Evaluation of Nanolime-Silica Core-Shell for Consolidation of Egyptian Limestone Samples with Application on an Archaeological Object

Abstract

The most of limestone objects in museums, storehouses and archaeological sites suffered from fragility and weakness which lead to the degradation of these artifacts. The present paper aims to evaluate the use of some nanolime-silica core-shell for consolidation process of these weak limestone artifacts. Two concentrations (5% and 10% w/w) were prepared for consolidating the aged limestone cubic samples. After complete drying, the cubic stones were exposed to the accelerated heat aging. The evaluation of consolidation process for the treated and aged treated samples was performed by some analytical methods such as measurement of physical properties and compressive strength. While, the investigation of surface morphology was carried out by scanning electron microscope (SEM) and measurement of contact angle. The characterization process for the prepared core-shell showed the smoothness and spherical shape of the grains with approximate size of 72 nm. The results of physical properties revealed that the treated samples with 10% of nanolime-silica core-shell gave the lowest porosity (15.57%) and water absorption (6.26%). Additionally, the treated samples with 10% concentration of nanolime-silica core-shell gave the highest values of compressive strength (21.23 Cm2/ Kg) and contact angle (122.78°). Moreover, the investigation using SEM revealed that the smoothness and good penetration for the treated sample with 10% concentration of nanolime-silica core-shell. The results of the present study revealed that the efficiency of consolidation process was maximum using 10% concentration of nanolime-silica core-shell and hence it was applied for consolidation of an archaeological limestone octagonal column, Egypt.