About OTANI TOSHIHIRO
About SATO YOSHIAKI
About NAGANO HIROKI
About 永野工業
About AKIYOSHI YOSHITADA
About concrete
About degradation(alteration)
About hot spring
About alum
About Oita prefecture
About sulfuric acid
About sulfate
About bath house
About Beppu
About public bath house
About Mortar,concrete
About 別府
About 明礬
About 温泉
About 公衆浴場
About コンクリート
About 劣化調査