in London uses a trabeated exoskeleton. structure In the modern era, stone has been largely relegated to being a cosmetic element of buildings, often used as decorative cladding on
steel-reinforced concrete. This is despite its wide historical use in large compressive structures: 50-m bridges and colosseums in Roman times, ~65-m tall cathedrals since the
Middle Ages, and 12-story apartment buildings built in the 1690s.
Modern stonemasonry techniques •
Stone veneer is used as a protective and decorative covering for interior or exterior walls and surfaces. The veneer is typically 1 in (25.4 mm) thick and must weigh less than 15 lb per square foot (73 kg m−2) so that no additional structural supports are required. The structural wall is put up first, and thin, flat stones are mortared onto the face of the wall. Metal tabs in the structural wall are mortared between the stones to tie everything together, to prevent the stonework from separating from the wall. •
Massive precut stone. Also known as "
prefabricated stone", "
massive stone", "pre-sized stone", or "pré-taille" stone. • Post-
tensioned stone. A high-performance composite construction material consisting of stone held in compression with tension elements. The tension elements can be connected to the outside of the stone, but more typically uses
tendons threaded internally through a duct formed from aligned drilled holes. • Pre-
tensioned stone. Using an epoxy shear connector, early experiments have shown that it is possible to pre-tension stone, maintaining the tendon under tension while the liquid epoxy is injected and allowed to set. • Digital stereotomy. Using
CAD and computer models of load, modern designers are able to cut complex vaults, arches, and other arrangements of precisely cut ashlars. Antecedents to this discipline include curved vaults, and also flat vaults that use a concentric
flat arch vault and the
Abeille flat vault. Using digital design and machining, such compression structures can be shapes into complex compressive structures. Leaders in this area include Giuseppe Fallacara and Philippe Block. • Trabeated stone exoskeleton. In the modern era, post-and-lintel construction was adapted use as a stone exoskeleton in the design of
15 Clerkenwell Close. The stone exoskeleton method is a variant of the
massive precut stone method: the ends of the posts and lintels are precisely precut offsite prior to assembly by crane. At least two more trabeated stone exoskeleton high-rise buildings are underway, one in London, and another in Bristol. • Stone bricks. Small stone ashlars that are cut by the quarry to brick sizing to allow their use in standardized brick-laying workflows. Cost is similar to clay composite bricks, but with greatly reduced carbon emissions. As stone does not change size like fired clay bricks, brick-sized stone ashlars do not require expansion joints. •
Cyclopean concrete. This method uses a combination of
cyclopean masonry and
rubble masonry: boulders and or rubble are placed in a form (or in a ditch), and concrete is poured on top to bind the stones together before removing the form. Variations of this include
Frank Lloyd Wright's 'desert masonry' and Institut Balear de l'Habitatge's cyclopean concrete blocks, which are cast in a large slab and precisely sawn for use as prefabricated masonry in the
massive precut stone system. •
Slipform stonemasonry is a variation of Cyclopean concrete stone-wall construction that uses formwork to contain the rocks and mortar while keeping the walls straight. Short forms, up to two feet tall, are placed on both sides of the wall to serve as a guide for the stonework. Stones are placed inside the forms with the good faces against the formwork. Concrete is poured behind the rocks. Rebar is added for strength, to make a wall that is approximately half reinforced concrete and half stonework. The wall can be faced with stone on one side or both sides. • Formwork stone. "Pierre banchée" in French. Uses stone tiles or ashlars as
shuttering for pouring concrete. These are left in place after the concrete sets. This is the inverse procedure to stone cladding, where the stone tiles are attached to the concrete after the temporary shuttering has been removed. Developed by
Fernand Pouillon to accelerate construction. Formwork stone is distinct from cyclopean concrete in that the former uses rectilinear tiles, while the latter uses boulders and/or
cobblestone.
Massive precut stone Massive precut stone is also known as "prefabricated", or "pre-sized" stone is a modern method of building with load-bearing stone. Precut stone is a
DFMA construction method that uses large machine-cut stone blocks with precisely defined dimensions to rapidly assemble buildings in which stone is used as a major or the primary load-bearing material. Massive precut stone construction was originally developed by
Fernand Pouillon in the postwar period. He referred to the method as "pierre de taille" or "pré-taille" stone. It became possible through innovations by Pouillon and Paul Marcerou, a masonry engineer at a quarry in Fontvieille, to adapt high-precision saws from the timber industry to quarrying and stone sawing. The key technique of massive precut (MP) stone is to cut stone ashlars to precise dimensions that match the architect's plan such that the stones can be dropped into place by crane for rapid construction. The concrete is sawn into massive ashlars for crane assembly. Enables reuse of rough plum stones from traditional stone masonry.
Benefits of massive precut stone construction MP stone construction has advantages over conventional masonry and concrete construction. • Build speed. The use of precisely cut and numbered ashlars, combined with crane-assisted assembly, significantly reduces construction time compared to traditional stone-masonry techniques. • Aesthetics. Compared to concrete and other materials, massive precut stone construction yields visually striking and distinctive buildings that showcase the natural beauty of stone. • Environmental benefits. The use of a material with lower embedded carbon contributes to a more sustainable building process, minimizing the environmental impact. Lower carbon emissions: load-bearing stone construction emits around one-tenth the carbon as a comparable concrete building. As 80% of energy is non-grid fossil fuel, and construction is responsible for 8% of carbon emissions, the replacement of coal-burning concrete production with lower-energy dimension-stone production could have a substantial impact on net-zero goals. • Reusability. When a building has reached the end of its usefulness, massive rectilinear ashlars are easily reused in new construction. Stone has great compressive strength, so is ideal in compressive structures like
stone arches. However, it has relatively weak flexural strength (compared to steel or wood), so in isolation cannot be safely used in wide spans under tension. == History of stonemasonry ==