The artificial weathering test was conducted to observe the change of the strength of the weathered rock for the purpose of the geotechnical assessment of historical monuments in Korea. It is shown that the largest reduction in tensile strength occurred from specimens experiencing both the crystallisation and heating-cooling cycles. It is suggested that in-door environment should be provided to the weathered historical monuments, especially located near the sea shore.
Nous avons eprouve la desagregation artificielle en vue d'evaluer Ie changement des roches desagregees des monuments historiques en Coree du Sud. Il en resulte que la grande reduction des valeurs de la force extensible s'est produit dans les echantillons, executes par deux experimentations à la fois, Ie selcristalisation et les cycles de chauffage-congelation. Il s'ensuit qu'on devrait construire l'environnement d'interieur pour prevenir contre la desagregation des monuments historiques, situes en particulier au bord de la mer.
Der kuenstiiche Verwitterungstest wurde durchgefuehrt zur Einschatzung der Festigkeitsveranderungen der wettergegerbten Steinen in den historischen Denkmalern. Daraus resultierte, daß die Munster, die durch die SaIz-Kristallisierung und zugleich den Erwarmung-Kuehlung-Zyklen getestet wurden, hinsichtlich der Zugfestigkeit am größten reduziert werden. Diese Resultate zeigten, daß die Zimmerumstande vorgesorgt werden sollen, um die fortdauemde Verwitterung der historischen Denkmaler vorzubeugen, die sich besonders nahe an der Kuste verbreiten.
In Korea, there exists a number of historical monuments which are made of rocks, especially granitic rocks. Most of them are highly valuable in terms of national history and culture. Older ones among them were built in A.D. 500 and have been weathered for 1500 years (Hur, 1994). The degree of weathering mainly depends on the location of the historical monuments, i.e. much more weathered in urban area and less weathered in rural area. Other factors affecting the degree of weathering are rainfall, temperature, freezing of water during the winter. Although it is known that these monuments have been severely weathered (Lee, 1993), no systematic work has been conducted to assess the weathering states and to suggest any method to slow down the weathering process. The purpose of this study is focused on the assessment of the geotechnical properties of the weathered rocks and the analysis of the main factors affecting the weathering.
From a literature review, it is generally known that most of Korean historical monuments were made of granite (Hur, 1994). Similar granites from the weathered outcrops in Taejon city were carefully selected based on their similarities, i.e. same composition, same weathering state, because no direct sampling of the historical monuments was allowed. By this, a total number of 20 granite blocks were selected for coring. A total of twelve cores having 50mm diameter and 25mm thickness, were prepared for the Brazilian test which was adopted in this study because tensile failure is more sensitive to the effect of weathering than the compressive failure (Park, 1994). A literature review showed a variety of artificial weathering conditions, i.e. weathering under the slow and continuous flow of acidic solution (Augustithis, 1983), weathering cycles under temperature changes and liquid treatment (Ihalainen and Uusinoka, 1994), combined weathering by cycled process of water soaking, drying, fly ash abrasion, acid dip, salt dip and freezing (Bortz and Wonneberger, 1995). Each process represents the specific weathering condition, e.g. acid dip simulating the acid rainfall in urban area.
