First iron
structures in
Europe have been constructed before the end of 18th century. In the
beginning, cast-iron
which was a material of low strength, was the main product
of ironworks for construction industry. Next, puddled-steel technology came,
and at the end of 19th century – cast steel
technology. There is a big difference in strength and in chemical composition
between structural steel manufactured today, and the iron/steel materials
mentioned above. Many iron/steel building
structures, constructed in the 19th century is still used. It is very often that, because of the historical
value they cannot be demolished, so they have to be renovated and strengthened.
Special technologies must be used for
strengthening of such old structures.
Usually welding is not possible. Case studies of renovating and strengthening
of iron/steel structures constructed 70 – 165 years ago are presented in the
paper. Properties of historical steel are presented as well.