[M-IS05] Geomaterials in cultural heritage: weathering, investigation techniques, and conservation

[MIS05-P03] Study on the effect of pore size distribution on brick deterioration

Mizuki Kasuga², *Chiaki T. Oguchi¹ (1.Institute for Environmental Science and Technology, Graduate School of Science and Engineering, Saitama University, 2.Department of Engineering, Saitama University)

Keywords:Brick, Salt weathering, Experiment

In Japan, there are more than 70 brick buildings designated as Important Cultural Properties, including Tokyo Station and Tomioka Silk Mill. Those bricks originally show a variety of physical properties depending on the material mixing ratio and firing conditions at the time of manufacture. Weathering and deterioration conditions of those brick buildings were caused by brick characteristics, especially pore size distribution which is considered to be the most important factor in salt weathering, ie., the most influential type of weathering. The present study examines 6 types of handmade bricks with voids of different shapes that were prepared and carried out salt weathering experiment. The salt weathering experiments were conducted using sodium sulfate and magnesium sulfate solutions, and 11 cycles of immersion at 20°C for 12 hours and drying at 40°C for 12 hours were repeated. The results show that bricks with many micropores cause greater damage.