Study of the historical mortars of the Holy Aedicule as a basis for the design, application and assessment of repair mortars: A multispectral approach applied on the Holy Aedicule

•Different lime-based and gypsum-based mortars determined in the Holy Aedicule.•Criteria are set to select a compatible and performing restoration mortar.•NDTs are used to examine the historical and restoration mortars on monument scale.•Analysis and evaluation throughout all stages of a restoration project.•An integrated methodology for complex monuments’ rehabilitation is presented. The rehabilitation of the Holy Aedicule of the Holy Sepulchre in Jerusalem, completed in March 2017, aimed to address the deformation problems encountered after its most recent reconstruction in 1810. A diagnostic study performed by the National Technical University of Athens (NTUA), indicated the cause of the deformations and revealed the Aedicule’s structural layers. The results permitted the design, selection and application of compatible and performing restoration mortars, while the assessment of their application was achieved through a multispectral approach and in combination with an integrated analysis throughout the rehabilitation project. The results acquired through analytical and non destructive techniques show that compatibility was ensured and the structure was adequately strengthened and concludes in a methodological approach regarding all stages of a rehabilitation project of a complex multilayered monument.