Asphalt Paving Charleston SC requires careful planning and execution to ensure quality results. It starts with grading to get the desired slope and profile. Next comes a strong aggregate base that enhances the load-bearing capability of the asphalt surface.
The hot asphalt mix is carefully formulated at an asphalt plant. It must be kept at a high temperature during the paving process in order to achieve proper compaction.
A sub-base is a layer of well-graded material laid on top of the ground to form the base upon which an asphalt surface is constructed. It may be omitted where there is only pedestrian traffic, but it is an essential part of any paving that will be used by vehicles. Sub-bases can be either bound or unbound, and there are a number of different materials that can be used to achieve the right level of performance for any given pavement. These materials include crushed stone, slag, fly ash and recycled aggregates. All are designed to provide good load-spreading and drainage properties when correctly laid and compacted.
The choice of sub-base material can have a considerable impact on the cost and quality of any paving project, so it is important to consult with your contractor at an early stage to discuss the best solution for your particular site. In general, a sub-base should be built up as a series of layers no deeper than 150mm. Each layer should be thoroughly compacted before the next is placed on it. This helps to ensure that there is no risk of settlement when the pavement is opened to traffic.
For larger projects such as roads and highways, it is recommended that the sub-base be constructed using a type 1 or type 2 construction graded granular material. This provides a durable, hard wearing and economical foundation for construction work. It also helps to avoid pumping of fine-grained soils beneath pavement edges and joints, which can occur when three conditions are present in combination: a pumpable soil; excess water; and frequent heavy truck loading.
It is not possible to build an asphalt surface over a poor sub-base without risking damage and subsequent costly repairs. A good quality sub-base can help to prevent weed growth and improve drainage around the paving slabs, which can help to prolong their life. If a paving contractor tells you that a sub-base is not required underneath your driveway, ask them how they plan to spread the load of the paving and what guarantee they can offer against future movement and settlement.
Binder
Asphalt is a versatile material used for a wide variety of applications including roads, driveways and parking lots. It is durable and easy to maintain. In addition, it is a greener choice than concrete because it uses less energy and emits fewer greenhouse gases during production.
The main components of asphalt are aggregates (like rocks, sand and gravel) and bitumen, a sticky black petroleum-based substance that holds the aggregates together. These ingredients are mixed and then baked together to create a hard, dense pavement. In recent years, the industry has been making great strides in improving the environmental footprint of asphalt paving. These advancements include Warm Mix Asphalt (WMA) that reduces the production and placement temperature of the asphalt mixture by 30°F to 120°F, which in turn lowers fuel consumption and cuts emissions.
WMA also requires the use of recycled asphalt shingles, a valuable resource that can be reused in the asphalt mixing process without losing its performance characteristics. The use of this recycled material reduces the need to purchase virgin asphalt, which in turn saves taxpayer dollars. Another green advancement is the use of porous asphalt, which has tiny holes that allow water to pass through the pavement into the ground beneath. Porous asphalt has the added benefit of melting ice and snow quicker than traditional pavements.
Before laying the asphalt, the contractor prepares the site by grading and sloping the ground so that water drains away from the new surface. This step is particularly important for rural roads where the pavement may be subject to higher volumes of water traffic.
Once the grading and sloping have been completed, a layer of coarse aggregate is laid as a base course. This is followed by a layer of stronger, load-bearing asphalt binder. The binder is commonly a hot mixture that is kept in a heated silo until it can be transported promptly to the job site. The asphalt must be kept hot throughout the paving process because if it cools it becomes too stiff to be easily compacted with roller machines.
Because REOB is a waste product, the composition of different batches can vary widely, even from the same producer on different days. To combat this, the TFHRC developed a test to compare the composition of REOB and asphalt binder samples from State highway agencies.
Surface
Asphalt is a popular paving material for roads, parking lots and driveways because it provides a smooth surface that resists skidding, which increases safety for vehicle drivers. It also helps reduce noise pollution. Its dark color makes it easy to see road markings and improves visibility at night, and its excellent traction helps prevent hydroplaning during rainy weather.
The paving process starts with clearing the area and excavation of the base materials, which can be either compacted stone or asphalt mix depending on the project requirements. Once the base is laid, it is rolled and compacted by specialized paving equipment to create a strong and sturdy surface. Proper drainage planning is an important step in the paving process as water accumulation can lead to pavement damage such as heaving and cracking over time.
Next, the sub-base and binder layer are mixed together to form a thick and durable asphalt mixture. The binder layer consists of large aggregates that are coated with a thick liquid called bitumen. The blending process ensures that the proper proportions of aggregate and bitumen are used. The mixture is then heated and dried to a workable consistency. It is then transported to the construction site while still hot.
At the construction site, the asphalt is poured and quickly rolled by multiple compaction roller machines to eliminate voids and improve density. The pavement is then left to cool and harden. Once the asphalt has cooled, it is safe for vehicle traffic.
Whether the asphalt is being used for a large highway or a small residential driveway, it must be properly installed to maximize its lifespan and performance. Proper installation includes testing the area for proper drainage and grading to ensure that water runoff is prevented from pooling in any areas where it shouldn’t be.
Compared to other paving materials, asphalt is one of the most environmentally friendly due to its minimal environmental impact and recyclability. It also requires less maintenance and repairs over its lifespan, which helps to save on both operational and construction costs. The cost efficiency of asphalt is a big reason why it remains the preferred paving material for many contractors and municipalities.
Maintenance
Asphalt is more affordable than other paving materials, but it requires routine maintenance to keep it looking and functioning its best. Regular sealing and crack filling can prevent damage and extend the lifespan of your asphalt paving, which can save you money in the long run. Asphalt is also recyclable, reducing the need for new materials and promoting sustainability.
When compared to other paving materials, asphalt has the added benefit of being skid-resistant, which makes it safer for both pedestrians and drivers. This feature helps reduce accidents caused by lack of traction, and is especially important in snowy or rainy conditions. Additionally, asphalt is easy to repair if a vehicle becomes stuck on it, and it will quickly revert back to its original condition.
However, asphalt can deteriorate due to traffic and weather over time. If left unattended, small cracks will expand, leading to water infiltration and temperature fluctuations. These changes can cause the aggregates to unravel and cause further damage underneath the surface layer of the asphalt.
It is important to have a professional asphalt contractor provide routine maintenance for your pavement to ensure it stays in good condition. These services include sweeping and cleaning to remove debris and dirt from the surface. The paving contractor may also apply a sealcoat to the surface, which protects against oil and gasoline spills, guards against oxidation, and protects the asphalt from harsh UV rays.
Pavement maintenance also includes repairing any potholes that appear on your property. These unsightly holes can not only impact the visual appeal of your parking lot, but they can also create tripping hazards for people who use your space. Having your asphalt potholes repaired promptly by a paving contractor can help you avoid the cost of tripping injuries and potential legal liability.
Asphalt is also versatile when it comes to design options, making it suitable for a variety of project types from elegant driveways to functional parking lots. It can be molded into many different shapes and colors to complement your architectural style, and it can even mimic the look of more expensive materials like brick or stone without breaking the bank.
