Comparing Water Repelling Penetrants on Antique Masonry

Antique, or low fire, brick has suffered critical damage from repairs using Portland Cement, specifically water damage, as moisture cannot move equally throughout both materials.The effects of this water intrusion include spalling, stains, efflorescence, algae growth, and a decrease in insulating properties.The best way to continue preservation is to block moisture from entering the brick using a water repelling penetrant.This research will compare the most commonly used penetrants on low-fire brick and determine which product is best for preservation.Water repelling abilities as well as water vapor permeability will be tested using: Rilem tubes, a freeze/thaw chamber, and the ASTM water vapor permeability test.The penetrants being tested are: siloxane and room temperature vulcanizing (RTV) silicone. Proceedings of the 2019 Conference for Industry and Education CollaborationCopyright ©2019, American Society for Engineering Education on the brick face.In accordance with ASTM testing standards measurements are taken at 5, 10, 15, 20, 30 and 60 minutes [20] [12] [11]. Preliminary resultsThis study is ongoing and there is limited data available with which to make conclusions.For the few tests done on the mock structure the RTV silicone has performed better at stopping the water from the RILEM tube, this was expected as the vulcanization produces a more robust repelling penetrant.The permeability test is a critical part of the function and has yet to be conducted, those results coupled with the repelling ability will be a better indicator of overall performance. Further InvestigationThe next steps in this study are to continue the weekly RILEM tube testing, conduct the water vapor permeability test IAW ASTM E96, analyze results from the XRD and take photos using an FTIR microscope.