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River Gravel
River gravel is a name given to gravel composed of small pieces of rounded stone of various colors, usually no larger than a large coin. It is named for the effect of many years of rounding of the edges of the stones due to a flow of water over it, as often takes place in a river. River gravel is often used in outdoor settings, such as a park walkway.{{cite web, url=http://www.anlscape.com.au/page/decorative_gravels.html , title=Australian Native Landscapes , accessdate=2009-04-14 , url-status=dead , archiveurl=https://web.archive.org/web/20090204070123/http://www.anlscape.com.au/page/decorative_gravels.html , archivedate=February 4, 2009 When a hard surface is also desired, river gravel is often set in a concrete aggregate mix. Owing to much higher cost than either asphalt or concrete pavement, the use of river gravel is generally limited to places where the appearance and/or its lack of sharp edges (when used alone) is of primary importance. The American National Park Servic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravel
Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone. Gravel is classified by particle size range and includes size classes from granule- to boulder-sized fragments. In the Udden-Wentworth scale gravel is categorized into granular gravel () and pebble gravel (). ISO 14688 grades gravels as fine, medium, and coarse, with ranges 2–6.3 mm to 20–63 mm. One cubic metre of gravel typically weighs about 1,800 kg (or a cubic yard weighs about 3,000 lb). Gravel is an important commercial product, with a number of applications. Almost half of all gravel production is used as aggregate for concrete. Much of the rest is used for road construction, either in the road base or as the road surface (with or without asphalt or other binders.) Naturally occurring porous gravel deposits have a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of water. Small rivers can be referred to using names such as creek, brook, rivulet, and rill. There are no official definitions for the generic term river as applied to geographic features, although in some countries or communities a stream is defined by its size. Many names for small rivers are specific to geographic location; examples are "run" in some parts of the United States, "burn" in Scotland and northeast England, and "beck" in northern England. Sometimes a river is defined as being larger than a creek, but not always: the language is vague. Rivers are part of the water cycle. Water generally collects in a river from precipitation through a drainage basin from surface runoff and other sources such as groundwater recharge, spr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most widely used building material. Its usage worldwide, ton for ton, is twice that of steel, wood, plastics, and aluminum combined. Globally, the ready-mix concrete industry, the largest segment of the concrete market, is projected to exceed $600 billion in revenue by 2025. This widespread use results in a number of environmental impacts. Most notably, the production process for cement produces large volumes of greenhouse gas emissions, leading to net 8% of global emissions. Other environmental concerns include widespread illegal sand mining, impacts on the surrounding environment such as increased surface runoff or urban heat island effect, and potential public health implications from toxic ingredients. Significant research and development i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Construction Aggregate
Construction aggregate, or simply aggregate, is a broad category of coarse- to medium-grained particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates. Aggregates are the most mined materials in the world. Aggregates are a component of composite materials such as concrete and asphalt; the aggregate serves as reinforcement to add strength to the overall composite material. Due to the relatively high hydraulic conductivity value as compared to most soils, aggregates are widely used in drainage applications such as foundation and French drains, septic drain fields, retaining wall drains, and roadside edge drains. Aggregates are also used as base material under foundations, roads, and railroads. In other words, aggregates are used as a stable foundation or road/rail base with predictable, uniform properties (e.g. to help prevent differential settling under the road or building), or as a low-cost exte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asphalt Concrete
Asphalt concrete (commonly called asphalt, blacktop, or pavement in North America, and tarmac, bitumen macadam, or rolled asphalt in the United Kingdom and the Republic of Ireland) is a composite material commonly used to surface roads, parking lots, airports, and the core of embankment dams. Asphalt mixtures have been used in pavement construction since the beginning of the twentieth century. It consists of mineral aggregate bound together with asphalt, laid in layers, and compacted. The process was refined and enhanced by Belgian-American inventor Edward De Smedt. The 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 denote ''asphalt content'' or ''asphalt cement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Park Service
The National Park Service (NPS) is an agency of the United States federal government within the U.S. Department of the Interior that manages all national parks, most national monuments, and other natural, historical, and recreational properties with various title designations. The U.S. Congress created the agency on August 25, 1916, through the National Park Service Organic Act. It is headquartered in Washington, D.C., within the main headquarters of the Department of the Interior. The NPS employs approximately 20,000 people in 423 individual units covering over 85 million acres in all 50 states, the District of Columbia, and US territories. As of 2019, they had more than 279,000 volunteers. The agency is charged with a dual role of preserving the ecological and historical integrity of the places entrusted to its management while also making them available and accessible for public use and enjoyment. History Yellowstone National Park was created as the first nationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colonial Parkway
Colonial Parkway is a scenic parkway linking the three points of Virginia's Historic Triangle, Jamestown, Williamsburg, and Yorktown. It is part of the National Park Service's Colonial National Historical Park. Virginia's official state classification for the parkway is State Route 90003. With portions built between 1930 and 1957, it links the three communities via a roadway shielded from views of commercial development. The roadway is toll-free, is free of semi trucks, and has speed limits of around . As a National Scenic Byway and All-American Road (one of only 31 in the U.S.), it is also popular with tourists due to the James River and York River ends of the parkway. Bridges and interchanges For most roads it crosses it does not have an intersection with that road. It normally goes on a bridge, under a bridge, or in a tunnel (the only tunnel runs beneath Colonial Williamsburg). Examples of this happening: when it crosses Interstate 64 and US Route 60. When it cros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Historic Triangle
The Historic Triangle includes three historic colonial communities located on the Virginia Peninsula of the United States and is bounded by the York River on the north and the James River on the south. The points that form the triangle are Jamestown, Colonial Williamsburg, and Yorktown. They feature many restored attractions and are linked by the Colonial Parkway in James City and York counties, and the City of Williamsburg. Describing the significance to the United States of the three main points of the Historic Triangle, the Reverend Dr. W.A.R. Goodwin, rector of Bruton Parish Church and co-founder of Colonial Williamsburg, said, "Williamsburg is Jamestown continued, and Yorktown is Williamsburg vindicated." Colonial Parkway The National Park Service's Colonial Parkway was constructed to connect the three historic attractions of Colonial Virginia with a scenic and bucolic roadway carefully shielded from views of commercial development. Intended to help visitors mentally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landscape Architect
A landscape architect is a person who is educated in the field of landscape architecture. The practice of landscape architecture includes: site analysis, site inventory, site planning, land planning, planting design, grading, storm water management, sustainable design, construction specification, and ensuring that all plans meet the current building codes and local and federal ordinances. The practice of landscape architecture dates to some of the earliest of human cultures and just as much as the practice of medicine has been inimical to the species and ubiquitous worldwide for several millennia. However, this article examines the modern profession and educational discipline of those practicing the design of landscape architecture. In the 1700s, Humphry Repton described his occupation as "landscape gardener" on business cards he had prepared to represent him in work that now would be described as that of a landscape architect. The title, "landscape architect", was first u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravel
Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone. Gravel is classified by particle size range and includes size classes from granule- to boulder-sized fragments. In the Udden-Wentworth scale gravel is categorized into granular gravel () and pebble gravel (). ISO 14688 grades gravels as fine, medium, and coarse, with ranges 2–6.3 mm to 20–63 mm. One cubic metre of gravel typically weighs about 1,800 kg (or a cubic yard weighs about 3,000 lb). Gravel is an important commercial product, with a number of applications. Almost half of all gravel production is used as aggregate for concrete. Much of the rest is used for road construction, either in the road base or as the road surface (with or without asphalt or other binders.) Naturally occurring porous gravel deposits have a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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