000002353 001__ 2353
000002353 005__ 20141118153435.0
000002353 04107 $$acze
000002353 046__ $$k2013-09-11
000002353 100__ $$aMtani, I.
000002353 24500 $$aSalt load in Tanzanian historic lime mortars

000002353 24630 $$n3.$$pProceedings of the 3rd Historic Mortars Conference HMC13
000002353 260__ $$bGlasgow : University of the West of Scotland, 2013
000002353 506__ $$arestricted
000002353 520__ $$2eng$$aFor many centuries salt remains the object of international scientific debate due to its destructive behaviour in porous building materials. Using the same procedures as the ones used by the current studies on the climatology of salt crystallisation, we replicated this effect on more specific and less subjective two buildings, selected based on their location, age, authenticity, historical value, and possible results deployment hence, the study of two Tanzanian historic buildings in salt prone areas and those located away from the ocean. Despite receiving only minor restorations, these buildings have lasted for more than 100 years. The main concern is their future existence, which is threatened by daily receipt of salty oceanic sprays. The objective of this study was to characterise them, determine the salt profile, salt load and salt damage on external walls and to predict environmental conditions necessary to limit salt deterioration. Chemical mineralogical techniques characterised samples collected at different heights and depths from building walls. The study used wet chemical methods to obtain water soluble salt contents (Cl -, SO42-, NO3-) supported by X-Ray Diffraction (XRD), Mercury Intrusion Porosimetry (MIP) and microscopical analysis using thin sections. The ECOS program RUNSALT determined the behaviour of salt mixtures in tropical climates for each building. Analytical results were correlated to provide the salt loads of the walls. Due to the porous nature of lime mortars (25 – 37vol%) used, the walls exposed to climatic conditions such as those facing the ocean revealed more surface crystallisation of salt, than the ones not facing the ocean. While, halite occupies the major part of the walls, there are traces of nitrate at the level of one meter on the walls of desolated buildings and sulphate is predominant at 3 m, especially in buildings located in urban areas. RUNSALT supported these results by showing that the local environmental conditions caused the crystallisation of halite, sylvite, niter and gypsum.

000002353 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000002353 653__ $$aHistoric Lime Mortars, Historic Buildings, Salt Load, Salt Damage, Salt Crystallisation

000002353 7112_ $$a3rd Historic Mortars Conference$$cGlasgow, Scotland (UK)$$d2013-09-11 / 2013-09-14$$gHMC13
000002353 720__ $$aMtani, I.$$iMiddendorf, B.
000002353 8560_ $$ffischerc@itam.cas.cz
000002353 8564_ $$s789315$$uhttp://invenio.itam.cas.cz/record/2353/files/Mtani - Salt load in Tanzanian historic lime mortars.pdf$$y
             Original version of the author's contribution as presented on CD, .
            
000002353 962__ $$r2223
000002353 980__ $$aPAPER