I need to know the mortar mix ratio for a 80 year old building with no design or construction records. I need references that did research on this topic and presented plausible methods to identify the mix rate. Thank you for your help!
Dear Ramoel,
That is difficult to answer, but this is a more practical question (what I like). - In 1936 (80 years ago - that is not this much antique) already cement was used. Do you have more information about the building itself. I assume the heritage (?) building is in Brazil? I would assume that it could be a lime-based plaster (test with HCl). As a binder for that in the best case lime putty was used, which today is difficult to get.
Authentic mortar also depends on grain size distribution of the sand and amount of loamy components (makes plaster mortar more malleable). - From a crafts point of view: mix 1 shovel lime with about 2.5 shovels of plaster sand and add not too much water (should stand on the trowel but being malleable).
A pricking-up coat with a coarse grain watery mix (cement-based) before the first plaster layer is quite helpful on the naked bricks. Bricks shall be cleaned with a wire brush before and the joints (in case that they are soft shall be scratched-out - not to deep). The plaster area needs to be wetted before and don't rub the plaster on the surface too much. You will generate unnecessary cracks.
For the final layer in the 30ties they used washed sand in a grain size range of less than 2 mm sometimes even 4 mm (lime bound with a trowel cement added).
hope that it what you wanted? - If yes, than rather try to buy old craftsmanship books, because I don't think that scientists dealing with such things, today.
Regards Ruediger
I found also some helpful documents on lime mortar:
kind regards Ruediger
Dear Ramoel: These are typically done on a case-by-case basis, sometimes using petrographic analysis. I presume that you have looked at general sources such as:
https://www.nps.gov/tps/how-to-preserve/briefs/2-repoint-mortar-joints.htm#mortarmatch
and
http://www.mapei.com/public/IT/linedocument/Mape-Antique%20GB.pdf
The following provides information on a select set of lime plasters in Mexico City dating to colonial times.
http://onlinelibrary.wiley.com/doi/10.1111/arcm.12074/full
This article provides some composition information from plasters used in Roman times.
http://onlinelibrary.wiley.com/doi/10.1111/j.1475-4754.2011.00617.x/full
Finally, the following article reports on petrographic analysis of plasters in colonial construction in Florianopolis, Brazil (the ancient capital):
https://www.researchgate.net/profile/Urs_Mueller6/publication/267566592_THE_MICRO_STRUCTURE_OF_TRADITIONAL_BRAZILIAN_LIME_PLASTERS__THE_CUSTOM_HOUSE_OF_FLORIANOPOLIS/links/54be39890cf218d4a16a5502.pdf
I hope this helps.
Conference Paper The micro structure of traditional Brazilian lime plasters -...
- Badges
- Science topic
- Similar topics
- Engineering
- Civil Engineering