chapter  32
14 Pages



Concrete has the most unique property: of all construction materials, it provides a safe and protective alkaline environment for embedded steel reinforcement. Further, it has the inherent potential to be durable, but its ability to resist external aggressive environmental agencies and sources of internal deterioration very much depends on the care and control exercised in proportioning, placing, compacting and curing the material. There are innumerable examples in practice of concrete structures that have success fully withstood the effects of time and environment; but equally, there are many instances where human factors, which are very much involved in moulding and fabricating concrete, have led to lack of quality control and subsequent reduced durability. Protection of embedded steel

has thus become an essential component of structural design if reinforced concrete structures are to remain serviceable for the period of their design life.