Rebar spacer
Encyclopedia
A rebar spacer is a device that secures the reinforcing steel or "rebar" in reinforced concrete
structures as the rebar is assembled in place prior to the final concrete pour. The spacers are left in place for the pour to keep the reinforcing in place, and become a permanent part of the structure.
The main categories of rebar spacers are:
You can also divide the rebar spacers in two raw materials categories:
The concrete spacers have the advantage of the same raw material which will improve the watertightness and strength of the concrete. Plastic spacers have the advantage of the low cost production and fast processing. This was the inspiration for a Dutchman who started producing concrete spacers with plastic clips in about 1995. This invention made working with concrete spacers more profitable and easy.
, a bearing wall or other structure, predicts the positioning of steel rebars at specific positions in the volume of concrete
(predicted cover of steel reinforcement bars). This cover typically varies between 10mm and 100mm. The statics of every concrete construction are designed in such a way that steel and concrete properties are combined in order to achieve the maximum possible strength for the particular construction (e.g. anti-earthquake
protection) as well as to prevent the long-term corrosion
of steel
that would weaken the construction. Rebar spacers secure the correct position of steel, thus assisting in the practical application of the theoretical specifications of concrete construction. The cover of the steel of a particular construction element (for example in a concrete slab
or a beam
) should be generally uniform within the element.
The use of spacers is particularly important in areas with high earthquake activity in combination with corrosive environment (like proximity to salt water
of sea), as for example Japan
, Iran
, Greece
, California
etc.
Reinforced concrete
Reinforced concrete is concrete in which reinforcement bars , reinforcement grids, plates or fibers have been incorporated to strengthen the concrete in tension. It was invented by French gardener Joseph Monier in 1849 and patented in 1867. The term Ferro Concrete refers only to concrete that is...
structures as the rebar is assembled in place prior to the final concrete pour. The spacers are left in place for the pour to keep the reinforcing in place, and become a permanent part of the structure.
The main categories of rebar spacers are:
- Linear Spacers (Π-section profiles, H-section profiles, or other 3 dimensional shapes),
- Point Spacers (wheel spacers, various tower or chair-like shapes)
You can also divide the rebar spacers in two raw materials categories:
- Concrete spacers
- Plastic spacers
The concrete spacers have the advantage of the same raw material which will improve the watertightness and strength of the concrete. Plastic spacers have the advantage of the low cost production and fast processing. This was the inspiration for a Dutchman who started producing concrete spacers with plastic clips in about 1995. This invention made working with concrete spacers more profitable and easy.
Function
The engineering study of every concrete construction, whether it is a building, a bridgeBridge
A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...
, a bearing wall or other structure, predicts the positioning of steel rebars at specific positions in the volume of concrete
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
(predicted cover of steel reinforcement bars). This cover typically varies between 10mm and 100mm. The statics of every concrete construction are designed in such a way that steel and concrete properties are combined in order to achieve the maximum possible strength for the particular construction (e.g. anti-earthquake
Earthquake
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...
protection) as well as to prevent the long-term corrosion
Corrosion
Corrosion is the disintegration of an engineered material into its constituent atoms due to chemical reactions with its surroundings. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen...
of steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
that would weaken the construction. Rebar spacers secure the correct position of steel, thus assisting in the practical application of the theoretical specifications of concrete construction. The cover of the steel of a particular construction element (for example in a concrete slab
Concrete slab
A concrete slab is a common structural element of modern buildings. Horizontal slabs of steel reinforced concrete, typically between 10 and 50 centimeters thick, are most often used to construct floors and ceilings, while thinner slabs are also used for exterior paving.In many domestic and...
or a beam
Beam (structure)
A beam is a horizontal structural element that is capable of withstanding load primarily by resisting bending. The bending force induced into the material of the beam as a result of the external loads, own weight, span and external reactions to these loads is called a bending moment.- Overview...
) should be generally uniform within the element.
The use of spacers is particularly important in areas with high earthquake activity in combination with corrosive environment (like proximity to salt water
Seawater
Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% . This means that every kilogram of seawater has approximately of dissolved salts . The average density of seawater at the ocean surface is 1.025 g/ml...
of sea), as for example Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
, Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
etc.