@techreport{oai:sucra.repo.nii.ac.jp:00012022,
 author = {小口, 千明},
 month = {},
 note = {An abandoned underground quarry of Oya-tuff has much salt efflorescence in winter. Besides salt weathering, freeze-thaw weathering and slaking must be considered because of winter temperature below 0℃ in this area and swelling clays as a component of the rock. Field survey was performed to collect salts and to measure moisture contents. Thenardate and gypsum are detected using XRD as main salts as well as zeolites. Moisture contents are relatively steady due to underground environment. Concerning concrete building, salt weathering is also observed on the pedestrian deck of Department of Engineering at Saitama University made in 1969. The observed salt minerals were trona (Na3H(CO3)2・2H2O) and calcite (CaCO3). Trona was much seen in winter but less in summer.
To know the influence of rock properties on weathering, three kinds of Oya-tuff and two kinds of concretes were used for salt experiments. In the case of Oya-tuff, the freeze-thaw and slaking experiments were performed for comparing salt experiment with Na2SO4 solution. The specimens were made square pillar specimens whose bottoms are sunk into distilled water for freeze-thaw and slaking experiments, or Na2SO4 saturated solution for salt weathering experiment. Dry conditions were performed for 24 hours in an oven set 40℃ for slaking and salt weathering experiments, and in a freezer of -15℃ for freeze-thaw experiment. Wet conditions were then carried out for 24 hours left in a room of ca. 20℃. This wet-dry cycle was repeated by 10 cycles. Through these experiments, it is cleared that the specimens for salt weathering experiment were the most severely destroyed. In the case of concretes, dense concrete specimens and porous ones (Spasars) were sunk in five solutions of H2O, trona (Na3H(CO3)2・2H2O), NaHCO3, Na2CO3 and CaSO4 in 24 hours at room temperature and then dried in an oven at 40℃. This wet-dry cycle is repeated and the specimens sunk in Na2CO3 and trona solutions are weathered. Weathering Susceptibility Index (WSI) of each case is calculated using crystallization pressure and data of pore size distribution. The WSI values are harmonized with the results of this salt weathering experiment., text, application/pdf},
 title = {塩類風化による地圏材料の劣化に関する研究},
 year = {2006},
 yomi = {オグチ, チアキ}
}