
b. Sodium sulfate
Sulfate attack is accelerated greatly if it is accompanied by time-dependent corrosion i.e. alternating wetting-drying. Dear reader we will discuss elaborately about sulfate resistant concrete in our upcoming post. But we like to include that sulfate resisting concrete is sometimes disadvantageous when it is suspected to have chloride ions within concrete; for further clarification you have to wait for these posts.
We know that PH=7 is neutral condition, in pile foundation when PH becomes less than 4.0 or above 9.5, metal piles like steel should be replaced by timber. The timber piles should be properly treated.
Monographs 58 & 127 by National Bureau of Standards and Technical Manual-27 by U.S. Army Corps of Engineers are only publications about steel piles to treat against corrosion. They recommended to use steel piles in conditions where they are submerged consistently, that is, not included wetting and drying cycles, this recommendation is also applicable for timber piling.
They were not recommended to use steel piles in marine environment where time dependent corrosion is observed. They have provided limited use of steel piles with proper coating that not subjected to alternate submergence which is almost impossible and so we provided that they did not recommend to use.
In such case, concrete piles are recommended which is properly proportion. So, now-a-days, time dependent corrosion is becoming a key factor for installing steel piles considering previous experiences of corroded foundation. We are providing some links regarding pile corrosion, please visit for more information: