In a study conducted by Girish C. Dubey, the chairperson of the Pavement Coatings Technology Center at the University of Nevada, Reno, it revealed that repairing and maintaining asphaltic pavements using sealcoats saves homeowners and business persons lots of dollars. From the study, if homeowners and business persons sealcoated their driveways and parking lots, they are able to save approximately $15.25 in every square yard of the road.
This amount translates to $152,500 for a parking lot or driveway that measures 10,000 square yard. What this means is that homeowners and business persons can save about 48 percent compared to unmaintained asphalt. Using sealcoats to cover pavements and protect them against environmental and manmade factors costs less amount but it can double or triple the lifespan of the driveways.
Driveways and parking lots are an investment for homeowners and business people because they not only enhance the aesthetic beauty of their premises but also improve the movement of traffic. But driveways and parking areas need proper maintenance. Asphaltic pavements are vulnerable to environmental conditions like ultraviolet rays, snow, anti-freeze effects, and rainwater. They may also be damaged by manmade elements like oil spills, vehicle transmission fluids, and salts and traffic loads.
One way in which the blacktop of roads can be protected is through use of sealcoating products. Sealcoating prolongs the lifespan of drives and parking areas. When sealcoats are applied, they provide a membrane cover, which is weatherproof. This means that the pavements are not directly exposed to effects of ultraviolet rays and rainwater.
Sun and water accelerate the natural oxidation of asphaltic material meaning that the paving surfaces will dry fast and become rigid. Initially, when you construct a new driveway, the asphaltic layer is flexible. It expands and contracts evenly without causing any distress. However, as it ages and continues to be exposed to weather conditions like sunlight and rainwater, it becomes inflexible. It is not able to contract and expand easily as it initially used to do.
With traffic turning over the driveways, coupled with the heating and effects of water, the pavements degrade in quality. Homeowners need to ensure that they constantly inspect their roads and driveways to ensure that they are in good condition. One way to detect that the drives and parking lots are deteriorating is the change in colour from jet-black to gray.
As the drives age, they begin to breakdown and this allows more problems like ravelling to start occurring. The first sealcoat should be applied after the asphalt has cured properly and this may take between 6 months to one year. This ensures that the sealants bind firmly on top of the blacktop. Other sealcoats can be applied after every 2 to 5 years depending on the rate at which the sealcoat loses its protection ability.
When rain water infiltrates the pavement layer, it settles on the bed and loosens the aggregate material. With heavy traffic, this causes the driveways to crumble. Similarly, when water settles on the bed, it may freeze during the cold weather and expand. Upon expansion, the frozen water widens the cracks underneath the pavement. When it melts, it leaves a void and this causes the blacktop layer to crumble down. Moreover, heat from the sun bakes the asphaltic pavement making it oxidize faster than usual.
This makes the pavement rigid and with continuous use, it begins to form cracks. If not repaired, the cracks allow water to collect in and settle on the bed. The cracks may intensify forming more pronounced cracking known as "allogatored cracks". These damages are very costly for the homeowner or business person but they can be prevented with use of sealcoats. One thing about the sealcoating is that it does not cure the problems in pavements. If there are cracks, they should first be repaired before a coat is applied.
Showing posts with label Sealcoating. Show all posts
Showing posts with label Sealcoating. Show all posts
Saturday, November 23, 2013
Friday, November 15, 2013
How Sealcoating Prevents Damages on Asphaltic Pavements
Sealcoats provide a protective barrier on asphaltic pavements, which allows the asphalt material to oxidize slowly. The sealcoating prevents ultraviolet rays from directly reaching and heating the blacktop. When ultraviolet rays directly heat the asphalt material, they accelerate the natural or normal oxidizing process meaning that the pavements dry up and harden too fast than expected. This results to premature damages of roads and parking lots since fine hairline cracks start forming.
A sealcoat provides a membrane cover, which bars the ultraviolet rays from directly baking the asphalt material. When cracks are formed due to effects caused by ultraviolet rays, they allow water to penetrate and settle at the subgrade layer of roads and parking lots. Water causes more harm to the aggregate base, which is the building block for your roads. The base of roads supports the pavement layer and the loads that turns over the roads.
Water loosens the aggregate material and thus makes it start crumbling down. In addition, when water remains in the cracks, during the winter condition, it may freeze. As it freezes, the water expands and it enlarges the cracks in areas where is has collected. After the cold season, that frozen water melts down through the process of thawing and the enlarged cracks are left as empty spaces or voids.
What happens is that the material, which is on top of the void, that is, the asphalt pavement material, collapses and fills the empty space. This leads to formation of potholes in roads and parking lots. One thing with potholes and extensive deep cracks is that they are costly to repair. When sealcoats are applied in the right time, they prevent the speedy drying or oxidation of asphalt material. Sealcoats help improve the elasticity of asphalt pavements ensuring that they easily expand when heated and contract when cooled. This way, cracking is minimized.
Chemical substances like gasoline, de-icing salts, oil spillage, and transmission fluids also accelerate the oxidizing process in asphalt material. When a sealcoat is applied, it helps prevent these chemicals from coming into direct contact with the asphaltic pavement thus preventing premature damages.
In short, the oxidation process of asphalt is a complex molecular behavior, which can help understand how asphalt pavements are affected or damaged by factors like sunlight, water, snow, de-icing salts, oils, gasoline, and transmission fluids. A pavement, which is treated with use of sealcoats, can last for long thus helping prevent unnecessary expenses associated with premature damages on asphalt pavements.
When is sealcoating done?
Sealcoating is done regularly as part of the maintenance process of asphalt pavements. When a new pavement is constructed, it should be allowed to cure or dry the surface oils before a sealcoat is applied. This may take a couple of months depending on the viscosity of the asphalt and how fast it dries up. If the sealcoat is applied before the asphaltic blacktop cures properly, the coating may not fasten or bond well with the asphalt material.
After the first coating is done, other coats are applied in a period of about 2 to 5 years. This is a continuous process, which should be undertaken periodically until the end of the life of the pavements. When you notice that the color of your asphaltic pavements has changed from dark black to gray, you need to ensure that you sealcoat your drives, parking lots, and road surfaces to prevent further damages from occurring due to accelerated oxidation.
| "Sealcoating preserves the blacktop" |
Water loosens the aggregate material and thus makes it start crumbling down. In addition, when water remains in the cracks, during the winter condition, it may freeze. As it freezes, the water expands and it enlarges the cracks in areas where is has collected. After the cold season, that frozen water melts down through the process of thawing and the enlarged cracks are left as empty spaces or voids.
What happens is that the material, which is on top of the void, that is, the asphalt pavement material, collapses and fills the empty space. This leads to formation of potholes in roads and parking lots. One thing with potholes and extensive deep cracks is that they are costly to repair. When sealcoats are applied in the right time, they prevent the speedy drying or oxidation of asphalt material. Sealcoats help improve the elasticity of asphalt pavements ensuring that they easily expand when heated and contract when cooled. This way, cracking is minimized.
Chemical substances like gasoline, de-icing salts, oil spillage, and transmission fluids also accelerate the oxidizing process in asphalt material. When a sealcoat is applied, it helps prevent these chemicals from coming into direct contact with the asphaltic pavement thus preventing premature damages.
In short, the oxidation process of asphalt is a complex molecular behavior, which can help understand how asphalt pavements are affected or damaged by factors like sunlight, water, snow, de-icing salts, oils, gasoline, and transmission fluids. A pavement, which is treated with use of sealcoats, can last for long thus helping prevent unnecessary expenses associated with premature damages on asphalt pavements.
When is sealcoating done?
Sealcoating is done regularly as part of the maintenance process of asphalt pavements. When a new pavement is constructed, it should be allowed to cure or dry the surface oils before a sealcoat is applied. This may take a couple of months depending on the viscosity of the asphalt and how fast it dries up. If the sealcoat is applied before the asphaltic blacktop cures properly, the coating may not fasten or bond well with the asphalt material.
After the first coating is done, other coats are applied in a period of about 2 to 5 years. This is a continuous process, which should be undertaken periodically until the end of the life of the pavements. When you notice that the color of your asphaltic pavements has changed from dark black to gray, you need to ensure that you sealcoat your drives, parking lots, and road surfaces to prevent further damages from occurring due to accelerated oxidation.
How Environmental and Man-Made Factors Cause Damages On Asphalt Pavements
Asphalt undergoes chemical changes at the molecular level and the intermolecular level also known as microstructure. Because of the complex nature of molecular interactions in asphalt, the oxidation of this material is complicated by the different molecules interrelation. There is a mixture of polar and non-polar molecules in asphalt. Polar molecules have a positive charge on one side and a negative charge on the other side while non-polar molecules have their electrons distributed in a way that there is no abundance of charges on both sides.
In essence, there are predominantly thousands of chemicals with open chain structure in asphalt, which makes the material to have a considerable level of un-saturation in its molecular structure. It is this open chain molecular structure of asphalt, which allows it to easily interact with weather elements, chemicals, and salts. Molecules from other substances can attack and disintegrate the asphaltic material molecules leading to changes in its structural composition.
In the microstructure of asphalt, there are three-dimensional relations of polar molecules, which are referred to as asphaltenes, and these are dispersed in a fluid made up of non-polar or low-polarity molecules, which are known as maltenes. The intermolecular bonds are weaker than the bonds of the fundamental hydrocarbons in asphalt material. This means that these intermolecular bonds break up first and determine the behavioral patterns of asphalt material.
The intramolecular and intermolecular relationships in asphalt material make it behave in two major ways. First, it is elastic due to the effects caused by polar molecules interrelation. Second, it is viscous since the different parts of the polar molecules are able to move relative to one another when dispersed in the fluid non-polar molecules.
When oxidation occurs in asphalt pavement, it makes the material become dry and brittle. Exposure of asphalt to oxygen triggers a molecular process, which leads to creation of new polar bonding sites or zones. What happens is that the increased polar sites or zones in asphalt materials make the molecules to rearrange and shuffle about as they search for bonds that can create equilibrium or bring a thermodynamic stable state.
This is a self-assemblage process, which continues for the rest of the life of the asphaltic pavement material. With time, as the polar sites discover molecules to attach on, the asphalt molecules bond firmly together with the aggregate material. The result is a pavement, which is stiffer, harder, and brittle. As asphalt oxidizes and dries up, it loses its elasticity and starts to fail.
One sign that signifies the failure of asphalt due to oxidation is the change in color. Initially, asphalt has a jet-black color but over time, due to oxidation process, it turns to light black and ultimately changes to gray. The drying asphaltic material begins to crack as it loses its bonding properties. Before the oxidation process reaches an equilibrium point, it may take about 5 to 15 years depending on how the material is affected by other factors like sunlight, chemicals, and water. This substantiates the reason why the estimated lifespan of asphalt pavements is about 20 to 25 years.
When oxidation process stiffens the paving materials, its ability to support heavy loads is reduced. This causes asphalt fatigue leading to formation of cracks and premature failure of asphalt. Heat from the sun causes the asphalt material to cure and dry fast than intended. Moisture from rainfall can accelerate the damage on oxidizing asphalt since it contains a large amount of polar-constituent molecules, which in turn attract the water molecules. Sealcoating can help delay or slow the rate at which asphalt naturally oxidizes.
| "Cracks developing on asphalt surface" |
In the microstructure of asphalt, there are three-dimensional relations of polar molecules, which are referred to as asphaltenes, and these are dispersed in a fluid made up of non-polar or low-polarity molecules, which are known as maltenes. The intermolecular bonds are weaker than the bonds of the fundamental hydrocarbons in asphalt material. This means that these intermolecular bonds break up first and determine the behavioral patterns of asphalt material.
The intramolecular and intermolecular relationships in asphalt material make it behave in two major ways. First, it is elastic due to the effects caused by polar molecules interrelation. Second, it is viscous since the different parts of the polar molecules are able to move relative to one another when dispersed in the fluid non-polar molecules.
When oxidation occurs in asphalt pavement, it makes the material become dry and brittle. Exposure of asphalt to oxygen triggers a molecular process, which leads to creation of new polar bonding sites or zones. What happens is that the increased polar sites or zones in asphalt materials make the molecules to rearrange and shuffle about as they search for bonds that can create equilibrium or bring a thermodynamic stable state.
This is a self-assemblage process, which continues for the rest of the life of the asphaltic pavement material. With time, as the polar sites discover molecules to attach on, the asphalt molecules bond firmly together with the aggregate material. The result is a pavement, which is stiffer, harder, and brittle. As asphalt oxidizes and dries up, it loses its elasticity and starts to fail.
One sign that signifies the failure of asphalt due to oxidation is the change in color. Initially, asphalt has a jet-black color but over time, due to oxidation process, it turns to light black and ultimately changes to gray. The drying asphaltic material begins to crack as it loses its bonding properties. Before the oxidation process reaches an equilibrium point, it may take about 5 to 15 years depending on how the material is affected by other factors like sunlight, chemicals, and water. This substantiates the reason why the estimated lifespan of asphalt pavements is about 20 to 25 years.
When oxidation process stiffens the paving materials, its ability to support heavy loads is reduced. This causes asphalt fatigue leading to formation of cracks and premature failure of asphalt. Heat from the sun causes the asphalt material to cure and dry fast than intended. Moisture from rainfall can accelerate the damage on oxidizing asphalt since it contains a large amount of polar-constituent molecules, which in turn attract the water molecules. Sealcoating can help delay or slow the rate at which asphalt naturally oxidizes.
How Sealcoating Delays Asphalt Oxidation Process and Prevents Premature Pavement Damage
Sealcoating is an integral part of asphalt maintenance. Asphalt is a commonly used paving material in driveways, parking lots, and roads. It is preferred in constructing road surfaces because it is relatively cheaper to install compared to other materials like concrete blocks. However, when asphalt is laid down, it undergoes chemical changes throughout its lifespan, which can affect its visco-elasticity properties and durability.
Asphalt pavements have a life expectancy of about 20 to 25 years but this lifespan can be reduced by effects caused by environmental factors like ultraviolet rays, snow, and water. Asphalt paving material used in road construction undergoes an aging process known as oxidative aging. From the time the asphalt is laid down, it starts undergoing oxidation. When examining how environmental and manmade factors affect the quality of asphalt pavements, it is important to consider the asphaltic molecular structure and its changes.
Manmade factors like oil spillage and de-icing salts can also degrade the quality of asphalt pavements. The vulnerability of asphaltic paving material to weather conditions and chemical substances can be reduced by applying a top membrane cover known as sealcoat through the process of asphalt pavement sealcoating.
Asphalt pavement material is made up of aggregate, fillers, and binders such as bitumen, which help in holding together the mixture. Since asphalt pavements will naturally degrade with time, understanding the elements, which speed up the degradation process, can help in putting up preventive measure thus prolonging the life of roads, driveways, and parking lots.
What is sealcoating?
Sealcoating is the application of a weatherproof membrane layer on top of the blacktop of a road surface. A sealcoat is a surface treatment aimed at preventing damages on blacktop caused by things like heat from the sun, moisture, and oil spillage. The sealcoats are made of asphaltic material like emulsions, cutbacks, and paving grade-asphaltic cement and are modified with asphalt liquid mixtures such as latex and polymers.
One thing with asphalt sealcoats is that they only provide a protective barrier and do not cure problems that may exist underneath the pavement such as large cracks and road foundation failure. This means that before a surface treatment is done with use of sealcoats, if there are any damages on pavements and sub-base layer, they should be repaired. Otherwise, the sealcoat may only mask the problems and soon cracks and other deformities on pavements begin to show up again.
| "asphalt contractors applying a sealcoat" |
Manmade factors like oil spillage and de-icing salts can also degrade the quality of asphalt pavements. The vulnerability of asphaltic paving material to weather conditions and chemical substances can be reduced by applying a top membrane cover known as sealcoat through the process of asphalt pavement sealcoating.
Asphalt pavement material is made up of aggregate, fillers, and binders such as bitumen, which help in holding together the mixture. Since asphalt pavements will naturally degrade with time, understanding the elements, which speed up the degradation process, can help in putting up preventive measure thus prolonging the life of roads, driveways, and parking lots.
What is sealcoating?
Sealcoating is the application of a weatherproof membrane layer on top of the blacktop of a road surface. A sealcoat is a surface treatment aimed at preventing damages on blacktop caused by things like heat from the sun, moisture, and oil spillage. The sealcoats are made of asphaltic material like emulsions, cutbacks, and paving grade-asphaltic cement and are modified with asphalt liquid mixtures such as latex and polymers.
One thing with asphalt sealcoats is that they only provide a protective barrier and do not cure problems that may exist underneath the pavement such as large cracks and road foundation failure. This means that before a surface treatment is done with use of sealcoats, if there are any damages on pavements and sub-base layer, they should be repaired. Otherwise, the sealcoat may only mask the problems and soon cracks and other deformities on pavements begin to show up again.
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