The type of concrete floor will depend largely on the design loading, subgrade conditions, the clients budget and expectations for flatness, joint layout, surface appearance, serviceability and future maintenance requirements. As such it is difficult to provide a one size fits all recommendation on which type of floor to specify. Most performance and maintenance issues in industrial floors occur at saw cut and formed joints. These are the areas that are most likely to become damaged and are also the areas most likely to interfere with the smooth operation of material handling equipment. It can therefore be extremely beneficial to look to minimize or completely eliminate the presence of these joints in a floor. This is achievable using both “joint free” steel fibre reinforced, post-tensioned floors.
There are a variety of methodologies for designing, detailing and reinforcing an industrial concrete floor. In some countries industrial floors are predominantly mesh reinforced, steel fiber reinforced, or post-tensioned. Other less popular options include floors incorporating shrinkage compensating concrete, and unreinforced or semi-reinforced floors. Each type of floor offers different characteristics in terms of performance,construction costs and likely future maintenance requirements. Commercial / Industrial (C/I) floors can be built on grade or can be suspended. Suspended floors are often built on metal decking, which is corrugated sheet metal supported by structural steel. Achieving high flatness and levelness values on these floors can be difficult since the decks and frames deflect under the weight of the concrete.
There are many types of concrete available, created by varying the proportions of the main ingredients below. In this way or by substitution for the cementitious and aggregate phases, the finished product can be tailored to its application with varying strength, density, or chemical and thermal resistance properties:
1. Aggregate
Aggregate consists of large chunks of material in a concrete mix, generally a coarse gravel or crushed rocks such as limestone, or granite, along with finer materials such as sand. Fine and coarse aggregates make up the bulk of a concrete mixture. Sand, natural gravel and crushed stone are used mainly for this purpose. Recycled aggregates (from construction, demolition and excavation waste) are increasingly used as partial replacements of natural aggregates, while a number of manufactured aggregates, including air-cooled blast furnace slag and bottom ash are also permitted.
The presence of aggregate greatly increases the robustness of concrete above that of cement, which is a brittle material in its pure state. Thus concrete is a true composite material. Redistribution of aggregates after compaction often creates inhomogeneity due to the influence of vibration. This can lead to strength gradients. Decorative stones such as quartzite, small river stones or crushed glass are sometimes added to the surface of concrete for a decorative "exposed aggregate" finish, popular among landscape designers. In addition to being decorative, exposed aggregate adds robustness to a concrete driveway.
2. Cement
Commonly Portland cement, and other cementitious materials such as fly ash and slag cement, serve as a binder for the aggregate.
Portland cement is the most common type of cement in general usage. It is a basic ingredient of concrete, mortar and plaster. English masonry worker Joseph Aspdin patented Portland cement in 1824. It was named because of the similarity of its color to Portland limestone, quarried from the English Isle of Portland and used extensively in London architecture. It consists of a mixture of oxides of calcium, silicon and aluminium. Portland cement and similar materials are made by heating limestone (a source of calcium) with clay and grinding this product (called clinker) with a source of sulfate (most commonly gypsum).
In modern cement kilns many advanced features are used to lower the fuel consumption per ton of clinker produced. Cement kilns are extremely large, complex, and inherently dirty industrial installations, and have many undesirable emissions. Of the various ingredients used in concrete the cement is the most energetically expensive. Even complex and efficient kilns require 3.3 to 3.6 gigajoules of energy to produce a ton of clinker and then grind it into cement. Many kilns can be fueled with difficult to dispose of wastes, the most common being used tires. The extremely high temperatures and long periods of time at those temperatures allows cement kilns to efficiently and completely burn even difficult to use fuels.
In recent years, alternatives have been developed to help replace cement. Products such as PLC (Portland Limestone Cement), which incorporate limestone into the mix, are being tested. This is due to cement production being one of the largest producers of global greenhouse gas emissions (about 5 to 10%).
3. Water
Water is then mixed with this dry composite, which enables it to be shaped (typically poured) and then solidified and hardened into rock-hard strength through a chemical process called hydration. The water reacts with the cement, which bonds the other components together, creating a robust stone-like material. "Chemical admixtures" are added to achieve varied properties. These ingredients may speed or slow down the rate at which the concrete hardens, and impart many other useful properties.
Combining water with a cementitious material forms a cement paste by the process of hydration. The cement paste glues the aggregate together, fills voids within it, and makes it flow more freely.
A lower water to concrete ratio will yield a stronger, more durable concrete; while more water will give a freer-flowing concrete with a higher slump. Impure water used to make concrete can cause problems when setting or in causing premature failure of the structure.
Hydration involves many different reactions, often occurring at the same time. As the reactions proceed, the products of the cement hydration process gradually bond together the individual sand and gravel particles and other components of the concrete, to form a solid mass.
Reaction:
Cement chemist notation: C3S + H → C-S-H + CH
Standard notation: Ca3SiO5 + H2O → (CaO)•(SiO2)•(H2O)(gel) + Ca(OH)2
Balanced: 2Ca3SiO5 + 7H2O → 3(CaO)•2(SiO2)•4(H2O)(gel) + 3Ca(OH)2
4. Reinforcements:
Reinforcements are often added to concrete. Concrete can be formulated with high compressive strength, but always has lower tensile strength. For this reason it is usually reinforced with materials that are strong in tension (often steel). Concrete can be damaged by many processes, such as the freezing of trapped water.
Concrete is strong in compression, as the aggregate efficiently carries the compression load. However, it is weak in tension as the cement holding the aggregate in place can crack, allowing the structure to fail. Reinforced concrete adds either steel reinforcing bars, steel fibers, glass fiber, or plastic fiber to carry tensile loads.
5. Chemical/Mineral admixtures:
Mineral admixture are becoming more popular in recent decades. The use of recycled materials as concrete ingredients has been gaining popularity because of increasingly stringent environmental legislation, and the discovery that such materials often have complimentary and valuable properties. The most conspicuous of these are fly ash, a by-product of coal-fired power plants, and silica fume, a byproduct of industrial electric arc furnaces. The use of these materials in concrete reduces the amount of resources required as the ash and fume acts as a cement replacement. This displaces some cement production, an energetically expensive and environmentally problematic process, while reducing the amount of industrial waste that must be disposed of.
The mix design depends on the type of structure being built, how the concrete will be mixed and delivered and how it will be placed to form this structure.
Chemical admixtures are materials in the form of powder or fluids that are added to the concrete to give it certain characteristics not obtainable with plain concrete mixes. In normal use, admixture dosages are less than 5% by mass of cement and are added to the concrete at the time of batching/mixing. The common types of admixtures are as follows.
• Accelerators speed up the hydration (hardening) of the concrete. Typical materials used are CaCl2, Ca(NO3)2 and NaNO3. However, use of chlorides may cause corrosion in steel reinforcing and is prohibited in some countries, so that nitrates may be favored.
• Retarders slow the hydration of concrete and are used in large or difficult pours where partial setting before the pour is complete is undesirable. Typical polyol retarders are sugar, sucrose, sodium gluconate, glucose, citric acid, and tartaric acid.
• Air entrainment add and entrain tiny air bubbles in the concrete, which will reduce damage during freeze-thaw cycles, thereby increasing the concrete's durability. However, entrained air entails a trade off with strength, as each 1% of air may result in 5% decrease in compressive strength.
• Plasticizers increase the workability of plastic or "fresh" concrete, allowing it be placed more easily, with less consolidating effort. A typical plasticizer is lignosulfonate. Plasticizers can be used to reduce the water content of a concrete while maintaining workability and are sometimes called water-reducers due to this use. Such treatment improves its strength and durability characteristics. Superplasticizers (also called high-range water-reducers) are a class of plasticizers that have fewer deleterious effects and can be used to increase workability more than is practical with traditional plasticizers. Compounds used as superplasticizers include sulfonated naphthalene formaldehyde condensate, sulfonated melamine formaldehyde condensate, acetone formaldehyde condensate and polycarboxylate ethers.
• Pigments can be used to change the color of concrete, for aesthetics.
• Corrosion inhibitors are used to minimize the corrosion of steel and steel bars in concrete.
• Bonding agents are used to create a bond between old and new concrete (typically a type of polymer) .
• Pumping aids improve pump ability, thicken the paste and reduce separation and bleeding.
Floor design is important to note that this approach assumes an unreinforced slab for structural purposes – steel mesh, bar or steel fiber reinforcement is not considered to act to resist loads – it is merely incorporated to control crack widths.
An alternative is the use of yield line analysis for the design of industrial concrete floors. . In New Zealand the yield line
analysis approach to floor design is typically only employed by steel fiber suppliers, however it should be noted that it is the predominant approach to designing floors in the United Kingdom, where it is applied to floors reinforced with both steel fiber and mesh reinforcement. Industrial concrete floors are generally subjected to the following load types:
-Product stored direct on the floor e.g. heavy cartons, pallets, bales or paper rolls.
-Wheel loads from trucks delivering product into the warehouse.
-Point loads from the legs of storage racks.
-Wheel loads from fork lift or reach trucks moving in either random or defined directions in the aisles or open areas of the floor.
Concrete degradation
Concrete can be damaged by many processes, such as the expansion of corrosion products of the steel reinforcement bars, freezing of trapped water, fire or radiant heat, aggregate expansion, sea water effects, bacterial corrosion, leaching, erosion by fast-flowing water, physical damage and chemical damage (from carbonatation, chlorides, sulfates and distillate water).
The concrete floor is one of the most crucial elements of an industrial building, providing the operating surface on which pallets are stacked, forklifts are operated and racks are installed. There are a myriad of ways to design and build a concrete floor, a multitude of finishes to choose from, a variety of reinforcing types to think about, countless curing methods to consider and endless ways to detail and locate joints. Variety is the spice of life, but unfortunately it creates a conundrum for the industry – for not all floors are created equal. To aid in the design and construction of quality floors MSC Consulting
Group, JAWA Structures and Conslab have produced a suggested specification for use by industry professionals. This paper discusses the principal considerations when specifying an industrial concrete floor and can also be considered a commentary on the appended specification.
Concrete floors, whether used in a residential basement, a big-box store or a manufacturing plant, are basically the same. In commercial or industrial settings, though, the slabs usually have special requirements based on the loads or flatness or levelness required. To get a slab that meets these requirements, the contractor will use special techniques in placing and finishing the concrete. Commercial or industrial floors can also have special requirements for surface hardness, finish, and even color. Wal-Mart, for example, has a specification for their exposed concrete floors that incorporates color, surface densifiers, and a hard troweled finish. That company has high expectations for everything and their concrete floors are no exception.
Placing a Bonded Floor Overlay
If a floor needs to carry greater loads than it was designed for, it can often be upgraded with a bonded overlay. A well-bonded overlay can give the floor the added thickness it needs to support the additional weight.
However, placing a bonded overlay presents many difficult challenges. Here are a few tips to help ensure success:
TIP #1
Keep the water content of the overlay as low as possible to minimize shrinkage and curling. The concrete should have a water-cement ratio of 0.45 or less and a minimum cement content of 600 lb/cubic yards (360 kg/cubic meters). The maximum aggregate size should be no more than one-third the thickness of the overlay.
TIP #2
Saw control joints to the full depth of the overlay directly over the underlying floor joints. An overlay joint and an underlying joint may begin and end at the same place, but they often are not aligned perfectly along the entire length of the joint. Sawing the overlay joint to its full depth reduces the chances of reflective cracking in the overlay in areas where the joints are not perfectly aligned.
TIP #3
Proper curing is even more important in bonded resurfacing than in ordinary concrete work because of the potential for rapid, early drying of the thin concrete overlay due to its high surface-to-volume ratio. Use a fog spray immediately after finishing, if necessary, to protect against rapid drying, and cover with wet burlap, plastic sheets, or waterproof paper as soon as they can be placed without marring the surface.
Concrete slabs on grade can be found in nearly every single industrial, commercial, and residential building. Whether they exist below a layer of flooring material or are exposed, slabs on grade provide foundation for all building foundations.
Concrete slabs on grade can be as simple as your residential driveway placed and finished by hand or as complex as this super-flat industrial floor installed with laser-guided screeds and power trowels. Regardless of the intended use, the engineering principles remain the same. Essentially, quality materials combined with good design and expert workmanship yield the best concrete slab.
Concrete technology was known by the Ancient Romans and was widely used within the Roman Empire—the Colosseum is largely built of concrete. After the Empire passed, use of concrete became scarce until the technology was re-pioneered in the mid-18th century. Concrete is widely used for making architectural structures, foundations, brick/block walls, pavements, bridges/overpasses, motorways/roads, runways, parking structures, dams, pools/reservoirs, pipes, footings for gates, fences and poles and even boats. Famous concrete structures include the Burj Khalifa (world's tallest building), Hoover Dam, the Panama Canal and the Roman Pantheon. Concrete is a composite construction material made primarily with aggregate, cement, and water. There are many formulations of concrete, which provide varied properties, and concrete is the most used man-made product in the world. The environmental impact of concrete is a complex mixture of not entirely negative effects; while concrete is a major contributor to greenhouse gas emissions, recycling of concrete is increasingly common. Structures made of concrete can have a long service life. As concrete has a high thermal mass and very low permeability, it can be used for energy efficient.
http://industrial-flooring.weebly.com/industrial-concrete-flooring.html
Thanks :
http://www.conslab.co.nz
http://en.wikipedia.org
http://www.cement.org
http://www.concretenetwork.com
There are a variety of methodologies for designing, detailing and reinforcing an industrial concrete floor. In some countries industrial floors are predominantly mesh reinforced, steel fiber reinforced, or post-tensioned. Other less popular options include floors incorporating shrinkage compensating concrete, and unreinforced or semi-reinforced floors. Each type of floor offers different characteristics in terms of performance,construction costs and likely future maintenance requirements. Commercial / Industrial (C/I) floors can be built on grade or can be suspended. Suspended floors are often built on metal decking, which is corrugated sheet metal supported by structural steel. Achieving high flatness and levelness values on these floors can be difficult since the decks and frames deflect under the weight of the concrete.
There are many types of concrete available, created by varying the proportions of the main ingredients below. In this way or by substitution for the cementitious and aggregate phases, the finished product can be tailored to its application with varying strength, density, or chemical and thermal resistance properties:
1. Aggregate
Aggregate consists of large chunks of material in a concrete mix, generally a coarse gravel or crushed rocks such as limestone, or granite, along with finer materials such as sand. Fine and coarse aggregates make up the bulk of a concrete mixture. Sand, natural gravel and crushed stone are used mainly for this purpose. Recycled aggregates (from construction, demolition and excavation waste) are increasingly used as partial replacements of natural aggregates, while a number of manufactured aggregates, including air-cooled blast furnace slag and bottom ash are also permitted.
The presence of aggregate greatly increases the robustness of concrete above that of cement, which is a brittle material in its pure state. Thus concrete is a true composite material. Redistribution of aggregates after compaction often creates inhomogeneity due to the influence of vibration. This can lead to strength gradients. Decorative stones such as quartzite, small river stones or crushed glass are sometimes added to the surface of concrete for a decorative "exposed aggregate" finish, popular among landscape designers. In addition to being decorative, exposed aggregate adds robustness to a concrete driveway.
2. Cement
Commonly Portland cement, and other cementitious materials such as fly ash and slag cement, serve as a binder for the aggregate.
Portland cement is the most common type of cement in general usage. It is a basic ingredient of concrete, mortar and plaster. English masonry worker Joseph Aspdin patented Portland cement in 1824. It was named because of the similarity of its color to Portland limestone, quarried from the English Isle of Portland and used extensively in London architecture. It consists of a mixture of oxides of calcium, silicon and aluminium. Portland cement and similar materials are made by heating limestone (a source of calcium) with clay and grinding this product (called clinker) with a source of sulfate (most commonly gypsum).
In modern cement kilns many advanced features are used to lower the fuel consumption per ton of clinker produced. Cement kilns are extremely large, complex, and inherently dirty industrial installations, and have many undesirable emissions. Of the various ingredients used in concrete the cement is the most energetically expensive. Even complex and efficient kilns require 3.3 to 3.6 gigajoules of energy to produce a ton of clinker and then grind it into cement. Many kilns can be fueled with difficult to dispose of wastes, the most common being used tires. The extremely high temperatures and long periods of time at those temperatures allows cement kilns to efficiently and completely burn even difficult to use fuels.
In recent years, alternatives have been developed to help replace cement. Products such as PLC (Portland Limestone Cement), which incorporate limestone into the mix, are being tested. This is due to cement production being one of the largest producers of global greenhouse gas emissions (about 5 to 10%).
3. Water
Water is then mixed with this dry composite, which enables it to be shaped (typically poured) and then solidified and hardened into rock-hard strength through a chemical process called hydration. The water reacts with the cement, which bonds the other components together, creating a robust stone-like material. "Chemical admixtures" are added to achieve varied properties. These ingredients may speed or slow down the rate at which the concrete hardens, and impart many other useful properties.
Combining water with a cementitious material forms a cement paste by the process of hydration. The cement paste glues the aggregate together, fills voids within it, and makes it flow more freely.
A lower water to concrete ratio will yield a stronger, more durable concrete; while more water will give a freer-flowing concrete with a higher slump. Impure water used to make concrete can cause problems when setting or in causing premature failure of the structure.
Hydration involves many different reactions, often occurring at the same time. As the reactions proceed, the products of the cement hydration process gradually bond together the individual sand and gravel particles and other components of the concrete, to form a solid mass.
Reaction:
Cement chemist notation: C3S + H → C-S-H + CH
Standard notation: Ca3SiO5 + H2O → (CaO)•(SiO2)•(H2O)(gel) + Ca(OH)2
Balanced: 2Ca3SiO5 + 7H2O → 3(CaO)•2(SiO2)•4(H2O)(gel) + 3Ca(OH)2
4. Reinforcements:
Reinforcements are often added to concrete. Concrete can be formulated with high compressive strength, but always has lower tensile strength. For this reason it is usually reinforced with materials that are strong in tension (often steel). Concrete can be damaged by many processes, such as the freezing of trapped water.
Concrete is strong in compression, as the aggregate efficiently carries the compression load. However, it is weak in tension as the cement holding the aggregate in place can crack, allowing the structure to fail. Reinforced concrete adds either steel reinforcing bars, steel fibers, glass fiber, or plastic fiber to carry tensile loads.
5. Chemical/Mineral admixtures:
Mineral admixture are becoming more popular in recent decades. The use of recycled materials as concrete ingredients has been gaining popularity because of increasingly stringent environmental legislation, and the discovery that such materials often have complimentary and valuable properties. The most conspicuous of these are fly ash, a by-product of coal-fired power plants, and silica fume, a byproduct of industrial electric arc furnaces. The use of these materials in concrete reduces the amount of resources required as the ash and fume acts as a cement replacement. This displaces some cement production, an energetically expensive and environmentally problematic process, while reducing the amount of industrial waste that must be disposed of.
The mix design depends on the type of structure being built, how the concrete will be mixed and delivered and how it will be placed to form this structure.
Chemical admixtures are materials in the form of powder or fluids that are added to the concrete to give it certain characteristics not obtainable with plain concrete mixes. In normal use, admixture dosages are less than 5% by mass of cement and are added to the concrete at the time of batching/mixing. The common types of admixtures are as follows.
• Accelerators speed up the hydration (hardening) of the concrete. Typical materials used are CaCl2, Ca(NO3)2 and NaNO3. However, use of chlorides may cause corrosion in steel reinforcing and is prohibited in some countries, so that nitrates may be favored.
• Retarders slow the hydration of concrete and are used in large or difficult pours where partial setting before the pour is complete is undesirable. Typical polyol retarders are sugar, sucrose, sodium gluconate, glucose, citric acid, and tartaric acid.
• Air entrainment add and entrain tiny air bubbles in the concrete, which will reduce damage during freeze-thaw cycles, thereby increasing the concrete's durability. However, entrained air entails a trade off with strength, as each 1% of air may result in 5% decrease in compressive strength.
• Plasticizers increase the workability of plastic or "fresh" concrete, allowing it be placed more easily, with less consolidating effort. A typical plasticizer is lignosulfonate. Plasticizers can be used to reduce the water content of a concrete while maintaining workability and are sometimes called water-reducers due to this use. Such treatment improves its strength and durability characteristics. Superplasticizers (also called high-range water-reducers) are a class of plasticizers that have fewer deleterious effects and can be used to increase workability more than is practical with traditional plasticizers. Compounds used as superplasticizers include sulfonated naphthalene formaldehyde condensate, sulfonated melamine formaldehyde condensate, acetone formaldehyde condensate and polycarboxylate ethers.
• Pigments can be used to change the color of concrete, for aesthetics.
• Corrosion inhibitors are used to minimize the corrosion of steel and steel bars in concrete.
• Bonding agents are used to create a bond between old and new concrete (typically a type of polymer) .
• Pumping aids improve pump ability, thicken the paste and reduce separation and bleeding.
Floor design is important to note that this approach assumes an unreinforced slab for structural purposes – steel mesh, bar or steel fiber reinforcement is not considered to act to resist loads – it is merely incorporated to control crack widths.
An alternative is the use of yield line analysis for the design of industrial concrete floors. . In New Zealand the yield line
analysis approach to floor design is typically only employed by steel fiber suppliers, however it should be noted that it is the predominant approach to designing floors in the United Kingdom, where it is applied to floors reinforced with both steel fiber and mesh reinforcement. Industrial concrete floors are generally subjected to the following load types:
-Product stored direct on the floor e.g. heavy cartons, pallets, bales or paper rolls.
-Wheel loads from trucks delivering product into the warehouse.
-Point loads from the legs of storage racks.
-Wheel loads from fork lift or reach trucks moving in either random or defined directions in the aisles or open areas of the floor.
Concrete degradation
Concrete can be damaged by many processes, such as the expansion of corrosion products of the steel reinforcement bars, freezing of trapped water, fire or radiant heat, aggregate expansion, sea water effects, bacterial corrosion, leaching, erosion by fast-flowing water, physical damage and chemical damage (from carbonatation, chlorides, sulfates and distillate water).
The concrete floor is one of the most crucial elements of an industrial building, providing the operating surface on which pallets are stacked, forklifts are operated and racks are installed. There are a myriad of ways to design and build a concrete floor, a multitude of finishes to choose from, a variety of reinforcing types to think about, countless curing methods to consider and endless ways to detail and locate joints. Variety is the spice of life, but unfortunately it creates a conundrum for the industry – for not all floors are created equal. To aid in the design and construction of quality floors MSC Consulting
Group, JAWA Structures and Conslab have produced a suggested specification for use by industry professionals. This paper discusses the principal considerations when specifying an industrial concrete floor and can also be considered a commentary on the appended specification.
Concrete floors, whether used in a residential basement, a big-box store or a manufacturing plant, are basically the same. In commercial or industrial settings, though, the slabs usually have special requirements based on the loads or flatness or levelness required. To get a slab that meets these requirements, the contractor will use special techniques in placing and finishing the concrete. Commercial or industrial floors can also have special requirements for surface hardness, finish, and even color. Wal-Mart, for example, has a specification for their exposed concrete floors that incorporates color, surface densifiers, and a hard troweled finish. That company has high expectations for everything and their concrete floors are no exception.
Placing a Bonded Floor Overlay
If a floor needs to carry greater loads than it was designed for, it can often be upgraded with a bonded overlay. A well-bonded overlay can give the floor the added thickness it needs to support the additional weight.
However, placing a bonded overlay presents many difficult challenges. Here are a few tips to help ensure success:
TIP #1
Keep the water content of the overlay as low as possible to minimize shrinkage and curling. The concrete should have a water-cement ratio of 0.45 or less and a minimum cement content of 600 lb/cubic yards (360 kg/cubic meters). The maximum aggregate size should be no more than one-third the thickness of the overlay.
TIP #2
Saw control joints to the full depth of the overlay directly over the underlying floor joints. An overlay joint and an underlying joint may begin and end at the same place, but they often are not aligned perfectly along the entire length of the joint. Sawing the overlay joint to its full depth reduces the chances of reflective cracking in the overlay in areas where the joints are not perfectly aligned.
TIP #3
Proper curing is even more important in bonded resurfacing than in ordinary concrete work because of the potential for rapid, early drying of the thin concrete overlay due to its high surface-to-volume ratio. Use a fog spray immediately after finishing, if necessary, to protect against rapid drying, and cover with wet burlap, plastic sheets, or waterproof paper as soon as they can be placed without marring the surface.
Concrete slabs on grade can be found in nearly every single industrial, commercial, and residential building. Whether they exist below a layer of flooring material or are exposed, slabs on grade provide foundation for all building foundations.
Concrete slabs on grade can be as simple as your residential driveway placed and finished by hand or as complex as this super-flat industrial floor installed with laser-guided screeds and power trowels. Regardless of the intended use, the engineering principles remain the same. Essentially, quality materials combined with good design and expert workmanship yield the best concrete slab.
Concrete technology was known by the Ancient Romans and was widely used within the Roman Empire—the Colosseum is largely built of concrete. After the Empire passed, use of concrete became scarce until the technology was re-pioneered in the mid-18th century. Concrete is widely used for making architectural structures, foundations, brick/block walls, pavements, bridges/overpasses, motorways/roads, runways, parking structures, dams, pools/reservoirs, pipes, footings for gates, fences and poles and even boats. Famous concrete structures include the Burj Khalifa (world's tallest building), Hoover Dam, the Panama Canal and the Roman Pantheon. Concrete is a composite construction material made primarily with aggregate, cement, and water. There are many formulations of concrete, which provide varied properties, and concrete is the most used man-made product in the world. The environmental impact of concrete is a complex mixture of not entirely negative effects; while concrete is a major contributor to greenhouse gas emissions, recycling of concrete is increasingly common. Structures made of concrete can have a long service life. As concrete has a high thermal mass and very low permeability, it can be used for energy efficient.
http://industrial-flooring.weebly.com/industrial-concrete-flooring.html
Thanks :
http://www.conslab.co.nz
http://en.wikipedia.org
http://www.cement.org
http://www.concretenetwork.com
RSS Feed