Evaluation of the Use of Permeable Interlocking Concrete Pavement in Chile: Urban Infrastructure Solution for Adaptation and Mitigation against Climate Change

Abstract

There is currently a context of climate change due to the way modern cities are developed, and they are made up mainly of impermeable surfaces and concrete buildings that change the hydrological cycle, causing (i) an increase in temperatures, (ii) the accumulation of stormwater on different surfaces, (iii) overflow in drainage systems, and (iv) the alteration of ventilation patterns, among others. This article presents a case study on the implementation of a permeable interlocking concrete paving (PICP) system, and it develops physical–mathematical modeling using software for the design of a parking lot that currently does not have adequate paving and urban drainage, resulting in sporadic flooding due to heavy rainfall in the city of Temuco, La Araucanía region, Chile. This article’s contribution highlights the application of new technology in Chile, discussing road infrastructure solutions based on sustainable urban drainage systems (SUDSs), which seek to implement feasible alternatives in urban sectors to improve human livelihood. The factors studied include structural and hydrological properties, along with the infiltration analysis of the system according to historical rainfall records in the area. This research concludes that the permeable pavement system with a drainage pipe and smooth roughness coefficient performs satisfactorily for an extreme hydrometeorological event corresponding to 140 mm considering 24 h of rainfall with a return period of 100 years equivalent to an inflow of 673 m³/day. Finally, the results indicate that, at least in the conditions of the city of Temuco, the use of permeable interlocking concrete pavement (PICP) proves to be a sustainable and feasible alternative to implementing measures of adaptation and mitigation against climate change, reducing the city’s flooding zones and allowing the irrigation of urban green areas.

1. Introduction

1.1. Urban Context of Stormwater Management Considering Climate Change

Both in Chile and many countries around the world, there is increasing urban growth, where the urbanization of natural basins causes an alteration of their corresponding hydrological processes [1,2,3]. These basins, which are subject to constant urbanization, present more rapid flooding, making the consequences of flooding increasingly severe; presenting a lack of sustainable urban rainwater management systems in which extreme hydrometeorological events test the performance of urban drainage systems; and causing countries to demand new solutions to adapt to climate change [4,5,6].

According to data from the 2017 population census, Chile is one of the most urbanized countries in Latin America, with 87.8% of the population urbanized; it continues to grow compared to previous censuses as it reached 83.5% in 1992 and 86.6% in 2002. According to the above, the progressive decrease in the rural population stands out both in terms of percentage and absolute terms [7]; these antecedents provide a signal of the changes in land use and the associated modification of the infiltration and runoff conditions of rainwater [8,9,10].

This research is developed with the objective of providing a pavement infrastructure solution for the adaptation and mitigation of climate change, considering the current lack of sustainable urban drainage infrastructure systems that can manage runoff caused by extreme precipitation events [11,12,13]. The exceedance of stormwater management capacity in cities due to the growth and waterproofing of soils causes urban flooding, directly affecting users within residential, commercial, and industrial areas [14,15]. Furthermore, cities currently lack a variety of stormwater drainage uses, such as irrigating a city’s green areas, thus allowing these ecosystems to capture more CO₂ and providing landscape benefits that improve the quality of human life thanks to the process of photosynthesis [16,17,18,19].

1.2. Urban Stormwater Management Infrastructure: Permeable Interlocking Concrete Paving

Permeable interlocking concrete pavement (PICP) consists of manufactured impermeable concrete units (pavers) that form permeable voids and joints when assembled in a placement pattern [20,21,22]. The openings normally comprise between 5% and 15% of the paver surface, which maintains high permeability with small-sized aggregates [23,24]. According to several authors [25,26,27], the cross-section of the PICP structure is detailed in Figure 1.

The openings allow stormwater to enter a layer of permeable bedrock and a base/subbase that supports the pavers while providing runoff storage and treatment. PICP replaces traditional impervious pavement in most pedestrian and vehicular applications, except high-volume/high-speed roads [28,29]. This has been used successfully on pedestrian crossings, sidewalks, driveways, parking lots, and low-traffic roads [25].

Figure 1. Typical cross-section of PICP [30].

Figure 1. Typical cross-section of PICP [30].

1.3. Urban Stormwater Management Problems in Chile

Urban development in Chile results in significant changes in land use and functional connections between urban and rural areas [31]. Currently, in Chile, there is a significant deficit in advances in stormwater management, resulting in flooding within urban areas due to the waterproofing of soils [32]. Changing the relationship between the use of urban and rural areas leads to changes in residents’ quality of life, the environment, and ecosystem services, including water resources [33].

The issue of water resources management is critical in the context of increasing urbanization, observed and projected climate change, and extreme events, such as floods and droughts, which have been particularly severe in Chile in recent decades [31].

This article presents a case study on the implementation of a permeable interlocking concrete paving (PICP) system for the design of a parking lot that currently does not have adequate paving and urban drainage, resulting in sporadic flooding due to heavy rainfall in the city of Temuco, La Araucanía region, Chile.

The research gap addressed by this study highlights the application of new technology in Chile, discussing road infrastructure solutions based on sustainable urban drainage systems (SUDSs), which seek to implement feasible alternatives in urban sectors to improve human livelihood and contribute to the adaptation and mitigation of climate change.

1.4. Aim of the Article

Based on the above information, this research seeks to respond to the following objectives throughout the course of the study, with these being relevant for its development and formulation:

• Identify the structural behavior of the design layers that make up a permeable interlocking concrete paving system.
• Demonstrate the performance of a permeable interlocking concrete paving system through physical–mathematical modeling addressing the construction development that its implementation entails.
• Evaluate the feasibility of using permeable interlocking concrete in the city of Temuco, La Araucanía region, Chile, considering historical precipitation records under a climate change scenario.
• Propose the use of new technologies in urban drainage paving systems to improve urban sustainability.

2. Materials and Methods

2.1. Research Type and Design

The research is descriptive, explanatory, and non-experimental, utilizing a quantitative approach. According to the information obtained, analyses were carried out to predict the behavior that the permeable paving system will have in the area where it is desired to be implemented, and at the same time, an evaluation of the impact that its use entails in the study areas was carried out, along with the effect that it will generate on citizens.

In this research, modeling and simulation were carried out using specialized software. Typical soil properties of the study area and representative climatic parameters based on historical statistical records were considered. The Pueblo Nuevo meteorological station (Temuco, Chile) was considered in this study, with a hydrological time series from 1953 to 2020 to obtain the maximum annual 24 h rainfall [34].

2.2. Research Material Resources

For the reasons presented above, physical–mathematical modeling was developed using specialized software to verify the structural and hydrological feasibility of sustainable urban drainage systems (SUDSs). Permeable interlocking concrete pavement (PICP) design software called “Permeable Design Pro” was used [35]. Permeable Design Pro Software version 2.1.0.0, corresponding to the year 2020, is a non-open-source software developed by Applied Research Associates Inc. and Interlocking Concrete Pavement Institute (ICPI). Similarly, digital meteorological databases were used, such as rainfall information provided by the Pueblo Nuevo station belonging to the General Directorate of Water. In the same way, a review of the literature related to the permeable interlocking concrete paving system was carried out based on scientific journals (reviews and articles) and research from undergraduate thesis projects at different universities, both national and international.

As for the research that refers to the regulatory framework, this was carried out based on associations, societies, and engineering institutions that specialized in the established area. Technical information on the design and serviceability of pavement structures was specifically investigated within the Guide for the Design of Pavement Structures, according to the American Association of State Highway and Transportation Officials (AASHTOs) [36,37]. Finally, the standards and methodologies implemented by both the American Society for Testing and Materials (ASTMs) and the Interlocking Concrete Pavement Institute (ICPI) were considered [35].

2.3. Software: Permeable Design Pro

When designing a permeable pavement, two relevant aspects must be taken into consideration: one of them refers to the structural behavior, that is, the support capacity of the pavement, and the other refers to the hydraulic–hydrological behavior, that is, the ability to drain and store predicted rainfall [38].

The software uses the Interlocking Concrete Pavement Institute (ICPI) design criteria [35], which reflect the most advanced practices based on experience in North America and abroad. Standard hydrologic and structural design procedures are integrated into a comprehensive method to estimate the pavement capacity necessary to support the traffic load and drain, store, and infiltrate surface water runoff. The software allows you to run a sensitivity analysis of the key variables to find the optimal design for the development of a project on a given site [35].

Permeable Design Pro Software was used to evaluate the viability of using the permeable interlocking concrete paving system proposed in this study.

2.4. Study Area Location

The study area location is in the parking lot called “Pablo Neruda Avenue 1100 Parking”, with a size of 5643 m², within the Germán Becker Stadium Park area, city of Temuco, La Araucanía region, Chile, with the following coordinates: latitude 38°44′28.7″ S and longitude 72°37′13.5″ W (Datum WGS 84), and an approximate elevation of 110 masl (Figure 2). The temperature ranges between −5.6 °C and 39.8 °C. Precipitation varies between 780.8 and 1421.5 mm annually, with two different seasons: the rainy season (April–October) and the dry season (November–March).

2.5. Study Area Characteristics and Sample Selection

The study area includes the road infrastructure of the Parque Estadio Germán Becker sector, located on Pablo Neruda Avenue within the City of Temuco, Chile. Specifically, the sample selection is defined within the area that covers the parking in the sector. Figure 3 shows the public space according to the present records, highlighting the pavement surface’s deterioration due to the accumulation of stormwater during intense rainfall events in the area, thus resulting in flooding and challenges for both adequate pedestrian and vehicle traffic.

The study area was selected because it is a critical place for rainwater drainage where waterlogging and flooding usually occur, which is a representative point of runoff discharge from the German Becker stadium sector.

2.6. Hydrologic–Hydraulic Analysis for Permeable Interlocking Concrete Pavement

2.6.1. Water Balance

A pavement system’s water amount is described as a water balance. This volume in the paving system is calculated according to Equation (1).

$$Water Vol. \left(Time\right)=Initial Water Vol.+{\int }_0^{Time}InFlow \left(Time\right)-OutFlow \left(Time\right)$$

(1)

where the Volume of Water is represented in m³ and Time is represented in h.

2.6.2. Stormwater Inflow

The water that enters the pavement comes from precipitation or contributing areas, due to which it can accumulate on the surface of the paving system and the contributing areas. Subsequently, water that falls onto the pavement can infiltrate the structure’s granular material or run off the pavement’s surface [35]. If runoff occurs within the system, it can be estimated based on Equation (2).

$$Q=\frac{{\left(P-0.2\ast \left(\frac{100}{CN}-10\right)\right)}^2}{\left(P-0.8\ast \left(\frac{100}{CN}-10\right)\right)}$$

(2)

where Q is the direct runoff represented in mm, P is the Precipitation represented in mm and CN is the curve number according to the SCS method.

Water infiltration is calculated in a series of regular time steps, where precipitation is converted to water input volume during each interval. Due to the additional distance that water must travel from the catchment areas to the pavement, an additional time lag is expected to affect the water inflow distribution [35]. The expected delay is calculated according to Equation (3).

$$T_t=\frac{0.007\ast {(n\ast L)}^{0.8}}{P^{0.5}\ast s^{0.4}}$$

(3)

where Tt is the travel time represented in hours, n is the Manning roughness number, L is the path length represented in m, P is the precipitation in 24 h represented in mm, and S is the longitudinal slope represented in %.

2.6.3. Stormwater Drainage System

The drainage rate into stormwater systems is limited by the speed at which water can move into the drainage system and the amount of water that can travel in the pipe [35]. To determine the flow rate through the base/subbase to the drainage pipe, Equation (4) is used.

$$Q_{granular}=k_{Base/Subbase}\ast \left(\frac{h^2}{b}\right)\ast L$$

(4)

where Q_granular is the flow through the base/subbase to the drainage pipe represented in m³/day, k_base/subbase is the hydraulic conductivity of the base/subbase material represented in m/day, h is the height of the level of water above the drain represented in m, b is the longest horizontal distance that water travels to reach a drainage system represented in m, and L is the length of the pipe throughout the project represented in m.

According to [35], if the base material can drain quickly, more water may try to pass through the drainpipes than gravity allows. This could be the limiting factor if some porous materials’ pipes are poorly designed. Manning’s equation (Equation (5)) estimates the amount of water flow in a pipe.

$$Q_{Pipe}=\frac{1}{n}\ast \pi \ast r\ast {\left(\frac{r}{2}\right)}^{\frac{2}{3}}\ast s^{\frac{1}{2}}$$

(5)

where Q_pipe is the maximum flow of water through any pipe represented in m³/day, n is the Manning roughness coefficient, r is the radius of the pipe represented in m, and s is the longitudinal slope of the pipe represented in %.

Next, as shown in Figure 4, the cross-sectional structure of the three types of permeable paving systems is described based on the water flows entering and exiting the system.

This research considers a permeable paving system, which specifies the complete structure of a permeable interlocking concrete pavement without infiltration into the subgrade layer.

3. Results

3.1. Structural Layer Design of Permeable Interlocking Concrete Pavement (PICP)

In accordance with the response to the first specific objective (i), the considered structural parameters of the design layers such as thickness, porosity, void ratio, permeability, and resistance in the case of the subgrade, as indicated in

Table 1. Structural layer design of permeable interlocking concrete pavement (PICP).

Structural Layers	Specifications	Results
Pavement layer (concrete pavers + aggregate ASTM No. 89)	Thickness	130 mm
Base layer material (aggregate ASTM No. 57)	Thickness	100 mm
	Porosity	0.319
	Void ratio	0.47
	Permeability	0.011 m/s
Subbase layer material (aggregate ASTM No. 4)	Thickness	180 mm
	Porosity	0.348
	Void ratio	0.53
	Permeability	0.145 m/s
Subgrade layer material (GP—gravels poorly graduated)	Subgrade strength	201.4 MPa
	Porosity	0.275
	Void ratio	0.38
	Permeability	0 m/s

, represent specifications, results, and influencing factors, with the purpose of understanding the behavior of permeable interlocking concrete paving layers.

Based on the determined design, the maximum water depth allowed in the base/subbase material is 85% of the thickness. Meanwhile, an assumption is made that there is no presence of water in the subbase material.

3.2. Typical Cross-Section of Structure of Permeable Interlocking Concrete Pavement (PICP)

Below, according to [35], a representative scheme (Figure 5) of a permeable paving system is shown, which specifies the complete structure of a permeable interlocking concrete pavement without infiltration into the subgrade layer in relation to the information obtained in Table 1.

3.3. Water Balance Results—Drainage Pipe with Smooth Roughness Coefficient

Within the design considerations, a case study was carried out, where the subbase layer had a thickness of 180 mm, demonstrating an optimal response capacity in the system with smooth drainage pipes. In

Table 2. Water balance results—drain pipe with smooth roughness coefficient.

$\mathbf{Inflow} \mathbf{(}{\mathbf{m}}^{\mathbf{3}}\mathbf{/}\mathbf{d}\mathbf{a}\mathbf{y}\mathbf{)}$			$\mathbf{Outflow} \mathbf{(}{\mathbf{m}}^{\mathbf{3}}\mathbf{/}\mathbf{d}\mathbf{a}\mathbf{y}\mathbf{)}$
Return Period (Years)	Initial Water Pavement	Surface Flow	Storage Pavement	Infiltration Subgrade	Drainage Pipe	Surface Flow	Superficial Stagnation
2	0.0	252.1	146.2	0.0	105.9	0.0	0.0
5	0.0	340.1	149.9	0.0	190.2	0.0	0.0
10	0.0	404.1	152.4	0.0	251.7	0.0	0.0
25	0.0	432.1	153.4	0.0	278.7	0.0	0.0
50	0.0	545.3	160.6	0.0	384.7	0.0	0.0
100	0.0	673.0	237.8	0.0	435.2	0.0	0.0

, the water balance results are presented for a system with drainage pipes with a smooth roughness coefficient, with the purpose of demonstrating the performance of the permeable interlocking concrete paving system through physical–mathematical modeling, thus addressing the constructive development that its implementation entails.

Table 2 shows the system’s response to the entry and exit of water flows, with the time represented in hours according to the storm return periods. According to these data, a visual representation is made, which describes the behavior of the attached data, as shown in Figure 6.

The recorded data represent the 2-, 5-, 10-, 25-, 50-, and 100-year return periods entered into the software. If these points are within 85% of the maximum allowable depth of water in the granular layer, it translates into optimal storage capacity during storm periods. It is seen that these values form a trend line that represents the saturation behavior for the thickness of the granular layer of the system.

Responding to the second specific objective (ii), for the return periods studied, the system could not produce saturation, complying with the results of water balances versus precipitation intensities, according to the analysis provided using the software. The above is corroborated according to Figure 6, projecting in the graph that this design effectively supports a return period of up to 100 years.

Therefore, the percentage of the maximum storage capacity that one proposes for the design will be directly influenced by precipitation events depending on the project’s location. Given the above, if the proposed percentage is exceeded, the area’s storage capacity against rainwater events will be compromised.

3.4. Water Balance Results—Drainage Pipe with Corrugated Roughness Coefficient

Although the analysis of the previously proposed model was prepared considering project pipes with smooth roughness and a Manning roughness coefficient with an index of 0.012, for this comparison case, a drainage system will be created applying pipes with corrugated roughness and a Manning roughness coefficient with an index of 0.024. As indicated,

Table 3. Water balance results—drainage pipe with corrugated roughness coefficient.

$\mathbf{Inflow} \mathbf{(}{\mathbf{m}}^{\mathbf{3}}\mathbf{/}\mathbf{d}\mathbf{a}\mathbf{y}\mathbf{)}$			$\mathbf{Outflow} \mathbf{(}{\mathbf{m}}^{\mathbf{3}}\mathbf{/}\mathbf{d}\mathbf{a}\mathbf{y}\mathbf{)}$
Return Period (Years)	Initial Water Pavement	Surface Flow	Storage Pavement	Infiltration Subgrade	Drainage Pipe	Surface Flow	Superficial Stagnation
2	0.0	252.1	146.2	0.0	105.9	0.0	0.0
5	0.0	340.1	152.2	0.0	187.9	0.0	0.0
10	0.0	404.1	198.4	0.0	205.7	0.0	0.0
25	0.0	432.1	225.4	0.0	206.7	0.0	0.0
50	0.0	545.3	332.5	0.0	212.8	0.0	0.0
100	0.0	673.0	448.8	0.0	222.3	0.0	1.9

presents the water balance results for a system with drainage pipes with a corrugated roughness coefficient.

According to Table 3, it is demonstrated that there is a correct response functioning for a rain return period of up to 50 years; however, at 100 years, superficial stagnation is evident.

However, if the system studied is considered with corrugated drainage pipes, a maximum stormwater storage response will be presented for a return period of 58 years, as shown in Figure 7.

It can be seen in Figure 7 that according to the 85% of the maximum storage capacity proposed in the granular layer, this design is only practical to withstand a storm period of 58 years since, with a longer return period, the target set margin for a successful long-term design decision is exceeded.

3.5. Hydrological Evaluation Results—Drainage Pipe with Smooth Roughness Coefficient

According to the previous results, in

Table 4. Hydrological evaluation results—drainage pipe with smooth roughness coefficient.

Storm Return Period (Years)	Rainfall Magnitude over 24 h (mm)	Satisfies Paver Infiltration Capacity	Satisfies Granular Infiltration Capacity	Satisfies Storage Goal	Satisfies Storage Capacity
2	53	Yes	Yes	Yes	Yes
5	72	Yes	Yes	Yes	Yes
10	85	Yes	Yes	Yes	Yes
25	91	Yes	Yes	Yes	Yes
50	114	Yes	Yes	Yes	Yes
100	140	Yes	Yes	Yes	Yes

, information is presented for verification purposes to both elucidate if the project satisfies the proposed conditions according to the proposed design and present results that evaluate the feasibility of using the permeable interlocking concrete pavement in the city of Temuco, considering the historical records of precipitation.

In response to the third objective (iii), the system modeled in the software satisfies the hydrological evaluation criteria in terms of the established infiltration and storage capacity. According to the above, the feasibility of a design suitable for the hydrological conditions in Temuco, Chile, is confirmed.

To drain, store, and reuse this water in a groundwater reservoir system, a procedure was designed based on zero infiltration into the subgrade layer. To achieve the above, three 100 mm diameter drainage pipes were implemented, with a distance to the bottom of the base of 75 mm and a smooth roughness coefficient, meeting the output capacity of the accumulated water within the system without causing surface runoff.

With a 130 mm pavement and transition layer, a 100 mm base, and a 180 mm subbase, the paving model is capable of withstanding a 100-year design storm return period, according to the conditions above, as shown in Table 3.

According to this return period, the accumulated volume was 673 m³ for the surface inflow. In the case of outlet drainage, the water storage collected in the pavement is 237.8 m³, so the pipes would drain a total of 435.2 m³ during a storm, as shown in Table 2.

Consequently, the total storage capacity of the permeable pavement was never exceeded, confirming the results using the volume management water balance presented in Equation (1).

3.6. New Sustainable Approaches to the Urban Management of Stormwater

It is demonstrated by the results obtained from the modeling studied that the application of permeable paving is a sustainable stormwater management infrastructure solution to face climate change, as it supports adaptation and mitigation actions, both allowing the reduction in the negative impact of natural disasters and providing water to urban ecosystems that can capture CO₂ [41,42,43].

Concerning the fourth objective (iv), it is suggested to provide new sustainable approaches that relate to the management and storage of water from these techniques, seeking to encourage actions against climatic and urban problems.

Within this framework, the scarcity of green areas in cities causes an increase in the probability of generating heat islands caused by the massive use of conventional paving, directly affecting urban climate change due to the waterproofing of soils [44,45]. Faced with the above, a permeable interlocking concrete paving system with the capacity to collect and store rainwater could be used to irrigate green areas, thus allowing the formation of ecosystems that contribute to the production of photosynthesis, thereby resulting in mitigation actions against climate change and, consequently, contributing to a reduction in the generation of greenhouse gases [46,47]. It is also possible to mention that it is an engineering solution that prevents the formation of waterlogging and drainage problems [4,48,49]. The information above is denoted in the balance for a water-sensitive urban design presented in Figure 8.

4. Discussion

According to the response to the first specific objective—Identify the structural behavior of the design layers that make up a permeable interlocking concrete paving system—the structural parameters considered, such as thickness, porosity, void ratio, permeability, and resistance, in the case of the subgrade, as indicated in Table 1, represent influential factors to understand the behavior of the permeable interlocking concrete paving layers, as illustrated in Figure 5.

The base layer comprises the ASTM No. 57 aggregate [35], presenting a permeability value of 0.011 m/s. However, the subbase layer made up of the ASTM No. 4 aggregate [35] has a permeability of 0.145 m/s. It is analyzed that the infiltration speed of rainwater is more significant in the subbase, thus highlighting the close relationship between the granulometric distribution of the aggregates and the porosity, which is directly linked to the void ratio.

Furthermore, in the subgrade layer, the permeability value is 0 m/s since the design system employed prevents infiltration (Figure 1), and there is the presence of a geomembrane and geotextile that covers the boundary and bottom of the layer to retain rainwater for future resource reuse. Another factor that affects the behavior of PICP modeling and is considered an essential aspect in the hydrological design of permeable pavements is the determination of the depth of the subbase.

This layer is defined by the storage capacity necessary to guarantee that the maximum depth of stored water does not exceed the paving layer to avoid surface flooding.

According to the analysis and deduction of results, the greater the thickness of the subbase, the better the response will be to the storm return periods simulated in the system. The subbase has a greater incidence of storm return periods than the other structural layers. In turn, there will be a greater capacity for water infiltration without it becoming saturated, ratifying the statements established by the ICPI [35], thus satisfying the response capacity against return periods in storms with a probability of occurrence of up to 100 years.

In summary, if the location where the permeable interlocking concrete paving project will be developed has higher rainfall records and return periods, greater sizing of the planned structural layers will be required to obtain higher infiltration and convenient storage. On the contrary, if the system is designed for storm parameters lower than those recorded, it will eventually become saturated and not fulfill its initial development function.

In response to the second specific objective proposed—Demonstrate the performance of a permeable interlocking concrete paving system through physical-mathematical modeling, addressing the constructive development that its implementation entails—for the return periods studied, the system was able to avoid saturation, complying with the results of water balances versus precipitation intensities, according to the analysis provided by the software, as reflected in Table 2. The above is corroborated according to Figure 6, projecting on the graph that this design is practical to withstand a return period of 100 years.

Since the system analyzed does not become saturated, it does not generate urban flooding; therefore, paving with permeable interlocking concrete is an effective solution that is aligned with resilience measures for adaptation to climate change since it reduces the vulnerability produced by the problem of runoff generated by conventional paving [50,51].

In response to the third specific objective—Evaluate the use of permeable interlocking concrete in the city of Temuco, La Araucanía Region, considering historical precipitation records under a climate change scenario—the system modeled in the program satisfies the criteria of hydrological evaluation in terms of the established infiltration and storage capacity, according to the information presented in Table 4. According to the above, the viability of an adequate design for the hydrological conditions established in Temuco, Chile, is confirmed.

By summarizing the information obtained according to Table 2, in comparison to Table 3, it is possible to deduce a significant influence regarding the type of drainage pipe used. Pipes with a smooth drainage coefficient have greater efficiency to meet the infiltration and storage capacity objectives for the system studied. However, pipes with a corrugated drainage coefficient do not completely satisfy the proposed needs according to the proposed design, resulting in a collapse due to oversaturation in the paving system for a return period of 100 years [52].

Based on the above, drainage pipes with rough surfaces have much higher friction factors than those with smooth surfaces, so roughness leads to a much higher pressure drop for the conduction and transport of water.

In addition, it is essential to emphasize the importance and relevance of another factor, such as the initial depth of water above the subgrade. The eventuality of the presence of a significant water level would lead to an increase in the initial precipitation storage capacity in the system, and therefore, there will be over-saturation based on the analysis of the return periods of subsequent storms. For modeling purposes within a feasibility or engineering analysis at a conceptual level, an initial presence of no water above the subgrade is assumed [53,54].

Implementing a sustainable infrastructure solution considering permeable interlocking concrete pavement positively impacts urban inhabitants since it reduces urban temperatures, mitigating the adverse effects of urban heat islands. In addition, the collection of rainwater allows the irrigation of green areas that benefit the inhabitants’ quality of life, both in their health and the urban landscape. The integration of ecosystems in a city allows the operation of recreational areas such as parks and squares, which promotes the use of urban territories by inhabitants who share and interact with the urban space, encouraging various activities such as walking, sports, social activities, and concerts, among others. All of this allows the humanization of the urban territory, generating benefits in people’s emotional states and health.

The results obtained signify the adequate drainage performance of the permeable interlocking concrete pavement with a drainage pipe with a smooth roughness coefficient considering 140 mm of rainfall from a storm with a duration of 24 h with a return period of 100 years, which confirms its feasibility. This directly affects the adaptation to climate change in the city of Temuco since it reduces flooding during extreme weather events and makes the infrastructure more resilient. In addition, this infrastructure solution makes it possible to mitigate the effects of climate change since by collecting rainwater through the permeable concrete pavement system, it is possible to store it in reservoirs and, subsequently, irrigate green areas of the city, thus promoting the natural process of photosynthesis that allows generating O₂ and, at the same time, capturing greenhouse gases, such as CO₂.

Asif lqbal et al. [22] considered a design for residential roads based on PICP systems of the complete infiltration type for runoff control using Design Pave V2.0 software. The study evaluated 107 towns and cities, and its objective sought to estimate a minimum thickness of the base layer for permeable paving in Australia regarding rainfall and the type of soil existing in the areas studied. Their results showed a minimum base layer of 100 mm and a maximum of over 250 mm for these areas. To reach these results, these authors considered the entire territory of Australia, unlike our research, which focused on a specific place, which was the city of Temuco. We can also mention that these authors used different software for modeling. It is also important to highlight that Australia’s climatic conditions differ from those present in Chile. Finally, concerning this research carried out in Australia, we can mention that its objective considered a complete infiltration type so that all the infiltrated water would flow into the subgrade, unlike our research that considers zero infiltration so that the drainage pipes transport the infiltrated water.

Igor Catao et al. [29], in their research, analyzed the potential saving of drinking water in university buildings (eight in different cities in Brazil) by taking advantage of rainwater collected by permeable pavements; they used the computer program Netuno to obtain the potential saving of drinking water in each building, and they used the AASHTO (American Association of State Highway and Transportation Officials) and ABCP (Brazilian Portland Cement Association) methods for the structural design of permeable pavements. Finally, they used Permeable Design Pro Software to calculate granular layer thicknesses, all for a system with zero infiltration.

The above Brazilian study, like the previous one carried out in Australia, conducts an investigation with a significantly higher number of cities, unlike ours carried out in Chile. This research carried out in Brazil has a graph of storm return periods of less than 10 years for a pipe with a smooth roughness coefficient for one of the specific places studied, which is Florianópolis. This is because the design made for the granular layers for the amount of precipitation in the area is too low, and this system cannot support such amounts of precipitation. Although rainfall differs between Florianópolis and Temuco, our permeable interlocking concrete pavement design modeled with Permeable Design Pro Software can perform adequately for a 24 h storm duration with a 100-year return period. This is because it has greater storage in the granular layers, preventing it from becoming saturated and failing the drainage system.

As part of the comparative analysis that is part of the discussion of this article, we can mention another main difference considering the research cited in this chapter [22,29], which is the approach given to the study. Its objective is to use permeable paving systems in buildings to reduce water use and reduce the demand for urban drainage systems. At the same time, our research focuses on making urban infrastructure resilient and mitigating the adverse effects of climate change through the conservation of urban ecosystems.

Figure 9 shows new technologies in the sustainability era applied to pavements in Temuco City, Chile; these images were generated using the artificial intelligence tool called DALL-E-2 [55].

Finally, the limitations of this research carried out in Temuco, Chile, include the following: (i) the type of parking lot under study, which, in this study, corresponds to a sports venue, as there may be differences if a shopping center, hospital, or residential parking lot is considered; (ii) the type of vehicles in the parking lot, which may vary, with light vehicles being representative for this case study, but in other cases, there may be heavy vehicles; (iii) the type of climate, as the area under study considers only precipitation and does not consider snow, permafrost, or freezing conditions; and (iv) the modeling of system performance considering the entry of sediments into the pavement structure.

5. Conclusions

Permeable pavements have great potential to improve the water quality from surface runoff, thus reducing urban flooding and attenuating the concentration of pollutants. Its philosophy is based on considering rainwater as a resource and not as a waste or problem.

According to the approach of the problem designated with central relevance in the face of multiple episodes caused by climate change, in correspondence to the rainfall caused in the study area, a construction design was determined in accordance with the modeling processes derived from Permeable Design Pro Software, carrying out feasibility analysis given the results obtained.

The research concludes that the permeable pavement system with a drainage pipe with a smooth roughness coefficient performs satisfactorily for an extreme hydrometeorological event corresponding to 140 mm considering 24 h rainfall with a return period of 100 years equivalent to an inflow of 673 m³/day.

After analyzing the research results developed in the city of Temuco, it is demonstrated that the new paving system, considered a multifunctional infrastructure, can satisfy structural, environmental, hydraulic/hydrological, and social criteria.

Considering the current urban vulnerability of Chile in the face of climate change, civil engineering solutions must be aligned with sustainability to contribute to the implementation of public policies for the execution of the fulfillment of Sustainable Development Goals (SDGs), carrying out adaptation measures to increase resilience to the adverse effects of climate change and offsetting heat island effects from existing large impervious surfaces.

The results obtained in this research contribute to the findings of researchers in the same field, researchers from other fields, and the community, contributing to achieving the Sustainable Development Goals (SDGs), specifically SDG 11 sustainable cities and SDG 13 action for the climate. The permeable interlocking concrete pavement infrastructure solution allows for resilient infrastructure that promotes adaptation to climate change and recovers rainwater, which can be used to irrigate green areas within the city and, thus, promote the photosynthesis of ecosystems, a process that allows for generating O₂ and capturing CO₂, thereby mitigating the adverse effects of climate change on society.

The corresponding results promote the use of permeable interlocking concrete paving (PICP) as a management measure at the country level in the construction area for the execution of future projects that involve elaborating and developing road works. The relevance of implementing infrastructure designs based on nature and engineering is emphasized, thus promoting the use of these solutions in the central and southern areas of Chile, in urban spaces such as parking lots, passages, or low-traffic volume streets, to address the climatic and urban problems recently registered in Chile.

The limitations of this research are mainly regarding the use of vehicular parking, the types of vehicles to be considered, the kind of climate in the study area, and the consideration of sediment entry into the pavement structure during its useful life, with a recommendation for future similar research being to carry out a case-by-case study considering the site-specific conditions of each place in the world.

The increased risks of floods and other natural and mixed technical hazards call for place-based responses, cooperation, coordinated policies, mitigation, and adaptation actions depending on the territorial context and require tailor-made responses at all levels. To cope with the challenges related to water management, especially in functional urban areas (FUAs), it is necessary to consider its numerous aspects, interests, and entities.

In this regard, it is the responsibility of engineers to establish more sustainable development in the pavement industry, including the selection of more sustainable pavement solutions and strategies for project design, manufacturing, construction, and maintenance.