1.
Leptis Magna
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Leptis Magna was a prominent city in Roman Libya. Originally a Punic foundation, it was expanded under emperor Septimius Severus. Diocletian re-instated the city as capital, and the city grew again in prosperity until it fell to the Vandals in 439. It was re-incorporated into the Eastern Empire in 533, but continued to be plagued by Berber raids and it fell to the Muslim invasion in c.647 and was abandoned. The ruins of Leptis Magna are located in Khoms, Libya,130 km east of Tripoli, the site is one of best preserved Roman ruins in the Mediterranean. The Latin name was Lepcis Magna The Greek name was Λέπτις μεγάλη Leptis megale or Νεάπολις Neapolis, the city was called Greater in contrast with Leptis Parva in modern-day Tunisia. The Neo-Punic name is recorded as lpqy, the name appears to be Semitic in origin, tentatively connected to the Arabic root lfq to fabricate, piece together, taken to refer to the foundation or construction of the city. The modern Arabic name is لَبْدَة Labdah, the Punic city was founded in the second half of the 7th century BC. Little is known about the old city, but it appears to have been enough to repel Dorieus attempt to establish a Greek colony nearby in c.515 BC. A 4th to 3rd century BC necropolis was found under the Roman theatre, during the reign of Augustus, Leptis Magna was classified as a Civitas libera et immunis, or a free community, over which the governor had an absolute minimum of control. As such Leptis retain its two suphetes at the head of its government, with the mhzm, similar to the Roman aediles, in addition there were such sacred officials as the addir ararim or praefectus sacrorum, the nēquim ēlīm, and probably a sacred college of fifteen members. These offices were still in operation when Leptis was made a Municipium with a certain degree of Roman rights. The city depended primarily on the fertility of its surrounding farmland, as early as 46 BC, its olive oil production was of such an extent that the city was levied by Caesar with a tax of three million pounds of oil annually. The Roman Republic sent some colonists together with a garrison in order to control the city. Since then the city started to grow and was allowed to create its own money. Soon Italian merchants settled in the city and started a profitable commerce with the Libyan interior, Leptis Magna remained as such until the reign of the Roman emperor Tiberius, when the city and the surrounding area were formally incorporated into the empire as part of the province of Africa. It soon became one of the cities of Roman Africa. The city grew rapidly under Roman administration and it was elevated to municipium in AD 64/5 and to colonia under Trajan Leptis achieved its greatest prominence beginning in AD193, as the hometown of emperor Septimius Severus
2.
Door
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A door is a moving structure used to block off, and allow access to, an entrance to or within an enclosed space, such as a building or vehicle. Doors normally consist of a panel that swings on hinges on the edge, similar exterior structures to doors are called gates. Typically, doors have a side that faces the inside of a space. In many cases the interior side of a door mostly matches its exterior side, when open, doors admit people, animals, ventilation or light. The door is used to control the atmosphere within a space by enclosing the air drafts. Doors are significant in preventing the spread of fire and they also act as a barrier to noise. Many doors are equipped with locking mechanisms to allow entrance to certain people, as a form of courtesy and civility, people often knock before opening a door and entering a room. Doors are used to screen areas of a building for aesthetics, keeping formal, Doors also have an aesthetic role in creating an impression of what lies beyond. Doors are often endowed with ritual purposes, and the guarding or receiving of the keys to a door, or being granted access to a door can have special significance. Similarly, doors and doorways frequently appear in metaphorical or allegorical situations, literature, the earliest in records are those represented in the paintings of the Egyptian tombs, in which they are shown as single or double doors, each in a single piece of wood. Doors were once believed to be the doorway to the afterlife. The stiles were the boards, one of which, tenoned or hinged, is known as the hanging stile. The horizontal cross pieces are the top rail, bottom rail, the most ancient doors were made timber, such as those referred to in the Biblical depiction of King Solomons temple being in olive wood, which were carved and overlaid with gold. The doors dwelt upon in Homer would appear to have been cased in silver or brass, besides olive wood, elm, cedar, oak and cypress were used. A5, 000-year-old door has been found by archaeologists in Switzerland. All ancient doors were hung by pivots at the top and bottom of the hanging stile which worked in sockets in the lintel and sill and those found at Nippur by Dr. Hilprecht dating from 2000 B. C. were in dolerite. The tenons of the gates at Balawat were sheathed with bronze and these doors or gates were hung in two leaves, each about 8 ft 4 in wide and 27 ft. high, they were encased with bronze bands or strips,10 in. High, covered with decoration of figures, etc
3.
Window
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A window is an opening in a wall, door, roof or vehicle that allows the passage of light and, if not closed or sealed, air and sound by using sheet glass. Modern windows are glazed or covered in some other transparent or translucent material. Windows are held in place by frames, many glazed windows may be opened, to allow ventilation, or closed, to exclude inclement weather. Windows often have a latch or similar mechanism to lock the window shut, the Romans were the first known to use glass for windows, a technology likely first produced in Roman Egypt, in Alexandria ca.100 AD. Paper windows were economical and widely used in ancient China, Korea, in England, glass became common in the windows of ordinary homes only in the early 17th century whereas windows made up of panes of flattened animal horn were used as early as the 14th century. In the 19th century American west, greased paper windows came to be used by itinerant groups, modern-style floor-to-ceiling windows became possible only after the industrial plate glass making processes were perfected. The English language-word window originates from the Old Norse vindauga, from vindr – wind and auga – eye, the Danish word is pronounced fairly similarly to window. Window is first recorded in the early 13th century, and originally referred to a hole in a roof. Window replaced the Old English eagþyrl, which literally means eye-hole, many Germanic languages however adopted the Latin word fenestra to describe a window with glass, such as standard Swedish fönster, or German Fenster. The use of window in English is probably because of the Scandinavian influence on the English language by means of loanwords during the Viking Age, in English the word fenester was used as a parallel until the mid-18th century. Fenestration is still used to describe the arrangement of windows within a façade, as well as defenestration, in the 13th century, the earliest windows were unglazed openings cut in a roof to admit light during the day. Later, windows were covered with animal hide, cloth, or wood, shutters that could be opened and closed came next. Over time, windows were built that both protected the inhabitants from the elements and transmitted light, using small pieces of translucent material set in frameworks of wood. In the Far East, paper was used to fill windows, the Romans were the first known to use glass for windows, a technology likely first produced in Roman Egypt. It would be over a millennium before a window glass became transparent enough to see through clearly, over the centuries techniques were developed to shear through one side of a blown glass cylinder and produce thinner rectangular window panes from the same amount of glass material. This gave rise to tall narrow windows, usually separated by a vertical support called a mullion, mullioned glass windows were the windows of choice among European well-to-do, whereas paper windows were economical and widely used in ancient China, Korea and Japan. In England, glass became common in the windows of homes only in the early 17th century whereas windows made up of panes of flattened animal horn were used as early as the 14th century. Modern-style floor-to-ceiling windows became possible only after the plate glass making processes were perfected
4.
Fireplace
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A fireplace is a structure made of brick, stone or metal designed to contain a fire. Fireplaces are used for the relaxing ambiance they create and for heating a room, modern fireplaces have variable heat efficiency, depending on the sophistication of the design. Historically they were used for heating a dwelling, cooking, and heating water for laundry, a fire is contained in a firebox or firepit, a chimney or other flue allows exhaust to escape. On the exterior there is often a brick crown, in which the projecting courses of brick act as a drip course to keep rainwater from running down the exterior walls. Some chimneys have a spark arrestor incorporated into the crown or cap, organizations like the Environmental Protection Agency and the Washington Department of Ecology warn that, according to various studies, fireplaces can pose a significant health risk. The EPA writes Smoke may smell good, but its not good for you, manufactured fireplaces are made with sheet metal fire boxes. Electric fireplaces can be built-in replacements for wood or gas or retrofit with log inserts or electric fireboxes, Masonry and prefabricated fireplaces can be fueled by wood, natural gas, biomass and propane fuel sources. Ventless Fireplaces are fueled by either gel, liquid propane, bottled gas or natural gas, in the United States, some states and local counties have laws restricting these types of fireplaces. They must be sized to the area to be heated. There are also air quality issues due to the amount of moisture they release into the room air. Direct vent fireplaces are fueled by either liquid propane or natural gas and they are completely sealed from the area that is heated, and vent all exhaust gasses to the exterior of the structure. Chimney and flue types, Masonry with or without tile-lined flue, fundamental design flaws bankrupted the US manufacturers and made the design obsolete. These chimneys often show vertical cracks on the exterior, metal-lined flue, Double or triple walled metal pipe running up inside a new or existing wood-framed or masonry chase. Newly constructed flues may feature a cover, a cap. All fireplaces require trained gas service members to carry out installations, a wide range of accessories are used with fireplaces, which range between countries, regions, and historical periods. For the interior, common in recent Western cultures include grates, fireguards, log boxes, andirons, pellet baskets, a grate is a frame, usually of iron bars, to retain fuel for a fire. Heavy metal firebacks are sometimes used to capture and re-radiate heat, to protect the back of the fireplace, fenders are low metal frames set in front of the fireplace to contain embers, soot and ash. For fireplace tending, tools include pokers, bellows, tongs, shovels, brushes, ancient fire pits were sometimes built in the ground, within caves, or in the center of a hut or dwelling
5.
Window sill
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A window sill is the surface at the bottom of a window. A dictionary of architecture categorically defined the characteristics of a windowsill as, windowsills hold pieces in place and slope downward to drain water. In a well hung window, the lower sash rests on the chin, The horizontal piece below a window unit in masonry construction or in wood framing
6.
Prestressed concrete
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Prestressed concrete is a concrete construction material which is placed under compression prior to it supporting any applied loads. A more technical definition is Structural concrete in which stresses have been introduced to reduce potential tensile stresses in the concrete resulting from loads. This compression is produced by the tensioning of high-strength tendons located within or adjacent to the concrete volume, tendons may consist of single wires, multi-wire strands or threaded bars, and are most commonly made from high-tensile steels, carbon fibre or aramid fibre. This can result in improved structural capacity and/or serviceability compared to reinforced concrete in many situations. Typical applications range through high-rise buildings, residential slabs, foundation systems, bridge and dam structures, silos and tanks, industrial pavements, first used in the late-nineteenth century, prestressed concrete has developed to encompass a wide range of technologies. Tensioning of the tendons may be undertaken either before or after the concrete itself is cast, tendons may be located either within the concrete volume, or wholly outside of it. Whereas pre-tensioned concrete by definition uses tendons directly bonded to the concrete, pre-tensioned concrete is a variant of prestressed concrete where the tendons are tensioned prior to the concrete being cast. Pre-tensioning is a common technique, where the resulting concrete element is manufactured remotely from the final structure location. It requires strong, stable end-anchorage points between which the tendons are stretched and these anchorages form the ends of a casting bed which may be many times the length of the concrete element being fabricated. Higher bond strength in early-age concrete allows more economical fabrication as it speeds production, to promote this, pre-tensioned tendons are usually composed of isolated single wires or strands, as this provides a greater surface area for bond action than bundled strand tendons. Unlike those of post-tensioned concrete, the tendons of pre-tensioned concrete elements generally form straight lines between end-anchorages, where profiled or harped tendons are required, one or more intermediate deviators are located between the ends of the tendon to hold the tendon to the desired non-linear alignment during tensioning. Such deviators usually act against substantial forces, and hence require a robust casting bed foundation system, pre-tensioned concrete is most commonly used for the fabrication of structural beams, floor slabs, hollow-core planks, balconies, lintels, driven piles, water tanks and concrete pipes. Post-tensioned concrete is a variant of prestressed concrete where the tendons are tensioned after the concrete structure has been cast. The tendons are not placed in contact with the concrete. At each end of a tendon is an anchorage assembly firmly fixed to the surrounding concrete, once the concrete has been cast and set, the tendons are tensioned by pulling the tendon ends through the anchorages while pressing against the concrete. The large forces required to tension the tendons result in a significant permanent compression being applied to the once the tendon is locked-off at the anchorage. Casting the tendon ducts/sleeves into the concrete before any tensioning occurs allows them to be profiled to any desired shape including incorporating vertical and/or horizontal curvature. Bonded post-tensioning has prestressing tendons permanently bonded to the concrete by the in situ grouting of their encapsulating ducting following tendon tensioning
7.
Beam (structure)
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A beam is a structural element that primarily resists loads applied laterally to the beams axis. Its mode of deflection is primarily by bending, the loads applied to the beam result in reaction forces at the beams support points. The total effect of all the acting on the beam is to produce shear forces and bending moments within the beam. Beams are characterized by their manner of support, profile, length, historically beams were squared timbers but are also metal, stone, or combinations of wood and metal such as a flitch beam. Beams generally carry vertical gravitational forces but can also be used to carry horizontal loads, the loads carried by a beam are transferred to columns, walls, or girders, which then transfer the force to adjacent structural compression members. In light frame construction joists may rest on beams, in carpentry a beam is called a plate as in a sill plate or wall plate, beam as in a summer beam or dragon beam. In engineering, beams are of types, Simply supported - a beam supported on the ends which are free to rotate and have no moment resistance. Fixed - a beam supported on both ends and restrained from rotation, over hanging - a simple beam extending beyond its support on one end. Double overhanging - a simple beam with both ends extending beyond its supports on both ends, continuous - a beam extending over more than two supports. Cantilever - a projecting beam fixed only at one end, trussed - a beam strengthened by adding a cable or rod to form a truss. In the beam equation I is used to represent the moment of area. It is commonly known as the moment of inertia, and is the sum, about the axis, of dA*r^2, where r is the distance from the neutral axis. Therefore, it not just how much area the beam section has overall. The greater I is, the stiffer the beam in bending, internally, beams experience compressive, tensile and shear stresses as a result of the loads applied to them. Above the supports, the beam is exposed to shear stress, there are some reinforced concrete beams in which the concrete is entirely in compression with tensile forces taken by steel tendons. These beams are known as prestressed concrete beams, and are fabricated to produce a more than the expected tension under loading conditions. High strength steel tendons are stretched while the beam is cast over them, then, when the concrete has cured, the tendons are slowly released and the beam is immediately under eccentric axial loads. This eccentric loading creates a moment, and, in turn
8.
Concrete slab
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A concrete slab is a common structural element of modern buildings. Horizontal slabs of steel reinforced concrete, typically between 4 and 20 inches thick, are most often used to construct floors and ceilings, while thinner slabs are also used for exterior paving. Sometimes these thinner slabs, ranging from 2 inches to 6 inches thick, are called mud slabs, in many domestic and industrial buildings a thick concrete slab, supported on foundations or directly on the subsoil, is used to construct the ground floor of a building. These can either be ground-bearing or suspended slabs, in high rise buildings and skyscrapers, thinner, pre-cast concrete slabs are slung between the steel frames to form the floors and ceilings on each level. On the technical drawings, reinforced concrete slabs are often abbreviated to r. c. c. slab or simply r. c, there are two main thermal considerations. The first is the question of insulating a floor slab, in older buildings, concrete slabs cast directly on the ground can drain heat from a room. In modern construction, concrete slabs are usually cast above a layer of such as expanded polystyrene. However, there are still uses for an uninsulated slab, typically in outbuildings which are not heated or cooled to room temperature. In those cases, casting the slab directly onto a substrate will maintain the slab at or near the temperature of the substrate throughout the year. The second consideration is the thermal mass, which applies to walls and floors. It is a disadvantage where the rooms are heated intermittently and require a response, as the concrete takes time to warm up. But it is an advantage in climates with large temperature swings. For a suspended slab, there are a number of designs to improve the strength-to-weight ratio, in all cases the top surface remains flat, and the underside is modulated, Corrugated, usually where the concrete is poured into a corrugated steel tray. This improves strength and prevents the slab from bending under its own weight, the corrugations run across the short dimension, from side to side. A ribbed slab, giving considerable extra strength on one direction, a waffle slab, giving added strength in both directions and it looks hollow from bottom. Reinforcement design A one-way slab needs moment resisting reinforcement only in its short-direction because the moment along long axes is so small that it can be neglected. When the ratio of the length of long direction to short direction of a slab is greater than 2 it can be considered as a one way slab. Long direction = ly Short direction = lx One way slab IF ly/lx >2 A two-way slab needs moment resisting reinforcement in both directions, if the ratio of the lengths of long and short side is less than two then moment in both direction should be considered in design
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