Pavement engineering is a discipline with a long history. Its practitioners have contributed to more innovative infrastructure that reduces maintenance needs, costs, and carbon emissions.
To reduce fatigue cracking that leads to potholes, the stiffness of pavements must be increased without inflating construction costs. By incorporating Tensar inter-layer geogrids in new pavement design, stiffness can be enhanced without increasing asphalt or granular layer thicknesses. Keep reading the article below to learn more about Pavement Solutions.
Porous pavement allows water to flow through the surface of the pavement rather than over it, reducing the volume of stormwater runoff that is carried into drains and stormwater management structures. This type of pavement is designed to replace conventional impervious pavements and can be constructed using a variety of materials, including pervious asphalt, pervious concrete or interlocking pavers. This type of paving can be used for residential driveways, sidewalks, parking stalls and bike paths, but is also appropriate for low-volume traffic areas such as alleys.
Porous paving reduces the amount of sediment that would otherwise be transported to lakes, rivers and streams. It also increases the rate at which stormwater can be absorbed into soils and can provide groundwater recharge. In addition, it can help reduce peak discharge rates and may qualify for Water Quality and Recharge Credits (up to 80% TSS removal) if the storage layer is sized to hold the required Water Quality Volume and designed to dewater within 72 hours.
However, porous paving has some disadvantages. It is more expensive to install than traditional paved surfaces and requires aggressive maintenance with jet washing and vacuum street sweepers. It is not recommended for areas that receive heavy vehicles and high speeds, as it does not have the same load-bearing capacity as traditional paving. Additionally, it is not suitable for cold climates because infiltrating stormwater can freeze below the paving, causing frost heaving and spalling damage.
Additionally, this type of paving is prone to clogging and can become inefficient when left unattended. Porous paving needs to be regularly rinsed or vacuumed to prevent the accumulation of fine aggregates that can clog pores and reduce the system’s ability to infiltrate stormwater.
Another concern with porous paving is its abrasion resistance. While most porous asphalt and concrete surfaces are durable enough for pedestrian use, it is not recommended for areas with high turning traffic or snow plows, as the abrasion can cause the surface to break down and clog the pores. Also, a porous paving system is not ideal for applications where road salt and/or deicer will be applied because the chlorides can migrate through the surface into groundwater.
Permeable Pavers
Many different kinds of paving are available, each suited to specific situations. At one end of the spectrum are lightly trafficked country roads where asphalt is best suited, while at the other are major airport runways and aprons which require highly engineered concrete. In between are pavement solutions such as paved patios, sidewalks, and driveways made from a variety of materials. Some of these are impervious while others allow rainwater to seep through them.
Permeable pavers, also known as porous pavements or green pavement, redirect stormwater runoff into the ground instead of dumping it into stormwater sewers or onto neighbouring property. This helps restore the natural hydrological balance of a site, reducing the speed at which water flows off a surface and decreasing the volume of precipitation that gets washed into drainage systems.
These types of pavements usually consist of paving stones or open pore pavers with an underlying stone reservoir. Rainwater and precipitation enters the reservoir, where it slowly infiltrates into the soil below or is drained through a drain tile system. The underlying stone acts as a filter, clearing the water of pollutants and contaminants.
In addition, the permeability of these pavements allows for the growth of grass and other vegetation. This creates a more natural and attractive appearance for the surface while helping to reduce soil erosion, especially on sloped sites. In urban areas, permeable pavements help reduce the stress of stormwater on local streams and rivers by cooling the temperature of the runoff water and allowing more of it to infiltrate.
Unlike traditional asphalt and concrete, these types of paving are generally more comfortable for bicyclists because they allow the movement of bicycle tires without creating the uneven surface that can cause discomfort. These types of paving can be used on residential driveways, sidewalks, and even commercial parking lots.
The maintenance requirements of this type of paving are somewhat higher than for non-porous pavements, because the spaces between the pavers can become clogged with dirt, dust, and other debris. It’s important to maintain the integrity of the permeability by frequent cleaning using jet washing and vacuum street sweepers, and adding joint material (such as sand) regularly.
Asphalt Overlays
Asphalt overlays are a great solution for parking lots and other surfaces that have been damaged, but do not need full reconstruction. They help to restore the surface and improve the look, as well as reduce maintenance costs by extending the lifespan of existing pavement. However, it is important to keep in mind that an asphalt overlay will not solve all issues and may create new problems if used in the wrong situation.
An overlay is a new asphalt section (generally 1.5’’ to 2’’ thick) that is placed over the top of an existing surface. Think of it like putting a new tablecloth over an old one to hide all the scratches and stains from use. This type of repair works best for minor surface distress including rutting, cracks, divots and more.
The first step is to ensure the surface is clean and free of any loose debris, especially gravel that could get stuck in the paving process. Then, a machine known as an asphalt mill is used to shave the top of the existing asphalt surface. The mill will also remove any areas that have very poor underlying base. This is done to ensure the base is able to support the overlay.
Once the surface has been prepared, a uniform coat of SS-1H is applied to ensure proper adhesion between the old and new asphalt sections. This is a very important step that many below-standard contractors fail to do.
After the SS-1H is applied, the overlay asphalt material can be put down. It is recommended to pave the overlay at a minimum of 1″ thick. If the paving is too thin, it will cause severe damage to the existing surface over time.
If the asphalt has heavy cracking, it must be corrected before the overlay is laid or the cracks will reflect through the new surface within a short amount of time. It is also not a good idea to overlay an asphalt surface if the underlying subgrade slab is compromised at a lower level.
Despite some shortcomings, asphalt overlays are an excellent option for commercial properties that want to increase the longevity of their asphalt and avoid costly full reconstruction projects in the future. With the proper planning and an experienced team, an asphalt overlay can provide a beautiful and durable surface that will last for years to come.
Sealcoating
Seal coating is a cost-effective way to extend the lifespan of asphalt. It prevents oxidation and weather damage, while also making the pavement look like new. However, it is not a permanent solution, as the seal coat will need to be refreshed every two to three years.
Before sealcoating, the asphalt surface should be thoroughly cleaned. This step is extremely important, as asphalt sealer will not adhere to dirt or mud. Professional pavement contractors will use powerful cleaning equipment, such as blowers, rotary brooms, and sweepers, to remove these substances from the surface. Additionally, any asphalt repairs, such as potholes or cracks, should be patched before the sealcoat is applied. Finally, all vehicle fluids, such as oil, should be removed from the pavement surface.
The sealcoating process involves spraying a liquid mixture of water and asphalt onto the pavement’s surface. Workers then spread this material around the entire surface, including the edges. It takes 24 hours for the sealer to dry, and cars can not be driven on it during this time. The weather will have a significant impact on how long it takes for the asphalt to cure. If it is a hot, sunny day, the sealcoat will dry much faster than if it is a cold, cloudy day with high humidity.
There are many different types of asphalt sealers, including coal tar and acrylic polymer. Each has its own advantages and disadvantages, but both provide effective results. Asphalt paving professionals will be able to recommend which type of sealer is best for your project.
Once the sealcoat is dry, it creates an impenetrable barrier on the surface of your asphalt, which protects the underlying layers from the elements. This includes UV rays, which can degrade asphalt and cause it to crack and crumble. Sealcoat also helps the underlying asphalt to stay flexible, so it can expand and contract with the weather.
Despite its benefits, sealcoating does not repair large cracks or potholes in your asphalt. These issues will need to be addressed with an asphalt resurfacing or other repair method. However, sealing your asphalt every two to three years can prevent further deterioration and help you save money on costly repairs in the future.
