The Burj Khalifa (formerly known as Burj Dubai) is the world's tallest building at 828 meters (2,717 ft). Located in Dubai, United Arab Emirates, the skyscraper took five years to build and opened in January 2010.
Asked in Burj Khalifa
Which is better - gunite or shotcrete?
Ask any structural engineer, when strength factors are to be recognized shotcrete is required. Gunite companies cannot guarantee their product to 2500 psi. Just ask one to put that in writing. Our shotcrete product is an engineered mix from the plant at a min of 4000psi. We can get an engineered design mix at 7500 psi if we need it. And yes, shotcrete has rock in it for structural strength. Gunite being man mixed at site has much more margin for error. Both are applied by air pressure. Gunite pools will lose their finish sooner and are more prone to crack because of lack of strength integrity. Simple test for those in question, take a mason drill bit or air chisel to Gunite and then Shotcrete and see which is less resistant. For the Shotcrete test bring a lunch, you'll be there a while! Gunite and Shotcrete are the same thing. They are both a force applied concrete application. The difference between Gunite and Shotcrete is this: one is concrete mixed with water at the site (Gunite) and the other is concrete mixed with water in a truck and then brought to the site (Shotcrete) One has aggregate in it and the other has none the aggregate strengthens the cement. Cement for other things like bridge's and road's has rock to make it stronger. Shotcrete is concrete has ,Gunite is not. Gunite is a nick name for shotcrete there are 2 kinds wet mix and dry mix dry mix is mixed at the nozzole wet mix comes wet and has rocks in it among other things to make it stronger for the frost we get in the mid-west gunite is the nick name of the first wet mix crew in 1942 during the war a man who owned the gunite gun smith shop invented the first shotcrete-wet mix nozzle when the air strips got shot up to keep our plains on the ground the gunite crew would spray and cut the air field in no time at all this is documented and i have seen pic of the first gunite crew i spray shotcrete-wet mix which is a lot stronger than shotcrete-dry mix. If there are no rocks in a wet mix the sand will dry pack in the hose causing a LONG day. Rock is needed to help float the material on pumping applications over 125 feet. I think both have there strong and weak points. The Dry process (Gunite) is a mixture of mainly sand and cement. The dry process is shot though the hoses like a sand blast operation with the water being applied at the very end of the hose.But when applied to a pool the crews mainly do the floors first due to the large amount of rebound produced. When the walls, benches , spas are shot the crews must throw out the rebound . The wet process which is a mixture of sand, cement, small pea gravel and water produces little or no rebound so the walls are applied first then the floor shot last.The wet process is brought out by cement truck and pumped with a small concrete pump then the air is applied at the very end to spray the material in place. All excess material pulled from walls are pulled in floor area and then shot over. This can't be done with the dry process. On the other hand during the summer months the dry process has an advantage as the wet process has a limited time to place and finish from the time of being batched at the concrete plant. The dry process is mixed on the job site allowing more time to work. I personally prefer the wet process as there is less equipment involved and I believe a more consistent product is produced. For a helpful discourse on the difference between gunite or shotcrete check out this web page http://www.monolithic.com/construction/shotcrete_gunite This site no longer exists. Do NOT let there be confusion between the two. SHOTCRETE is DIFFERENT from GUNITE. There was a recent legal action that forced shotcrete companies claiming they were Gunite, to remove all references to Gunite from their work. Any Engineer that knows these two applications will tell you the difference. GUNITE is a dry mix of sand and cement blow through a hose, water is added at the nozzle. as the material comes out, you have complete control over the water content, you can make it as dry or wet as you want. you add just enough water to make the material sticky (MUCH less water than a normal, if you tried to pump this material, you would probably blow up your pump. the material is moving at a high rate of speed as it comes out of the hose, the trickle of water doesn't even slow it down. Resulting in a higher PSI application, packing material tighter than Shotcrete can. Since you can make this material as dry as you want, you can achieve the strongest known form of concrete. Gunite is used on the space shuttle launch pad. each time a shuttle is launched, they must re-apply more gunite. it seems to crystallize. If you used shotcrete, it would melt and disintegrate. (they've done it). There is NO Wet/Dry mix gunite... if it comes out of the truck WET, it's shotcrete. if it comes out of the truck DRY, it's GUNITE. Shotcrete has less waste (rebound). Gunite has MORE waste (rebound). If it doesn't stick, THROW it OUT... if you pull this rebound into your floor, it will eventually crack up. REBOUND is BAD MATERIAL! trowel it into your floor, then pressure wash it, watch it come out like sand pockets. I have been doing Gunite for over 4 years, under a family of Gunite/Shotcrete work. they knowt he differences, and apply them accordingly. The family has been doing Gunite and Shotcrete for well over 50 years. If you spray gunite on glass, and let it cure, you will NOT get it off, you'll break the glass first. I, personally, would build no pool, other than a Gunite pool. Gunite pools will net you 90-100% of your investment in Appraising. Shotcrete 70-75% Pools: liners, fiberglass, fiberglass with concrete floors, etc, only 30-40% return on investment. Please do not confuse the two, GUNITE is stronger. the only thing that would make gunite or shotcrete crack up, is bad nozzling techniques. (get a reputable company, view their work before it is plastered or covered with whatever materials used) if it doesn't look perfect/near perfect, find another company. Gunite, Drymix, is dispatched in a cement truck just like wet mix, except that no water is added. This eliminates that "extra equipment" required. It CAN be mixed by hand from a pile of cement and a pile of sand, but all that shoveling, the labor, the mixer, CLEANUP, (i hate cleanup). We use the cement truck.. MUCH less messy. For a LONG time, it was just My boss and I doing the work. maximum crew required is 4, minimum 2. plus the truck driver to maintain flow of material into the Reed Machine. Another thing: When you shoot a pool, using Shotcrete OR Gunite... you shoot the FLOOR FIRST... THEN you shoot the walls. ALL rebound must be thrown out. if you pull rebound into the floor, and shoot over it (Gunite or Shotcrete) you create weak points. for consistency, all material should be BLOWN/SHOT into place.. If it was not BLOWN/SHOT there, it needs to be removed. YES, there IS more work to throw it out, clean it up, and haul it away. We are the only gunite company in our area, there are numerous Shotcrete companies here. Only a handful of them do the floors and wall CLOSE to proper. SO many people have cracked floors and/or walls due to pulling the WASTE/REBOUND into the floor. If you were not trained to nozzle/finish by someone that's been doing the work for 30 years, you most likely haven't learned everything you NEED to know. I myself have a LOT to learn, but REBOUND is BAD, THROW it OUT! With gunite, by the time the second truck arrives, i can usually walk on the first section of floor. When the Third truck arrives, i can shovel and jump up and down on the first section shot. I'm not sure how fast shocrete hardens, since I'm a Gunite Man. shotcrete is better by far gunite is okay but only as good as the crew I've been doing pools for 16 years seen it all tile guys like gunite because its a lot smoother surface and you ca scrape crap off very easy.but if its smooth then the marcite won't stick. gunite is like a sponge the pool wont hold water lay a hose on the top step the water wont even make it to the floor we shoot two pools every day and done a lot of repairs on gunite shells if gunite is so good then how come bridges and dams rant made from it gunite is no more then stucco mix sand and cement shotcrete has sand cement and stone, gunite has rebound lots of it if you don't stand over them and make them get rid of it they will bury it in floor i seen a guy drop his nail gun of the roof and it busted a hole in the gunite floor.you can backfill a shotcrete shell right away a gunite you have to let cure for some time they say 30 days with water sprayed on to get it to harden properly because they are shooting way to dry it stand up better but no better than beach sand till it gets some water i personally wouldn't have a gunite shell seen way to many problems.
Asked in Home Buying, Seasons, Dubai, Burj Khalifa
When will the Seasons Community in Dubai be built?
What is the height of the Burj Khalifa?
The Burj Khalifa in Dubai, United Arab Emirates is the world's tallest building. It is also the tallest manmade structure as of its opening in 2010. The total height is 828 m (2717 feet). From its opening (4th Jan 2010) the final height was announced to be 828 meters (2,717 ft) which easily makes it the worlds tallest building.It has 160 habitable floors plus 46 maintenance levels in the spire and 2 parking levels in the basement.
Asked in Engineering, Interior Design, Burj Khalifa
Define tender and types of tender?
There are three types of tendering methods used in construction industry! 1. Open Tendering 2. Selective Tendering 3. Negotiated Tendering. Open tender is an arrangement where an advertisement in local newspapers or trade journals invites contractors to apply for tender documents. A deposit is usually required to ensure that only serious offers are made; Presumably it is needed to cover the cost of copying the documents. Local authorities have been advised against open tendering because it often leads to excessive tender lists where the cost of abortive tendering is considerable. There are instances of selection criteria being applied after the tender has been submitted, so a bid could be rejected if a contractor does not belong to an approved trade association. Advantages of Open Tender The main advantage of such tendering is as follow: Give high level of competition and contractors tend to give best prices as compare to other tendering method There is no list of restrictive tenderer, which does not allow favoritism It is very transparent process which ensures that only the contractor with the best price and meeting all the technical requirements will win the tender. This process is usually manage by procurement board where its staff are trained for such exercises and board ensure that all the procedures involved in tender are followed. Disadvantages of Open Tender The low price usually detriment of quality and often result in the client obtaining poor quality job and late completion of work. Given that its open tender and thus there are no restrictions on the number of contractor who can bid and become bulky and lengthy job for tender analyses which often result in delays and high cost. Selective tender: Selective tendering consists of drawing up a list of chosen firms and asking them to tender. It is by far the most common arrangement because it allows price to be the deciding criterion; all other selection factors will have been dealt with at the pre-qualification stage. There are three ways in which selective tendering lists are drawn up: An advertisement may produce several interested contractors and suitable Firms are selected to tender. The consultants may contact those they would wish to put on an ad-hoc list. Many local authorities and national bodies keep approved lists of contractors in certain categories, such as work type and cost range. Contractors who ask to be included on select lists of tenderer are usually asked to provide information about their financial and technical performance, particularly about the type of work under consideration. The National Joint Consultative Committee for Building (NJCC) has written the 'Standard form of tendering questionnaire - private edition' so contractors can prepare friendus to relevant questions in advance. The questions mainly deal with projects carried out during the previous three years. Once the form has been completed, it can be used for specific projects or for those compiling lists of selected contractors. Ngotiated Tender :under this method normally one contractor is approached and such tender mainly used for specialist work such as lift system or airport project at big level, in such case there are limited number of contractor who do such work in the market .it is based on one-to-one discussion with contractors to negotiated the terms of contract
Asked in United Arab Emirates, Dubai, Burj Khalifa
How many floors does the Burj Khalifa have?
Asked in Civil Engineering, Burj Khalifa
How is rcc column design?
DESIGN OF AXIALLY LOADED COLUMN (SQUARE) 15.1 Data : Column No. : ………. Load on column = …………..KN. Design constant a) Grade of concrete = ……….. b) Grade of steel = ……….. L = Unsupported length of the column in mm = …………mm Design load Pu = 1.5 x …………. = ………….. KN. Assume percentage of comp. steel between 0.8 to 6% of gross c/s area Assume Asc = … …%Ag = , Ac =………%Ag MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION ♦ 31 Design of structures (RCC) Exercise No. 1 15.2 Find the section of the column (Ag): Pu = 0.4 fck Ac +0.67 fy Asc =……………………….. Ag = ………………… mm2. Adopt square column. Size of column =……….x…………. mm Say ……… X ………mm. 15.3 Find the No. of bars (not less than 4) Asc = ……. % Ag Calculate no. of bars For ∅ = …….. No of Bar = N1 = = ------- = For ∅ = …….. No of Bar = N2 = = …………… = Use diameter of bars not less than 12 mm 15.4 Lateral ties. a) Select diameter of lateral ties least of 5 mm or 1/4 diameter of the largest longitudinal bar not less than16 mm diameter. Diameter of the lateral ties / link = ………. mm b) Spacing of lateral ties / link Least of i) Least lateral dimension of column =…………..mm ii) Sixteen times the smallest dia. of bar = 16 x ……=………..mm and iii) 300 mm Provide … mm dia. @ ………. C/c 15.5 Check for minimum eccentricity e min >/ 0.05 D =……………..= ………….mm > e min e min = 20 mm L = Unsupported length of the column in mm D = Lateral dimension of column in the direction under consideration in mm 32 ♦ MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION Exercise No. 1 Design of structures (RCC) 15.6 Summary of design : 1. Column size ……………x…………. mm 2. Longitudinal Steel …………………………………………. 3. Lateral Steel …………………………………………… Note : Draw the diagram showing the reinforcement details for the above column on drawing sheet with the guidance of teacher. 16.0 DESIGN OF PLINTH BEAM 16.1 Data : Sr. No. (from load calculation sheet) = beam mark = Design constant a) Grade of concrete = b) Grade of steel = span = -------m. Singly Reinforced Rectangular Beam Maximum load = ----------kN Factored load = -----------kN Given Fact B.M. = ..................................kN. m. Fact S.F. = ...................................KN. 16.2 Find dimension of rectangular beam Mu lim = Mu Mu = 0.148 fck bd 2 for Fe 250 steel = 0.138 fck bd2 for Fe 415 steel = 0.133 fck bd2 for Fe 500 steel Assume b = ……………. (Generally equal to width of the wall or 230 mm) Mu = .................................... = d2 = d = ...............................mm Say ------- mm (Assume diameter of bar) Over all depth (D) = d+ + cover ( Assume 25 mm cover) D = ..................mm Round up the value of D say ………..mm d = D - - cover d = .........................mm :. b = ..........................mm MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION ♦ 33 Design of structures (RCC) Exercise No. 1 16.3 Find Longitudinal steel. = ……………………………………… =................................m m2 Calculate no. of bars For ∅ = …….. No of Bar = N1 = = ------- = For ∅ = …….. No of Bar = N2 = = …………… = Provide --- # -- mm ∅ bars 16.4 Design of shear reinforcement. 1. Find nominal shear stress τv = = ……………. = .......................N/mm2 2. Find shear strength of concrete (τc) With referring IS 456 - 2000 clause Pt = Pt = ...................... % find τc = τc = .................. N/mm2 3. Compare a) if τv < τc Provide nominal shear reinforcement. b) if τv > τc Design shear reinforcement. a) When τv < τc Provide nominal shear reinforcement as fallows : Assuming -- mm Ø two legged M.s. stirrups. Asv =2 x π/4 x d2 = ……….=……….. Spacing of stirrups Sv ≤ = ……………….. = ………….. mm 34 ♦ MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION Exercise No. 1 Design of structures (RCC) Spacing should be less than ……. 1. as calculated = ………..mm 2. 0.75 d = 0.75 x ……. = …….mm 3. 450 mm. Provide -- mm ∅ two legged M.S. stirrups @ ----mm c/c. b) when τv > τc Design shear reinforcement as fallows : Find shear to be resisted Vus Vus = Vu - τc bd = ............ - ........... Vus = ......................N. Find shear resisted by bent up bars Vub = 0.87 fy Asv. Sin 450 = 0.87 x ............x................sin 450 Vub =....................... N Contribution of bent up bars should not be greater Vus / 2 Shear to be resisted by stirrups Vus V'us = Vus - (Vub or Vus / 2 whichever is lesser) = ……… - ……….. =………… Assuming -- mm Ø two or …. legged M.s. stirrups. Asv =2 x ð/4 x d2 = ……….=……….. mm2 Spacing of stirrups Sv ≤ = ……………….. = ………….. mm Spacing should be less than ……. 1. as calculated = ………..mm 2. 0.75 d = 0.75 x ……. = …….mm 3. 450 mm. Provide -- mm ∅ two or …. legged M.S. stirrups @ ----mm c/c.
Would the earth's curvature be seen from top of Burj Dubai?
What materials were used to build the Burj Dubai?
It is constructed mainly of massive re-enforced steel and glass. Scientifically improved concrete to support such mass, Heat and radioactive deflection window panels. The type of windows that were scientifically designed to absorb solar energy to make reusable energy within its own structure also to with stand the sever heat and blistering cold at those altitudes
Where is the tallest building in the world?
Difference between bottom and top fermenting yeast?
Yeast are single-celled microorganisms that reproduce by budding. They are biologically classified as fungi and are responsible for converting fermentable sugars into alcohol and other byproducts. There are literally hundreds of varieties and strains of yeast. In the past, there were two types of beer yeast: ale yeast (the "top-fermenting" type, Saccharomyces cerevisiae) and lager yeast (the "bottom-fermenting" type, Saccharomyces uvarum, formerly known as Saccharomyces carlsbergensis). Today, as a result of recent reclassification of Saccharomyces species, both ale and lager yeast strains are considered to be members of S. cerevisiae. Top-Fermenting Yeast Ale yeast strains are best used at temperatures ranging from 10 to 25°C, though some strains will not actively ferment below 12°C (33). Ale yeasts are generally regarded as top-fermenting yeasts since they rise to the surface during fermentation, creating a very thick, rich yeast head. That is why the term "top-fermenting" is associated with ale yeasts. Fermentation by ale yeasts at these relatively warmer temperatures produces a beer high in esters, which many regard as a distinctive character of ale beers. Top-fermenting yeasts are used for brewing ales, porters, stouts, Altbier, Kölsch, and wheat beers. Bottom-Fermenting Yeast Lager yeast strains are best used at temperatures ranging from 7 to 15°C. At these temperatures, lager yeasts grow less rapidly than ale yeasts, and with less surface foam they tend to settle out to the bottom of the fermenter as fermentation nears completion. This is why they are often referred to as "bottom" yeasts. The final flavour of the beer will depend a great deal on the strain of lager yeast and the temperatures at which it was fermented. Some of the lager styles made from bottom-fermenting yeasts are Pilsners, Dortmunders, Märzen, Bocks, and American malt liquors.
Asked in United Arab Emirates, Buildings, Burj Khalifa
What was the positive effect of the Burj Dubai tower?
Is Fire-walking Psychic Power or Science?
Asked in Buildings, Burj Khalifa
What was the tallest building before burj khalifa?
Asked in United Arab Emirates, Dubai, Burj Khalifa, Height
How tall is the Burj Khalifa?
The Burj Khalifa in Dubai, United Arab Emirates is the world's tallest building. It is also the tallest manmade structure as of its opening in January 2010. The total height is 828 m (2717 feet). There are 163 above-ground floors, the top floor being just 1918 feet (584.5 meters) high. The Burj Khalifa, located in Dubai, is the tallest building in the world. It stands at 2,717 feet and has a total of 163 floors.