Introduction
Concrete, in contrast with subsequent structural edifice substance, permeates an architect as well as engineers to select not only its approach of fabrication, but its material characteristics in addition. Myriad factors are put into consideration especially when architects and engineers call for a corporeal structural configuration, this constitute, strength, durability, forming techniques, hardening attributes, nature and the extent of buttressing as well as visual among others. Ultimately the domain of concrete tall structural constructions are rapidly being altered and its precincts are continuously being experienced and long-drawn-out.
The prologue of intricate erection to soaring tubular constructions, were conceptualized and employed by Khan Fazlur of SOM (Skidmore, Owings and Merrill) in the 60s. This move cemented the journey towards supertall intricate structures the reminiscent of Petronas and Jin Mao skyscrapers in our modern epoch. Ali, M.M (2001:44-50)
Early Tangible Skyscraper
The genesis of the skyscraping is deep rooted in the first two decades of the 20th century. The first ever skyscraper to be constructed was Ingalls the 15 storied concrete tower, that was erected by Elzner, A. O (1904:220). Components that were employed in the construction of this earliest landmark comprise of; square casting structures, warped, reinforced taverns with tangible as structures with chunks as well as tangible perimeter walls.
During this embryonic epoch in the building domain, a lot of rumour-mongering by the mass media that the building was destined to splintering and disintegrating underneath its heaviness immediately the shoring was confiscated. Auspiciously, time proved them wrong when the structure stood eminently. Initially tall buildings made up of steel were destroyed by fires globally. The success of erecting this building marked embraced the use of concrete as a fire resistant material. Ali, M.M (2001:39-43)
Developments in Elevated structures
Water Tower in Chicago
In the construction of the Ingalls structural building that stood at 210 ft (64m) every major development that was made at that time was emphasized. This building took advantage of a heavy gigantic grin-column casing structure. Bottom hanks constituted double edged buttressing structures. The grins were buttressed with twisted taverns in the vicinity of the shore ups. Rings and unremitting helixes were embraced in columns to tie the vertical strengthening jointly.
The Ransome’s square, cold-twisted buttressed tavern was employed for the brace throughout the entire for parallel as perpendicular fortification. While the construction of the Ingalls structural design, scarcely, has any structural construction surpassed the 20 storied towering smudge till the 60s. The Marina Doppelganger Towers was erected in 1962 at the epicenter of the built-up square. Bertrand Goldberg, who was the chief architect, was cognizant of the fact that those who would dwell in the building required 24- hour tune-ups, amusement, parking as well as bureaus all in one configuration. The structure contained a film theater, sinking passageway, stores, bureaus, bistros, conference rooms, gymnasium, slithering rink, and automobile parking place and vessels and ultimately habitations. Nimeiri E & Khan F.R (1983:103)
Marina Twin Tower was the first structural building of its kind in Chicago and as the tallest buttressed structure globally it stood at 179 meters. The architect’s layout in erecting a globular building, which was ground-breaking at the time, is centered on efficacy of HVAC makeup’s as well as minimizing the overhauled interior of the configuration. Elzner, A. O (1904:220)
A further novelty was the twenty storied parking garage unswervingly beneath the 900units of residences. A globular interior wall was established in anticipation that it would take the entire imaginative consignment from plank as well as grins flanked by petals were curtailed. Even with these alterations, the globular interior phase carries 70% of the overall ingenious weights. The interior that acts as spherical accessible cut off barrage was carefully designed with spread out apertures and by curtailing their size in an attempt to sustain enough stiffness. The subsequent towering structure was the Water Tower Place, positioned in the downtown area of Chicago.
Blueprinted by Loebl, Schlossman, Dart and Hackl, it stands at 262 meters. The potency of concrete employed in this structure to a dramatic jump to as high as 62.1 MPa. Mix-up strengths could vary from 20.7 Mpa for slabs to 62.1MPa for columns. The construction illustrates material know-how’s capacity to challenge that of brace for elevated edification as it was 2/3 the loftiness of the soaring brace construction of the epoch. The building design for Water Tower amalgamates reinforced concrete edge structured tube, core brace files and a brace slab system with a complex tangible crowning. Nimeiri E & Khan F.R (1983:103)
A superlative Mile structural construction in Chicago finished in 1983 was blueprinted by SOM as is one of the final constructions engineered by Khan. Mile was drawn with the same impressions that made the Sears Tower probable. The bagged cylinder structures had already proved successful in the brace like in the Sears magnificent Tower. Mile comprises of three hexagonal cylinders that are mutually bugged. Fixed cylinders give the structure beneficial firmness. Cylinders expire at dissimilar elevations, as the magnitude loads decrease. Ali, M.M (2001:33-38)
Magnificent Mile Building in Chicago
Ontario Center was erected in Chicago in 1985, as an additional SOM structural design, the skyscraper was deemed as the concluding structural design by Fazlur Khan. The building utilizes a tethered cylinder configuration in concrete. SOM lucratively transformed a structural arrangement initially oriented for Hancock; a strut soars into a buttressed material.
The upshot is a concrete cylinders structure that has aesthetical transverse rigid steel on the periphery. Even though the transverse steel of John Hancock Center was composed of unremitting crossway steel ingredients, this line of attack was not strictly probable intangible. Alternatively, the crossway steel is realized by blocking out the transoms along the frontages by satisfying them with solid. Khan F.R (1972:28-30)
311 South Wacker Drive of Chicago
The 311 South Wacker Drive is another skyscraper buttressed tangible structural building that was erected in Chicago. The building stands at 295 meters with (82.7m) as the uppermost tangible potency. The system configuration is a tailored cylinder with a buttressed exterior tangible structure, core brace files as well as amalgamated brace and concrete hunk.
311 is illustrated to be an authentic example of shear barrage-casing interface arrangements. The structural building is engineered in a way that is relatively stiff of both internal and external components maintain the same height in the construction of the structure. A double strong point of the concrete material was employed, 10,000 and 12,000 psi. A self-ascending propel with a disconnected escalated insertion boom pumped concrete to the top of the configuration. Ali, M.M (2001:31-33)
Placement strained floor chunks diminished the quantity of brace consumption while that for concrete was diminished with thinner elements due to the substances gigantic potency. Two deposits of soaring structures were rounded every five days through the arrangement. In 1991 a magnificent center known as Peachtree Center was erected in Atlanta, Georgia. The structure is elevated at 257m of height. It embraces cylinder minted blueprint that incorporates three reinforced concrete columns (58.6, 68.9 as well as 82.7 Mpa) segments as well as on the shear walls. Designers employed equipment expanded in the 60s and 70s by Substance Service Corporation in Chicago.
Architectural obligations uttered a discourse-complimentary core and thus a 15.2m floor outline was consummated with HSC and placement-pressured brace taverns. Silica seethes and sandstone comprehensive were utilized to accomplish the essential strengths. Of extraordinary note for the proprietor of the construction, each floorboard has about 36 rentable bend headquarters. The structure is stupendous since its blueprint augments numerous desired spaces for renters, the structural design and its desired employed in Chicago’s high-strength concrete style. Ali, M.M (2001: 28-30)
Petronas Towers of Malaysia and Jin Mao building of Shanghais China
In 1999 two gigantic structural designs were erected in the Far East region; the edifices comprise the Petronas Towers in Kuala Lumpur, Malaysia and the Jin Mao construction in Shanghai, China. These are high-quality illustrations to show that existing has significantly progressed as a material in a century since the days of Ingalls Construction structures. Huxtable A., L (1957:122-124)
The structural skeleton for the 452m tall Petronas Towers employ files, core and sphere grins of HSC, and bottom grins and punching of steel to present an economical, high-speed structure and future alteration to the domestic and exterior atmosphere. The interior and framework mutually present an adequate lateral stiffness for such a tall building. Jin Mao structural blueprint is a sundry of brace outrigger tethers that fasten the building’s substantial interior towards the periphery’s complex mammoth columns. Huxtable A., L (1957:120-122)
Conclusion
Concrete application stretch as back as before 1200BC, these include societies like Phoenicians, Minoans as well as Egyptians just but to cite a few. The concrete renaissance emerged in the closing years of 18th century and the wee years of the 19th century. Buttressed concrete was widely employed in America as well as in Europe in the building of gigantic warehouses, factory structures, residential designs and also homes during this period. With the spontaneous progression of tangible structure and machinery, the applicability of concrete for skyscraping has become an invariable reality. The pattern capacity of concrete is a fundamental aspect in developing electrifying structure forms with well-dressed as well as visual appearance. Harries, A.K (1996:20-34)
In the capital city of China, a 66 storied tower was erected. The structure was fashioned in the sense that could resist typhoon winds. Based on Colaco Joseph’s reviews, buildings that are more than two kilometers of height are also achievable with the application of concrete expertise. Concrete has become outstanding building material owing to various factors that include; its incombustible aspect as well as gigantic tangibles could suck up thermal tilting, contraction and crawl in addition to groundwork tilting. More so, concrete configurations are intrinsically rigid with a great deal of redundancy.
In comparison with brace, tangible tall structural designs exhibit superior loads as well as humid ratios that assist in curtailing proposition awareness. Weighty tangible configurations present authentic permanence in opposition to knock over created by sideways weights. Modern structural systems including the compound ones which are trendy have allowed concrete high-rises that have boomeranged into new heights for the last forty years.
Foundational composition sequence period for corporeal towers has surpassed that of brace structures, however, brace will persist to be a structural component of choice for most tall structures owing to its strength and ductility, and much more of corporeal towers are anticipated to revolutionize the skyline in foremost cities of the world in the coming years. Khan F.R (1972:25-27)
References
Huxtable A., L (1957) Buttressed Corporeal Edifice: Design by Ransome: Developmental Architecture. Pp. 120-128.
Harries, A.K (1996) Buttressed Corporeal towards the end of 20th Century; Transnational Tangibles, pp. 20-34.
Elzner, A. O (1904) Prologue of the Tangible Towers; Structural Design Accounts; pp. 220.
Nimeiri E & Khan F.R (1983) Building Configurations for Towers; Progressive Erection in Elevated Edifice, Reinhold Company, NY; pp. 103.
Khan F.R (1972) Control of Architectural Pattern in Towering Structures; Canadian Edifice Expertise Convention, Montreal, Canada, pp.25-35.
Ali, M.M (2001) the Knack of Towers; Brilliance of Khan F, Rizzoli transnational publications, NY, pp. 28-50.