Terrazzo is a composite material, poured in place or precast, which is used for floor and wall treatments. It consists of chips of marble, quartz, granite, glass, or other suitable material, poured with a cementitious binder (for chemical binding), polymeric (for physical binding), or a combination of both. Metal strips often divide sections, or changes in color or material in a pattern. Additional chips may be sprinkled atop the mix before it sets. After it is cured it is ground and polished smooth or otherwise finished to produce a uniformly textured surface. "Terrazzo" is also often used to describe any pattern similar to the original terrazzo floors. [1]
Although the history of terrazzo can be traced back to the ancient mosaics of Egypt, its more recent predecessors come from Italy. The form of terrazzo used today derives partly from the 18th century pavimento alla Veneziana (Venetian pavement) and the cheaper seminato.Pavimento alla Veneziana had workers place marble fragments next to each other in a mortar base. Terrazzo is also related to the technique seminato for which workers tossed larger marble chips into the cement that was then ground and polished. Together, these methods create the generic form of terrazzo that involves pieces of stone that are bonded to a cement bed. Terrazzo was first introduced in the United States in the late 1890s, but did not achieve popularity until the 1920s. [2] Until then it was hand polished with a long handled tool called a galera. [2] Due to its likelihood of cracking, terrazzo was used at a small scale in comparison to the large expanses we see today. Two inventions resulted in its rise in popularity: divider strips and the electric grinding machine. The invention of divider strips by L. Del Turco and Bros. in 1924 contained the cracking of terrazzo by allowing the material greater space to expand and shrink after installation. This invention made terrazzo a durable and reliable material in addition to allowing for further design work within the floor. [3] Installers use the dividing strips as guides when they work with different colored terrazzo. Additionally, the electric grinding machine and mechanization of the production process cut down on costs and installation time, making terrazzo an affordable flooring option.
Art Deco and Moderne styles from the 1920s to 1940s favored terrazzo with the dividers allowing for straight or curved lines that increased the decorative potential. [4] The popularity of terrazzo led to an increase in installers in the 1920s. The National Terrazzo and Mosaic Organization was formed in 1931 to further professionalize the practice of terrazzo installation. [5] One of the best-known examples of terrazzo is the Hollywood Walk of Fame. Created in 1958, the walk honors celebrities in the form of a terrazzo star that displays their name. [6]
Archaeologists have adopted the term terrazzo to describe the floors of early Neolithic buildings (PPNA and PPNB, ca. 9,000–8,000 BC) in Western Asia constructed of burnt lime and clay, colored red with ochre and polished. The embedded crushed limestone gives it a slightly mottled appearance. The use of fire to produce burnt lime, which was also used for the hafting of implements, predates production of fired pottery by almost a thousand years.[ citation needed ] In the early Neolithic settlement of Çayönü in eastern Turkey about 90 m2 (970 sq ft) of terrazzo floors have been uncovered. The floors of the PPN B settlement of Nevalı Çori measure about 80 m2 (860 sq ft). They are 15 cm (5.9 in) thick, and contain about 10–15% lime.
These floors are almost impenetrable to moisture and very durable, but their construction involved a high input of energy. Gourdin and Kingery (1975) estimate that the production of any given amount of lime requires about five times that amount of wood. [7] [ clarification needed ] Recent experiments by Affonso and Pernicka [8] have shown that only twice the amount is needed, but that would still amount to 4.5 metric tonnes of dry wood for the floors in Çayönü. Other sites with terrazzo floors include Nevalı Çori, Göbekli Tepe, Jericho, and Kastros (Cyprus).
Terrazzo artisans create walls, floors, patios, and panels by exposing marble chips and other fine aggregates on the surface of finished concrete or epoxy-resin. Much of the preliminary work of terrazzo workers is similar to that of cement masons. Marble-chip, cementitious terrazzo requires three layers of materials. First, cement masons or terrazzo workers build a solid, level concrete foundation that is 3 to 4 inches (76 to 102 mm) deep. After the forms are removed from the foundation, workers add a 1 inch (25 mm) layer of sandy concrete. Before this layer sets, terrazzo workers partially embed metal divider strips in the concrete wherever there is to be a joint or change of color in the terrazzo. For the final layer, terrazzo workers blend and place into each of the panels a fine marble chip mixture that may be color-pigmented. While the mixture is still wet, workers toss additional marble chips of various colors into each panel and roll a weighted roller (100–125 pounds (45–57 kg)) over the entire surface.
In the 1970s, polymer-based terrazzo was introduced and is called thin-set terrazzo. Initially polyester and vinyl ester resins were used as the binder resin. Today, most of the terrazzo installed is epoxy terrazzo. The advantages of this material over cementitious terrazzo include a wider selection of colors, 1⁄4 to 3⁄8 inch (6.4 to 9.5 mm) installation thickness, lighter weight, faster installation, impermeable finish, higher strength, and less susceptibility to cracking. The disadvantage of epoxy resin–based terrazzo is that it can only be used for interior, not exterior, applications. Epoxy-based terrazzo will lose its color and slightly peel when used outdoors, whereas cement-based terrazzo will not. In addition to marble aggregate blends, other aggregates have been used, such as mother of pearl and abalone shell. Recycled aggregates include: glass, porcelain, concrete, and metal. Shapes and medallions can be fabricated on site by bending divider strips, or off site by water-jet cutting.
When the terrazzo is thoroughly cured, helpers grind it with a terrazzo grinder, which is somewhat like a floor polisher, only much heavier. Slight depressions left by the grinding are filled with a matching grout material and hand-troweled for a smooth, uniform surface; it is then cleaned, polished, and sealed. [9]
Terrazzo installation includes both bonded and unbonded methods. Bonded systems include: bonded underbed, monolithic, chemically bonded, and the most recent, thin set method (epoxy resin). Bonded terrazzo is applied over a sand-cement mortar underbed which sits on top of a concrete slab. The sand-cement layer allows for variations in the finished concrete slab that it sits on. Monolithic terrazzo is applied directly over an extremely flat and high quality concrete sub-floor. Thin-set terrazzo does not require a concrete sub-floor. Instead, a flexible membrane can be installed so that cracks do not appear on the surface. [10] Unbonded includes the sand cushion method which uses wire reinforcing, an isolation sheet, and sand dusting that absorbs any movement from the concrete slab. [11]
Although terrazzo derives from the mosaic artform, it does not place individual pieces in a decorative pattern. Instead, small pieces are thrown into the mortar base creating a more uniform surface appearance. Decorative patterns are created by using dividers which creates lines between different colored terrazzo mixtures.
Cracking is the most common form of failure and is typically caused by the structural system that supports the terrazzo rather than the material itself. Contact with alkalis or acids can deteriorate the bonding agents used in terrazzo. As the aggregates are often marble dust which is calcium carbonate, strong acid can also cause deterioration to the aggregates. When partial replacement is necessary, a "bracketing" system mixing and matching different chips is used to create potential matches. [11] Aged terrazzo can be resurfaced to restore its original look by re-polishing. [12]
Concrete is a composite material composed of aggregate bonded together with a fluid cement that cures to a solid over time. Concrete is the second-most-used substance in the world after water, and is the most widely used building material. Its usage worldwide, ton for ton, is twice that of steel, wood, plastics, and aluminium combined.
Flooring is the general term for a permanent covering of a floor, or for the work of installing such a floor covering. Floor covering is a term to generically describe any finish material applied over a floor structure to provide a walking surface. Both terms are used interchangeably but floor covering refers more to loose-laid materials.
A road surface or pavement is the durable surface material laid down on an area intended to sustain vehicular or foot traffic, such as a road or walkway. In the past, gravel road surfaces, macadam, hoggin, cobblestone and granite setts were extensively used, but these have mostly been replaced by asphalt or concrete laid on a compacted base course. Asphalt mixtures have been used in pavement construction since the beginning of the 20th century and are of two types: metalled (hard-surfaced) and unmetalled roads. Metalled roadways are made to sustain vehicular load and so are usually made on frequently used roads. Unmetalled roads, also known as gravel roads or dirt roads, are rough and can sustain less weight. Road surfaces are frequently marked to guide traffic.
Stucco or render is a construction material made of aggregates, a binder, and water. Stucco is applied wet and hardens to a very dense solid. It is used as a decorative coating for walls and ceilings, exterior walls, and as a sculptural and artistic material in architecture. Stucco can be applied on construction materials such as metal, expanded metal lath, concrete, cinder block, or clay brick and adobe for decorative and structural purposes.
Lime plaster is a type of plaster composed of sand, water, and lime, usually non-hydraulic hydrated lime. Ancient lime plaster often contained horse hair for reinforcement and pozzolan additives to reduce the working time.
A countertop, also counter top, counter, benchtop, worktop or kitchen bench, bunker is a raised, firm, flat, and horizontal surface. They are built for work in kitchens or other food preparation areas, bathrooms or lavatories, and workrooms in general. The surface is frequently installed upon and supported by cabinets, positioned at an ergonomic height for the user and the particular task for which it is designed. A countertop may be constructed of various materials with different attributes of functionality, durability and aesthetics, and may have built-in appliances, or accessory items relative to the intended application.
Engineered stone is a composite material made of crushed stone bound together by an adhesive to create a solid surface. The adhesive is most commonly polymer resin, with some newer versions using cement mix. This category includes engineered quartz (SiO2), polymer concrete and engineered marble stone. The application of these products depends on the original stone used. For engineered marbles the most common application is indoor flooring and walls, while the quartz based product is used primarily for kitchen countertops as an alternative to laminate or granite. Related materials include geopolymers and cast stone. Unlike terrazzo, the material is factory made in either blocks or slabs, cut and polished by fabricators, and assembled at the worksite.
Metakaolin is the anhydrous calcined form of the clay mineral kaolinite. Rocks that are rich in kaolinite are known as china clay or kaolin, traditionally used in the manufacture of porcelain. The particle size of metakaolin is smaller than cement particles, but not as fine as silica fume.
A diamond tool is a cutting tool with diamond grains fixed on the functional parts of the tool via a bonding material or another method. As diamond is a superhard material, diamond tools have many advantages as compared with tools made with common abrasives such as corundum and silicon carbide.
Damp proofing in construction is a type of moisture control applied to building walls and floors to prevent moisture from passing into the interior spaces. Dampness problems are among the most frequent problems encountered in residences.
Decorative concrete is the use of concrete as not simply a utilitarian medium for construction but as an aesthetic enhancement to a structure, while still serving its function as an integral part of the building itself such as floors, walls, driveways, and patios.
Polymer concrete, also known as Epoxy Granite, is a type of concrete that uses a polymer to replace lime-type cements as a binder. In some cases the polymer is used in addition to Portland cement to form Polymer Cement Concrete (PCC) or Polymer Modified Concrete (PMC). Polymers in concrete have been overseen by Committee 548 of the American Concrete Institute since 1971.
Granolithic screed, also known as granolithic paving and granolithic concrete, is a type of construction material composed of cement and fine aggregate such as granite or other hard-wearing rock. It is generally used as flooring, or as paving. It has a similar appearance to concrete, and is used to provide a durable surface where texture and appearance are usually not important. It is commonly laid as a screed. Screeds are a type of flooring laid on top of the structural element to provide a level surface on which the "wearing flooring" is laid. A screed can also be laid bare, as it provides a long-lasting surface.
Cement render or cement plaster is the application of a mortar mix of sand and cement, and water to brick, concrete, stone, or mud brick. It is often textured, colored, or painted after application. It is generally used on exterior walls but can be used to feature an interior wall. Depending on the 'look' required, rendering can be fine or coarse, textured or smooth, natural or colored, pigmented or painted.
Polished concrete is a multi-step process where a concrete floor is mechanically ground, honed and polished with bonded abrasives in order to cut a concrete floor's surface. It is then refined with each cut in order to achieve a specified level of appearance.
Concrete is produced in a variety of compositions, finishes and performance characteristics to meet a wide range of needs.
Concrete degradation may have many different causes. Concrete is mostly damaged by the corrosion of reinforcement bars due to the carbonatation of hardened cement paste or chloride attack under wet conditions. Chemical damage is caused by the formation of expansive products produced by chemical reactions, by aggressive chemical species present in groundwater and seawater, or by microorganisms Other damaging processes can also involve calcium leaching by water infiltration, physical phenomena initiating cracks formation and propagation, fire or radiant heat, aggregate expansion, sea water effects, leaching, and erosion by fast-flowing water.
Concrete has relatively high compressive strength, but significantly lower tensile strength. The compressive strength is typically controlled with the ratio of water to cement when forming the concrete, and tensile strength is increased by additives, typically steel, to create reinforced concrete. In other words we can say concrete is made up of sand, ballast, cement and water.
A diamond grinding cup wheel is a metal-bonded diamond tool with diamond segments welded or cold-pressed on a steel wheel body, which usually looks like a cup. Diamond grinding cup wheels are usually mounted on concrete grinders to grind abrasive building materials like concrete, granite and marble.
Flexible stone veneer is a veneer with a layer of stone 1 to 5 mm thick. Flexible stone veneers should not be confused with traditional stone veneers. It is used for both interior and exterior and especially where bending to a curved surface is required. Flexible stone veneers are made from various types of slate, schist, or marble.