エジプト産モカタム層石灰岩の塩害とスレーキング特性

抄録

The Great Sphinx-Giza, Egypt was carved out of Middle Eocene limestone formations. The upper part of the statue, including the neck and the head, consists of soft and marly formations (named Maadi Formation). They are highly porous and cavernous showing the evidence of having been greatly affected by water erosion. At present, the Great Sphinx as one of the most important World Heritages is being seriously subjected to aggressive deterioration of limestone members.
Since it was not possible to employ any specimen sampled from the immediate site of the Sphinx, it was tried to investigate the process of deterioration of marly limestone in terms of Mokkatam Limestone (called Pyramid Stone) which is considered to be a little older than Maadi Formation. In the present study the process of recrystallization of salt substance on limestone surface and the transportation of salt and water through micro-pores were observed for the period of three months. The electron microscopic scanning was used to illustrate the pore-size, pore distribution and recrystallization of salt. The same test as described in this paper is recommended to be applied to the Maadi Formation for the feasibility study on the preservation of the Great Sphinx.