Results for: Concrete

9,196 Contributions

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What is concrete?

Concrete is formed by a chemical reaction called hydration between water and cement. The cement is usually a compound called Portland cement. . In addition to water and ceme… (MORE)

Amberthebitch

6 Contributions

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In Earth Sciences

What is a concretion?

A concretion is a volume of sedimentary rock in which a mineral cement fills the porosity (i.e. the spaces between the sediment grains).

Glenn Summers

145 Contributions

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In Gardening

Can you bond concrete to concrete?

Yes, provided you use a bonding agent. Unfortunately, the term Bonding Agent is used very loosely! In actuality a "Bonding Agent" winds up being a material placed on the exis… (MORE)

Keebobaik

2 Contributions

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In Science

What is concretion?

concretion is a volume of sedimentary rock in which a mineral cement fills the porosity (i.e. the spaces between the sediment grains). Concretions are often ovoid or spherical… in shape, although irregular shapes also occur. The word 'concretion' is derived from the Latin con meaning 'together' and crescere meaning 'to grow'. Concretions form within layers of sedimentary strata that have already been deposited. They usually form early in the burial history of the sediment, before the rest of the sediment is hardened into rock. This concretionary cement often makes the concretion harder and more resistant to weathering than the host stratum. There is an important distinction to draw between concretions and nodules. Concretions are being formed from mineral precipitation around some kind of nucleus while a nodule is a replacement body. Descriptions dating from the 18th century attest to the fact that concretions have long been regarded as geological curiosities. Because of the variety of unusual shapes, sizes and compositions, concretions have been interpreted to be dinosaur eggs, animal and plant fossils (called pseudofossils), extraterrestrial debris or human artifacts. Septarian_concretions">Septarian concretions Septarian concretions or septarian nodules, are concretions containing angular cavities or cracks, which are called "septaria". The word comes from the Latin word septum; "partition", and refers to the cracks/separations in this kind of rock[1]. There is an incorrect explanation that it comes from the Latin word for "seven", septem[2], referring to the number of cracks that commonly occur. Cracks are highly variable in shape and volume, as well as the degree of shrinkage they indicate. Although it has commonly been assumed that concretions grew incrementally from the inside outwards, the fact that radially oriented cracks taper towards the margins of septarian concretions is taken as evidence that in these cases the periphery was stiffer while the inside was softer, presumably due to a gradient in the amount of cement precipitated. The process that created the septaria, which characterize septarian concretions, remains a mystery. A number of mechanisms, i.e. the dehydration of clay-rich, gel-rich, or organic-rich cores; shrinkage of the concretion's center; expansion of gases produced by the decay of organic matter; brittle fracturing or shrinkage of the concretion interior by either earthquakes or compaction; and others, have been proposed for the formation of septaria (Pratt 2001). At this time, it is uncertain, which, if any, of these and other proposed mechanisms is responsible for the formation of septaria in septarian concretions (McBride et al. 2003). Septaria usually contain crystals precipitated from circulating solutions, usually of calcite. Siderite or pyrite coatings are also occasionally observed on the wall of the cavities present in the septaria, giving rise respectively to a panoply of bright reddish and golden colors. Some septaria may also contain small calcite stalagtites and well-shaped millimetric pyrite single crystals. A spectacular example of septarian concretions, which are as much as 3 meters (9 ft) in diameter, are the Moeraki Boulders. These concretions are found eroding out of Paleocene mudstone of the Moeraki Formation exposed along the coast near Moeraki, South Island, New Zealand. They are composed of calcite-cemented mud with septarian veins of calcite and rare late-stage quartz and ferrous dolomite (Boles et al. 1985, Thyne and Boles 1989). Very similar concretions, which are as much as 3 meter (9 ft) in diameter and called "Koutu Boulders", litter the beach between Koutu and Kauwhare points along the south shore of the Hokianga Harbour of Hokianga, North Island, New Zealand. The much smaller septarian concretions found in the Kimmeridge Clay exposed in cliffs along the Wessex Coast of England are more typical examples of septarian concretions (Scotchman 1991). (MORE)

Texasduude

207 Contributions

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In Building and Carpentry

What can you do with concrete?

With concrete and precast concrete you can build fences, walls, concrete sound walls, pre-cast concrete perimeter walls, masonry walls, masonry screen walls and more! If you… (MORE)

Manikkpudur

565 Contributions

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In Uncategorized

How a concrete pump push concrete?

Pumps consist basically of pressure vessels and equipments for supplying compressed air. Concrete is delivered in to the pressure vessel and the vessel sealed tightly… (MORE)

Hayesconcrete

17 Contributions

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In Building and Carpentry

How much concrete is in a yard of concrete?

27 cubic feet okay from hayesconcrete.com 81 sq ft is= 4 inches 54 sg ft is = 6 inches

Paul La Chance

1 Contribution

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In Building and Carpentry

Can you pour concrete on old concrete?

not normally. it depends on what you are trying to accomplish. if you need a thin layer than you can pour a thin set layer which hardens and adheres better than concrete. if t… (MORE)

Answered

In Technology

What is the concrete mix for concrete?

Normally it's a one-two-three mix. One part cement, 2 parts sand, 3 parts aggregate. The sand is graded which means it has a variety of grain sizes.

Ken Hawkins

18 Contributions

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In Building and Carpentry

Who places concrete bolts in concrete?

I assume you are talking about anchor bolts for securing walls and or equipment. Most masonry or carpentry contractors can perform this job. It can also be done DIY, but requi… (MORE)