Monitoring of a historic building's masonry moisture content

This work presents the results of a permanent monitoring system installed at the Holy Aedicule in the Temple of Resurrection in Jerusalem. The monitoring system consisted of capacitance sensors embedded in the masonry at various heights (from the foundation to the roof), for the evaluation of the moisture content, along with thermistors for measuring the temperature inside the masonry. The results showed that the temperature inside the masonry followed the environment thermal variations around the Holy Aedicule with a small swift and voltage values change for the different heights or locations of the masonry. To convert voltage to moisture content values, samples were prepared in the laboratory, using the same grouting mortar and equipment installed at the Temple. The samples underwent tests of drying of capillary absorbed water, while simultaneously measuring their weight loss and voltage values. An optimized linear model was found appropriate to convert the voltage to moisture content values with high accuracy. With the aid of this model Holy Aedicule masonry content was assessed, for different areas and heights. Rising dampness, and human activities were identified as the main sources of moisture, especially on the south side of the monument and its foundation. The use of a network of capacitance sensors, along with suitable calibration, can serve as a promising approach for obtaining the moisture content of historic materials in real time. This low-budget, long-term, non-invasive online monitoring technique contributes to the preventive conservation of historic structures, an important step toward making them more intelligent in the digital era - Results of a monitoring system for evaluation materials' moisture content with the aid of capacitance sensors embedded in masonry with grouting mortar: The case of the Holy Aedicule, inside the Temple of Resurrection in Jerusalem - A methodology for the calibration of the voltage to moisture content values using samples and the same configuration of the installed equipment in the laboratory - A qualitative/quantitative analysis of the possible moisture sources at the Holy Aedicule