Characterization of natural and consolidated stones from Jordan with non-destructive ultrasonic technique and physico-mechanical methods

摘要

The purpose of this dissertation was to investigate different stone samples (limestone, basalt and marble) from five important archaeological sites in north and northeast Jordan for the purpose of their conservation. This research focused on the use of non-destructive ultrasonic technique as validated by traditional physico-mechanical methods for the study of the weathering of the selected stones and their durability and the evaluation of the effectiveness of consolidation treatments. The selected stones were characterized and the changes in their properties after artificial weathering and consolidation were studied.It was found that the susceptibility of the studied stone samples to salt damage is determined by their petrophysical rather than mechanical properties. In terms of loss of stone material, the damage induced by the crystallization of salt in the stones seems to be dependent on their proportion of micropores and free porosity. Durability estimators for the evaluation of the weathering resistance of stone were consequently developed.The study provided additional evidence that ultrasonic technique is an effective method for estimating the degree of cracking and evaluating the effectiveness of stone consolidation treatments. Ultrasonic velocity seemed to correlate well with the degree of cracking in the stones. This implies that weathering classification schemes, such as those already existed for marble, based on correlation between ultrasonic velocity and increasing porosity can be developed for the studied stones. However, it is necessary to study these correlations for the particular stones in fresh and different weathering conditions. This dissertation recommends the in situ application of ultrasonic technique for the assessment of the weathering condition of Jordanian archaeological stones and for the evaluation and control of consolidation treatments.