Core-and-veneer

Core-and-veneer, brick and rubble, wall and rubble, ashlar and rubble, and emplekton all refer to a building technique where two parallel walls are constructed and the core between them is filled with rubble or other infill, creating one thick wall. ^[1] Originally, and in later poorly constructed walls, the rubble was not consolidated. Later, mortar and cement were used to consolidate the core rubble and produce sturdier construction.

Modern masonry still uses core and veneer walls; however, the core is now generally concrete block instead of rubble, and moisture barriers are included. ^[2] Often such walls end up as cavity walls by the inclusion of space between the external veneer and the core in order to provide for moisture and thermal control. ^[2]

History

Greeks and Phoenicians

Both the early Phoenicians and Greeks used rubble-filled masonry walls. ^{[3] [4]} The word emplekton was borrowed from Greek ἔμπλεκτον and originally meant "rubble" but came to apply to the construction technique as well. ^[5]

Romans

The Romans started with basic emplekton masonry walls, ^[6] but developed the technique further using temporary walls (forms) that were removed after the cemented rubble (concrete) had cured. This technique was called opus caementicium , and eventually led to modern ferroconcrete construction. ^[7]

India

The buildings of the Taj Mahal are constructed with walls of brick and rubble inner cores faced with either marble or sandstone locked together with iron dowels and clamps. Some of the walls of the mausoleum are several metres thick. Koch, Ebba (2006). The Complete Taj Mahal: And the Riverfront Gardens of Agra. London: Thames & Hudson. p.  97. ISBN   978-0-500-34209-1.

Ancestral Puebloans

Chacoan Masonry types by Stephen H. Lekson

In the large complexes at Chaco Canyon, the Ancestral Puebloans used the wall and rubble technique, with walls of carefully shaped sandstone. ^[8] The Ancestral Puebloans used mud as their mortar, both with the veneer and to consolidate the core. ^[9] This core and veneer technique was also used at other Ancestral Puebloans sites outside of Chaco Canyon. ^[10] Later pueblos used mud bricks (adobe) for the veneer.

Mayan

In the Puuc region, and as far south as at least Tikal, the Mayans developed core-and-veneer walls to the point where, by the classic period, they were filled with concrete. ^{[11] [12] [13]}

Problems

Traditional core-and-veneer walls suffered from moisture migration and thermal expansion and contraction. ^[14] They had a low tensile strength, hence a poor resistance to twisting or stretching. ^[15] Tensile strength was increased by increasing the width of the walls or by providing masonry "piers" (vertical columns or ribs), either inside the wall or as additional exterior support. ^[16]

See also

• Bungaroosh
• Cavity wall

Notes

1. Vitruvius. "II.8.7". De architectura (On Architecture).
2. Weber, Richard A. (19 February 2013). "Building Envelope Design Guide – Masonry Wall Systems". Whole Building Design Guide. National Institute of Building Sciences. Archived from the original on 14 March 2013.
3. Sharon, Ilan (1987). "Phoenician and Greek Ashlar Construction Techniques at Tel Dor, Israel". Bulletin of the American Schools of Oriental Research. 267 (267): 21–42. doi:10.2307/1356965. JSTOR   1356965.
4. "Monuments and Archaeological Sites (Lesvos, Greece)" (PDF). 2011. Archived from the original (PDF) on 2 May 2014. Retrieved 13 August 2017.
5. Schofield, Richard V. (2009). "Glossary: emplekton". On architecture by Vitruvius. London: Penguin. pp. 171–172. ISBN   978-0-14-144168-9.
6. Dennis, George (1848). "Emplecton masonry". The Cities and Cemeteries of Etruria. London: John Murray.
7. Caviasca, Massimiliano (2008). "L'evoluzione della tipologia e la materia costruttiva: il muro a emplecton" (PDF) (in Italian). Politecnico di Milano (Polytechnic University of Milan). Archived from the original (PDF) on 2 May 2014. Retrieved 2 May 2014.
8. Reed, Paul F. (2008). "An Overview of the Archaeology of Chaco Canyon". In McManamon, Francis; Cordell, Lind; Lightfoot, Kent; Milner, George (eds.). Archaeology in America: An Encyclopedia. Vol. 3. Westport, Connecticut: Greenwood Press. p.  72. ISBN   978-0-313-33187-9.
9. "Masonry of the Southwest". United States National Park Service. Archived from the original on 19 June 2012.
10. Cameron, Catherine. "The Bluff Great House and the Chaco Phenomenon". Arizona Archaeological and Historical Society. Archived from the original on 1 May 2014.
11. Yant, Anna Catesby (2011). Powerful buildings: The evolution of non-domestic architecture and social interaction in the Puuc (PDF). Dissertations. Vanderbilt University. p. 133. Archived (PDF) from the original on 1 May 2014.
12. Andrews, George F. (2012). "Architectural survey Tikal, Guatemala: the great temples". Archived from the original on 1 May 2014.
13. Andrews, George F. (1999). Pyramids, Palaces, Monsters and Masks: The Golden Age of Maya Architecture, Volume 1, Architecture of the Puuc region and the northern plains areas. Lancaster, California: Labyrinthos Press.
14. Martinez, M.; Carro, G. (2007), "Ancient building requirements and the evaluation of different lime-cement mortars compositions" (PDF), 2º Congresso Nacional de Argamassas de Construção, Lisbon: Associação Portuguesa dos Fabricantes de Argamassas de Construção
15. Valcárcel, J. P.; Martín, E.; Domínguez, E.; Escrig, F. (2001), Lourenço, P. B.; Roca, P. (eds.), "Structural modelling of medieval walls" (PDF), Historical Constructions, Guimarães, archived (PDF) from the original on 21 August 2007
16. Sugiyama, Tomoyasu; Ota, Naoyuki; Nunokawa, Osamu; Watanabe, Satoshi (2006). "Development of Quakeproof Reinforcement Methods for Masonry Walls". Quarterly Report of RTRI. 47 (2): 105–110. doi: 10.2219/rtriqr.47.105 .

External links

• "Figure 14. The large number of stones used, requires strong and stable scaffolding inside the building". Contribution to the medieval building technology based on the reconstruction of a rounded church. EXARC. Archived from the original on 2 May 2014. Retrieved 2 May 2014. shows construction and cross-section of core-and-veneer wall
• "Drystone Walls in England". Britain Express. Archived from the original on 10 August 2013. showing cross-section of a core-and-veneer wall.