Porous Asphalt Research Articles

Numerical simulation of layout and landscape elements on the thermal environment of urban squares

Extreme urban heat poses significant challenges to the resilience and livability of cities. Urban squares are important open public spaces in cities, serving as main locations for residents' leisure and recreational activities and reflect the identity and cultural background of the cities. Improvement in thermal comfort in urban squares can improve the quality of the urban environment and help mitigate the urban heat island effect. This study developed 18 layout and landscape combination scenarios based on statistical analysis of data from 100 urban squares in regions with hot summers and cold winters. Further, the effectiveness of the proposed design solutions in improving the thermal environment was comprehensively analyzed. The results show that: 1) The block array layout with vegetation, water bodies, and permeable tiles is the most effective scenario, with a PET of 31.84 °C, approaching a comfortable level of heat stress; 2) Among the three layouts, the block array layout optimizes thermal comfort better than the main view entrance layout and main view center layout, and reduces physiological equivalent temperature by 10.51–10.77 °C compared with that of the other two layouts; 3) Scenarios incorporating water bodies provide better optimization effects than those with only trees, even when the total area covered by greenery remains unchanged; and 4) Permeable paving materials with high albedo more effectively improve the thermal comfort. Our results highlight a great potential of comprehensively using multiple landscape strategies to improve outdoor thermal comfort, and provides design basis for enhancing thermal comfort in similar sized urban squares in hot summer and cold winter areas.

Characterization of Air Voids and Permeability in Porous Asphalt Mixtures with Eggshell Ash as an Eco-Friendly Additive

Recently, there has been a lot of interest in the use of eco-friendly additives in asphalt mixtures in the field of pavement engineering. Such additives have been found to have the potential to enhance pavement performance while also mitigating the environmental impact of road construction. Eggshells are a restaurant waste product that is one of the additives that have been investigated in this study. The research aims to investigate the effect of eggshell ash (EA) on the air voids and permeability of porous asphalt mixtures. Two temperatures, 100°C (EA100) and 200°C (EA200), were used to prepare EA with varying percentages of 2%, 5%, 7%, 10% and 12% by weight of bitumen. The samples were then prepared and compacted by applying 50 blows on each side to measure air voids, and permeability testing was performed in the laboratories. The results indicated that the use of EA had impacted the permeability and air voids of the porous asphalt mixture. The amount of air voids in the mixes had a direct impact on the permeability coefficient, as the value of the permeability coefficient decreased with decreasing air voids. EA can serve as an additive to improve the permeability of asphalt mixtures, which may increase the pavement's durability and longevity. Furthermore, the use of EA has the potential to reduce the environmental impact of the egg industry while improving the sustainability of road construction

Paving the Way for Sustainability: A Study on Porous Asphalt Mixtures Reinforced with LDPE Plastic Waste and Freshwater Mussel (Pilsbryoconcha Exilis) Shell Filler

This study aimed to explore the impact of different fillers, namely conventional (stone ash) and alternative (mussel shell powder), along with varying percentages of Low-Density Polyethylene (LDPE) additives, on the performance of porous asphalt mixtures. Asphalt mixtures' Marshall Stability and Flow were examined with LDPE percentages of 0%, 2%, 4%, and 6%. Results highlighted that the choice of filler and LDPE content significantly influences the mixture's stability and flow. A shift from 100% stone ash to 50% mussel shell powder resulted in a slight decrease in stability for 0% and 2% LDPE. In contrast, the stability was notably higher for 4% and 6% LDPE, including the alternative filler. Mixtures with 100% stone ash exhibited increased flow values with rising LDPE concentrations, while mixtures with 100% mussel shell powder showed an opposite trend. Furthermore, mixtures containing mussel powder generally had higher flow values than those with stone ash at similar LDPE percentages. The study underscores the intricate relationship between filler types and LDPE additives in influencing the properties of asphalt mixtures. These findings pave the way for the potential use of alternative fillers in asphalt mixtures, emphasizing the importance of understanding material interactions for optimal pavement design.

Multifunctional Porous Pavement Prototype for Urban Pluvial Flood Protection: Preliminarily Findings on Contribution of Attitudes to Acceptance Willingness Toward Proposed Scientific and Engineering Solutions

Rapid urbanization and climate change correlate with an increase in frequency of flood events, globally. For many cities worldwide pluvial floods bring significant risk. Permeable/pervious paving (PePav), as an essential sustainable urban drainage technique, is one of the key environmental solutions for urban flooding. Waste and recycled materials in the construction industry for PePav production comply with the principles of circular economy and sustainable development. The influence of the human factor is well recognized in efforts to apply those solutions and make them self-sustainable. The preliminary results show that younger female students and students with lower family monthly income are prone to express more positive attitudes toward PePav generally. Students from different study groups (Departments of Psychology, Hydraulic and Environmental Engineering, and Construction Project Management) show significantly different attitudes toward PePav. Statistical models indicate that the PePav acceptance willingness can be predicted with moderate accuracy by knowing attitudes toward PePav and personal experience in construction. The contributions of the fact that someone's close person has been affected by a flood may vary depending on the type of PePav scientific and engineering solutions.

A macro-level life cycle environmental-economic impact and benefit assessment of sponge cities in China

Urban runoff source control facilities (URSCFs) are integral components of Sponge City (SC), playing a pivotal role in providing ecosystem services and managing water quality and quantity. To accurately assess the performance of URSCFs, it is crucial to quantify their environmental and economic impacts. However, previous studies have predominantly focused on location-specific case studies, lacking a macro-level perspective necessary for informing public policy development pertaining to SC initiatives. This study aims to bridge this gap by conducting a macro-level life cycle assessment across China's 16 initial pilot SCs, categorized into three zones based on their annual rainfall volume control rate α (i.e., Zone II (80 % to 85 % for α), Zone III (75 % to 85 % for α), and Zone IV (70 % to 85 % for α)). By simulating five rainfall drainage scenarios, we delve into the environmental benefits of SC construction. The results indicate that Zone III incurs the highest environmental and economic costs during the construction phase, followed by Zones II and IV. In Zone III, bioretention contribute significantly to the environmental impact and economic cost, while constructed wetland and detention cells are the key contributors for Zone II. During the operation phase, Zone III demonstrates the largest environmental and economic benefits, with Zone IV and II trailing behind. The investment payback period for SCs in all zones is less than eight years, with Zone IV recovering costs the fastest (3.9 years) and Zone II the slowest (7.5 years). Facilities like detention cells, green roofs, and permeable pavements tend to have longer payback periods. Based on our findings, we recommend that Zone II exercise caution in constructing detention cells, permeable pavements, and wetlands, while Zone III should carefully consider green roofs and bioretention to optimize SC investments. Due to the fewer URSCFs constructed in Zone IV, it exhibits the lowest environmental impact compared to Zones II and III. Our research provides valuable insights to support policymaking with regards to future SC planning and development.

Can blue–green infrastructure counteract the effects of climate change on combined sewer overflows? Study of a swiss catchment

Abstract Combined sewer overflows (CSOs), the discharge of untreated sewage mixed with stormwater into surface waters, are expected to increase under climate change as a result of more extreme rainfall. Blue–green infrastructure (BGI), such as bioretention cells and porous pavements, can help to reduce the amount of stormwater entering combined sewer systems, thus reducing CSO discharge. However, our understanding of the potential for BGI to mitigate CSOs in a future climate is still lacking, as performance is typically evaluated for individual BGI elements with fixed implementation areas under historical climate conditions or limited future scenarios. In response, this study investigates the performance of 30 combinations of BGI elements and implementation rates to prevent increases in CSOs under a range of future climate scenarios in an urban catchment near Zurich, Switzerland. Median total annual rainfall, projected to increase by as much as 46%, could double the median annual CSO volume and increase median annual CSO frequency by up to 52%. Four BGI combinations that include bioretention cells show the most promise to prevent increases in CSO volume and frequency in a future climate; and given the diverse responses of BGI elements to distinct rainfall patterns, their combinations can enhance CSO discharge reduction across varying climate patterns. BGI is also likely to become more cost-effective under future climatic conditions as projected increases in total rainfall led to larger CSO volume reductions obtained through BGI. However, there is a trade-off between robustness to climate change and cost-effectiveness, since CSO volume reduction capacity scales with BGI implementation rate but cost-effectiveness declines. Our study illustrates the effectiveness of various BGI combinations to prevent increases in CSOs in a future climate, calling for a range of BGI elements and implementation areas to be considered for urban drainage adaptation.

Multi-Objective Optimization of Urban Drainage System by Integrating Rule-Based Control with Permeable Pavement

Multi-Objective Optimization of Urban Drainage System by Integrating Rule-Based Control with Permeable Pavement

The Addition of Pore Holes in Paving Blocks in an Effort to Increase Infiltration

The problem of waterlogging and surface runoff on impermeable pavement surfaces requires finding new ways to manage water flow, especially from rainwater. The type of permeable pavement that is often used is paving block. The use of paving blocks for pavement materials is expected to reduce puddles that occur after rain. One way is to modify the paving block to be greater in seeping water into the soil. This study aims to determine the extent to which the effect of adding pore holes in paving block can increase water infiltration in surrounding soil. This research was conducted through testing in the Laboratory. The type of research is quantitative with experimental method using a rain simulator tool with variations of paving block. From the research results obtained that the addition of pores in the paving block affects the infiltration that occurs. This is evidenced by the increae in the value of infiltration, the infiltration rate value of normal paving block is 182.92-10.43 mm/hour, 2% ratio is 183.75-10.75 mm/hour, 5% ratio is 190.00-11.30 mm/hour, 7% ratio is 231.33-11.46 mm/hour, 10% ratio is 236.88-17.61 mm/hour. From the test results between pore holes with infiltration rate has a significant relationship of 0.037 (<0,05).

Prediction of runoff characteristics in permeable pavements using experimental data and intelligent models.

Considering the growing use of permeable pavements, the prediction of runoff passing through this pavement model is of considerable importance. The prediction of rainfall-runoff relationships can be a challenge because of several factors including data uncertainty, non-linear relationships, and high temporal and spatial variability. To deal with these challenges, intelligent algorithms are often used to predict such complex phenomena. In this research, runoff control parameters were investigated in two types of permeable pavements (permeable interlocking concrete pavement (PICP) and high strength clogging resistant permeable pavement (CRP)) using support vector machine (SVM), support vector machine-bat (SVM-BA) and support vector machine-grasshopper (SVM-GOA). Variables used in the models included percentage of coverage by permeable pavement (A), rainfall intensity (I), slope (S), and pavement type coefficient (K) as input data, and runoff coefficient (C), time to runoff (Tr), and peak discharge (Qp) as output data. In this research, from the total of 108 data extracted from the experimental results, 86 data were used in the training period, and 22 data were used in the test period. The results of the test period show that the SVM-BA model has the best performance with values of MAE = 0.010 in predicting C, MAE = 1.330 min in predicting Tr, and MAE = 0.029 lit/min in predicting Qp. The SVM-GOA model is ranked second with values of MAE = 0.051 in predicting C, MAE = 3.285 min in predicting Tr, and MAE = 0.097 lit/min in predicting Qp. Also, the SVM model is ranked third with values of MAE = 0.063 in predicting C, MAE = 4.470 min in predicting Tr, and MAE = 0.121 lit/min in predicting Qp. In summary, the SVM-BA algorithm showed the best performance and the SVM algorithm showed the weakest performance in predicting runoff characteristics in permeable pavements.

Phase and group speeds of airborne surface waves over porous layers and periodically rough hard surfaces.

Sound fields above porous layers or rough acoustically hard boundaries may include airborne surface waves. The surface wave properties depend on the effective surface admittance. Analytical expressions for surface wave speeds are derived from models for the acoustical properties of rigid porous media. Surface wave effects on measurements of level difference spectra over porous asphalt are investigated and predictions of phase, group speeds, and vertical attenuation of the surface waves over externally reacting hard backed layers corresponding to a porous asphalt are compared. Predictions of surface wave characteristics above an identical vertical slit medium are compared with data obtained over arrays of parallel aluminum strips on an acoustically hard surface. Group speeds of surface waves over lattices, parallel regularly spaced strips, and snow obtained by numerical differentiation of the phase speed spectra corresponding to admittance spectra deduced from complex excess attenuation are found to compare well with those estimated from time domain data. An effective admittance, deduced from a boundary element method simulation of the excess attenuation spectrum over regularly spaced ribs so that the frequency of the peak corresponds with that in the measured spectrum, is used to estimate the group speed of the associated surface wave.

Multi-criteria analysis of low impact development practices: a case study in the Tan Hoa - Lo Gom basin, Ho Chi Minh city, Vietnam

Abstract Urban flooding poses a significant challenge for cities globally. In recent years, Low Impact Development (LID) has been recognized as an effective and sustainable solution for managing urban floods. This study employs the EPA-Storm Water Management Model (EPA-SWMM), social surveys, and multi-criteria analysis (MCA) to assess the effectiveness of LID practices from environmental, social, and economic sustainability perspectives. Results demonstrated that implementing LID techniques such as rain gardens, infiltration trenches, permeable pavements, and their combinations in the Tan Hoa - Lo Gom basin can reduce the average total runoff volume by 8.77% to 30.80% under the current land use-land cover and the design hyetograph with a 3-hour duration and a 5-year return period. Moreover, there is a reduction of approximately 7.42% to 30.59% in the average total runoff volume for the design hyetograph with a 3-hour duration and a 5-year return period, aiming to assess the climate change impact. Additionally, sociological and economic aspects are integrated to comprehensively assess each LID practice through MCA via the Analytical Hierarchy Process (AHP) method. Overall, the analysis results indicated that the scenarios involving the application of rain gardens, infiltration trenches, and their combinations are more effective than other scenarios. These findings will provide valuable insights for decision-making and planning of other LID projects in Ho Chi Minh City (HCMC) to mitigate urban flooding, particularly in light of the escalating challenges posed by urbanization and climate change.

Effect of Clogging and Cleaning on the Air Void Microstructure of Porous Asphalt Concrete

Effect of Clogging and Cleaning on the Air Void Microstructure of Porous Asphalt Concrete

Pengaruh Penggunaan Abu Bata Merah Sebagai Filler Pada Aspal Porus Terhadap Karakteristik Marshall

Roads are an important infrastructure for the community in mobilizing. Therefore, it needs special attention in terms of safety and comfort. In several parts of Indonesia, during the rainy season, especially in North Aceh District, Lhoksukon often experiences flooding and the water inundates the roads. This disrupts road users and mobilization. Porous asphalt is a flexible pavement which has excellent advantages for countries with tropical climates such as our country, Indonesia. The advantages of porous asphalt are planned to have large cavities so that they can absorb water freely. In this study the authors will examine the use of red brick ash as a filler obtained at a brick factory in Blang Panjoe Village, Peusangan District, Bireuen Regency. The varying levels of brick ash as filler in porous asphalt mixtures are 0%, 30% and 50%. Furthermore, the determination of KAO and the manufacture of porous asphalt mixing specimens were carried out with red rock ash as a filler substitute of 0%, 30% and 50%. The maximum percentage variation in brick ash content was obtained at 50% substitution with a stability value of 591 kg, a yield value of 3.27 mm, MQ 181.26 kg/mm and VIM 18.8%. The results of the research on the stability and flow values and the Marshall parameters meet the AAPA specifications.

Effect of High Polymer, Crumb Rubber, and Epoxy-Modified Asphalt Binders on Laboratory Performance of Open-Graded Friction Course Mixtures

Open-graded friction course (OGFC) is a thin asphalt mixture surface layer. It is gap-graded with a high percentage of coarse aggregates that are nearly uniform in size, resulting in a high percentage of interconnected air voids and asphalt binder, which provides improved skid resistance, visibility, and decreased pavement–tire noise. However, construction personnel at the Louisiana Department of Transportation and Development reported that conventional OGFC mixtures have durability issues and shorter service life, compared with thin asphalt mixture lifts. Hence, effects of different asphalt binder types on the performance of OGFC mixtures were evaluated. Five types of asphalt binder were utilized: conventional styrene-butadiene-styrene (SBS) asphalt binder PG 76-22M; high SBS content asphalt binder PG 88-28; diluted epoxy asphalt (EA) binder with two different dosages (25% and 50%); and a hybrid modified asphalt binder prepared with SBS and crumb rubber modifier PG 76-22G. The optimal aggregate structures were determined based on minimum required air voids and voids in coarse aggregate. Physical and mechanical tests were conducted to assess the performance of OGFC mixtures, including draindown, permeability, loaded wheel track, and Cantabro abrasion loss. Results indicate that OGFC mixtures incorporating diluted EA binder exhibited lower draindown values than mixtures containing PG 76-22M and PG 88-28. Moreover, mixtures with PG 88-28 and 50% EA binders demonstrated improved resistance to rutting. Mixtures with 50% EA and PG 88-28 binders demonstrated improved durability, compared with mixtures with PG 76-22M for unaged and aged conditioning, as measured by Cantabro abrasion loss values.

Dynamic response and sound radiation of cracked asphalt pavements under moving loads and variable thermal profiles

ABSTRACT This study investigates the acoustic performance and dynamic response of cracked, viscoelastic porous asphalt pavements under moving loads and variable thermal conditions. Realistic pavement cracks are modelled using an advanced line spring model with fracture compliance coefficients. The novelty lies in the synergistic integration of a heterogeneous triple-porosity media model, a non-uniform depth-dependent temperature profile, and an advanced fracture mechanics-based line spring model with arbitrary crack orientation. Variations in temperature that are uniform, linear, and nonlinear with respect to the thickness layer axis are taken into account. The governing equations are derived by Hamilton’s principle and solved analytically via Fourier-Laplace transforms. The acoustic pressure is first-time predicted through Rayleigh integral analysis. Durbin’s numerical inversion validates the model’s accuracy versus sophisticated finite element simulations. Parametric analysis offers new insights into the effects of crack length, pore size distribution, loading frequency, and thermal gradients on noise pollution and fatigue cracking. The integrated chemo-thermo-mechanical modelling enables optimal structural design and accelerated pavement testing to limit acoustic radiation and premature failure in porous asphalt pavements. It allows for the development of noise-reducing porous asphalt mixtures by modifying aggregate gradation, binder content, and air void distribution.

Improving the Durability of 12.5 mm Open-Graded Friction Course using 9.5 mm Nominal Maximum Aggregate Size Gradation and High Polymer-modified Binder

Improving the Durability of 12.5 mm Open-Graded Friction Course using 9.5 mm Nominal Maximum Aggregate Size Gradation and High Polymer-modified Binder

Optimizing porous asphalt mix design for permeability and air voids using response surface methodology and artificial neural networks

Easy infiltration of grouting material in Porous Asphalt Mixture (PAM) is one of the crucial phases in the construction of semi-flexible pavement (SFP). The gradation and compaction primarily influence the pores and their arrangement in PAM, which affects the air voids and permeability of porous mixes and effectiveness of slurry infiltration. Complexity of gradation and compaction makes it very difficult to predict air voids and permeability in PAM. Statistical analysis of these parameters based on experimental data requires very high volume of samples which is missing in literature. Compaction effort has been kept constant in most of them which otherwise is important for stability. Also, machine learning models to predict mix design of PAM has not been explored. This study investigates the PAM using systematic experimentation and modelling approaches such as Response Surface Methodology (RSM) and Artificial Neural Networks (ANN) to establish new and low trial-based guidelines for establishing a relationship between air voids and permeability greater than 0.12 cm/sec, while ensuring the stability of the mix. Using a Simplex Lattice design approach, five distinct types of aggregates were utilized as input variables and twenty-six PAM mixes were generated, which were subjected to 5 compaction levels. A total of 260 mixes were tested and then models were prepared based on RSM and ANN, which considered two output variables: air voids and permeability. RSM and ANN models demonstrated strong agreement between predicted values and actual experiment outcomes. It is observed that optimal permeability in PAM is achieved by adjusting aggregate proportions based on compaction levels. Proportion limits for low compaction suggested 60–70 % coarse aggregates and up to 20 % fines. For higher compaction (25–75 blows), it is recommended to increase the coarse aggregates up to70–90 % and limit fines up to 10 %. All proposed limits satisfied minimum permeability criteria (> 0.12 cm/sec) while ensuring the stability of the mixes. The proposed modelling approach offers greater efficiency and accuracy and reduces trial batch time, minimizing the need for destructive experiments and material wastage.

Innovation in Water Management: Designing a Recyclable Water Resource System with Permeable Pavement

Innovation in Water Management: Designing a Recyclable Water Resource System with Permeable Pavement

Research on the treatment and utilization of hydrophobic soil in sponge city construction

This paper provides a comprehensive analysis of the characteristics of hydrophobic soil, including its strong hydrophobicity, poor water retention capacity, and unstable mechanical properties. It explores treatment technologies for hydrophobic soil such as soil amendments, bioremediation techniques, and physical treatment methods. Based on these findings, the paper proposes the utilization of hydrophobic soil as permeable paving material, filling material for rain gardens and ecological retention ponds, covering layer for green roofs, and for ecological slopes and dikes. These suggestions provide theoretical support and practical guidance for the effective use of hydrophobic soil in sponge city construction.

Heavy metal removal by porous asphalt in cyclical wetting and drying

Porous asphalt pavement (PAP) is subjected to wetting and drying cycles involving storms of varying intensity and inter-event drying periods to study the impact of continuous weather systems on heavy metal removal in runoff. Four physical models: a complete PAP system, a PAP surface, a geotextile fabric and a reservoir of cobblestone aggregate, were created at the lab-scale and tested with stormwater contaminated with dissolved Mn(Ⅱ), Zn(Ⅱ), Cu(Ⅱ), and Cr(Ⅵ). The models were exposed to repeated wetting and drying cycles spanning over 27 days in triplicate. Wetting involved light, moderate and heavy rainfall intensities. All pavement material designs performed well at removing Cu(Ⅱ) and Cr(Ⅵ). The PAP system had an overall better performance at removing Mn(Ⅱ), Zn(Ⅱ), Cu(Ⅱ), and Cr(Ⅵ) than any of the individual pavement materials but was unable to remove all of the heavy metals simultaneously to sufficiently high levels. The materials used in the filter layer and reservoir structure and their adsorption and desorption capacities should be assessed for potential contamination (leaching) of Zn(Ⅱ) and Mn(Ⅱ), respectively, prior to construction. Wetting and drying cycles had the greatest impacts on the reservoir structure’s performance versus any of the other layers. Leaching of Mn(II) observed from cobblestone aggregate was affected by the solution composition and pH. Removal of selected heavy metals was rapid in first flush and fluctuated with storm event intensity.