Assessment of the effectiveness of water repelent and antigraffiti treatments on Itararé Sandstone
DOI:
https://doi.org/10.11606/issn.2316-9095.v18-144298Keywords:
Water repellent products, Antigraffiti product, Itararé Sandstone, Stone Conservation, RestorationAbstract
In stone heritage, the rock is exposed to the effects of weathering. There are treatment and protection products to delay this process. However, they can damage the heritage more than the weathering itself if they are not compatible with the rock. The Municipal Theater of São Paulo is an important building in the old center of the city. Its front façade is cladded with Itararé Sandstone, which is a very fragile rock due to the presence of smectite in its composition. This mineral degrades very easily in the presence of water. Aiming to study a means of protecting this stone against the action of moisture, two water repellents (siloxane — H1 — and oligomeric propyl siliconate — H2) were tested. Another problem that strikes urban centers is graffiti vandalism, mainly when it comes to Itararé Sandstone since it is porous and its cleaning is not totally effective. Also, the products used leave residues that harm its durability. To protect the stone from graffiti, an antigraffiti (AG) product was also tested. The tests performed were capillarity, Karsten tube, contact angle measurement, scanning electron microscope, mercury porosimetry, wetting and drying cycles, ultrasonic pulse velocity, spectrophotometry and depth of penetration. The water repellents showed similar behavior, however, H1 decreased the porosity of the rock and did not completely polymerize. The antigrafitti product darkened the rock and changed the distribution of pores’ size.
Downloads
Downloads
Published
Issue
Section
License
Authors who publish in this journal shall comply with the following terms:
- Authors keep their copyright and grant to Geologia USP: Série Científica the right of first publication, with the paper under the Creative Commons BY-NC-SA license (summary of the license: https://creativecommons.org/licenses/by-nc-sa/4.0 | full text of the license: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode) that allows the non-commercial sharing of the paper and granting the proper copyrights of the first publication in this journal.
- Authors are authorized to take additional contracts separately, for non-exclusive distribution of the version of the paper published in this journal (publish in institutional repository or as a book chapter), granting the proper copyrights of first publication in this journal.
- Authors are allowed and encouraged to publish and distribute their paper online (in institutional repositories or their personal page) at any point before or during the editorial process, since this can generate productive changes as well as increase the impact and citation of the published paper (See The effect of Open Access and downloads on citation impact).