Summary/Reader Response Draft #1: Porous Asphalt Pavement

 

The article “Porous Asphalt Is Kind Of The Road” (PaveGreen n.d.) introduces the features and application of porous asphalt, a type of road surface used to improve safety, diminish water pollution and decrease erosion. The article state that porous asphalt is made up of rocks glued together with asphalt cements while lowering the amount of fine aggregate. This allow rainwater to seep through the space between the rocks and limiting the flow rate of water therefore reducing surface runoff, there are multiple way to combine porous asphalt to achieve different objective. It was further stated in the article that during winter climate porous asphalt require less anti icing agent which reduce the amount of chloride from being released into the environment which is toxic to aquatic life. On highways, spaces in between the rocks allow rainwater to seep in between and reduce the splashes thus improving visibility and safety for vehicles.

The article mentioned that the porous asphalt roads cost relatively the same as conventional asphalt, typically porous asphalt have to be used together with a base layer such as stone recharge bed to achieve optimal result this results in a higher cost for installing porous asphalt.  However the cost different can be offset from the reduced amount of stormwater pipe and inlet to be built.

The article explained the benefits and multi-purpose application of the porous asphalt, however the routine assessment and maintenance required for porous asphalt for it to perform optimally and when compared the durability of porous asphalt against the traditional dense asphalt pavement, the porous asphalt are deem have a lifespan as compared to the latter. These disadvantages of will significantly affect the applicability of and cost of maintaining porous asphalt when compared with traditional roads. However, if provided a suitable condition and specialist personnel, porous asphalt can be a more ecological and greener alternative to traditional roads.

Firstly, while porous roads asphalt act as a filtration for containment such as oil and minerals, without routine assessment and maintenance and over a period of time as containments and sediment are constantly being filtered out, the pores of porous asphalt will be blocked. The article “Effect of Clogging on the Permeability of Porous Asphalt Pavement” (Yaolu Ma, Xianhua Chen, Yanfen Geng, and Xinlan Zhang) it is stated that clogging characteristic of the porous asphalt pavement is a common problem owing to deposition of sediments on the pavement surface, the storm water, and vehicles. The clogging causes 59% - 75% reduction in permeability, which causes the ideal characteristic of porous asphalt to be obsolete. Therefore routine assessment of porous asphalt is required to determine the number of when are maintenance required to ensure that the condition of porous asphalt is optimal. The article “A Review of Permeable Pavement Clogging Investigations and Recommended Maintenance Regimes mentioned that there is no universal superior maintenance method, assessment and monitoring of porous asphalt should be conducted early after installation even if there are no sign of blockage. Continuous monitoring of permeable pavement surfaces is necessary to better understand the in situ clogging mechanisms for a particular region.

 

Secondly, the existence of high void content in between porous asphalt which provide its permeability causes the structure of porous asphalt to be weaker than traditional dense asphalt when place under consistent strain where multiple vehicle run over. The article “Investigation of microstructure characteristics of porous asphalt with relevance to acoustic pavement performance” states that the problem with high void content of porous asphalt is intentionally designed for its functional properties and the drawback of such design consist of material deterioration, such as ravelling effect and increased physical aging effect. This affect the applicability of porous asphalt in expressway and roads that experience high amount of traffic. The lifespan of porous asphalt roads in such area will be greatly reduced.  

 

Lastly, one of the key characteristic of porous asphalt that are not mentioned in the article is that it is able to reduce noise created. This characteristic is especially useful in countries and area where the land is a limited resource such as Singapore. In Singapore, due to the constraint of limited land, roads and express are built in the vicinity of our HDB Flat. As vehicle went past the roads and express way in large quantity, large amount of noise are created. The article “Noise reduction effect of double-layered porous pavement[AT1]  (KONDO, N OHNISHI, H Hattori, T ISHIKAWA, KNAKANO, T, 2000) state that porous pavement are considered to be one of the most effective countermeasures for countering traffic noise, result shown that noise reduction on porous pavement is about 3-4dB compare with the traditional roads.

In conclusion, even with benefits and advantages of porous asphalt, when deciding to replace traditional roads it is important to take into consideration of the climate and location of implementation as building it in location that are unfavourable might cause more cost and effort into maintaining its functionality.

 

Effect of Clogging on the Permeability of Porous Asphalt Pavement

https://www.hindawi.com/journals/amse/2020/4851291/

 

Noise reduction effect on double-layer porous pavement

https://trid.trb.org/view/732871#:~:text=Porous%20pavements%20are%20considered%20to,with%20a%20dense%20asphalt%20pavement.

 

Effects of double layer porous asphalt pavement of urban street on noise reduction

https://www.sciencedirect.com/science/article/pii/S2212609016000029

 

Porous Asphalt is king of the road

http://www.pavegreen.org/index.php?option=com_content&view=article&id=58:king-of-the-road&catid=35:porous-asphalt&Itemid=110

 

Investigation of microstructure characteristic of porous asphalt  with relevance to acoustic pavement performance.

https://www.sciencedirect.com/science/article/pii/S2046043017300722

 



Comments

Popular Posts