ELAICH - Educational Linkage Approach in Cultural Heritage. For more information and presentations, please visit: http://elaich.technion.ac.il/ Historic structural systems - behaviour and typical damages. Types of structural members and their effect on the behaviour of historic structures. Methods for the in situ investigation of historic structures

1. Educational Linkage Approach In Cultural Heritage Prof. Elisabeth Vintzileou – National Technical University of Athens Knowing the built heritage Module 2 Basic Cour s e Teaching Material Topic 2 . 4 Historical structural systems – behavior and typical damages Types of structural members and their effect on the behavior of historic structures Methods for the in situ investigation of historic structures Educational Toolkit

2. Prof. Elisabeth Vintzileou – National Technical University of Athens Copyright ©ELAICH Beneficiaries 2009-2012 This material is an integral part of the “ELAICH – educational toolkit” and developed as part of the project ELAICH – Educational Linkage Approach in Cultural Heritage within the framework of EuroMed Cultural Heritage 4 Programme under grant agreement ENPI 150583. All rights reserved to the ELAICH Beneficiaries. This material, in its entirety only, may be used in "fair use" only as part of the ELAICH – educational toolkit for the educational purposes by non-profit educational establishments or in self-education, by any means at all times and on any downloads, copies and or, adaptations, clearly indicating “©ELAICH Beneficiaries 2009-2011” and making reference to these terms. Use of the material amounting to a distortion or mutilation of the material or is otherwise prejudicial to the honor or reputation of ELAICH Beneficiaries 2009-2011 is forbidden. Use of parts of the material is strictly forbidden. No part of this material may be: (1) used other than intended (2) copied, reproduced or distributed in any physical or electronic form (3) reproduced in any publication of any kind (4) used as part of any other teaching material in any framework; unless prior written permission of the ELAICH Beneficiaries has been obtained. Disclaimer This document has been produced with the financial assistance of the European Union. The contents of this document are the sole responsibility of the ELAICH Consortium and can under no circumstances be regarded as reflecting the position of the European Union. Educational Linkage Approach In Cultural Heritage

3. Prof. Elisabeth Vintzileou – National Technical University of Athens Abstract The current presentation examines the historical structural systems, as well as their behavior under various loads and actions. The role of mortar is explained in connection with the developed compressive and tensile strength. Important aspects for masonry structures are examined, such as the box action and the impact of large openings. A description of the phenomenon of the earthquake is given and the most common damages observed in historic structures due to earthquake are explained. The role of timber used for the improvement of the behavior of historic structures is presented. Finally, reference is made to diagnosis, the “medicine” of historic structures, and to specific in situ investigation techniques (radar and endoscopy), which allow for the identification of the construction type of the masonry. Educational Linkage Approach In Cultural Heritage

4. Prof. Elisabeth Vintzileou – National Technical University of Athens Content Educational Linkage Approach In Cultural Heritage Table of contents of this presentation 2.4.1 Historical structural system – Historic Centre 2.4.2 Historical structural systems in Greece 2.4.3. The role of mortar 2.4.4. Important aspects for masonry structures 2.4.5. The earthquake 2.4.6. The use of timber 2.4.7. Diagnosis - The “medicine” of historic structures 2.4.8. References

6. 2.4.2. Historical structural systems in Greece Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage MATERIALS: Stones, adobe, bricks Mortar (for their connection) Timber (ties), metal (ties) Reinforcing masonry CONSTRUCTION TYPES (on wall facades): Masonry Dry stone masonry (Seldom) Adobe

7. 2.4.2. Historical structural systems in Greece Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage Rubble stone masonry “ Plinthoperiklisti ” Semi-cut or cut stone masonry CONSTRUCTION TYPES ( within the thickness ): THREE-LEAF (OR MULTI-LEAF) MASONRY: A general term, including a large variety of construction types and combination of materials.

8. 2.4.3. The role of mortar Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage It connects stones / It “ smoothens ” their “ angles ” / It fills voids (air, water, temperature, insects , … ) It constitutes, however, the weak material !!! 20-100 MPa 1 - 5 MPa Fortunately, the strength of masonry lies between the two Very small ( it depends , mainly on the properties of mortar) Therefore, masonry is working well under COMPRESSION, but very poorly under TENSION. Moreover Failure under very small deformation ( 1,0-1,5 mm for a wall, 1m high) But, …

9. 2.4.4. Important aspects for masonry structures Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage 1. The “ box ” action The cube (consisting of walls, floors or floor and roof) is not deformable . If we reduce the number of sides (for example, if the roof has collapsed), then the “ box ” becomes more deformable. Thus, the occurrence of damages to masonry becomes more probable. This is also the case when the walls are not well tied together in the corners of the building. 2. We should not have large openings (doors and windows) The available area of masonry is reduced and the flow of forces deviates from its (favorable) vertical path.

10. 2.4.5. The earthquake Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage The soil is moving Simplification: We assume that for an acceleration of the earthquake equal to α g, the building is subject to an “ inertial force ” , F=( α g)M Μ the mass of the building Horizontal (and vertical) « Force » plan

11. 2.4.5. The earthquake Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage Α D C Β The length of the diagonal Α C is increased . In-plane shear

12. 2.4.5. The earthquake Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage

13. 2.4.5. The earthquake Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage Out-of-plane bending

14. 2.4.5. The earthquake Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage

15. 2.4.6. The use of timber Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage Is there any way of improving the behavior of historic structures and, thus, limit their damages? The use of timber . Example : Tension in the timber element. Its tensile strength is high. Thus, either the opening of the crack is prevented, or (if the crack opens) its width is limited. Were the old Constructors aware of the contribution of timber elements? Yes, indeed. And they applied this solution systematically, since (at least) 2500 B.C.

16. 2.4.6. The use of timber Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage 17 th -19 th : More than 70 historic centres throughout the country Large variety in typology

17. 2.4.6. The use of timber Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage The multiple role of timber ties Uniform distribution of loads Connecting the leaves of masonry Connecting perimeter and interior walls Reinforcing the regions around openings Reinforcement

18. 2.4.6. The use of timber Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage Tying the entire building !!! Timber ties . For the Byzantines, IMANDOSIS (from the word imas, gen. imandos-strap) Saint John Chrysostom ( 349 ? -407 A.D .) Epistle to the people of Antioch (Homily VI): “ … for what the stay-beams (timber ties) are in houses, that rulers are in cities; and in the same manner, as if you were to take away the former, the walls being disunited would fall in upon one another …” Dictionary of Souda (10 th century ) Imandosis is defined as a tying system

19. 2.4.6. The use of timber Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage The disadvantage is that timber has a limited lifetime. Under constant humidity conditions, it is quite durable. Under changing humidity conditions and when humidity exceeds a certain limit, timber is liable to biological attack and disintegration. The structure is deprived of the positive effect of timber ties and, furthermore, the strong regions become weak regions for the building .

21. 2.4.7. Diagnosis - The “medicine” of historic structures Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage INVESTIGATION THROUGH RADAR A high frequency electromagnetic sign (100ΜΗz-1GHz) is emitted in masonry and it is reflected. One can locate interfaces, or different materials or regions of high humidity or voids, or metallic objects, … Katholikon (main church) of Dafni Monastery, LCPC Example of application RADAR SIR2000 File 477 ( Path C ): the thickness of stones is schematically shown on the picture .

22. 2.4.7. Diagnosis - The “medicine” of historic structures Prof. Elisabeth Vintzileou – Topic 2.4: Historical structural systems – behavior and typical damages Educational Linkage Approach In Cultural Heritage Katholikon of Dafni Monastery ENDOSCOPY A small diameter hole is drilled, a camera is inserted (~1cm in diameter). Observation and pictures taking.