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 Rubble is broken stone, of irregular size, shape and texture; undressed especially as a filling-in. Rubble naturally found in the soil is known also as 'brash' (compare cornbrash)."Rubble" def. 2., "Brash n. 2. def. 1. ''Oxford English Dictionar ...

or other infill, creating one thick wall. 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 Masonry is the building of structures from individual units, which are often laid in and bound together by mortar; the term ''masonry'' can also refer to the units themselves. The common materials of masonry construction are bricks, building ...

still uses core and veneer walls; however, the core is now generally concrete block instead of rubble, and moisture barriers are included. Often such walls end up as

cavity walls A cavity wall is a type of wall that has a hollow center. They can be described as consisting of two "skins" separated by a hollow space (cavity). The skins typically are masonry, such as brick or cinder block. Masonry is an absorbent material ...

by the inclusion of space between the external veneer and the core in order to provide for moisture and thermal control.

History

Greeks and Phoenicians

Both the early Phoenicians and Greeks used rubble-filled masonry walls. The word ''emplekton'' was borrowed from

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

ἔμπλεκτον and originally meant "rubble" but came to apply to the construction technique as well.

Romans

The Romans started with basic emplekton masonry walls, 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 Roman concrete, also called , is a material that was used in construction in ancient Rome. Roman concrete was based on a hydraulic-setting cement. It is durable due to its incorporation of pozzolanic ash, which prevents cracks from spreading. B ...

'', and eventually led to modern ferroconcrete construction.

India

The buildings of the

Taj Mahal The Taj Mahal (; ) is an Islamic ivory-white marble mausoleum on the right bank of the river Yamuna in the Indian city of Agra. It was commissioned in 1631 by the Mughal emperor Shah Jahan () to house the tomb of his favourite wife, ...

are constructed with walls of brick and rubble inner cores faced with either marble or sandstone locked together with iron

dowel A dowel is a cylindrical rod, usually made of wood, plastic, or metal. In its original manufactured form, a dowel is called a ''dowel rod''. Dowel rods are often cut into short lengths called dowel pins. Dowels are commonly used as structural ...

s and clamps. Some of the walls of the mausoleum are several metres thick.

Ancestral Puebloans

In the large complexes at Chaco Canyon, the

Ancestral Puebloans The Ancestral Puebloans, also known as the Anasazi, were an ancient Native American culture that spanned the present-day Four Corners region of the United States, comprising southeastern Utah, northeastern Arizona, northwestern New Mexico, a ...

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

Mayan

In the Puuc region, and as far south as at least

Tikal Tikal () (''Tik’al'' in modern Mayan orthography) is the ruin of an ancient city, which was likely to have been called Yax Mutal, found in a rainforest in Guatemala. It is one of the largest archeological sites and urban centers of the pre- ...

, the Mayans developed core-and-veneer walls to the point where, by the classic period, they were filled with concrete.

Problems

Traditional core-and-veneer walls suffered from moisture migration and thermal expansion and contraction. They had a low tensile strength, hence a poor resistance to twisting or stretching. 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.

Notes

External links

* shows construction and cross-section of core-and-veneer wall * showing cross-section of a core-and-veneer wall. {{DEFAULTSORT:Core-and-veneer Masonry Construction Types of wall