In January, we reported on the devastating earthquake centred near the historic site of Bam in Iran. Many were killed, and the old mud-brick city was levelled. There are other archaeological sites that lie in threatening earthquake zones. Now, a new metal alloy is set to secure their existence.
Dubbed ‘Shape Memory Alloys’, the metal has the same strength as steel and can stretch up to seven percent, but nevertheless returns to its original form – if the temperature is stable. The alloy consists of titanium and nickel, and when made into metal wires, can either be entwined as a safety net around the monument or used to strengthen elements inside it.
The need for a constant temperature has been posing a particular challenge for research scientists on this project. Many of the world’s monuments under threat from earthquakes are located in desert areas, where it can be very hot during the day and equally as cold at night. In such conditions, the metal will perform as it should only during parts of a typical 24-hour period.
Now, Norwegian research scientists at Trondheim, under the leadership of SINTEF research scientist Casper van der Eijk, have come up with a solution to this problem: they are attempting to find several alloys that react under different temperatures. They will then join several threads with different properties into one wire. An important factor will be to keep the wires slim enough since historical monuments require support that is not too visible.
SINTEF is now finding and characterising the different alloys of titanium and nickel. The next stage will be to model the results on a computer program. Thereafter, Shape Memory Alloys will be used to secure those monuments most under threat.
Ultimately, this will hopefully mean that sites never again need endure the same level of utter destruction that was suffered at Bam.
This article is an extract from the full article published in World Archaeology Issue 8. Click here to subscribe