Gravel roadA gravel road is a type of unpaved road surfaced with gravel that has been brought to the site from a quarry or stream bed. Gravel roads are common in less-developed nations, and also in the rural areas of developed nations such as Canada and the United States. In New Zealand, and other Commonwealth countries, they may be known as metal roads.
Unpaved roadAn unpaved road is a type of road whose surface has not been sealed with a pavement treatment, such as concrete or bitumen. An unpaved road can be a dirt road, whose surface is the native material of the land surface (known as subgrade material), or it could be a gravel road, where the subgrade material has been covered by gravel but not sealed. There are approximately 13 million km (8.1 million mi) of unpaved road in the world, making up 57% of the total road length.
MacadamMacadam is a type of road construction pioneered by Scottish engineer John Loudon McAdamc. 1820, in which crushed stone is placed in shallow, convex layers and compacted thoroughly. A binding layer of stone dust (crushed stone from the original material) may form; it may also, after rolling, be covered with a cement or bituminous binder to keep dust and stones together. The method simplified what had been considered state-of-the-art at that point.
GravelGravel () is a loose aggregation of rock fragments. Gravel occurs naturally on Earth as a result of sedimentary and erosive geological 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 (2–4 mm or 0.079–0.157 in) and pebble gravel (4–64 mm or 0.2–2.5 in).
Off-road vehicleAutomotive vehicle capable of driving across difficult terrain beyond sealed roads Mercedes-Benz Unimog in the Dunes of Erg Chebbi in Morocco. The vehicle's portal gear axles provide high ground clearance. An off-road vehicle (ORV), also known as an off-highway vehicle (OHV), overland vehicle or adventure vehicle, is a type of transportation specifically engineered to navigate unpaved roads and surfaces. These include trails, forest roads, and other low-traction terrains.
Aggregate (composite)Aggregate is the component of a composite material that resists compressive stress and provides bulk to the material. For efficient filling, aggregate should be much smaller than the finished item, but have a wide variety of sizes. Aggregates are generally added to lower the amount of binders needed and to increase the strength of composite materials. Sand and gravel are used as construction aggregate with cement to make concrete and increase its mechanical strength.
ChinaCountry in East AsiaChina, officially the People's Republic of China (PRC), is a country in East Asia. It is divided into 33 province-level divisions, including two special administrative regions. Beijing is the capital, while Shanghai is the most populous city by urban area. Its geography features the Central Plain, major rivers such as the Yangtze and Yellow River, deserts, subtropical and temperate forests, plateaus, and mountain ranges such as the Himalayas.
FinlandCountry in Northern EuropeFinland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, opposite Estonia. Its capital and largest city is Helsinki. Finland has a population of 5.7 million.
AustraliaCountry in OceaniaAustralia, officially the Commonwealth of Australia, is a country comprising the mainland of the Australian continent, the island of Tasmania and numerous smaller islands. It has a land area of 7,688,287 km (2,968,464 sq mi), making it the sixth-largest country in the world, and is the world's flattest and driest inhabited continent.
New ZealandNew Zealand is an island country in the southwestern Pacific Ocean. It comprises two main landmasses—the North Island (Te Ika-a-Māui) and the South Island (Te Waipounamu)—and over 700 smaller islands. It is the sixth-largest island country by area and lies east of Australia across the Tasman Sea and south of the islands of New Caledonia, Fiji, and Tonga.
SubgradeIn transport engineering, subgrade is the term used in the US for the native material underneath a constructed road, pavement or railway track (US: railroad track). In British English it is called formation level. The subgrade provides support to the subbase level and acts as an integral load-bearing layer. Failure of the subgrade can cause depressions and rutting of the upper base and surface courses.Embankment (earthworks)An embankment is a raised wall, bank, or mound that is made of earth or stone and used to hold back water or carry a roadway. A road, railway track, or aqueduct is normally raised onto an embankment made of compacted soil (typically clay or rock-based) to avoid a change in level required by the terrain, the alternatives being either to have an unacceptable change in level or detour to follow a contour.Special:Search/Dirt roadRelated word or term.*As an Amazon Associate I earn from qualifying purchases.