Introduction
Cities are constantly growing, increasing urbanised areas which, consequently, increase impervious surfaces. This development disrupts the natural infiltration of rainwater into the ground, increasing the volume and speed of runoff, which influences the maximum flow to be discharged. Drainage systems show increasing difficulties in handling the excess water, leading to a higher occurrence of flooding (Construction Industry Research and Information Association [CIRIA], 2007).
One of the ways to mitigate this problem is the use of pervious concrete, which features interconnected voids that allow water to easily flow through its structure (American Concrete Institute [ACI], 2010). Despite its potential benefits, the adoption of pervious concrete remains limited. This is due to the lack of comprehensive technical information to determine the strength requirements associated with the different pavement applications. Additionally, there is a lack of clearly defined construction procedures for pavements with this type of concrete.
The ACI 522 (2010) document outlines several applications for pervious concrete. However, its use in pavements has been restricted due to its lower stress resistance. While pervious concrete is established as a promising solution for low-traffic roads, sidewalks, and driveways, there remains a gap in research. Further development and the establishment of design standards are necessary for its effective implementation as a pavement material (Chandrappa & Biligiri, 2016).
Table 1 summarises research associated with test sections constructed with pervious concrete, where the studies are mostly focused on constructability and, to a lesser extent, on structural design.
Table 1
Investigations carried out on pervious concrete test sections.
| REFERENCE | TEST SECTION | RESEARCH | ||
|---|---|---|---|---|
| STRUCTURAL DESIGN | MIX | CONSTRUCTABILITY | ||
| Shaefer et al. (2010) | Causeway | – | – | ü |
| Shu et al. (2011) | Parking | – | ü | – |
| Batezini (2013) | Parking | ü | ü | ü |
| Gupta (2014) | Parking | – | – | ü |
| Batezini (2019) | Sidewalk | ü | ü | ü |
| Balbo (2020) | Bike track | ü | ü | ü |
The Table shows the varied results obtained depending on the methods used. In the case of the compaction method, the main challenge in this type of concrete is to obtain adequate permeability without significantly affecting its compressive and flexural strength. For this reason, adequate mix characteristics and technical specifications are needed to control these factors that produce uncertainty in the results. In Brazil, mixture resistance and constructability aspects have been established for the case of bicycle lanes (Balbo, 2020), but this type of research has not been done for parking lots.
It has been established through international experience that compaction of the material is necessary. For this process, a steel roller is used to reach the required pressures, which allow obtaining the necessary permeability and the objective resistances. Table 2 presents compaction pressures established by different sources.
Table 2
Compaction pressures used in investigations.
| REFERENCE | COMPACTION PRESSURE |
|---|---|
| SERVIU (2005) | 0,069 MPa |
| Batezini (2013) | 0,07 MPa |
| Castro et al. (2009) | 0,08 MPa |
Studies of permeable concretes have been carried out by Castro et al. (2009), who compacted samples in a laboratory with a heavy roller all the way up to 0.08 MPa. This enabled them to establish the proportions that maximise the structural and hydraulic properties of the material.
Kevern et al. (2009) studied gyratory compaction in order to characterise workability in pervious concrete mix. One of the commonly used methods is the rising strip method, where the concrete is placed approximately up to an additional height called “riser.” Subsequently, a heavy roller is used to compact the mix to the final height, and the compaction pressure achieved will depend on the contact area of the roller with the concrete mix. The greater the number of rollers that passes, the lower the area decreases, thus increasing the compaction pressure achieved.
Table 3 shows that the contact area of the roller with the mixture varies with the number of passes, and these depend on the D value, which is the diameter of the roller, and the L value, which is the length.
Table 3
Ratio of the number of rollers passes to the area determined by Kevern et al. (2009).
| NUMBER OF ROLLER PASSES | ROLLER CONTACT AREA WITH THE SAMPLE |
|---|---|
| 1 | |
| 2 | |
| 3 |
The compaction in this type of concrete must be particular and different from conventional concrete, so the heavy roller affects and produces better strength and porosity indexes, permeability, and determined unit weight, in compliance with the standards associated with permeable concretes (Kevern et al., 2009).
Currently in Chile, the Housing and Urbanism Service (SERVIU, 2005) provides general technical specifications for permeable concrete pavements, including the average flexural strength to be considered 28 days after construction. However, the specifications provide only general requirements without differentiating between types of roads, such as expressways, collector roads, trunk roads, local streets, or passageways.
Table 4 shows that there is variability in the required flexural strength between a permeable concrete for bicycle lanes and parking lots compared to the strength of general applications specified by SERVIU (2005). Actually, the proposals of Balbo (2020) and Batezini (2013) correspond only to 35% and 45% respectively, of the general requirement of SERVIU (2025). As lower demand of traffic loads can be associated with lower concrete strength, the strength requirement should be differentiated by the pavement application.
Table 4
Minimum flexural strength according to the application.
| REFERENCE | APPLICATION | FLEXURAL STRENGTH |
|---|---|---|
| SERVIU (2005) | General | 2,75 MPa |
| Balbo (2020) | Bike truck | 0,975 MPa |
| Batezini (2013) | Parking of light vehicles | 1,25 MPa |
The results obtained in the research of Batezini (2013) and Balbo (2020) determine minimum flexural strengths in specific applications, which were obtained through structural analysis.
Materials and Methods
Parking lot mix strength
The loads to which the pavement would be subjected were established for the use of pervious concrete in car parks. This made it possible to analyse the flexural response generated in the slab, thereby determining the required strength of the mix order to ensure a design that meets the defined objectives.
The modelling was carried out in EverFe 2.26, a finite element analysis software that enables the determination of stresses and deformations in the pavement, allowing the assessment of different design strategies.
In this study, two geometric slab configurations were defined. The first is the full slab (5.0 m × 2.5 m), which corresponds to the minimum regulatory size for a parking space according to the General Ordinance on Urban Planning and Construction (MINVU, 2022). The second configuration is `the short slab (2.5 m × 1.25 m), obtained by subdividing the full slab into four equivalent sections, as specified in Table 5.
This subdivision methodology has been employed in previous studies because reducing the slab length also mitigates the warping phenomenon. Warping refers to the curvature that the slab develops resulting from construction gradients and cyclic effects, both associated with temperature and moisture variations across the slab thickness (Covarrubias, 2011). By dividing the traffic surface into smaller slabs, vehicular loads are distributed across a larger number of elements, thereby reducing tensile stresses in the concrete as well as stresses induced by warping. Consequently, this reduction in stresses translates into greater pavement durability and, from a design perspective, allows for a decrease in slab thickness while maintaining the same performance conditions as in conventional design.
For the structural modelling, four short slabs were considered within the total parking area, which allowed for a comparison of their performance with that of the full slab under identical loading conditions. The analysis in EverFe software considered three representative axle types (22 kN, 40 kN, and 80 kN), in order to cover both light and heavy vehicles. The loads of two of the axles correspond to those permitted by the Highway Manual [MC], Vol. 3. The third axle represents a light vehicle with a single-wheel axle carrying a 22 kN load, as reported by Batezini (2013). Table 6 visualises these different axles types and corresponding loads.
Table 6
Axle dimensions depending on load.
| DIMENSION | CHARGES | ||
|---|---|---|---|
| 22 kN | 40 kN | 80 kN | |
| Large tyre contact area. L (mm) | 670 | 150 | 200 |
| Wide tyre contact area. W (mm) | 284 | 100 | 150 |
| Shaft length. A (mm) | 1630 | 1700 | 1500 |
| Distance between wheels. B (mm) | – | – | 300 |
As established by San Martín (2018), the position of the load influences the modelling outcomes. Depending on where the axis is located on the slab, it generates different solicitations. In the same study, loading conditions were established by simulating the advance of a vehicle over the pavement in two conditions: a central trajectory and a near-end axis trajectory along the longitudinal edges. As mentioned above, the analysis revealed that the condition generating the greatest stress for the total area corresponds to the slab edge trajectory. In the current investigation, San Martín’s (2018) assertion was verified as shown in Figures 1 and 2.
Figure 1
Full slab load positions.
Figure 2
Short slab load positions.
In the case of a short slab, the forward trajectory of the vehicle was also considered to determine the most unfavourable position on the pavement slab, as shown in Figure 2.
The parking slab to be designed with permeable concrete has initial properties that have been determined in previous research at the Concrete Laboratory in the Universidad of Concepción by Oviedo et al. (2022), where permeable concrete mixtures were worked on. They established the mixtures that obtained the best resistance, which were the blends used in this research.
For the selected dosage in this research, the relevant properties of the concrete under study are shown in Table 7. These data were used for modelling the EverFe software.
Table 7
Properties Permeable concrete.
| PROPERTIES | VALUE |
|---|---|
| Compressive strength (MPa) | 16.5 |
| Tensile bending strength (MPa) | 2.85 |
| Modulus of elasticity (MPa) | 16133 |
| Poisson’s ratio | 0.22 |
| Coefficient of thermal expansion (1/°C) | 1.1 × 10–5 |
| Density (Kg/m3) | 2177 |
According to Goede (2009), the modulus of elasticity is lower for permeable concrete. This is obtained with the compressive strength and the unit weight of the concrete, through the following equation:
Batezini (2019) found that the use of the equation to obtain the modulus of elasticity delivers values approximately 40 % lower than those obtained in the laboratory by other methodologies, this being a more conservative option. For the modelling, the base and subgrade were not considered, which was replaced in the modulus of subgrade reaction (k) of an average quality, i.e., 0.05 MPa/mm.
Materials
For the constructability process in permeable concrete, two types of mixtures, previously developed at the laboratory by Oviedo et al. (2022), were analysed. The mixtures were tested for flexural strength at 7 and 28 days, which made it possible to determine which one met the structural design requirements best.
Cement, coarse aggregate, fine aggregate, and water were used to mix permeable concrete in the laboratory, which will be explained below:
The cement used for the total of the permeable concrete confections corresponded to Bio Cement. According to NCh 148 (INN, 1968), this cement complies with the standards established for pozzolanic cement, which is obtained from the joint grinding of clinker, pozzolan, and gypsum.
The coarse aggregate used corresponds to 3/8″ gravel, which was provided by a fixed supplier, to avoid variation in the characteristics of this type of aggregate.
The sand used was Bío Sand, obtained from a fixed supplier for all the concrete mixes.
Drinking water was used in the manufacture of permeable concrete, which complies with the physical, chemical, radioactive, and bacteriological requirements in force and present in NCh 409 (INN, 2005).
Mixing Details
The dosages used correspond to those established by the research developed by Oviedo et al. (2022) at the concrete laboratory of the Universidad de Concepción. The selected PC-39-15 and PC-35-20 mixes differ mainly in the water-cement ratio and the quantities of fine aggregate to be used. For transparency the exact ratios of the two blends are also depicted in Table 8.
Table 8
Dosages used.
| PC-39-15 | PC-35-20 | |
|---|---|---|
| Coarse aggregate [Kg/m3] | 1345,16 | 1325,08 |
| Fine Aggregate [Kg/m3] | 201,74 | 265,00 |
| Cement [Kg/m3] | 345,31 | 341,77 |
| Water [Kg/m3] | 134,67 | 119,62 |
| A/C | 0,39 | 0,35 |
| % AF/AG | 15,00 | 20,00 |
The nomenclature used for each mix is conserved according to previous research, which corresponds to PC-XX-YY. PC stands for Pervious Concrete, XX corresponds to the A/C ratio used for the preparation, and YY corresponds to the percentage of fine aggregate over coarse aggregate (AF/AG).
Compaction
Compaction was carried out in accordance with NCh 1017 (INN, 2009). The concrete was placed in prismatic moulds in two layers of similar thickness. A rammer rod, a smooth cylindrical steel bar that is 16 mm in diameter and 600 mm long and ends in a hemisphere of 16 mm in diameter, was used for compaction. During compaction, 66 blows were evenly distributed throughout the entire section of the mould. Special care was taken not to hit the bottom of the mould so as not to affect compaction. When tamping the second layer, the tamper rod was inserted approximately 2 cm into the underlying layer. For the top layer, a slight excess of mix was maintained to allow for subsequent screeding without the need to add uncompacted material.
The compaction of the concrete in the tile moulds was carried out with a roller previously designed to simulate soil conditions. To determine the compaction pressures that can be obtained with the roller, the area of contact with the mix was initially determined. Considering that the mould has a width of 0.3 m. According to Kevern et al. (2009), with the diameter of the roller, the perimeter that touches the mix is obtained. With this, it is established that in the second pass, a pressure greater than 0.06 MPa was reached (see Table 9), which aligns with the recommendations of available literature (Serviu, 2005; Batezini, 2013).
Table 9
Pressures according to Kevern’s areas (2009).
| PASS | PERIMETER CONTACT (m) | AREA (m2) | Prodillo (N) | PRESSURE (MPa) |
|---|---|---|---|---|
| 1° | 0,05890 | 0,0176715 | 588,6 | 0,0333 |
| 2° | 0,02945 | 0,0088357 | 588,6 | 0,0666 |
| 3° | 0,01473 | 0,0044179 | 588,6 | 0,1332 |
Through laboratory experiments, it became evident that a correction factor was necessary to accurately assess the actual compaction pressure achieved. It was found that with three passes of the roller, the achieved contact area was larger than anticipated, which resulted in lower compaction pressures. This inconsistency was attributed to the mix’s water-cement ratios of 35% and 39%. In order to reach the theoretical compaction levels, a firmer and more homogeneous mix, ideally achieving the edge of the mould with a water-cement ratio of 27%, was required.
Table 10 shows the laboratory results, which verified that the roller did not reach the desired theoretical contact area with the second pass because of the mixture’s consistency. Instead, it was established that the pressure associated with the area of the second pass was theoretically reached at the third pass in the laboratory.
Table 10
Compaction with the area measured in the laboratory.
| PASS | PERIMETER CONTACT (m) | AREA (m2) | Prodillo (N) | PRESSURE (MPa) |
|---|---|---|---|---|
| 1º | 0,05000 | 0,0150000 | 588,6 | 0,0392 |
| 2º | 0,04500 | 0,0135000 | 588,6 | 0,0436 |
| 3º | 0,03000 | 0,0090000 | 588,6 | 0,0654 |
The roller used is made of steel, as shown in Figure 4b, which was previously designed to meet the compaction pressure over 0.06 MPa required in the tile moulds, according to the literature studied (Serviu, 2005; Batezini, 2013).
Preparation, curing, and testing
The moulds made correspond to slabs, which have a dimension of 300 mm width × 150 mm height × 560 mm length. The criterion for sizing the slabs is what is recommended for the size of the specimens to be tested in flexotraction, as established in NCh 1017 (INN, 2009). These were used without division for permeability tests and divided into two for the use of beams in the flexural tensile test.
To determine the amount of material required for each slab, dosages were established beforehand. Each slab needed a volume of 25.2 litres, along with an additional 10% to account for potential material losses. Before mixing the concrete, moisture corrections were applied to the gravel and sand to minimise any variations in the mixture caused by environmental factors that could occur during preparation. To ensure accuracy, these corrections were made on each day of preparation.
After establishing the quantities and separating the material to be used, the mixing was carried out in a bitumen mixer, depicted in Figure 3a. This tool was suited for working with smaller volumes, thereby providing greater control of the mix through docility tests and constant visual inspection. The composites were added to the bituminous mixer in the order of coarse aggregates, fine aggregates and cement first. The materials were mixed before the water was added progressively.
Figure 3
a) The used concrete mixer b) Tile mould with risers.
Figure 4
a) Mould with riser b) Manual roller compaction method.
Once a homogeneous mixture was obtained, a docility test was performed, and the mixing continued. It is important to note that the mixes made during this research did not contain additives that optimise the mixture.
Upon completion of the mixing, the mixture was taken to the tile moulds, which was a quick process so as not to affect the workability of the mixture. The moulds were previously greased to facilitate later demoulding. In addition, a 19 mm high wooden riser was placed on their structure, as shown in Figure 3b. This allowed the generation of an additional initial height of the mixture for its subsequent compaction (Kevern et al. 2009).
The mould filling process was carried out in a single layer, spreading the mixture homogeneously and then flush with the edge of the riser. This made it possible to avoid any jolts in the compaction process. In addition, care was taken to avoid hitting the mould and producing any additional compaction.
For compaction, a manual roller was employed. The weight of the roller and the contact area of the roller with the mix allowed establishing a compaction pressure that varies depending on the number of passes (Kevern et al., 2009).
Before compaction, the riser was removed, and the heavy roller was quickly positioned at the edge of the mould. The roller was pushed at a constant speed and smoothly rotated, which accomplished equal compaction. It is important to clear any mixture from the edges of the mould, since this prevents the roller from resting homogeneously on the mixture, which would influence the area that the roller touches. Building on the laboratory testing, this process was carried out in three phases to achieve the required compaction. After removing the roller, any unevenness was levelled out with a plate.
Finally, the moulds were covered with the compacted mixture for subsequent demoulding 48 hours after manufacture, just like the prismatic mould, in accordance with the provisions of NCh 1017 (INN, 2009). The tiles were kept until the corresponding tests, in a humid chamber that presents conditions for curing, with a humidity of 90% and a temperature between 17ºC and 23ºC.
Permeability tests were carried out with the slab shown in Figure 5, and core samples were extracted to measure density and porosity.
Figure 5
Permeable concrete slabs.
For the flexural tensile test, slabs with a separation were made with the help of a thin zinc sheet, which allowed us to obtain two joists (Figure 6). Great care was taken to ensure that the specimens to be tested were of appropriate dimensions according to NCh 1017 (INN, 2009) for flexural tests.
Figure 6
a) Division of slabs with foil b) Joists obtained from slabs.
Results and Discussion
Parking resistors
The modelling of a parking lot pavement was carried out considering the temperature gradient conditions of the city of Concepción, Chile. The climatic conditions in this city are classified as temperate and moderate. Figures 7 and 8 show the results of the modelling performed with EverFe software, which were associated with the different slab thicknesses, depending on the load axis considered.
Figure 7
Variation of maximum stresses depending on slab thickness.
Figure 8
Variation of maximum stress depending on the thickness variation in short slabs.
First, the modelling was performed for the total area of the parking lot (Figure 7), which obtained the maximum stress for each design requirement associated with a representative load. For the 80 kN axle, corresponding to a single axle dual wheel (ESRD), a pavement strength of 3.4 MPa is required. The result is higher compared to a 22 kN axle, representing a light vehicle, where 2.4 MPa is requested, which is 29% less.
Figure 8 corresponds to the modelling of the short slab parking lot. For the ESRD axle, 3.3 MPa is needed as a requirement, while for the light vehicle axles, 1.5 MPa is enough to comply with the structural requirement, i.e., 55% less than for the case of the larger axle.
The results show that the required resistances between the modelling of the full area and short slab vary, with the stresses being 38% lower than when having a short slab for the case of a light vehicle.
In the case of the 22 kN axle, the necessary resistances remain lower across all modelled slab thicknesses in both scenarios. This finding suggests that light vehicles do not negatively impact the pavement and do not contribute to deterioration. This observation aligns with the guidelines in the Highway Manual Volume 3, which states that an 80 kN axle is the minimum load that significantly affects a pavement.
Flexural strength of permeable concrete slab mixtures
In the first stage, a slab was made for each dosage, with which the average flexural strength values at 7 days were determined, as shown in Figure 9.
Figure 9
Flexural strength 7 days.
A relationship is established in the tests carried out, where the compaction method differs between the tamper rod and the roller. The compaction performed according to NCh 1017 shows higher resistance at 7 days than the specimen compacted with a roller, the latter being 13% lower for the PC-39-15-R mix and 18% lower for the PC-35-20-R mix.
Subsequently, in a second stage, two slabs were made for each mix, and two joists were obtained from each one, testing one at 7 days and three at 28 days.
As shown in Figure 10, at 7 days, there were higher strengths in PC-39-15-R corresponding to 2.36 MPa. The PC-35-20-R mix, on the other hand, reached a lower strength of 1.46 MPa during the same timeframe. At 28 days, the mix with the higher initial strength reached an average of 2.77 MPa, marking a 34.5% increase over the strength of the PC-35-20 mix.
Figure 10
Flexural and tensile strength of 7 and 28-day-old tiles.
For both mixtures, the tendency for increasing strength between the ages of 7 and 28 days is observed (Table 11). The PC-39-15-R mix presents an increase corresponding to approximately 17% and the PC-35-20-R mix obtained an increase corresponding to approximately 41%.
Table 11
Results of flexural strength depending on compaction method.
| COMPACTACTION | SAMPLES | 7 DAYS | 28 DAYS | INCREASE |
|---|---|---|---|---|
| Roller | PC-39-15-R | 2,36 MPa | 2,77 MPa | 17% |
| PC-35-20-R | 1,46 MPa | 2,06 MPa | 41% | |
| Tamping rod | PC-39-15-P | 2,57 MPa | 2,81 MPa | 9% |
| PC-35-20-P | 1,91 MPa | 2,38 MPa | 25% |
Dosage PC-39-15 corresponds to the highest resistance at 28 days obtained for both types of compactions. In the case of roller compaction, a 1.4% lower resistance is obtained in relation to the case compacted with a rammer rod.
Permeability in permeable concrete slabs and cores of pervious concrete mixtures
Table 12 shows the permeability results for the case of tiles with PC-39-15 mix.
The method for measuring permeability corresponding to American Society for Testing Material (ASTM) C1701 can be effectively used for measurement in pervious concrete pavements. Li et al. (2012) made a comparison between porous asphalt, porous concrete, and cobblestone pavements. The study found that pervious concrete achieved a maximum permeability of 0.42 cm/s. Chen et al. (2019) further established the permeability of this type of concrete by performing three measurements for the method. The PC pavement obtained an average permeability ranging from 0.66 cm/s to 0.89 cm/s with the ASTM method.
As depicted in Figure 11, the PC-39-15 dosage has a higher permeability than reported in the literature, ranging between 1.8 and 3.8 times greater than the values documented by Chen et al. (2019) and Li et al. (2012). For the case of the PC-35-20 dosage, a lower permeability compared to the literature is obtained in one case.
Figure 11
Permeability obtained with ASTM C1701.
The permeability of the cylindrical core extracted from the slabs with the PC-39-15 and PC-35-20 mixes was obtained, establishing a comparison with the permeability obtained in cylindrical specimens compacted with a tamper, as shown in Figure 12.
Figure 12
Permeability obtained with a cylindrical specimen and tile core.
For the mix corresponding to PC-39-15, an increase in permeability is obtained when compacting with a roller of approximately 100 %, obtaining 1.47 cm/s, compared to the mix PC-35-20, which decreases its permeability by 12 % to 0.58 cm/s. In both cases, the minimum permeability established by ACI 522R-10, which is 0.14 cm/s, is met.
Limitations
This study presents some limitations that should be considered when interpreting the results. First, the research was carried out under the specific conditions of the city of Concepción, Chile, whose geographical location and climatic characteristics directly influenced both the structural modelling and the experimental tests. Therefore, extrapolating the results to other regions with different environmental conditions should be done with the respective considerations.
Second, the structural analyses were conducted considering a single subgrade condition, which restricts the applicability of the results to other constructive realities. Including different types of subgrades in future research would allow for a broader evaluation of the structural response of pervious concrete pavements.
Finally, certain simplifications were applied in the modelling process and during the experimental stage as regards the number of slabs and their dimensions. Although these simplifications facilitated the comparative analysis between full and short slabs, they do not fully represent the complexity of construction at a real scale. These simplifications should be acknowledged as an initial approximation framework, rather than an exhaustive representation of all possible design and construction conditions.
Conclusions
This research sought to establish the necessary mix resistances to encourage and support the use of these types of solutions for parking lots. A minimum of 2.4 MPa for full slabs and 1.5 MPa for short slabs was determined, considering the use of light vehicles. To obtain these values, a structural design developed in EverFe software was carried out, which allowed establishing the target resistance in the mix for this specific application.
Through experimental verification and analysis of the behaviour of two concrete samples, it is established that the mixture meets the structural design requirements for light vehicles corresponding to PC-39-15, since flexural strengths of 2.77 MPa were obtained at 28 days, obtaining an increase of 35% with respect to the second dosage analysed.
In the experimental study, the construction of permeable concrete slabs was carried out, which allowed the evaluation of the constructability, establishing the critical aspects such as the concrete dosage and its compaction method. The compaction was carried out with a heavy roller that reached compaction pressures of 0.066 MPa. Notably, these values showed a 13-18% reduction in resistance when compared to the standard compaction with a rammer rod.
Roller compaction does not impair permeability, according to the results of the application of the ASTM-C1701 method, which showed 100% improvements in permeability, compared to the tamper rod method studied in previous research.
The minimum strength required for permeable concrete pavements in parking lots was established depending on their intended use. The structural design was determined based on three types of axles, which represent the loads of light and heavy vehicles. In the case of heavy vehicles, a minimum of 3.4 MPa was established for the full slab and 3.3 MPa for the short slab.
Finally, although there are no regulations on the construction methodology and use of permeable concrete, this research contributes to the experience of using this material in parking lot applications. However, its use can be expanded to other applications. Despite its lower strength compared to conventional concrete, permeable concrete presents a sustainable alternative. It contributes positively to addressing contemporary issues such as flooding and pollution resulting from runoff.
Acknowledgements
I thank Dr. Mauricio Pradena for his interest, willingness, and support in the development of the research. I am also grateful to the Concrete Laboratory of the Civil Engineering Faculty of the Universidad de Concepción for allowing me to use its facilities.
Competing Interests
The author has no competing interests to declare.