Permeable paving is a vehicle paving method and a pedestrian path that allows for fluid infiltration. In the sidewalk design, the base is the top of the road through which pedestrians or vehicles pass. The medium used for the penetrating paving base can be porous to allow fluid to flow through the medium or not in a sealed chamber so that fluid flowing between the gaps can be used. In addition to reducing surface runoff, permeable paving can trap suspended solids thus filtering pollutants from stormwater. Examples include roads, trails, and parking spaces affected by light vehicle traffic, such as bicycle lanes, emergency access points or services, road shoulders and airports, and sidewalks of housing and driveways.
Although some porous paving materials appear almost indistinguishable from nonporous materials, their environmental effects are qualitatively different. Whether it is translucent concrete, porous asphalt, paving or concrete or plastic-based paver, all these translucent materials allow rainwater to seep and infiltrate the surface area, traditionally resistant to the ground below. The goal is to control rainwater at the source, reduce runoff and improve water quality by filtering pollutants in the substrate layer.
Video Permeable paving
Deskripsi dan aplikasi
Permeable solutions can be based on: porous asphalt and concrete surfaces, concrete pavers (concrete interlocking paving systems - PICP), or grass-based paver grasses, grids and geocells. Porous sidewalks and concrete pavers (actually cavities between them) allow the stormwater to flow through the base layer of the rock for infiltration and screening in place. Grass-based polymers or cellular paver systems provide load-bearing reinforcement for gravel or unpaved grass surfaces.
Grass pavers, plastic grass reinforcing grid (PTRG), and geocell (cellular confinement system) are 3D honeycombed mobile network systems, made of thin-walled HDPE plastic or other polymer blends. It provides grass strengthening, soil stabilization and gravel retention. 3D structures strengthen the contents and transfer the vertical load from the surface, distributing it to a wider area. The selection of cellular network types depends heavily on surface materials, traffic and cargo. Cellular grid mounted on pre-prepared open stone layers (higher blank spacing) or engineering (stronger) stones. The surface layer may be a compacted pebble or a topsoil planted with grass and fertilizer. In addition to load support, cellular networks reduce soil compaction to maintain permeability, while roots increase permeability due to their root canals.
In the growth of new suburbs, porous sidewalks protect watersheds. In existing built-in areas and cities, rebuilding and reconstruction are opportunities to implement rainwater management practices. The permeable paving is an important component of Low Impact Development (LID), a process for land development in the United States that seeks to minimize impacts on water quality and similar concepts of sustainable drainage systems (SuDS) in the UK.
The original soil infiltration capacity is a major design consideration for determining the depth of bedrock for stormwater storage or for whether underdrain systems are required.
Maps Permeable paving
Benefits
Managing runoff
Permeabel paving surfaces have proven effective in managing runoff from paved surfaces. The large volume of urban runoff causes serious erosion and sediment on the surface of water bodies. Permeable pavers provide a strong ground surface, strong enough to take heavy loads, such as large vehicles, while at the same time they allow water to filter the surface and reach the underlying soil, mimicking the absorption of natural soil. They can reduce downstream flooding and erosion of river cliffs, and maintain the basic flow in the river to preserve the ecosystem. Pillar permeables also fight erosion that occurs when the grass is dry or dead, by replacing grass areas in the suburbs and residential neighborhoods.
Controlling pollutants
The permeable paving surface keeps the pollutants in the ground or other underlying material, allowing seepage of water into groundwater infiltration while preventing river erosion problems. They capture the heavy metals that fall on them, preventing them from washing downstream and accumulating accidentally in the environment. In a vacuum, natural microorganisms digest car oil, leaving little but carbon dioxide and water. Infiltration rainwater is usually less than a sidewalk resistant with a separate stormwater management facility downstream somewhere.. in areas where infiltration is not possible due to unsuitable soil permeable sidewalk conditions used in attenuation mode where water is maintained on the sidewalk and slowly. released to the surface of the water system between storm events.
Tree
The permeable sidewalks can give urban trees the root space they need to grow into full size. The "structural-ground" sidewalks combine structural aggregates with soil; The porous surface recognizes the air and vital water to the rooting zone. It integrates a healthy ecology and a thriving city, with a canopy of live trees on top, city traffic on the ground, and tree roots alive below. The permeable benefits on urban tree growth have not been proven to be certain and many researchers have observed that tree growth does not increase if the construction practices solid material before permeable sidewalks are installed.
Disadvantages
Runoff Volume
Curb permeables are designed to replace Effective Impervious Areas (EIAs), not to manage stormwater from other resistant surfaces on the site. The use of this technique should be part of the overall site management system for stormwater, and not a substitute for other techniques.
Also, in the event of a massive storm, the water table below the porous pavement can rise to a higher level preventing the deposition from being absorbed into the soil. Additional water is stored in an open graded rock drainage base and remains until the subgrade can absorb water. For clay-based soil, or other 'non-draining' low soils, it is important to increase the depth of the crushed rock bottom to allow additional capacity for water as it waits for infiltration.
The best way to prevent this problem is to understand the extent of soil infiltration, and design the sidewalks and bottom depths to meet the water volume. Alternatively, allow sufficient rain water at the sidewalk design stage.
Pollutant load
Highly contaminated runoff can be generated by some land use where pollutant concentrations exceed those commonly found in stormwater. These "hot spots" include commercial plant nurseries, recycling facilities, refueling stations, industrial storage, marinas, some outdoor loading facilities, public yards, dangerous material generators (if containers exposed to rain), vehicle and maintenance services, and vehicles and equipment for washing and cleaning steam facilities. Since porous sidewalks are an infiltration practice, they should not be applied in flood prone areas because of potential groundwater contamination. All contaminated runoff must be prevented from entering the city storm exhaust system using the best management practices (BMPs) for certain industries or activities.
Weight and traffic volume
Reference sources differ if the traffic volume and weight are low or are suitable for porous sidewalks. For example, around truck loading docks and high commercial traffic areas, porous sidewalks are sometimes referred to as inappropriate. However, given the variability of available products, the growing number of North American installations and research targeted by both manufacturers and user agents, the range of applications received appears to be growing. Some paver companies have developed special products for industrial applications. Examples of work are in the fire auditorium, the parking lot of a busy retail complex, and on public and private roads, including intersections in parts of North America with fairly severe winter conditions.
Positioning
Permesable sidewalks may not be appropriate when the ground around or pour onto the sidewalks exceeds a 20 percent slope, where sidewalks descend the slopes of buildings or where the foundation has drainage pipes in their footers. The key is to ensure that drainage from other parts of a site is intercepted and handled separately rather than directed to the permeable surface.
Climate
The cold climate can present a special challenge. Road salts contain chlorides that can migrate through porous sidewalks into the groundwater. Snow plow can catch the edge of the block and damage the surface. Sand can not be used for snow and ice control on porous surfaces because it will clog the pores and reduce permeability. Although there are design modifications to reduce risk, the shrinking runoff can freeze under the sidewalk, causing frost. Another problem is spalling damage. Spalling damage exclusively occurs on porous concrete pavement of salt applications during winter. So porous paving is recommended for warm climates. However, other ingredients have proven effective, even lowering winter maintenance costs by keeping salt on the sidewalk itself. It also reduces the amount of rainwater runoff contaminated with chloride salts. Porous sidewalks designed to reduce frost and spalling damage have been used successfully in Norway. Furthermore, experience shows that precautions with rapid drainage beneath the porous surface are taken to increase the rate of melting snow over the soil.
Cost
Some estimates place the cost of permeable paving at two to three times that of conventional asphalt paving. Using paving permeables, however, can reduce the cost of providing larger or more stormwater BMPs on site, and these savings should be taken into account in cost analysis. In addition, the off-site environmental costs of not reducing the volume and water pollution in the field have historically been ignored or left to other groups (local government parks, public works and environmental restoration budgets, fisheries losses etc.) Olympia, Washington studied the use of penetrating concrete quite closely and found that new stormwater regulations make it a viable alternative to water storms.
Long life and maintenance
Some permeable sidewalks require frequent maintenance because sand or gravel can block open pores. This is generally done by industrial vacuums that suck up all the sediments. If maintenance is not done regularly, porous pavements can start to function more like waterproof surfaces. With a more sophisticated paving system, the required level of maintenance can be greatly reduced, elastomer-bound glass sidewalks require less maintenance than ordinary paving concrete because glass-bound sidewalks have a 50% vacuum.
Plastic grid systems, if properly selected and installed, are becoming increasingly popular with local government maintenance personnel due to reduced maintenance efforts: reduced gravel migration and weed suppression in public parks.
Some paving permeable products are susceptible to damage from misuse, such as drivers that tear out plastic patches & amp; gravel grid system by "joy riding" in long distance parking at night. The damage is not difficult to repair but can look unsightly at the time. Lawn makers need additional watering in the first year to establish vegetation, otherwise they may need to be replanted. The regional climate also means that most grass applications will be inactive during the dry season. While brown vegetation is just a matter of aesthetics, it can affect public support for this type of paving permeable.
Traditional permeable paving concrete bricks tend to lose color in a relatively short time that can be expensive to replace or clean and especially because of crystallization problems.
Efflorescence
Flowering is a hardened crystalline precipitate of salt, which migrates from the center of concrete or rock pairs to the surface to form a hardened calcium carbonate that hardened on the surface. Given time, these deposits are formed just as how the stalactites formed in the cave, except in this case on a flat surface. Rejuvenation usually looks white, gray or black depending on the region.
Over time, crystallization begins to negatively affect the overall appearance of masonry and can cause the surface to become slippery when exposed to moisture. If left unchecked, this crystallization will harden where calcium/lime deposits begin to affect the integrity of the cemented surface by slowly eroding the cement paste and the aggregate. In some cases it will also blacken the colored or coated surface.
Blooms form faster in areas exposed to excessive moisture such as deck near swimming pools, spas, and fountains or where irrigation runoff is present. As a result, the affected areas become very slippery when wet, causing significant loss of "friction coefficient". This can be a serious concern especially as a matter of public security for individuals, principals and property owners by exposing them to possible injury and increasing public liability claims.
Chemicals efflorescence remover can be used to eliminate the formation of calcium/lime without damaging the integrity of the paving surface.
Type
Installation of a porous pavement is no more difficult than a dense pavement, but has different specifications and procedures that must be strictly adhered to. Nine different families of porous paving materials present special advantages and disadvantages for special applications. Here's an example:
Translucent concrete
Translucent concrete is widely available, can generate frequent, universally accessible traffic. The quality of translucent concrete depends on the knowledge and experience of the installer.
Plastic Grid
The plastic grid allows for 100% porous systems using structural grid systems to contain and stabilize either gravel or grass. These grids come in different shapes and sizes depending on usage; from the lane to the commercial parking lot. This system has been used easily in Europe for over a decade, but gained popularity in North America because of the requirements by governments for many projects to meet LEED environmental building standards. Plastic grid systems are also popular among home owners due to lower installation costs, ease of installation, and versatility. The ideal design for this type of grid system is a closed cell system, which prevents gravel/sand/grass from lateral migration. It is also known as Grass pavers/Turf Pavers in India.
Asphalt porous
Porous bitumen is produced and placed using the same method as conventional asphalt concrete; it differs in the small (small) aggregate removed from the asphalt mixture. The remainder of the remaining single-sided aggregate particles leave open cavities that give the material its porosity and permeability. To ensure the pavement strength, the fibers may be added to the polymer modified asphalt mixer or binder as may be used. Generally, porous asphalt pavement is designed with a subsurface reservoir that retains water passing through the sidewalk, allowing it to evaporate and/or seep slowly into the surrounding soil.
The open-friction course (OGFC) is a porous asphalt surface line used on the road to improve the safety of driving by removing water from the surface. Unlike the full depth of pavement sidewalks, OGFC does not drain water to the bottom of the sidewalk. Instead, they allow the water to infiltrate to the top 3/4 to 1.5 inches from the sidewalk and then flow to the side of the road. This can improve the road friction characteristics and reduce road spraying.
Single-size aggregates
Single-sized aggregates without any binders, e.g. loose gravel, broken pieces of stone, is another alternative. Although it can only be used securely in very low low-speed traffic settings, e.g. cars and drives, the potential cumulative area is very good.
Porous grass
Porous areas , if properly constructed, can be used for occasional such parking in churches and stadiums. Plastic turf reinforcement grids can be used to support increased loads. Turf lives scattering water, actively warding off "hot island" with what appears to be green open grass.
Concrete sidewalks overlap
Concrete linked concrete sidewalks are concrete units with open space and permeables between units. They provide an architectural appearance, and can bypass heavy and heavy traffic, especially concrete pavers that lock each other, except high-speed or high-speed roads. Some products are polymer coated and have a fully porous face.
Permewable brick sidewalks
Curved piece of permeable clay brick is a clay brick unit fired with open space, permeable between units. Clay pavers provide a durable surface that allows stormwater runoff to penetrate through joints.
Paving bound resin
Paving bound resin is a mixture of resin binder and aggregate. Clear resins are used to fully coat each aggregate particle before laying. Sufficient resin is used to allow each aggregate particle to stick to each other and to the base but allow the cavities to permeate the water. Paving resin bound provides a robust and durable surface suitable for pedestrian traffic and in-app vehicles such as lanes, driveways, parking lots and access roads.
Recycled recycled porous glassed glass
Elastomer bonded recycled porous glass consisting of post consumer-processed glass bonds with a mixture of resins, pigments, granites and bonding agents. About 75 percent of glass in the US is dumped in landfills.
See also
Stormwater management practices related to highways:
- Bioretention
- Bioswale
Note
References
External links
- Avoiding Stormwater Running and Rain Nitterhouse Masonry (US)
- PaveShare - Patch Resources Permeabel
- Technical Note 14D - Permeable Clay Brick Surfaces - Brick Industry Association (USA)
- "Allowable Paving & amp;" Destruction - Precasting Paving & amp; Curb Assn. (UK)
- Sustainable Drainage: Review of Published Materials on Performance of Various Components of SUDs - Research on Construction & amp; Information Assn. (UK)
- "Pervious Concrete Pavement: An Overview" - National Ready Mixed Concrete Assn. (US)
- Aquastone - Technical data of porous paving
Source of the article : Wikipedia
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