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Rollcrete
Roller-compacted concrete (RCC) or rolled concrete (rollcrete) is a special blend of concrete that has essentially the same ingredients as conventional concrete but in different ratios, and increasingly with partial substitution of fly ash for portland cement. The partial substitution of fly ash for Portland Cement is an important aspect of RCC dam construction because the heat generated by fly ash hydration is significantly less than the heat generated by portland cement hydration. This in turn reduces the thermal loads on the concrete and reduces the potential for thermal cracking to occur. RCC is a mix of cement/fly ash, water, sand, aggregate and common additives, but contains much less water. The produced mix is drier and essentially has no slump. RCC is placed in a manner similar to road paving; the material is delivered by dump trucks or conveyors, spread by small bulldozers or specially modified asphalt pavers, and then compacted by vibratory rollers. In dam construc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Willow Creek Dam (Oregon)
Willow Creek Dam is a dam in Morrow County of the U.S. state of Oregon, located just east of Heppner's city limits. It was the first major dam in the United States constructed of roller-compacted concrete. The dam's drainage basin is of arid rolling hills in the lower basin but with headwaters in the northern Umatilla National Forest. The dam's original purpose was primarily to store water for flood control, but also to serve recreation, fish and wildlife, and irrigation uses. The dam impounds Willow Creek to create Willow Creek Lake. The lake level can be a maximum of elevation and a minimum of for a total usable storage capacity of . History A major flood killed approximately one quarter of Heppner's population in June 1903—about 250 people. The flooding creek flow was as a result of a flash flood caused by thunderstorms, known as the Heppner Flood of 1903. A flood control study was completed in 1962 at a total cost of $219. In 1965, a flood control project was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Concrete
Concrete is a composite material composed of aggregate bound together with a fluid cement that cures to a solid over time. It is the second-most-used substance (after water), the most–widely used building material, and the most-manufactured material in the world. When aggregate is mixed with dry Portland cement and water, the mixture forms a fluid slurry that can be poured and molded into shape. The cement reacts with the water through a process called hydration, which hardens it after several hours to form a solid matrix that binds the materials together into a durable stone-like material with various uses. This time allows concrete to not only be cast in forms, but also to have a variety of tooled processes performed. The hydration process is exothermic, which means that ambient temperature plays a significant role in how long it takes concrete to set. Often, additives (such as pozzolans or superplasticizers) are included in the mixture to improve the physical prop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Asphalt Concrete
Asphalt concrete (commonly called asphalt, blacktop, or pavement in North America, and Tarmacadam, tarmac or bitumen macadam in the United Kingdom and the Republic of Ireland) is a composite material commonly used to surface road surface, roads, parking lots, airports, and the core of embankment dams. Asphalt mixtures have been used in pavement construction since the nineteenth century. It consists of Construction aggregate, mineral aggregate Binder (material), bound together with bitumen (a substance also independently known as asphalt, Pitch (resin), pitch, or tar), laid in layers, and compacted. The American English terms ''asphalt'' (or ''asphaltic'') ''concrete'', ''bituminous asphalt concrete'', and ''bituminous mixture'' are typically used only in engineering and construction documents, which define concrete as any composite material composed of mineral aggregate adhered with a binder. The abbreviation, ''AC'', is sometimes used for ''asphalt concrete'' but can also denot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
:Category:Roller-compacted Concrete Dams
The category lists dams constructed primarily with roller-compacted concrete (RCC). They include arch and gravity dam A gravity dam is a dam constructed from concrete or stone masonry and designed to hold back water by using only the weight of the material and its resistance against the foundation. Gravity dams are designed so that each section of the dam is ...s currently proposed, under construction or completed. {{CatAutoTOC Dams by type Concrete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Diamer-Bhasha Dam
Diamer-Bhasha Dam is a concreted-filled gravity dam, in the preliminary stages of construction, on the River Indus between Kohistan district in Khyber Pakhtunkhwa and Diamer district in Gilgit Baltistan, Pakistan administered Kashmir. Its foundation stone was laid by the then Prime Minister of Pakistan in 1998. The dam site is situated near a place called "Bhasha", hence the name which is 40 km downstream of Chilas town and 315 km from Tarbela Dam. The eight million acre feet (MAF) reservoir with 272-metre height will be the tallest roller compact concrete (RCC) dam in the world. Upon completion, Diamer-Bhasha dam would (i) produce 4800 megawatts of electricity through hydro-power generation; (ii) store an extra of water for Pakistan that would be used for irrigation and drinking; (iii) extend the life of Tarbela Dam located downstream by 35 years; and (iv) control flood damage by the River Indus downstream during high floods. However, in response to using Basha D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Gilgel Gibe III Dam
The Gilgel Gibe III Dam is a 250m high roller-compacted concrete dam with an associated hydroelectric power plant on the Omo River in Ethiopia. It is located about west of Sodo in the South Ethiopia Regional State. Once fully commissioned, it will be the third largest hydroelectric plant in Africa with a power output of about 1,870 Megawatt (MW), thus more than doubling Ethiopia's total installed capacity from its 2007 level of 814 MW.Ethiopian Electric Power CorporatioGibe III Hydroelectric Project Official Website, accessed on May 7, 2012 The Gibe III dam is part of the Gibe cascade, a series of dams including the existing Gibe I dam (184 MW) and Gibe II power station (420 MW) as well as the planned Gibe IV (1,472 MW) and Gibe V (560 MW) dams. The existing dams are owned and operated by the state-owned Ethiopian Electric Power, which is also the client for the Gibe III Dam. The US$1.8 billion project began in 2006 and electricity generation started in October 2015. The rem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Omo Gibe III, Wolayita 3
Omo or OMO may refer to: Geography Ethiopia * Omo River (Ethiopia), in southern Ethiopia is the largest Ethiopian river outside the Nile Basin and namesake for all the topics below * Omo Nada, one of the woredas in the Oromia Region of Ethiopia * South Omo Zone, a zone in the Ethiopian Southern Nations, Nationalities and Peoples' Region (SNNPR) * Omo National Park, Ethiopia * Omo Kibish Formation, an East African rock formation * Omo remains, a collection of hominid bones Elsewhere *Omo River (Yamanashi) *Omø, an island in Denmark * Omo River (Quebec), a tributary of Maicasagi River in Quebec, Canada People * Omo Aikeremiokha, (born 2005), British trampoline gymnast * Omo Osaghae (born 1988), American hurdler * Suleiman Omo (born 1985), Nigerian footballer for clubs in southeastern Europe Acronyms and codes * Open market operation, by the Federal Reserve or other central banks * Open Market Option allows someone approaching retirement to ‘shop around’ * One-man operat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Sulfuric Acid
Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, and hydrogen, with the molecular formula . It is a colorless, odorless, and Viscosity, viscous liquid that is Miscibility, miscible with water. Pure sulfuric acid does not occur naturally due to its Dehydration reaction, strong affinity to water vapor; it is Hygroscopy, hygroscopic and readily absorbs water vapor from the Atmosphere of Earth, air. Concentrated sulfuric acid is a strong oxidant with powerful dehydrating properties, making it highly corrosive towards other materials, from rocks to metals. Phosphorus pentoxide is a notable exception in that it is not dehydrated by sulfuric acid but, to the contrary, dehydrates sulfuric acid to sulfur trioxide. Upon addition of sulfuric acid to water, a considerable amount of heat is releas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Hydrogen Sulfide
Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is toxic, corrosive, and flammable. Trace amounts in ambient atmosphere have a characteristic foul odor of rotten eggs. Swedish chemist Carl Wilhelm Scheele is credited with having discovered the chemical composition of purified hydrogen sulfide in 1777. Hydrogen sulfide is toxic to humans and most other animals by inhibiting cellular respiration in a manner similar to hydrogen cyanide. When it is inhaled or its salts are ingested in high amounts, damage to organs occurs rapidly with symptoms ranging from breathing difficulties to convulsions and death. Despite this, the human body produces small amounts of this sulfide and its mineral salts, and uses it as a signalling molecule. Hydrogen sulfide is often produced from the microbial breakdown of organic matter in the absence of oxygen, such as in swamps and sewers; this process is commonly known as anaerobic digestio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Grout Curtain
A grout curtain is a barrier that protects the foundation of a dam from seepage and can be made during initial construction or during repair. Additionally, it can be used to strengthen foundations and contain spills. Characteristics A grout curtain usually consists of a row of vertically drilled holes filled with pressurized grout, a process commonly known as pressure grouting. The holes are drilled in intervals and in such a way that they cross each other, creating a curtain. Method Grout is injected with grouting jets, which use a high-pressure fluid stream (i.e., slurry or water) to erode a cavity in the soil. See also *Levee *Dam failure A dam failure or dam burst is a catastrophic type of structural failure characterized by the sudden, rapid, and uncontrolled release of impounded water or the likelihood of such an uncontrolled release. Between the years 2000 and 2009 more than ... References External linksCurtain Grouting the Georgetown Lighthouse [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
American Scientist
''American Scientist'' (informally abbreviated ''AmSci'') is an American bimonthly science and technology magazine published since 1913 by Sigma Xi, The Scientific Research Honor Society. In the beginning of 2000s the headquarters was moved to Research Triangle Park, (Durham), North Carolina. Each issue includes feature articles written by scientists and engineers who review research in fields from molecular biology to computer engineering. Each issue also includes the work of cartoonist A cartoonist is a visual artist who specializes in both drawing and writing cartoons (individual images) or comics (sequential images). Cartoonists differ from comics writers or comics illustrators/artists in that they produce both the litera ...s, including those of Sidney Harris, Benita Epstein, and Mark Heath. Also included is the ''Scientists' Nightstand'' that reviews a vast range of science-related books and novels. ''American Scientist Online'' () was launched in May 2003. Re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
