: A review and perspectives.
SUBMITTED BY DIBESH MAN MALEGO (078MSEEB005)
SUPERVISEDBY
AR. YAM PRASAD RAISubmitted to DEPARTMENT OF ARCHITECTURE
MARCH 2023
I want to extend my profound appreciation to all of the important informant people who directly or indirectly assisted in countless ways throughout the project. I would like to thank my project supervisor Ar. Yam Prasad Rai and Associate Professor Dr. Sanjaya Uprety for the chance to conduct research on the Permeable pavement material for the project work as a part of academic requirement. The critical analysis of the study aims to provide a reference for future academic studies as well as any enthusiast regarding the subject.
I’d would like to express my gratitude to the Department of Architecture for include this Project work as one of the courses for the Master of Science in Energy Efficient Building program. Finally, I would like to thank all of my friends, previous researchers and everyone for their contribution to accomplish the study.
Any feedback to improve the study is always appreciated.
Pavement is a structure consisting of superimposed layers of processed materials above the natural soil sub-grade. Pavement is a multi-layer system that distributes the vehicular loads over a larger area.
(Source: https://pikeconservation.org/soil-profile/
Pavements form the basic supporting structure in transportation. Each layer of pavement has a multitude of functions to perform which has to be considered during the design process. Different types of pavement can be adopted depending upon the traffic requirements. Improper design of pavements leads to early failure of pavements affecting the natural topography of the soil.
A sustainable pavement is one that achieves its specific engineering goals while, on a broader scale,
Meets basic human needs, Uses resources effectively, and Preserves/restores surrounding ecosystems.
Sustainability is context sensitive and thus the approach taken is not universal, but rather unique for each pavement application.
(Source: https://constrofacilitator.com/pavementlayer)
• (Jelena, et.al, 2017) refers that paving has numerous functions in the cities and often covers more than 30% of the entire urban area within the city.
• Until recently, landslides were only thought to be associated with high intensity rainstorms on steep inclines. However, it was found that the rainfall intensity plays a more important role in increasing the chances for landslides to occur due to the sheer quantity of water draining over a short amount of time.
• These conditions can be exasperated by human development, which alters the drainage path of the rainwater, increasing the likelihood of a landslide (Ozdemir. A, et al. 2008).
• The extent to which subjective and objective perceptions of the street environment complement or overlap each other in influencing property values has not been stressed adequately in the Hedonic Pricing Model (Qiu et.al 2023) which refers to consideration of internal and external values.
• The prospect of permeable pavement material (PPM) can help researchers to create more efficient and sustainable streetscapes that can have a positive impact on the environment and the communities they serve.
• This study can provide a reference for decision makers to choose the costeffective and sustainable pavement project.
• To investigate prospect of permeable pavement material in context of street of Patan,Lalitpur.
The study uses both qualitative and quantitative methods. The qualitative method comprises the interpretation of the literature review on approaches to energy planning. Whereas, the quantitative method is based on article published on regarding topic in renowned and credible online platform. In this sense, the study lies within the pragmatic paradigm.
Detailed literature study on the prospect of permeable pavement material was done through various secondary sources. Similarly, the contextual details of Patan, Lalitpur such as site location, geography, climatic data and socio-cultural comtext were also reviewed.
Full infiltration
Storm water is infiltrated into the subgrade
No additional storm water features are required.
Used in areas where subgrade materials have high infiltration rates.
Partial infiltration
Water is encouraged to infiltrate subgrade.
Excess water from higher intensity storms is removed using outlet pipes
Low infiltration
• Used for applications where infiltration is undesirable such as:
• Water harvesting
• Brownfield sites
• Frost susceptible subgrade.
(Source: Hein.k, 2014)
4.2.1 Materials production: Activities involved in pavement materials acquisition (e.g., mining) and processing (e.g., refining, manufacturing, mixing), including plant processes and transport.
4.2.2 Pavement design: The process of identifying the functional requirements of a pavement, gathering relevant information (e.g., subgrade, traffic, weather), and then selecting and specifying materials and the pavement structural composition.
4.2.3 Construction: Processes and equipment associated with the construction of pavement systems, including both new construction and reconstruction efforts.
4.2.4 Use: Pavement characteristics (e.g., roughness, stiffness/rigidity) that affect vehicle energy consumption and corresponding emissions as well as the surrounding environment.
4.2.5 Preservation, maintenance, and rehabilitation. The application of treatments to an existing pavement that slows the rate of deterioration or that addresses functional or structural deficiencies
4.2.6 End-of-life. The final disposition and subsequent reuse, processing, or recycling of any portion of a pavement system that has reached 10 year life span of its performance life.
Generally, there are permeable assortment of concrete, asphalt, and interlocking pavers that illustrates depending upon the kind of materials used the PPS are classified into different kind.
It is also known as porous, pervious, "popcorn," or open-graded asphalt, is criterion hot-mix asphalt (HMA) with decreasing in fines or sand and permission water to
drain through it. It generally consists of coarse and soft aggregate stone restricted by a bituminous-based binder course. Porous asphalt over an aggregate stockpiling bed will minimize rainwater runoff rate, volume, and pollutants.
Permeable concrete, also recognized as penetrable (or) porous concrete, gapgraded is concrete with miniature sand or fines and let water to drain through it. The pervious concrete pavement is an effective and unique way to tackle critical environmental problem and assist green and sustainable growth by apprehend rainwater and allowing it to infiltrate into the soil. Porous concrete helps recharge groundwater and minimize rain runoff.
Permeable interlocking Pavement (PICP) consists of producing concrete units that decrease the volume, rate and contamination of rain water runoff. Immobilized modules are designed with little openings between joints.
The openings usually consist of 5-15% of the paved flatness area loaded with small and high permeability aggregates. The knuckles allow the rain water to enter the bed layer as a stone break and "open- graded" base i.e., crushed stone layers with no soft or small particles. That backing the pavers whereas providing runoff treatment and storage.
The void spaces in the midst of the crushed stones store the water and seep it back in the soil layer. The stones in the joints provide 100% surface permeability, and the essential filters lead to de-watering and reducing contaminants.
Concrete grid pavements “green parking lots” offer a cool, green surface. This could be considered as solution for vehicular access lanes, emergency access areas, and overflow parking areas, and even residential driveways.
Grids are confirmed contributors to decrease ambient urban temperatures thereby contributing to decrease heat island in the same time catch some rainfall and runoff.
Plastic reinforcement grid pavers also known as geocells consists of flexible plastic interlocking units that permit for infiltration through large gaps loaded with top soil planted with turf grass or gravel.
5. Pavement Design Guidelines: (Department of Roads, 2014)
• The design procedure of flexible pavement involves the interplay of several variables such as wheel loads, traffic, climate, terrain and sub-grade soil condition.
• Sub grade should be well compacted to utilize its full strength and to economize overall thickness of the pavement required.
• Gravel , Sands, silty and clayey sand could be used for construction of sub base course.
• Recommended minimum thickness of granular base (crushed stone) is 150 mm.
(Liyuan. Q, et.al , 2020) refers that there are common two sizes of the permeable bricks: 100 mm × 200 mm × 40 mm and 98 mm × 193 mm × 40 mm in practice with compressive strength >/= 44.3 MPa and effective porosity >/= 7.45%
• (Lori et. al, 2019) states that with an increased interest in low impact design and green infrastructure incentives, permeable pavements are becoming increasingly popular as an alternative pavement solution to minimize storm water runoff and to improve water quality. The design of permeable pavement shoulders requires a balance between providing a structurally sufficient pavement to withstand traffic loading as well as achieving the storm water management/ hydrologic design goals.
• (Daniel et.al, 2021) mentions COVID-19 pandemic have uncovered, or in some cases intensified, the need to rethink public space share, and to bolster active forms of mobility through concrete interventions. Street pacification
thus demands that careful attention shall be given to the interdependencies between a city’s sidewalk and road networks, making a systemic, data-driven strategy necessary. Connecting these sidewalk geometries with two simple rules (change in direction or surface).
• (Jianlei L ,et.al, 2019) refers that the conventional brick used in sidewalk construction in cities has caused water logging during a thunderstorm because of the low permeability, which has given rise to so-called “urban heat island effect” and the destruction of the urban environment in which people live. There is lack of quantitative analysis on the influence of permeable brick pavement with consideration of three aspects (i.e. society, economy and ecology) throughout the life cycle.
Fig: Initial Cost comparison
The initial per unit cost of permeable pavements is typically higher than a comparable conventional pavement section:
• Specialized surface mixes
• Specialized install
• More expensive aggregate materials
• Drainage elements
• Less strength = more material
However, permeable pavement contributes to overall storm water management. Potential to eliminate conventional storm water conveyance systems such as curbs, storm drains, underground piping, and treatment/detention (Hein. K, 2019).
While the use of permeable shoulders may have significant benefits in terms of storm water management, their application is not suitable for all situations. (Hein.K, 2019).
Proper and timely maintenance is critical for all pavement types.
Inspect and clean all outlet structures to ensure positive water flow.
Provide inspection ports and regularly monitor drainage rates of the stone reservoir to identify logging.
Limit the use of winter deicing chemicals for sensitive vegetation areas, sensitive receiving waters, or for pavements designed to capture and reuse water.
Vacuum sweeping of surface helps keep sediment from clogging deeper layers
Extensive use of winter sanding or biomass loading from surrounding vegetation can substantially reduce system infiltration
Studies have shown that permeable pavements require 75 percent less deicing (removing snow/frost) than conventional pavements
Contamination spills may require complete removal and replacement of the permeable pavement to prevent washout
However, relatively infrequent occurrence, and spill containment benefits should also be considered. (Hein, 2014)
International Case study: Niel Garden
Toulouse, France.
9.1 Rationale: Along with natural disposition of elements , the openwork pavement allows vegetation to grow interspread, improves soil absorption, reduces impact of heavy rain and creates aesthetic effects.
• The paving of the paths has been done by means of a fast, economical system using metal mesh containing red bricks matching the traditional dimensions of Toulouse bricks, measuring thirty by five centimeters.
• The drainage system has been designed to permit total filtration of water.
• The flexibility of the system makes it easier to adapt to the undulations (move up and down) of the ground as a garden that appears clear and balanced where the topography, the vegetation, the pathways, the water, the materiality merge into a single intervention, which was simple as precise.
• From the whole city, a green corridor connecting with Garona river and Midi canal, to the surrounding area with its playgrounds, amphitheater and little squares with topography that allows the protection of the archaeological remains, manages to generate different spatial experiences in an enclosure of rectangular and uniform dimensions.
• It is the support for the different pathways and the base for the different types of vegetation, which evoked by the agricultural landscape of the region as sustainable construction with a self-management of the water, recycling materials – excavation lands of the surrounding buildings and the preexisting asphalt – and a differentiated garden management.
• It functions as a new island of freshness in the middle of the city.
• A materiality typical of Toulouse city. The bricks, ingeniously put by a system that combines the constructive efficiency, the ability to follow the new topography and the magic to erase the boundaries between mineral and vegetable.
• A single gesture, a single movement, an undulating veil that goes gradually from the mineral to the vegetal. Nowadays, it seems so natural that people wonder if the landscapers have really worked there.
The study is dedicated to explore prospect of PPM and technology to be implemented on ground level in street of Patan, Lalitpur.
Walking distance: 1 K.M. (12 minutes)
The studied stretch of the streetscape of Patan from contemporary landmark, Labim mall to the Patan Durbar square that is one of the world heritage site (1979).
The street intersects as festival route for two major chariot jatras of the city which are Bungdyo Jatra and Bhairav jatra.
Material:
Bituminous street is observed in majority of street with stone pavement nearby the palace area.
Street width:
The street width varies from 30 feet wide nearby Labim Mall which is congested upto 16 feet in Gabahal area.
Patan typically receives about 357.1 millimeters (14.06 inches) of precipitation and has 212.06 rainy days (58.1% of the time) annually.
• The district’s yearly temperature is 19.51ºC (67.12ºF) and it is 2.49% lower than Nepal’s averages.
(Source : Meteoblue.)
• This study recommends using Geographic Information System (GIS) in determining the suitable type of soil which fits the use of permeable pavement.
• It is essential to foster acceptance of permeable pavement systems as a viable alternative for Sustainable Urban Drainage System. (SUDS).The water consumption of 1 sq.m. permeable sidewalk pavement is 253kg, which is 41kg higher than that of conventional pavement.
• The self-sustainability of these relatively new systems in comparison to traditional pavements requires further assessment. t. Moreover, the longterm impact of PPS on the environment is still unclear.
• More research has to be put into improving the lifespan as well as decreasing the costs of permeable pavement
• The design of permeable pavement shoulders requires a balance between providing a structurally sufficient pavement to withstand traffic loading as well as achieving the stormwater management/ hydrologic design goals
• Presence of organic content in strom water may create drainage problem in unwanted areas as there is potential for both growth and decline.
• It is troublesome issue in structural designing works when the sub-grade is found to be clay soil. Soils having high clay content tend to swell when their dampness content is permitted to increment. Soil stabilization is required in such cases.
• Prior studies have found some evidence of poorer sidewalk conditions in lower income and minority communities.
• Use of permeable pavement materials can aid in concept of ‘sponge city’ which improves water quality as it impacts deeper than binary concept of material selection.
• Permeable pavement materials requires a balance between providing a structural durability and achieving the storm water management.
• Conventional brick used in sidewalk construction has contribution to ‘urban heat island’ effect in compact urban area where almost 30% of city area is covered by sidewalk. It can be mitigated by using permeable pavement system.
• Use of sustainable material and technology can prevent environment degradation as well as contribute in Property value of area based on subjective and objective perspective.
• Future research is needed to improve the quantitative models and data quality, reduce the limitation of assumptions, and make the case closer to practical applications with possible adaptation of Photovoltaic pavement and solar road.
Future research can investigate how permeable pavement can be designed with climate adaptation to withstand extreme weather conditions and energy efficiency specific in following direction as given below :
Durability
Maintenance
Material development
Pollutant removal
Embodied energy
Thermal conductivity (U-value)
Enhancing water treatment capabilities
Environmental and ecological impact.
• Anne ,C.L., Demóstenes, F. S. , (2018) Dobbert , L. Pedestrian and cyclist preferences for tree locations by sidewalks and cycle tracks and associated benefits: Worldwide implications from a study in Boston, MA. ELSVIER Cities.
• Hein ,D.K. (2013) Permeable Pavement Design and Construction: What Have We Learned Recently?
• Layth ,A.M. , Hamid, A. A. (2018) Prospect of Using Permeable Pavement in Some Regions of Najaf Region.
• Lori Schaus, P.Eng., and David K. Hein, P. Eng. (2019) PERMEABLE PAVEMENTS FOR ROADWAY SHOULDERS
• Daniel, R., Albert, S.R., Marta C. (2021) A sustainable strategy for Open Streets in (post) pandemic cities.
• Jianlei L, Changwei L, Taoyong L, Lei H ,Xuefeng S, Cui L, Anxian L. (2019) An eco-friendly permeable brick with excellent permeability and high strength derived from steel slag wastes.
• Hein ,D.K. Aaron, P. (2014) Permeable Shoulders for pavements.
• Qingsong. W, Zhi Ma , Xueliang Yuan a, * , Juntao Wang b , Zhaoyang Mu c , Jian Zuo d , Jian Zhang e , Jinglan Hong e , Shuguang Wang e (2019) Is cement pavement more sustainable than permeable brick pavement? A case study for Jinan, China
• Liyuan. Q, Yu Zhang, Sheng. Z, Zhao. J, Tengfei. W, Qiang.W (2020) Rainfall runoff features of permeable sidewalk pavement. Journal of Water and Climate Change.
• Jelena. D, Aleksandra D, Milena V, Petar D. and Milena B.(2017) Thermal Comfort of Pedestrian Spaces and the Influence of Pavement Materials on Warming Up During Summer.
• https://pavementinteractive.org/reference-desk/pavement-types-andhistory/pavement-history/
• https://www.uniquepavingmaterials.com/asphalt-paving-throughouthistory/
• https://www.publicspace.org/works/-/project/k295-niel-garden
• https://landezine-award.com/niel-garden/
• https://www.archdaily.com/catalog/us/products/30381/ceramic-textilesfor-pavementsflexbrick?ad_source=neufert&ad_medium=gallery&ad_name=close-gallery
• https://flexbrick.net/jardin-niel/
• https://www.meteoblue.com/en/weather/historyclimate/climatemodelled /patan_nepal_1282931
• https://tcktcktck.org/nepal/bagmati/patan#:~:text=Patan%20typically%20r eceives%20about%20357.1,%25%20of%20the%20time)%20annually
• https://www.thetranstecgroup.com/pavement-surface-characteristics/
• https://streetmix.net/basethee/1/patan-lalitpur