lime and earthquakes

[rebeccac]

What's the thinking on lime mortar in Earthquake zones? Our Italian house is 30 miles from L'Aquila where the large earthquake struck last week and so far its shaken but not stired ! I'll be seeing exactly how it is next week.

We are using lime throughout and have only been able to do this as we haven't needed full planning permission - that would mean using cement . We haven't added pozzolana or brick dust to our mortar but should we have ? Our thinking was to try to achieve a more flexible material that would be able to move slightly but was this the right thing to do?

Interestingly its been the modern buildings that seem to have caused the most damage in L'Aquila but lots of that is because of local corruption - not using the best quality materials etc. Old buildings have collasped but mainly those that have been abandoned for years or not maintained.

 

[Jon Maine]

My mother in law lives in Umbria and the buildings there are all very limey. However they do seem to put big slabs of reinforced concrete at floor and roof levels to tie it all together.

Anything flexible is better for absorbing shock. Bamboo scaffolding is used in some earthquake zones still purely because if a quake hit steel scaffold would fold up.

 

[biffvernon]

Bamboo scaffolding is used in some earthquake zones still purely because if a quake hit steel scaffold would fold up.

That's an interesting notion, but is it true. Bamboo scafflolding is used across much of SE Asia, not all of which is in earthquake zones. I'd have though the main reasons for using it were tradition and price. Even in an earthquake zone, the chances of a big quake just when you had the scaffolding up must be pretty slim.

A concrete beam roof must be about the worst possible thing to have over your head in an earthquake. I'd prefer a timber frame. In The Great Market Rasen Earthquake of 2008 ( I don't suppose many of the good folk of L'Aquila heard about that one) our house was a little rattled and some of the cracks in the plaster are now wider and longer than formerly.

 

[Jon Maine]

A concrete beam roof must be about the worst possible thing to have over your head in an earthquake. I'd prefer a timber frame. In The Great Market Rasen Earthquake of 2008 ( I don't suppose many of the good folk of L'Aquila heard about that one) our house was a little rattled and some of the cracks in the plaster are now wider and longer than formerly.

My thoughts entirely, but it seems to be what they do.

 

[michael]

My wife’s family are from southern Italy and their hill top village plus many other surrounding villages was destroyed by an earth quake in the 1980’s killing hundreds. The original village, beautiful as it was, was constructed entirely out of stone and lime mortar and had stood for centuries but fell like a pack of cards when the earthquake struck. The entire village was rebuilt with reinforced concrete frame buildings and is now as ugly as sin but is apparently now earthquake proof.

 

[rebeccac]

Actually if the buildings are like those in Abruzzo the mortar consists of mud or earth and if you are very lucky just a bit of lime. Mostly people were too poor to afford it so they used clay .This is what we had in our place.Very unstable.

There is a common misconception that old stone houses are not safe in earthquakes but there are now lots of ways to retro-fit the house without losing its appeal or its historic materials.

Unfortunately its a lot easier and cheaper to construct these ugly concrete block houses that blight much of the beautiful Abruzzi landscape.

 

[michael]

I’ve always wondered what happened to the piles of stone that was left after the 1980’s earthquake close to the Avelino area in southern Italy. No doubt it was unscrupulously whisked away to repair Tuscan villas. Ironically the people in my in-laws village are very happy with their concrete apartments which have white marble staircase treads and all mod cons like kitchens, bathrooms and running water. A far cry from the days before the earthquake when they shared part of their homes with the livestock.