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Self-healing asphalt, which is designed to achieve autonomic damage repair in asphalt pavement, offers a great life-extension prospect and therefore not only reduces pavement maintenance costs but also saves energy and reduces CO2 emissions. The combined asphalt self-healing system, incorporating both encapsulated rejuvenator and induction heating, can heal cracks with melted binder and aged binder rejuvenation, and the synergistic effect of the two technologies shows significant advantages in healing efficiency over the single self-healing method. This study explores the fatigue life extension prospect of the combined healing system in porous asphalt. To this aim, porous asphalt (PA) test specimens with various healing systems were prepared, including: (i) the capsule healing system, (ii) the induction healing system, (iii) the combined healing system and (iv) a reference system (without extrinsic healing). The fatigue properties of the PA samples were characterized by an indirect tensile fatigue test and a four-point bending fatigue test. Additionally, a 24-h rest period was designed to activate the built-in self-healing system(s) in the PA. Finally, a damaging and healing programme was employed to evaluate the fatigue damage healing efficiency of these systems. The results indicate that all these self-healing systems can extend the fatigue life of porous asphalt, while in the combined healing system, the gradual healing effect of the released rejuvenator from the capsules may contribute to a better induction healing effect in the damaging and healing cycles.

Previous studies have reported the effects of aggregate gradation and angularity on the pavement performance of hot asphalt mixtures, while little work has been done on the role of aggregat...

Fine solid wastes such as coal fly ash (CFA), diatomite, and red mud have been widely applied as alternative fillers for porous asphalt pavement (PAP), and have varying impacts on the mechanical performance of materials. However, whether they will affect the runoff purification performance of PAP has not been studied yet. Based on the laboratory simulation rainfall test, this study investigated the purification performance of porous asphalt mixture (PA) with three fine solid wastes fillers. Combined with the analysis of multi-scale pore characteristics of PA, the purification mechanism was further discussed. The results show that pollutants are mainly removed within 3 cm on the surface of PA in 20–30min rainfall. Diatomite and red mud fillers can effectively increase the removal rates of some heavy metals and nutrients by 20–40%. On the one hand, diatomite and red mud can leach some ions, which are conducive to physical adsorption and chemical degradation (including chemical precipitation and ion change) of pollutants. On the other hand, they also contain abundant porous structures and large specific surface areas, which significantly improve the micro-surface physical properties of PA and enhance the interaction between PA and pollutants.

The hydrologic characteristic of a permeable friction course (PFC) pavement is dependent on the rainfall intensity, pavement geometric design, and porous asphalt properties. Herein, the hydrologic characteristic of PFC pavements of various lengths and slopes was determined via numerical analysis. A series of analyses was conducted using length values of 10, 15, 20, and 30 m and slope values of 0.5%, 2%, 4%, 6%, and 8% for the equivalent water flow path. The PFC pavements were simulated for various values of rainfall intensity, which ranged from 10 to 120 mm/h, to determine the time taken for water to flow over the PFC pavement surface. The results show that the time for water overflow decreased when the pavement length or rainfall intensity increased, and it increased when the slope increased. Finally, a series of design charts was developed to determine the time taken for water to flow over the PFC pavement surface for given rainfall intensities. Since this study was conducted based on numerical analysis, further studies are recommended to verify experimentally the results presented.

Microwave heating has been shown to be an effective method of heating asphalt concrete and in turn healing the damage. As such, microwave heating holds great potential in rapid (1–3 min) and effective damage healing, resulting in improvement in the service life, safety, and sustainability of asphalt pavement. This study focused on the microwave healing effect on porous asphalt concrete. Steel wool fibres were incorporated into porous asphalt to improve the microwave heating efficiency, and the optimum microwave heating time was determined. Afterwards, the microwave healing efficiency was evaluated using a semi–circular bending and healing programme. The results show that the microwave healing effect is largely determined by the steel fibre content and the mix design of the porous asphalt concrete.. Besides, the uneven heating effect of microwave contributes to an unstable damage recovery in the asphalt mixture, which makes it less efficient than induction heating. However, microwaves exhibited the ability to penetrate further into the depth of the test specimen and heat beneath the surface, indicating deeper damage recovery prospects.

Porous asphalt pavement is a sustainable infrastructure tool used to benefit urban resilience. This paper summarizes the design, construction, and maintenance practices of porous asphalt pavements (PAPs) specific to cold regions. It includes discussions on the structural design considering frost depth and frost heave of subgrade soils, material selection and design for adequate freeze-thaw durability, construction of PAPs in cold weather, winter maintenance of PAPs for snow and ice control, and performance deterioration caused by other winter activities such as studded tires. Distinguished from other review works on this topic, the major contributions of this review paper employ case studies of PAPs to address design, construction, and maintenance concerns of PAPs in cold regions. These projects have demonstrated the success of using PAPs in cold regions and design practitioners can refer to these case studies for the new design and installation of PAPs in cold regions.

Porous asphalt (PA) pavements are widely employed in areas with wet climates. As particle enhancement inclusions in asphalt mastic, mineral fillers play essential roles in improving the performance of PA pavements. This study developed a coupled multiscale finite element (FE) model, involving the mesostructure of PA mixture and PA pavement. Four types of mastic properties were employed with four mineral fillers (Granodiorite, Limestone, Dolomite, and Rhyolite) in the mesoscale portion of the pavement model to analyse the effects of filler types on the performance of pavements. The performances (load-bearing capacity, rutting resistance, and ravelling resistance) of pavements with different fillers were identified and ranked, and their correlations with the chemical components of the four fillers were analysed. The computational results showed that pavements with Rhyolite and Granodiorite fillers have higher load-bearing capacities and rutting resistance, while the Limestone and Dolomite fillers can improve the ravelling resistance of the PA pavements. In the correlation analysis, the chemical components Al2O3 and SiO2 play dominant roles in improving the load-bearing capacities and rutting resistance of the PA pavements, and the fillers with high percentages of CaO can improve the ravelling resistance of the PA pavements.

Porous asphalt pavement is widely used due to its adequate water permeability, noise reduction and skid resistance. The study aims at exploring the potential of using the crumb rubber/styrene–butadienestyrene (CR/SBS) modified bitumen as high-viscosity binder for porous asphalt mixture, and investigating the effect of swelling and degradation degree of crumb rubber as well as SBS dosage on the performance of porous asphalt binder and mixture. The conventional, rheological and engineering properties of CR/SBS modified high-viscosity porous asphalt binders and mixtures were characterized. The results revealed that the CR swelling-degradation degree significantly affected the physical and viscoelastic properties of CR/SBS modified high-viscosity binders. With the swelling time prolonged, the viscosity of rubber bitumen enhanced gradually until reaching the equilibrium state, which kept falling during the degradation process dramatically. The full-swelling binders exhibited the highest complex modulus, zero-shear viscosity, rutting resistance, which deteriorated as the degradation degree increasing. However, the degradation of crumb rubber would be beneficial to improve the workability, thermal cracking resistance and deformation recovery ability of high-viscosity binder. Meanwhile, the incorporation of SBS copolymer could further strengthen both high-and-low temperatures viscoelastic performance of high-viscosity bitumen. In addition, the performance of porous asphalt with CR/SBS modified high-viscosity bitumen could meet the requirements of Marshall stability, air void content, Cantabro loss, run-off loss, anti-rutting, moisture damage resistance and permeability performance. Although the full-swelling asphalt mixture presented the best rutting resistance, it showed the poor adhesive and moisture damage resistance when compared with partial and full-degradation asphalt mixtures.

Porous asphalt is a bituminous material prepared in such a manner that it has a very high content of interconnected voids that allow passage of water and air in order to provide the compacted mixture with better drainage and noise reducing characteristic. The analysis of available regulations and scientific literature shows that the national standards of porous asphalt mixtures differ in type of granulometric envelopes, the type of bitumen and its content in the mixture and the limits of the air voids content in the mixture. In this paper, standards used for porous asphalt in Croatia are compared with the US, Australian and Dutch standards for this type of asphalt. In addition, samples prepared based on HRN EN 13108-7 and HRN EN 12697-17 requirements were tested and results were compared using Croatian and other available standards. This paper also investigates the effects of ambient temperature on abrasion loss of porous asphalt. The abrasion loss results are compared to the other standards.

Şehirleşmenin yoğun olduğu bölgelerde, yağmur suyu büyük oranda geçirimsiz yüzeylerde toplanmakta, yeraltı suyuna sızması engellenmektedir. Özellikle yerleşim bölgeleri için çevre dostu olarak nitelendirebileceğimiz geçirimli kaplama uygulamaları, yüzey akışını büyük oranda azaltarak, yağmur suyunun temiz kalması ve sızma yoluyla yeraltı suyunun beslemesine olanak sağlamaktadır. Geçirimli Kaplamalar boşluklu yapısı itibariyle, çevresel gürültü kirliliğini azaltmaktadır. Bu faydaları düşünüldüğünde bu kaplamaların kentleri insan doğasına daha uygun hale getirmeye yardımcı olacağı açıktır. Diğer yandan, boşluklu yapısı itibariyle hizmet ömürleri kısa olan bu kaplamaların, performansının geliştirilmesine ihtiyaç duyulmaktadır. Bu bağlamda, geçirimli asfaltın daha yaygınlaştırılmasına katkı sunmak amacıyla, kaplama karışımların hidrolik geçirgenlik düzeyinden ödün vermeden, bazalt elyaf, polipropilen, cam elyaf ve atık lastik kullanılarak performansının iyileştirilmesi düşünülmüştür. Geçirimli asfalt karışım tasarımında, agrega olarak ferrokrom üretim sürecinde açığa çıkan cüruf malzemesi kullanılmıştır. Ferrokrom cürufunun özelliklerine uygun bir alanda geri dönüşümü ile ekonomik ve çevresel açılardan optimum fayda amaçlanmıştır. Çalışmada, Elazığ Ferrokrom Tesisinden temin edilen ferrokrom cürufu ve İstanbul Asfalt Fabrikaları Sanayi ve Ticaret A.Ş.' den temin edilen PMB 76-22 polimer bitümlü bağlayıcı yanında, filler takviyesi olarak F tipi uçucu kül ve bitüm stablizasyonu için selülozik elyaf kullanılmıştır. Çalışmada ferrokrom cürufu agrega için bir karışım tasarımı gerçekleştirilmiştir. En iyi tasarım sonuçlarının elde edildiği %6,0 ve %6,5 bitüm oranlarında, karışım ağırlığının %0,2, %0,4, %0,6, %0,8 ve %1,0 oranlarında polipropilen, bazalt elyaf, cam elyaf ve kırıntı kauçuk ilavesinin karışım performansı üzerindeki etkileri belirlenmiştir. Hazırlanan numunelere hacim analizi, permeabilite, Cantabro aşınma kaybı, dolaylı çekme mukavemeti ve nem hasarına karşı dayanım gibi tasarım deneyleri gerçekleştirilmiştir. In areas where urbanization is intense, rainwater is mostly collected on impermeable surfaces and leakage into groundwater is prevented. Permeable coating applications, which can be qualified as environmentally friendly especially for residential areas, greatly reduce the runoff, keep the rainwater clean and allow groundwater to be fed through infiltration. Permeable Coatings reduce environmental noise pollution due to their porous structure. Considering these benefits, it is clear that these coatings will help make cities more suitable for human nature. On the other hand, there is a need to improve the performance of these coatings, which have a short service life due to their porous structure. In this study, in order to contribute to the more widespread use of permeable asphalt, it was considered to improve the performance of the coating mixtures by using basalt fiber polypropylene, glass fiber and crumb rubber without compromising the hydraulic permeability level. The slag material released during the ferrochrome production process was used as aggregate in the permeable asphalt mixture design. With the recycling of ferrochrome slag in an area suitable for its properties, optimum benefit is aimed in economic and environmental terms. In the study, besides the ferrochrome slag obtained from Elazığ Ferrochrome Plant and polymer bituminous binder (PMB 76-22), F-type fly ash as filler addition and cellulosic fiber for bitumen stabilization were used. In the study, a mixture design was carried out for ferrochrome slag aggregate. The effects of the addition of polypropylene, basalt fiber, glass fiber and crumb rubber at the rates of 0.2%, 0.4%, 0.6%, 0.8% and 1,0% of mixture weight on the blend performance at 6.0% and 6.5% bitumen rates where the best design results are achieved has been determined. Design tests such as volume analysis, permeability, Cantabro abrasion loss, indirect tensile strength and resistance to moisture damage were carried out on the prepared samples.

Aramid fibers and glass fibers are widely used in dense-graded asphalt mixtures to improve the mechanical characteristics. However, their effect on the characteristics of porous asphalt mixtures has not been widely explored. This study evaluated the influence of aramid fiber, aramid pulp, glass-hybrid fiber, and cellulose fiber to improve the abrasion resistance and strength of the porous asphalt mixtures while maintaining their functional characteristics. The performance of PA-16 mixtures incorporated with fibers was evaluated using the Cantabro test, permeability test, indirect tensile strength (ITS) test, and moisture susceptibility test. Finally, a multi-criteria decision method (MCDM), weighted aggregated sum product assessment (WASPAS) in combination with criteria importance through inter-criteria correlation (CRITIC) as a weighting method, is applied to make a multifaceted decision and select the best option among the variety of fibers included in the study. Results concluded aramid pulp remarkably enhanced the abrasion resistance while glass-hybrid fibers improved the ITS of the mixtures. Particularly, aramid pulp was selected as the best fiber to improve the mechanical resistance, according to the proposed methodology. This work was possible thanks to the research project entitled ‘Resilient and sustainable Permeable Pavements For Urban Flood Mitigation (RePP4FM). This project is funded by SAFERUP! from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 765057.

In order to solve the pores clogging of porous asphalt mixture, the self-designed constant water head permeameter was used in the clogging simulation test of PA-13 standard Marshall specimens with different porosities, and the decay law of the water permeability was studied. The results showed that the clogging process of porous asphalt mixture was divided into four stages: fast clogging, partial recovery, slow and stable clogging. The particulate matter was mainly blocked at a depth of 15-20 mm in the asphalt mixture.

In this study, the effect of mastics with four different mineral fillers (limestone, granodiorite, dolomite and rhyolite) on the mechanical performances of porous asphalt (PA) mixtures was investigated. X-ray computer tomography (X-ray CT) scanning and digital image processing (DIP) techniques were applied to detect and reconstruct the microstructure of PA specimens. Finite element (FE) simulations were conducted to simulate indirect tensile tests. The results show that the mastics with different fillers have significant influence on the mechanical performances of PA mixtures. The PA mixture with limestone exhibits the least load-bearing capacity while the specimen with granodiorite exhibits the highest values. Although the distribution and the magnitude of the creep strain in the different mastic are similar, the locations of the maximum creep strain are not the same. Further investigations should be carried out to facilitate the improvement of the pavement design process.

Porous asphalt pavement can reduce noise and improve road safety and driving comfort on rainy days. The seepage model derived from the one-way gradient flow theory cannot truly reflect the ...

This laboratory study investigated the performance of open-gradation cold patch asphalt mixtures using two new solvents, mineral spirit and isoamyl acetate, for patching potholes in porous ...

The objective of this paper was to investigate the evolution of air voids (AV) and deformation and the failure mechanism of porous asphalt (PA) mixtures under high temperatures. An advanced...

Researchers developing pervious pavements over the past few decades have commendably demonstrated long-term run-off reduction using a diverse collection of materials. Today, pervious pavements are widely recognized as a low impact development technique and a type of green infrastructure, and installations are proliferating throughout the United States and worldwide. The entire field of pervious pavements though, is being profoundly stunted by three persistent problems: conflicting nomenclature, flawed testing standards, and the absence of a holistic green design framework. This study examines each problem and proposes novel solutions. On nomenclature, a multi-channeled study of the terms “pervious”, “permeable”, and “porous” considers each word’s etymology and usage in the academic literature, in ASTM International standards, and by (U.S.-based) governmental entities. Support is found for using pervious pavements (i.e., “through” the “road”) as the over-arching category of all water passable pavements, branching down into porous pavements (i.e., “full of pores”, including porous asphalt and porous concrete) and permeable pavements (i.e., “containing passages”, often between paver units). ASTM International standards are shown to insufficiently account for the impact of paver unit size on infiltration rate, warranting the development of a more reliable testing method featuring variable infiltration ring size, shape, and placement. Finally, a ten-part holistic green design framework is elucidated for use in assessing candidate pavements and engineering new pavements, contextualizing the latest pervious pavement research and illuminating a brighter path forward.

The permeability of porous asphalt pavement is an important hydraulic property that is affected by the microstructure of connected pores. This paper investigates the pore characteristics an...

Pavement materials have significant influence on the urban heat island effect (UHIE). This paper presents a study on the potential effects of pavement materials on UHIE in a natural environment. Three typical pavement materials, including cement concrete, dense asphalt concrete and porous asphalt mixture, were selected to evaluate their anti-UHIE properties by testing. In this paper, heat island potential (HIP) is proposed as a new index to analyze the influence of pavement materials on UHIE. It is shown that the temperature inside a pavement distinctly depends on the depth, and varies, but is usually higher than the air temperature. Solar radiation in the daytime significantly contributes to the temperature of pavement surface and the upper part. The correlation becomes weak at the middle and the bottom of pavements. Among the three materials tested in this study, the anti-UHIE performance of cement concrete is significantly higher than that of the other asphalt mixtures, while the porous asphalt mixture is slightly better than the dense asphalt concrete in anti-UHIE. Published version

Porous asphalt pavements have been used successfully in practice to improve stormwater management, increase wet-weather driving safety and reduce traffic noise. However, the sustainability of these functional performances is a major practical concern because they are often seriously affected by clogging during service. This paper proposes a laboratory evaluation procedure to compare the clogging potential of two common forms of porous pavement design, and how their drainage capacity, skid resistance and sound absorption properties are affected by clogging. For illustration, the following four designs were considered: (A) Single-layer design with 25% porosity; (B) Single-layer design with 20% porosity; (C) Double-layer design having on top of Design A a 20% porosity upper layer with 11.2 mm top size aggregate; and (D) Double-layer design having on top of Design A a 20% porosity upper layer with 8.0 mm top size aggregate. Test results show that Design A was least prone to clogging, followed by Designs B and C, and Design D was most prone to clogging. However, Designs A and B suffered severe losses in their sound absorption capability when fully clogged, while the other two designs were significantly less affected by clogging. These different behaviors of the porous asphalt designs with respect to clogging potential and sound absorption capability have important implications on pavement drainage capacity, skid resistance and noise management, and the frequency and method of declogging maintenance. They provide useful information for pavement engineers in the selection of porous asphalt surface course design.

This study aims to investigate the relationship between the anisotropy of permeability and the directional distribution of connected voids in permeable friction course (PFC) mixture. The compacted ...

Porous asphalt pavements allow designers to introduce more sustainability into projects and lessen their environmental impact. Current design procedures are based primarily on hydrologic considerations; comparatively little attention has been paid to their structural design aspects. As their use grows, a design procedure and representative material structural properties are needed to ensure that porous pavements do not deteriorate excessively under traffic loads. The objective of this project was to develop a simple, easy to apply design procedure for the structural design of porous asphalt pavements. Two methodologies were considered for such a structural design procedure: ( a) the 1993 AASHTO Pavement Design Guide empirical approach, and ( b) the mechanistic–empirical approach employed by the AASHTOWare Pavement ME Design software. A multifactor evaluation indicated the empirical 1993 AASHTO design procedure to be the most appropriate platform at this time. It is noted, however, that both design procedures lack validation of porous asphalt pavements against field performance. AASHTO design parameters and associated material characteristics are recommended, based on an extensive literature review. For “thin” open-graded base structures (12 in. or less), the AASHTO procedure is performed as published in the 1993 Guide. For “thick” base structures (>12 in.), the base/subgrade combination is considered a composite system which supports the porous asphalt layer; an equivalent deflection-based approach is described to estimate the composite resilient modulus of the foundation system, prior to applying the 1993 AASHTO design procedure.

Введение. Рассматривается актуальное в настоящее время зеленое строительство, которое осуществляется в соответствии с экологической целесообразностью. Приводится перечень экологических проблем, связанных с непроницаемостью почвенного покрова в городах и предлагаются меры по устранению негативных эффектов воздействия жизнедеятельности человека на экологию. Материалы и методы. Исследовано применение пористых тротуаров как средство борьбы с экологическими проблемами и создания благоприятной городской среды. Дано определение пористой мостовой, рассмотрено ее отличие от обычного дорожного покрытия. Приведено описание составных частей устройства тротуарной системы, включающей основание, ткань фильтра, резервуар из наполнителя и пористый поверхностный слой. Проанализированы основные виды пористых покрытий: пористый бетон, пористый асфальт и брусчатка. Проведен мониторинг экологических, эстетических и экономических преимуществ пористых тротуаров: пополнение запаса грунтовых вод, борьба с наводнениями в результате снижения объема ливневых вод, сохранение растений в городской среде, контроль городского теплового режима, охлаждение поверхностных вод рек и других водоемов, повышение безопасности движения, контроль шума. Результаты. Приведены ситуации, при которых использование пористых тротуаров не эффективно. Это автомобильные дороги с плотным движением, крутые склоны, территории с эрозией и размыванием почвы, дороги, на которых в зимний период активно используются химические реагенты для борьбы с гололедом, места вероятных разливов вредных веществ. Для эффективного использования пористых тротуаров, они должны надлежащим образом обслуживаться в зависимости от типа пористого покрытия. Даны рекомендации по эксплуатации пористых тротуаров. Выводы. Пористые дорожные покрытия в силу своих особенностей не могут применяться повсеместно. Такой вариант дорожных покрытий должен быть рассмотрен всеми участниками капитального строительства, заинтересованными во внедрении технологий зеленого строительства в нашей стране.

Both spatial characteristics and the structure of air voids have certain impacts on the acoustic properties of porous asphalt, with regard to sound absorption behavior. Aside from global parameters of the microstructure, like porosity, certain geometrical characteristics of air voids also have an effect on sound absorption and acoustic parameters. Spatial parameters of the microstructure like 3D fractal dimension or pore diameter distributions are determined from X-ray CT scans, using methods of digital image processing. Geometrical parameters of different porous asphalt samples are compared, and the relationship between the geometry and the acoustic behavior is studied in great detail. In particular, an evolution of the microstructure caused by long-term soiling processes – changes which usually materialize during porous asphalt’s service life – and their effects on spatial and acoustic parameters are analyzed. A defined laboratory procedure for artificial soiling has been used to study soiling mechanisms, enabling the correlation to certain soiling states to be drawn. The design of the study shows how more basic analyses of the acoustic deterioration of porous asphalt due to soiling effects during its service life are possible, with the consideration of changes in the air void microstructure. Keywords: Porous asphalt, Acoustical properties, Air voids, X-ray CT, Soiling processes

This study assessed the potential for potable water savings in a building by using stormwater filtered by a porous asphalt pavement located in a parking lot. Stormwater is meant to be used for non-potable purposes (flushing toilets and urinals). Two models of porous pavement systems were constructed, both with porous asphalt mixture over a different combination of porous granular layers. The models were assessed for their filtering capacity; samples of stormwater runoff were collected in a parking lot located near the building where filtered stormwater is meant to be used. The models showed to be capable of filtering some pollutants. However, additional water treatment would be necessary to obtain the quality required for non-potable uses. Then one model was selected for a theoretical analysis on using it in a parking lot. The potential for potable water savings was analysed considering four scenarios as a function of daily local rainfall data. The thickness of the temporary stormwater reservoir layer was calculated in order to meet the design rainfall adopted, and the stormwater tank capacity was estimated using the Netuno computer programme. As a result, using a 45,000-litre stormwater tank, potable water savings of at least 53% would be obtained if filtered stormwater were used to flush toilets and urinals. This indicates that porous pavements show a great potential for filtering stormwater runoff to be used in buildings.

Porous asphalt is a solution to avoid puddles on the road because it has a pore large enough to drain the surface water. However, porous asphalt has low stability, so it is necessary to improve the Marshall stability on a porous asphalt mixture. The purpose of this research is to know the optimum composition of the asphalt content, the coconut fiber content and the coconut fiber length and to determine whether or not there is an effect of adding coconut fiber to the Marshall properties on a porous asphalt mixture. In this study, the treatment used is by making porous asphalt mixture with a variation of the asphalt content of 4%, 5% and 6% and a variation of the coconut fiber content of 0.5%, 0.75% and 1% and a variation of the coconut fiber length of 2.5 mm 5 mm and 7.5 mm to determine the optimum composition of the porous asphalt mixture. The gradation standard used in this study is the Australian Asphalt Gradient Standard and for its specifications using the Marshall characteristics of the Australian Standard (AAPA). Using the response surface method, the optimum value for the asphalt content is 4% and the optimum value of the coconut fiber is 0.75%. The addition of coconut fiber was able to increase the MQ value by 119% from 112.56 kg / mm to 246.64 kg / mm and the stability value 61.56% from 388.32 kg to 627.38 kg. However, the addition of coconut fibers decrease the VIM rate by 18.6% from 20.27% to 18.6% and the flow value by 20% from 3.24 mm to 2.7 mm. These values meet the requirements of porous asphalt’s Marshall characteristics for Australian gradation standard. It is necessary to do a further research using other gradation standard.

An accurate tire-pavement noise prediction model is highly needed by transportation agencies and pavement designers during the porous asphalt mixture design to reduce the tire-pavement noise which has been recognized as a dominant contributor to the overall traffic noise. In this paper, the surface texture level and distributions of porous asphalt mixture are acquired by a recently developed program named as 2-Dimensional Image Texture Analysis Method (2D-ITAM). The acoustic absorption coefficient of porous asphalt mixture is calculated using a proposed sound absorption model based on the micro-structure of porous asphalt mixture. Also, a prediction model correlating the tire-pavement noise level with macro-texture and short wavelength of mega-texture of pavement is established using a multivariate non-linear regression analysis. This prediction model is validated through laboratory experiment demonstrating its effectiveness of predicting the tire-pavement noise level. The model is anticipated to serve as an improved tool which could be considered by practitioners in an optimized porous asphalt mixture design incorporating the evaluation of noise produced by asphalt pavement.

Porous asphalt (PA) mixtures work real coupled conditions of high temperature and rainfall in rainy summer weather. The objective of this study is to develop a multi-physics repeated loading permanent deformation (MRLPD) test that can evaluate the rutting resistance of the PA mixture under such real coupled conditions. A multi-physics chamber was designed for the MRLPD test to achieve real coupled conditions of dry, rainfall onset, ongoing rainfall, and rainfall end, which are consistent with the rainfall process. Under the rainfall onset and ongoing rainfall conditions, the rutting resistance of the PA mixture is lower than that under the dry condition. PA mixture shows the poorest rutting resistance under the ongoing rainfall condition. The presence of water in the pores creates pore pressure, which facilitates moisture damage and consequently decreases the rutting resistance. The more time the PA mixture stays in a saturated state, the lower the rutting resistance is. PA mixture exhibits the best rutting resistance under the rainfall end condition because the pore pressure absorbs part of the loads and the decreased temperature of the specimen. The rutting resistance of the PA mixture is more sensitive to temperature and overloading than to moisture damage. Under the coupled conditions, high temperature accelerates the evolution of moisture damage, which leads to the acceleration of rutting failure.