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 M. Apostolopoulou, E.T. Delegou, Emm. Alexakis, M. Kalofonou, K.C. Lampropoulos, E. Aggelakopoulou, A. Bakolas, A. Moropoulou ⇑ Laboratory of Materials Science and Engineering, School of Chemical Engineering, National Technical University of Athens, Athens, Greece highlights  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. article info Article history: Received 27 February 2018 Received in revised form 1 June 2018 Accepted 2 June 2018 Keywords: Historical mortar Restoration mortar Compatibility Performance Holy Aedicule NDTs Scientific support Multispectral assessment Multiscale analysis abstract 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, selec- tion 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 anal- ysis 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 mul- tilayered monument. Ó 2018 Elsevier Ltd. All rights reserved. 1. Introduction The study of a monument’s historical mortars prior to any restoration interventions is crucial, both for the determination of the decay mechanisms its building materials are subjected to, as well as for the establishment of the demands which a restoration mortar should fulfill in order to achieve compatibility and at the same time the desired performance. Compatibility, in international literature, is assessed in terms of a material having no negative impact on the historical materials and the structure as a whole, whilst performance is interlinked with the improvement of the structure to sustain static and dynamic loads. Thus, compatibility of the restoration mortar can be addressed in relation to the histor- ical mortars of the masonry, through a reverse engineering methodological approach, and assessed in relation to all building elements of the structure by achieving a homogenous mechanical and hygric behavior [1–7]. Performance of a restoration mortar is linked with compatibility criteria and is evaluated through the improvement of the dynamic behavior of the structure as com- pared to its original state [8]. During the restoration mortar design and selection process, compatibility and performance are assessed on material level through analytical techniques (physical- chemical, mechanical characteristics) and on monument level https://doi.org/10.1016/j.conbuildmat.2018.06.016 0950-0618/Ó 2018 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: amoropul@central.ntua.gr (A. Moropoulou). Construction and Building Materials 181 (2018) 618–637 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat