CONCRETE

In construction, concrete is a composite building material made from a combination of aggregate and cement binder. The most common form of concrete is Portland cement concrete, which consists of mineral aggregate (usually gravel and sand), cement and water.

Usually it is believed that the concrete dries after mixing and laying. Actually, not a solid concrete because the water evaporates, but the cement hydratious, gluing the other components together and eventually form a material like stone. Concrete is used to make the pavement, structures, foundations, roads, pedestrian bridges, parking structures, the basis for the fences / gates, and cement brick or block walls. The old name for concrete is molten rock.In the development of many found new concrete modifications, such as lightweight concrete, concrete spray (eng: shotcrete), fiber concrete, high strength concrete, high strength concrete, concrete incompressible own (eng: self-compacted concrete) etc. Currently concrete is a building material that is most widely used in the world.

The use of concrete and materials such as volcanic ash as a pozzolan constituent has been started since the days of the Greeks and Romans probably even earlier. With a mixture of lime, pozzolan, and pumice, the Romans many build infrastructure such as aqueducts, buildings, drainage and others. In Indonesia a similar use can be seen in several ancient buildings remaining. Fortress Indrapatra in Aceh which was built in the 7th century by the royal Lamuri, building materials such as limestone, clay, and stone mountain. The Egyptians had found earlier that the use of volcanic ash additives can improve the compressive strength of concrete.

The use of massive concrete begins at the beginning of the 19th century and the beginning of the era of reinforced concrete. In 1801, F.Coignet published his writings about the construction principles by reviewing concrete material against taruknya moisture. In 1850, J.L. Lambot for the first time make a small boat from the cement material to be exhibited in the Expo 1855 in Paris. J.Moiner, an expert in the garden of the French patent as concrete reinforcement metal framework for addressing taruknya used for crops. In 1886, Koenen published literature on the theory and design of concrete structures. CAP Turner developed a slab without beam plate 1906.Excess concrete is that it can easily be formed in accordance with the needs of the construction. Beside that concrete also has a powerful strength, resistant to high temperatures and low maintenance costs.

Moderate weakness is the form that has made it difficult to change without damage. In concrete structures, if you want to do the destruction it will be costly because it can not be used anymore. Differences with a steel structure that remains valuable. Weight, compared with the strength and great bounce.

Concrete has a high compressive strength but weak in its appeal. If the structure was immediately if not given sufficient reinforcement will easily fail. According to rough estimates, the value of tensile strength of about 9% -5% compressive strength. Therefore it is indispensable in strengthening concrete structures. Retrofitting common is to use a steel spine which when combined are often referred to as reinforced concrete. [

As mentioned previously, the concrete has a high compressive strength but poor tensile strength. For compressive strength, in Indonesia frequently used units of kg / cm with the symbol K for specimen cubes and fc for cylindrical test specimen. Strong crushed concrete is influenced by several factors: The type and quality of cement.Type and pits, through lekul aggregate surface area. The fact shows that the use of aggregate will produce concrete with compressive strength and tensile strength is greater than the use of fine gravel from the river.Care Of. Loss of strength up to about 40% can occur when drying held prematurely. Maintenance is very important in the work field and in the manufacture of the test object.The Temperature. In general, concrete hardening rate increases with increasing temperature. At the freezing point of the compressive strength will remain low for a long time.Age. In normal kekeadaan concrete strength increases with ageSummaryconcrete is a composite building material made from a combination of aggregate and cement binder. The most common form of concrete is Portland cement concrete, which consists of mineral aggregate (usually gravel and sand), cement and water.Concrete is used to make the pavement, structures, foundations, roads, pedestrian bridges, parking structures, the basis for the fences / gates, and cement brick or block walls.

The use of concrete and materials such as volcanic ash as a pozzolan constituent has been started since the days of the Greeks and Romans probably even earlier, and In Indonesia a similar use can be seen in several ancient buildings remaining. Fortress Indrapatra in Aceh which was built in the 7th century by the royal Lamuri.The use of massive concrete begins at the beginning of the 19th century and the beginning of the era of reinforced concrete. In 1801, F.Coignet published his writings about the construction principles by reviewing concrete material against taruknya moisture.

Excess concrete is that it can easily be formed in accordance with the needs of the construction. Beside that concrete also has a powerful strength, resistant to high temperatures and low maintenance costs.Moderate weakness is the form that has made it difficult to change without damage. In concrete structures, if you want to do the destruction it will be costly because it can not be used anymore. Differences with a steel structure that remains valuable. Weight, compared with the strength and great bounce. The concrete has a high compressive strength but poor tensile strength and Strong crushed concrete is influenced by several factors: The type and quality of cement, Type and pits, through lekul aggregate surface area, Care Of, The Temperature and age.

In the development of many found new concrete modifications, such as lightweight concrete, concrete spray (eng: shotcrete), fiber concrete, high strength concrete, high strength concrete, concrete incompressible own (eng: self-compacted concrete) etc. Currently concrete is a building material that is most widely used in the world.