In the world dominated by monolithic concrete construction
Why do many years monolithic way of construction of buildings could not compete with constructions? Because he was inferior to the two most important indicators - labor and construction deadlines. The problem, quite significant, has been doing concrete work in the winter. The interest in monolithic construction beginnings grow significantly with the transition of the building complex on market relations. And this is clear: the new method allowed to improve space-planning solution of apartments offered to consumers vsilyakishe and comfortable housing. There are developments that make it possible to build monolithic housing with indicators, compared with the same when using precast concrete. Annual production of concrete for monolithic building in the world - more than half a billion cubic meters. In terms of production and consumption of monolithic concrete considerably ahead of other materials oyitelnyh pp. Indicator use in the U.S. it is 0.75; in Japan - 1.2; in Germany - 0.8; in Italy - 1.1 in France - 0.5; in Israel - 2.0. For comparison: in Turkey - 0.35, in Russia - 0,15-0,2. In the production of concrete for monolithic construction consumes more than half of world cement production. In a monolithic implementation of reduced industrial and residential buildings, objects sotskulta, dams, energy facilities, the television tower. The highest building on all continents are monolithic reinforced concrete frame. In the United States built more than 100 skyscrapers with monolithic frame, concrete and steel steadily pushed out of this area of construction. In Moscow, eight vysotok Stalinist period, three are monolithic reinforced concrete frame. The program building in Moscow on 60 high-rise buildings, including skyscrapers, mostly in-situ reinforced concrete. Annual production of monolithic concrete and reinforced concrete in Russia, by experts, is 20-30 million m3. The average consumption of n and 1 m2 of total floor area of 0,4-0,7 m3 of concrete, steel - 20-70 kg depending on the constructive schemes prochnostnyh characteristics of materials, loading, operating, and other factors. Particularly effective appear in-situ reinforced concrete TV tower. In built 20 years ago Ostankynskoy tower at the height of 537 meters of reinforced concrete is 380 meters. Tower passed the test by fire two years ago. Despite the fact that 70 percent napruzhuvanyh ruynuvalosya ropes, she stood, as evidenced by the high construction and technical properties of cast concrete. Technology monolithic building has a portfolio outstanding. As a result of using sliding formwork in Norway to the concrete caisson oil platform concreted simultaneously perimeter walls and membranes, cumulatively reached 2 km. Sliding formwork overnight peremischalasya 1000 by hydraulic jacks. Modern samopod'emnyye form to change the angle of walls. For example, in Disneyland in Florida with concrete walls of the building sundial minyavsya angle of inclination from 11 to 5 degrees. Leaning Tower of Pisa If the slope is 6 degrees, the inclination of the walls of the exhibition pavilion at Expo 92 in Seville was 15 degrees. When performing high concrete work with samopod'emnoy formwork for the construction of skyscraper height of 200 meters in Frankfurt holes in the walls of the monolithic performed with a tolerance of 5 mm. External perimeter walls of the building in the plan amounted to 210 m. Rate of concreting - 8 days per floor. The quality of surface modifying walls formwork allowed to perform without additional machining of Evidence (zaterly). Very wide use of monolithic concrete found in low construction. For example, Sheathing of the French company Utinord allow team of 7 people betonuvaty daily one-block section of two kvirity three-four-model building. Good prospects in the stationary form of pen opolistirola. Her collected using dry connections between the outer and inner layers of the blocks 7.10 cm thick, several tiporazmerov. After curing of concrete filled inside, outside this wall shtukaturytsya polymer solution on grids with fiberglass or cement mortar on a steel grid. In-situ concrete number of advantages over the use of metal frames in tall buildings. First of all effective dissipation (scattering) energy hesitation buildings in wind loads. Next advantage - that the cross-sections of nuclei may have large areas, providing a significant increase in the moments of resistance and therefore insignificant deformativnost such buildings. When construction of monolithic high-rise buildings are the most common system of nuclei (trunk) rigidity in the heart of the plan. Usually, the core hardness is the elevator shaft. Nezridka instead of core stiffness on the perimeter of the building plan betonuyetsya spatial control p-shell, working with disks overlap and are located inside the columns that accept mainly vertical loads.
Thus, the horizontal deviation of the top of the building relative height is usually not exceed 1 / 1000. But with the development of high-strength concrete vysokoruhlyvyh feed material to a height can be maintained with the use of concrete pumps that much better for the operation of cranes, inevitable in the installation of steel structures. For such buildings used high-strength concrete. In Dallas, United States, while erecting 58-storey administrative building of "Tu Union Square in the columns used in concrete (cylinder) strength of 133 MPa, in terms of kubikovuyu strength at about 160 MPa. As a result, consumption of steel is reduced by more than 2 times and 30% reduced cost. Usually in practice for these purposes apply concrete strength 60 MPa and above. Foreign construction - a high culture of working with concrete. For example, the construction of skyscrapers Uoter Tower in Chicago (74 floors) applied 24 SOS Tawau concrete mixture, depending on the height of different areas. To stem stiffness and column frame exterior walls with 1 to 25 floor using concrete strength 62 MPa. On floors used lightweight concrete strength of 45, 38 and 34 MPa. This allowed for 26% lower gravity load, decrease the depth zastavlyannya foundations receive significant economic benefits. Building oil company Petronas in Kuala Lumpur - Skyscraper. Made it two in a series of towers that are that are connected in the middle of a steel bridge. Each tower round contour in terms of perimeter concrete columns 16 has a diameter of 2.4 meters each, connected to each floor level, ring tanks, forming the outer frame, that is. Clamped monolithic and in profiled steel decking based on ring beams and stiffening tube center section. The full height of building from foundation to top of pile foundation teleanteny point on the roof - 582 m. Concreting was carried out in resettable opalubtsi with p omoschyu concrete pumps. Conclusion produce significant amounts of concrete, usually with powerful concrete pumps. In Germany their fate at the conclusion of cast concrete is 35%, Sweden - 55% of large Concrete boom height reaches 60 m and capacity - 150 m per hour and more. There is a world record submission concrete mixes height - 500 meters - Putzmeister pump company in the Italian Alps. When erecting skyscrapers Petronas height feed mixture was 432 feet. World record for pumping concrete on the ground less than 2 km. More than 100 million m2 monolithic ceilings with tension reinforcement of concrete built in recent years in the U.S., then followed by Canada. Pre-strained valves in monolithic concrete structures overlap starts taken no grip the surrounding concrete. To protect the reinforcing elements (cables) from corrosion, they are placed in special envelopes, filled with corrosion-resistant composition. In Russia, until no such overlap. There was a time when American experts studied the possibility of building concrete plants on the Moon. Studies have shown: concrete for aggregates of lunar soil is a valuable construction material and has compressive strength of 78 MPa. Normal concrete is also the same composition - 56 MPa. Dynamic module - under 21200 and 28100 MPa, strength stretch - 9.4 and 9.6 MPa. Experts have output that concrete for the construction of stations on the Moon mainly what other materials with the high radionepronitsayemosti, and, most importantly, almost all the components for its preparation can be refined on the spot, including manufactured and cement. For example, to construct a three-storey circular building 62 feet in diameter, will require 1.5 thousand tons cement. Water can be connected by hydrogen, drawn from some minerals Luna, and oxygen delivered to the Earth. To obtain the necessary materials for the construction of this building from Earth will need to deliver only 55 tons of oxygen. However, expansion builder stva monolithic buildings associated with the following problems: - the danger of technological cracks in structures by temperature-usadkovyh deformations of concrete in the process of curing, which depends on the composition of concrete, curing conditions and the size of plots concrete structures - need a reliable estimate tverdnuchoho strength of concrete at the time that that rozpalubyla and transfer the load from vyscherozmischenyh elements of design, where concrete has not reached the design capacity - the need to develop design rules to establish an interim allowable strength of concrete at the removal of formwork and perestanovtsi floors for different types monolithic structures (floors, walls, columns) in terms of treschynostoykosti and strength of structures during construction of a monolithic building, and the inclusion of the work plan of action to accelerate the recruitment strength of concrete - you want an effective quality control of monolithic structures. Meanwhile, testing trial loading of monolithic structures are complex and control of concrete strength on the samples is insufficient, especially in winter. The center of gravity control strength to move on non-destructive methods. That the erection of the building must be accompanied with serious monitoring to ensure its reliability and safe operation of the future. Currently in Europe the process of creating a single regulatory framework for the countries - EU members. In the construction work is about 200 documents with them on concrete, reinforced concrete and composite materials including methods of testing - more than a hundred. According to many experts, for the climatic conditions of Russia's excessive admiration monolith is not very rational. Abroad, the same interest in precast concrete building with no slabiye, but rather reinforced.