The present experience in construction and service of reinforced concrete structures shows that there are numerous problems related to foundations causing severe damage, and often, compromising the bearing capacity of structures and the durability. The reasons for this are its interaction with soil, incorrect assessment of moisture and water effects on:
Foundations soil and
Concrete of the foundations.
Foundations are exposed to following aggressive environmental effects :
Physical -The most drastic form of the physical impact leading to concrete degradation is frost action. Namely, water which is retained in pores and cracks freezes in low temperatures and exposes concrete to often very high pressures (up to 220 MPa).
Biological -The biological effects comprise the impact of vegetation, which causes the existing cracks to widen as the root systems of trees expand Particularly detrimental in these terms are fig, willow and liquidambar (it is common in warm climates, grown locally as decorative tree whose leaves and fruit resemble those of a chestnut tree)
– Aggregate expansion,
– Salt weathering,
Since the foundations, after the construction has been completed, are usually hardly accessible, it is necessary to pay attention to prevention of the adverse impacts of potentially aggressive actions, than to repair the damage.
As Fusion bonded Epoxy coatings are inert to alkaline as well as acidic media and have very low diffusion rate for corrosive elements like chlorides, water, oxygen etc epoxy coated rebar is the best corrosion protection strategy for foundations.