Concrete Repairs Performance in service and current practice
Structural concrete in its modern form has been in use since the late 1800s and many early structures have continued in operational use for over 100 years. At the time they were constructed there were no design codes and little was known about durability. There was a general belief that concrete was a problem-free material requiring little or no maintenance. Indeed, concrete was used as a
cladding on steel structures to protect them from corrosion and fire and for the most part it has been very successful in such applications. Performance of these early structures has been surprisingly good when it is considered that cover thicknesses over the steel reinforcement were very low. Moreover, the concrete was placed by hand with no vibration, invariably had cold
construction joints, and voids were commonplace.