VOL. 1, ISSUE 1, 44 – 53
DOI: https://doi.org/10.15282/cons.v1i1.6502
*CORRESPONDING AUTHOR | K. A. Masri | khairilazman@ump.edu.my 44 ORIGINAL ARTICLE
Porous Asphalt Modification using Different Types of Additives: A Review
S. M. Shahnewaz, K. A. Masri*, N. A. A. A. Ghani
College of Engineering, Universiti Malaysia Pahang, Lebuhray Tun Razak, 26300 Gambang, Kuantan, Pahang, Malaysia
ARTICLE HISTORY Received: 1st June 2021 Revised: 20th June 2021 Accepted: 30th June 2021 KEYWORDS
Porous Asphalt Asphalt Modification Aggregate Gradation Image Processing Incorporating Fibers
POROUS ASPHALT
A permeable asphalt surface built over a granular working platform on top of a large stone reservoir is made of porous asphalt pavement. By designing it with an open-grade friction path, the asphalt surface is rendered permeable. The coating under the porous asphalt has the capacity for storage to retain the water obtained. The idea of porous asphalt was initiated in the late 1960s to "promote percolation, decrease storm sewer loads, raise water tables and replenish aquifers." The concept was developed in the 1970s to a point where the Environmental Protection Agency funded programs to assess the cost and quality capacities of various types of porous pavements for urban runoff management [1]. For new and redevelopment schemes, the use of porous pavements for parking lots is one watershed-based approach that can fulfil these requirements. Due to the potential to clean up, porous pavements can both reduce impacts from new construction and reverse results in areas of reconstruction and cool runoff for which reduce the volume of runoff [2].
The advantage of using permeable paving are the ability to remove contaminants from groundwater before the sewer systems or outflow rivers are relocated. A number of tests have found that porous asphalt can eliminate from vehicles 90- 80% of the total suspended solids (TSS), large proportions of total metals (e.g., up to 88% of lead), and up to 90% of hydrocarbons, including oil and grease. Although encouraging, this major reduction in contaminants also leads to a need for prevent the permeable advantages of the concrete from being damaged, regular pavement maintenance [3]. While some noise on the highway comes from the cars themselves, the pavement-tire relationship produces a significant portion of this noise. By interaction between the tyre and the surface, a porous pavement will dissipate sound energy produced.
This is particularly true when the velocity of the highway is over 70 kph. Owing to the near proximity of businesses and residences to the highway, urban cities have the biggest need for noise control. The quality of life of the population is the apparent explanation for the need for noise control. Porous asphalt concrete (PAC) pavements typically minimize pavement-tire contact noise above 1,000 Hz in general [4]. Porous asphalt (PA) provides numerous environmental and safety advantages by increasing storm water drainage, eliminating scraping and blowing on vehicles and pedestrians, enhancing skid resistance, minimizing noise emissions and rutting resistance. Stempihar et al. has been observed that PA has a higher surface layer temperature during the day time and a lower surface layer temperature at night time relative to other forms of pavement. The efficiency of the porous asphalt is influenced by many factors, such as the properties of the asphalt binder and the packaging composition of the aggregates. The aggregate packing in PA, which has a small number of fine aggregates, consists primarily of particle-to-particle interlocking with the coarse aggregates. Rutting tolerance of PA has been reported to be lower than typical dense graded asphalt, and rutting is the dominant distress in summer.
Rutting not only increases the permeability and service life of the PA, but also poses a safety issue for the street [5].
There are two major drawbacks of the porous asphalt bituminous mixture: the mortar ages more easily when it is subjected to environmental conditions due to the high number of voids, which also improves the aggregates' stripping. In the PA mixture, which is its normal form of failure, both processes create ravaging problems, dramatically shortening its useful life. In fact, the PA mixture may display issues with clogging, these mixtures need to be laid in places with a high proportion of rainy days; otherwise, voids are packed with dust and stones, and water will not be able to flow into the PA mixture afterwards [6]. The PA mixture demonstrates the lowest rutting resistance as part of the continuing the state of rainfall. The presence of water in the pores generates a pore pressure that encourages moisture damage and therefore decreases rutting resistance. The PA mixture exhibits the best rutting resistance under the precipitation ends because the pore pressure absorbs part of the load and the temperature decreases of the specimen [7]. Another major drawback of
ABSTRACT – Nowadays porous asphalt pavement increase usage other than the traditional type of asphalt pavement. In that sense porous asphalt specially use in the parking areas and walk ways for pedestrian. There are diverse ways that has been done in order to stick up to permanent degradation such as adding fibers and modifiers like polymers, chemical modifiers, expandars, oxidants and antioxidents, hydrocarbons and antistripping to enhance the fatigue and service life of the pavement. To use these type of additives in porous asphalt pavement some additive increase the mechanical performance of porous asphalt mixture and improve the serviceability of the pavement. Digital image processing use these type of pavement to reduce the air void of the asphalt mixture and increase the physical properties of the porous asphalt pavement. This review paper mainly discuss the overall performance and advantage of porous asphalt using different types of additives.
permeable pavement like porous asphalt is cost impeccancy. Some Given variables such as lifetime, geographic location, type of permeable paving method and site-specific conditions, it can be difficult to compare cost impacts between traditional impermeable surfaces and permeable surfaces. Some figures place the cost of permeable paving at about one third more costly than that of standard impermeable paving [8].
Application of Porous Asphalt
Specially for parking areas and low-volume roadways, porous asphalt pavements are normally advised. Pedestrian walkways, bridges, driveways, bike paths, and shoulders are additional uses of porous asphalt. For suburban and urban avenues, as well as highways, porous asphalt pavements have also been widely used. With typical impervious asphalt pavements, porous asphalt pavements may be constructed as a whole or in part. Porous asphalt may properly contain and treat the additional runoff produced when built in conjunction with impervious pavements or exterior to building roofs [9]. Xu et al. used four separate forms of preventive repair products rejuvenating material (RJ), the type of polymerizing materials (GL1), chemical enhanced material (CEM), emulsified asphalt (EA) in four parts of a 9-year-old porous asphalt pavement. Performances of porous asphalt before and after healing has been analysed. CEM content has been shown to raise the surface roughness and enhance the skidding resistance of the pavement; GL1 and RJ will greatly boost the ravelling resistance and low temperature cracking resistance of the mixture [10]. The PAC specimens contained a considerable number of voids, most of which were less than 1 mm in equal diameter and were mainly located between 0.4 – 0.5 mm. The association study identified several parameters that were strongly correlated with the sound absorption coefficient: estimated air voids, recovered air voids, total air-free volume, average air-free volume, total air-free surface area and average air-free surface area. A prediction model for the sound absorption coefficient was established. This prediction model will provide a guide for the realistic use of the PAC in noise control, sound absorption and shock absorption [11]. The advanced repeated loading permanent deformation (ARLPD) test and the multi-physics repeated loading permanent deformation (MRLPD) test were carried out on the PA mixing and AC under warm and constant rainfall condition. The average strain rate (ASR) of the PA mixture is increased by 1.42 µɛ / cycle under continuous rainfall, while the ASR of the AC is decreased by 0.05 µɛ/ cycle under continuous rainfall. Wang et al. reveal that the moisture disruption has a more severe impact on the PA mixture's rutting resistance than on AC. The same result was drawn by Gubler et al., using the Coaxial Shear Test (CAST) method. Based on the above review, the MRLPD technique is able to provide a reasonable test to assess the rutting resistance under coupled conditions [7]. According to the analytical process, aggregate sizes above 4.75 mm are classified into seven grades in this article, and aggregate sizes below 4.75 mm are classified to 2.36 – 4.75 mm and 0 – 2.36 mm. By planning the contents of each volume class of aggregates, 262,144 schemes were developed using a complete system of factorial design, and 5966 schemes were screened.
Description of volume material equal to 1. The simulated packing density is directly proportional to the volume content of finer aggregates and inversely proportional to the volume content of coarse particles. For a rise of more than 31.5 mm in thickness, the simulated packing density slowly decreases [12]. Digital image processing (DIP) methods have been used to assess the gradation of the asphalt mixture. For the compacted asphalt combination, the percentage of pass-through sieves that are not less than 4.75 mm may be accurately determined; the percentage of pass-through sieves that are not more than 2.36 mm is not so reliable owing to the picture resolution limitations. For the sum of 9.5 ~ 13.2 mm, the threshold value was set to 2 mm after the review of many images. This approach can minimize the risk of false segmentation as much as possible. At present, square-hole sieves are used to evaluate the gradations of different aggregate sizes in many countries. It is therefore appropriate to transform square-hole sieves into identical round-hole sieves, because the sieving of the connected regions of the binary picture is centred on round-hole sieves. Existing work has demonstrated that the conversion coefficient of 1.2 is sufficient for a compacted porous asphalt mixture [13].
Asphalt Modification Types of Modifier
Polymers, chemical modifiers, expanders, oxidants and antioxidants, hydrocarbons and antistripping additives are modifiers and additives used to improve asphalt concrete efficiency. Polymers cover a wide variety of modifiers that are most widely used for elastomers and plasterers. Frequently used elastomers include Styrene-Butadiene-Styrene (SBS),Styrene-Butadiene rubber (SBR) and crumb rubber. The most commonly used modifier is SBS. To decrease rutting and to increase fatigue and thermal cracking tolerance, these modifiers are used. Crumb rubber is manufactured from field tyres and is an elastomer. The rutting properties of modified materials are used for plastomers. Examples of plastomers used in asphalt alteration include low density polyethylene and Ethylene-vinyl acetate (EVA)[14].
Table 1. Types of modifier
Sources Modifier Optimal content
Crude petroleum oil Bituminous binder 55.55gm
Bamboo plant Bamboo fiber 0 to 5.50gm
Limestone OPC 22gm
Types of Factor
In recent years, increasing demand for Hot Mix Asphalt (HMA) pavements, traffic frequency, traffic loads and tire pressure have increased considerably, forcing HMA to be more prone to rutting. The Superpave binder design allows the asphalt binder to meet both high and low pavement service temperatures in order to meet the stiffness specifications.
Environmental and economic demand to dispose of such waste materials and agricultural goods as additives in HMA (such as tires, bottles, sulphur and ash). The desire of the public body to pay a higher first price for pavements with a longer service life or which decreases the probability of premature failure[14].
Asphalt Modification Characteristics
Jiang et al. noticed that styrene-butadiene-styrene (SBS) and crumb rubber (CR) were the preferred polymers to boost the damping efficiency of the base asphalt based on four parameters (base, non-polymer modified, polymer modified, and stress-absorbing modified asphalt). The damping efficiency of the SBS and CR modified asphalts was further enhanced by the clear insight of the crosslinker and plasticizer, and the SBS / CR modified asphalts had reasonable damping efficiency for an additional benefit [15]. The modified binders of various layers (top, middle and bottom) of the PA have been assessed by chemical and rheological characterization. After undergoing outdoor aging, the chemical analysis revealed that the carbonyl and sulfoxide content of the modified binders had improved for the upper layers. The average amplitude for the bottom layers was smaller, indicating that the upper portion of the PA was more exposed to actual environmental ageing. Ageing in the deterioration of SBS, evaporation of lighter elements, oxidation and condensation of asphalt cause differences in the rheological properties of the recovered binder [16]. Ding et al. observed that specific forms of base asphalt exhibit varying temperature response and fluid properties after manipulation of the SBS [17]. SBS can enhance the temperature stability of design B asphalt; however, it has detrimental effects on design A and design C asphalt. Relative to base asphalt, the non-Newtonian index (n) values of the SBS- modified asphalt are all smaller than 1, reflecting that the asphalt is transformed from Newtonian to non-Newtonian and that the non-Newtonian properties of different asphalt forms vary with temperature [17]. Zhang et al. reveal that the high and low temperature output of the composite modified asphalt specimen is superior to that of the single modified asphalt specimen [18]. In terms of the contrast between SK- 90 asphalt and SK- 110 asphalt, SK- 110 asphalt has worse low temperature efficiency, while SK- 90 asphalt has higher temperature output; the quality of the water is not substantially different. Among the six composite modified asphalt mixtures assessed, the SBS / rubber composite modified asphalt mixture of SK- 110 has the best road results, particularly with regard to high temperature efficiency [18]. The construction workability, high temperature efficiency and fatigue output of high viscosity modulus (HVM) asphalt mixture with SBS adjusted asphalt are similar to HVM asphalt mixture with TPS additive or HVM asphalt mixture with sinoTPS modified asphalt and the former low temperature efficiency and water stability are better than HVM asphalt mixture with TPS additive and HVM asphalt mixture with sinoTPS modified asphalt. The change in the dosage of SBS compound modifier in the HVM asphalt is only 6.0 % and the mixing ratio of the linear SBS-modifier and the star SBS-modifier in the compound-modifier is 2:1. The efficiency of the SBS / PU compound HVM asphalt mixture is weaker than the sinoTPS- HVM asphalt mixture, but the viscosity of the SBS / PU compound HVM asphalt at 135 ͦ C is fairly small. This indicates that the construction workability of the asphalt mixture cannot be explicitly measured by asphalt viscosity, and that the design workability of the asphalt mixture must be checked [19]. Ding et al. using the viscosities of six forms of asphalt were measured under varying temperature conditions at a shear rate of 18.60 s^(-1) to evaluate the viscosity transition properties of the base and the changed asphalt. As the temperature rises, viscosity of the core and modified asphalt reduces [17]. When the temperature rises from 120 ͦ C to 165 ͦ C for design A, design B and design C, the viscosity reduced by 87.8 %, 85.9 % and 85.8 % respectively. Viscosity reduction levels for the three respective SBS-modified asphalts the number was 88.1 %, 81.2 % and 92.5 %. Consequently, the temperature tolerance of design B and design C is nearly similar and slightly stronger than that of design A. The viscosity-reducing impact of the temperature change on the asphalt can be induced by two factors:
the elevated temperature, which enhances the thermal motion of the asphalt molecules, and the kinetic energy, which contributes to the creation of further 'holes' within the asphalt [17].
Asphalt Modification Application
Luo et al. [19] find out that the construction efficiency of the SMA-13 combination is greatly impaired. The asphalt form and the mixing temperature and the effect of the mixing temperature on the workability of the construction are more apparent. In addition, it has been established that the workability of the asphalt combination is determined by the viscosity of the asphalt and the mineral aggregate. Thus, the above asphalt may be used for the preparation of the SMA mixture added to the steel deck pavement [19]. Jie et al. demonstrate that the rutting resistance of mixtures poses a negative linear affiliation with the load or the temperature [20]. Comparing the load, the temperature has a more important effect on the resistance to mix of rutting. The Direct Coal Liquefaction Residue (DCLR) modified asphalt mixture had higher values of Va ,Vb ,WL and WT than the other two mixtures under the coupling influence of temperature and load. However, for certain conditions of the study, the DCLR modified asphalt mixture has better dimensional stability than the SK-90 asphalt mixture [20]. Jie et al. also discussed the dynamic stability of three asphalt mixtures with differing temperatures under equal loads and the dynamic stability of three asphalt mixtures with similar loads at various temperatures. Dynamic stability of three mixtures shows negative linear interaction with temperature, independent of load, and the coefficients of determination (R2) are all greater than 0.9. With the temperature increase, the DCLR modified asphalt mixture displays
the least spike in dynamic consistency, complemented by the SK-90 asphalt mixture and the SBS modified asphalt mixture. Dynamic stability of three mixtures shows negative linear interaction with load, independent of temperature and the coefficients of determination (R2) are all greater than 0.9 as well. When temperature rises, the dynamic flexibility of the SK-90 asphalt mixture reduces much, showing the maximum load vulnerability. It is notable that in the medium temperature between 30–55 ͦ C, the adjusted asphalt mixture between DCLR illustrates low dynamic stability relative to the SBS modified asphalt mixture and under a temperature of even more than 55 ͦ C, the DCLR modified asphalt mixture displays a greater tolerance to rutting than the SBS modified asphalt. It is often shown that under the light load 0.7 – 0.8 MPa and a low temperature of 30–35 ͦ C, the updated DCLR modified asphalt mixture shows lower mechanical consistency than the SK-90 asphalt mixture [20]. Zhang et al. outlines the mechanical properties of different forms of composite modified asphalt mixtures based on PG technologies and rheological techniques. The pavement efficiency of SK- 90 asphalt and SK- 110 asphalt differs with the adjustment dosage of the modifier [18]. When two types of asphalt are added to the same modification, the changes in penetration, ductility, and softening point are follows the same dosage of the modifier. High temperature performance of complex shear modulus (G*) and phase angle (δ) of the asphalt DSR are SK- 90 modified asphalt, the G*sin δ of SK- 110 modified asphalt is comparatively high and has a higher fatigue tolerance. Compared to the composite modified asphalt, the single modified asphalt has greater fatigue resistance. Low temperature performance of creep stiffness S (t) of asphalt BBR specimens are 7%TPS/4% SBS and 15% rubber powder/4% SBS composite asphalt materials increase the low temperature performance of asphalt, and 15% rubber powder/4% SBS composite asphalt materials have the worse low temperature performance. High-temperature rutting test devices and collections of various material modified asphalt mixtures are tested. The dimensional stability of the different modified asphalt mixtures is graded from the highest to the smallest. SBS / rubber powder modified SK- 90 carbon formulated asphalt mixture has the highest high- quality performance of temperature. Various plastic modified asphalt mixtures are tested for low-temperature bending tools and specimens. When SBS and other modifiers are used to adjust asphalt, the potential of rubber powder to increase the low-temperature efficiency of asphalt is greater than that of SBR and TPS. When the same modification is used to change various asphalts, the asphalt is strengthened by SK- 110 and the adjustment result is greater. The freeze-thaw splitting test of various composite modified asphalt mixtures is discussed.
The TSR of modified asphalt mixtures of SBS reduces, except for modified asphalt of TPS mixtures that demonstrate that TPS increases the surface quality of the asphalt better than SBR or rubber coating, as SBS and other additives are used to change the asphalt. If the same process is used to modify different asphalts, the asphalt of SK- 110 is greatly enhanced and its water quality is increased [18].
Asphalt Modification Connectivity
For base asphalt, the damping value of the ground according to the CGDP, asphalts became low. A good supply of oil the damping properties of the asphalts were impaired and the link between high penetration and high damping efficiency was not solid. In the case of non-polymer modified asphalt, the damping efficiency of non-polymer modified based asphalt, it was weak and varied with non-polymers groups and dosages. The influence of different types of non-polymers on the damping properties of the base asphalt was mainly as follows: (a) Modified forms of asphalt: TLA and RA lowered DTS to some degree and the latter had a more apparent impact, (b) Filler modified types: DE may be used to adjust the value of the LF, (c) Chemical modified types: Sulphur reduced LF value with improved DTS Some amount, while the effect on different dosages was minimal. In the case of polymer modified asphalts (single modification), the effect of modification varied for different types of polymers. Good damping efficiency for the CRM asphalt was achieved as indicated by the high LF value, low DTS and higher EDTR value. In the case of polymer modified asphalts (compound modification), the damping efficiency and reliability of the SM asphalts can be further enhanced by using a combined crosslinker and plasticizer. The stress-absorbing modified asphalt preserved a strong quality damping performance with a high LF value, low DTS and a wide range in NWTRP, EDTR. So, it could be concluded that these stress- absorbing asphalts were probably SM asphalt [15]. Rasool et al. reveals that long-term outdoor ageing of asphalt binders is attributed to the influence of sunshine, air penetration, temperature, water and packing. The sum of all these diverse conditions determines the composition of the pavement. FTIR was used for the systemic evaluation chemical shifts in the changed binders during the ageing cycle. From a chemical perspective, ageing is stimulated by irreversible oxidation reactions, producing carbonyl (C = O based in 1700 𝑐𝑚−1) and sulfoxide (S = O based in 1030 𝑐𝑚−1) of functional groups. Both classes change the structure of the asphalt (increase in molecular size, aromaticity and polarity of the asphalt) and the asphalt binders are become more fragile. Carbonyl absorption peaks are assumed to be a significant measure for evaluating the degree of ageing of the asphalt and higher absorption is aligned with deeper ageing. According to the crude oil refining cycle, sulfoxide is emitted more rapidly during weathering than by carbonyl groups [16].
DESIGN CONSIDERATION OF POROUS ASPHALT
When deciding the thickness of the layers of porous pavements, there are three factors needed: 1) site considerations to make sure that the location is acceptable; 2) hydrological design to make sure that the porous pavement satisfies the possible criteria for storm water runoff; and 3) structural design to make sure that the porous pavement withstands the projected traffic load. More frequently, rather than structural criteria, the thickness of the stone recharge bed will be influenced by the quantity of water (hydrological design) and soil penetration rates (site considerations), whereas the
porous asphalt surface layer will be measured by the traffic loads (structural design) [9]. The experimental research protocol to be tested and compare the clogging potentials of the two construction modes and the effect of clogging on their drainage and sound absorption properties. Two typical single- layer (Design A&B) and two typical double-layer (Design C&D) porous asphalt designs were considered. Design A was the least vulnerable to clogging, followed by design B and C, and design D was the most vulnerable to clogging. Nevertheless, designs A and B experienced substantial reductions in their sound absorption potential when completely clogged, while the other two designs were slightly less impacted by clogging [21]. The CPM model can simulate packing state. A new gradation for LSPM was developed and configured on the basis of the CPM, taking into consideration packing density. Subsequently, the basic pavement efficiency of the current LSPM was tested and compared to the existing one suggested by NCHRP 04 -18. The central efficiency of the latest and current LSPM, cracking resistance, has been calculated by OT [12]. For that purpose, two ways of expressing the percent clogging achieved in a test specimen which is % clogged based on porosity and % clogged based on permeability. With the definition of porosity, the level of clogging will have a meaning below 100 %, while the average clogging value should have been 100 % for other porous materials when the permeability is adopted. The definition of permeability is known to be a more realistic concept since it is fairly straightforward to calculate permeability both in the laboratory and in the field. In addition, it is nearly difficult to calculate changes in porosity in the region in a non-destructive way. There is a distinct difference of infiltration process between single and double-layer porous asphalt design. The single-layer specimens were penetrated by the clogging material virtually over their whole range, while the double-layer specimens were capable of handling the clogging material; mainly within their top layer, but some signs of clogging material could also be found in the porous bottom layer [21].
Aggregate Gradation of Porous Asphalt
Aggregate gradation one of the major parts of porous asphalt design consideration. For the sake of aggregate gradation to know the soil condition is very important factor. The California Bearing Ratio is the standard soil commonly used for highway building load power. Based on the rock type and gradation, CBR is calculated. There are some soil types that have a high CBR due to the sources of rock hardness, but proper gradation, such as proper gradation, must be assisted like stone crush, limestone. In general, since it has a wide bearing strength, the use of crushed stone pavement on the base layer and other type of aggregate also used. Maximum porosity will be given to the specified gradation band of each type of soil at permissible CBR for porous pavement. Aggregate gradation depends on many other factors as well just like percent passing, sieve size, reservoir base, upper limit, lower limit etc [22]. PAC-13 gradation with a full aggregate size of 16 mm was used for the mixing method in this report. There were also four gradations, namely SPG-4.75, SPG-9.5, BPG-4.75 & 9.5 and PAC-13. adopted to study the effect of simple to complex level gradation on aggregate migration.
Motion trend of these four particles is more or less similar to the PAC-13, but the PAC-13 smaller than that of the following three mixtures in gradation. In addition, parallel experiment findings reveal that the dispersion of PAC-13 interlayer distance data is greater than other gradations, since the overall particle size in GSP- 4.75, GSP-9.5, and BPG- 4.75 & 9.5 is fairly uniform and it is simpler to obtain a comparable compaction state with the same compaction conditions [23]. It is indicating that cold recycle mixture with asphalt emulsion (CRME) with the three gradations chosen have a good efficiency, suggesting that the expanded gradation selection for directing CRME engineering activities is to some degree feasible. If the ageing era begins, the indirect tensile strength (ITS) and the ITS-freezing ratio of all CRME will first increase rapidly and then increase gradually or even decrease, and the ageing of asphalt in CRME will become more and more extreme. Compared to three gradations, the better gradation of the CRME has increased final and long-term efficiency [24]. Although some studies have studied the impact of gradation on the final performance of CRME, long- term performance has been overlooked. RAP is actually commonly known as "black rock" in the gradation phase of the CRME. It is well known that certain gross particles in RAP are simply the arrangement of fine RAP particles bound to the aged asphalt. The gradation of the CRME can then change as the service time move ahead. As the lubrication effect of the water is more apparent than that of the asphalt emulsion, the optimum water content (OWC) approach is used instead of the optimum solvent content process. The optimum water content (OWC) of cold recycle mixture with asphalt emulsion (CRME) with G 37, G 41 and G 45 are 4.31 %, 4.74 % and 5.02 %, respectively. It indicates that the further fines in CRME contribute to a wider region of CRME, which requires further water to soak the aggregate [24]. Koohmishi
& Shafabakhsh et al., obtained indicate that supplying a smaller gradation of the aggregate (especially with a lower effective diameter) contributes to a decrease in the permeability of the reservoir. Consideration of a standard gradation for a small variety of particle sizes helps in the calculation of higher values for the hydraulic conductivity coefficient. In addition, the influence of media porosity with various particle size distributions on hydraulic conductivity is further expanded by the calculation of the air void content between particles and the application of the hydraulic conductivity by the image processing system [25]. Investigation of the impact of flow levels and layer thicknesses on the predicted precision of the combined gradation to track the gradation of the asphalt mixture in real time. Influences of the flow rate and the thickness of the coating on the gradation the combination of asphalt AC-13 has been determined. Ultimately, the rise in the flow rate reduced the forecast accuracy of the aggregate gradation by segmentation of the image; the forecast accuracy decreased with an increase in the thickness of the sheet [13]. It was discovered that the macrotextures single grain size aggregates have been expanded as grain size has increased, macrotextures of mixed grain size aggregates have been expanded as the proportion of small grain size particles has declined and both fine aggregates and mineral powders have improved aggregate shape. In the meanwhile, the impact of the aggregate scale on the macro-structure of the pavement was greater than that of the proportion of voids in coarse aggregate (VCA) in the dry rodded condition [26].
DIGITAL IMAGE PROCESSING
With respect to sound absorption behaviour, both spatial features and the composition of air voids have some effects on the acoustic properties of porous asphalt. Microstructure statistical variables such as 3D fractal dimension or pore diameter distributions are evaluated from X-ray CT scans using digital image processing techniques. The design of the research demonstrates how to examine the acoustic more fundamentally, in view of changes in the air vacuum microstructure, degradation of porous asphalt due to soiling effects during its service life is probable [27]. The characteristic parameters of the microscopic void were found to have little effect on the resistance to moisture sensitivity at high temperature and cooling efficiency, but to have a clear correlation with other characteristics such as ravelling resistance, permeability, connective porosity and noise reduction. The experimental findings suggested that the size of the pore could decide whether or not clogging particles would obstruct or move through the pores [19]. Several researchers have used non- destructive assessment by way of civil engineering assessment using X-ray computed tomography (CT) for materials. The internal configuration of the asphalt mixture and the distribution of voids is accomplished by X-ray CT. Moreover, to research the void formation of permeable pavement, image processing technology was used. Before and after rapid pavement experiments, Erdem et al., obtained CT images of the asphalt mixture to analyse improvements in void and aggregate distribution with image analysis and particle tracking methods. Obtaining easily distinguishable void variations is very critical. Porous asphalt mixtures have been prepared by several researchers by porosity. Five types of gradations have been selected to achieve porous asphalt mixtures with distinguishable void variations, as seen in figure 1. The association between mixture properties and void characteristic parameters was visually evaluated using R Studio.
The analysis of R correlation will help discern the major difference in correlation and facilitate the analysis of data [19].
Figure 1. (a) X-ray CT images; (b) images processed with threshold
To determine the migration characteristics, the main axis orientation and interlayer distance are used as evaluation measures obtained by digital image processing (DIP) and Image-pro plus (IPP) software with concrete particles in mixtures with asphalt. The findings suggest the self-organization and immigration of in PAC, aggregate particles are united and statistical regularity is provided in the migration data of particles. In order to form a stable aggregate skeleton during the vibration compaction, the aggregate particles are steadily deflected into the horizontal direction [23]. Several studies are dedicated to exploring the association between the internal structure and PAC efficiency. In order to describe the distribution, scale, and connectivity of the internal structure in PAC, Pei et al. used an image processing technique.
The productivity of the PAC is highly determined by the internal configuration during the compaction phase, characteristics related to the skeleton formation. The Charge-coupled device (CCD) camera imaging technique and X-ray CT scanning technique are used with the advancement of technologies to obtain photographs of the internal composition of asphalt mixtures, and then the digital imaging processing (DIP) technique is used to determine the aggregate migration and forming of skeletons. The aggregate shape characteristic of red sandstone with a particle size greater than 4.75 mm in porous asphalt mixtures is used to examine the aggregate motion characteristics and the skeleton forming phase is shown in figure 2. The observational results of specimens moulded with the same vibration parameters should stay substantially stable in order to ensure the reliability and persuasiveness of the research observations [23].
Figure 2. The analysis process of internal structure in the PAC
INCORPORATING FIBERS IN POROUS ASPHALT Cellulose Fiber
The French chemist Anselme Payen discovered cellulose in 1838, isolating it from plant matter and establishing its chemical composition. Cellulose was used by the Hyatt Manufacturing Corporation in 1870 to manufacture the first popular thermoplastic polymer, celluloid. In the 1890s, the manufacture of rayon ('artificial silk') from cellulose began, and in 1912, cellophane was invented. Cellulose fibres are fibres formed from ethers or cellulose esters that can be derived from plant bark, wood or leaves, or from other plant materials. The fibres can also include hemicellulose and lignin in addition to cellulose, with varying ratios of these components changing the mechanical properties of the fibres. Other choices for bio composites and polymer composites are the major uses of cellulose fibres in the textile industry, both as chemical filters and as fibre reinforcement composites, because of their similar properties to engineered fibres. Cellulosic fibres have a low elasticity modulus. This dictates its application, with high energy absorption and resistance to dynamic forces, in building components operating in the post-cracked stage. Cellulose fibres have major benefits in contrast to engineered fibres, such as low density, low cost, recyclability and biodegradability. Cellulose fibres can be used as a replacement for glass fibres in composite materials because of their advantages. In fact, what is sometimes sold as
"bamboo fibre" is not the fibres from the bamboo plants that emerge in their natural state, but instead a highly engineered bamboo pulp that is extruded as fibres. Although the procedure is not as environmentally friendly as' bamboo fibre' seems, in some situations, planting and harvesting bamboo for fibre may be more sustainable and environmentally friendly than harvesting slower growing trees and clearing natural timber plantation forest ecosystems [28].
According to Afonso et al., cellulose fibres increase the PAM rutting resistance due to high bitumen absorption, but there was no change in ravelling resistance when combined with tidy binders. cellulose fibres, in particular, had negative effects in the wet Cantabro test, increasing particle loss [29]. Adding cellulose fibres has little role in accounting for stiffness, moisture susceptibility, and ITS. Lyons used cellulose fibres with a length of 6 mm and stated that cellulose fibres would minimise porosity by up to 22%. A strong absorption of binder by cellulose fibres is found when cellulose fibres are well spread, which may be responsible for less binder drainage and permeability. Eskandarsefat et al. discovered that mixtures with cellulose fibres had a high Marshal stability due to the high binder absorption ability of cellulose fibers [30].
Figure 3. Images of vegetable fibers in different forms: (a) strands, (b) staple, and (c) pulp
Steel Fiber
Steel fibre is a metal reinforcement. Steel concrete reinforcement fibres are classified as short, distinct lengths of steel fibres with an aspect ratio (length to diameter ratio) of approximately 20 to 100, with separate cross-sections and relatively small to be uniformly distributed using the normal mixing techniques in an unhardened concrete mixture. A certain volume of concrete steel fibre can induce qualitative improvements in the physical property of concrete, significantly enhancing resistance to breaking, impact, fatigue, and bending, tenacity, toughness, and other characteristics. Essentially, based on the production process and its form and/or portion, steel fibre can be divided into five groups: cold-drawn wire, cut sheet, melt-extracted, mill cut, and modified cold-drawn wire (as shown in Figure 4) [31].
Figure 4. Examples of steel fibers
In the construction sector, the application of steel fibres needs vast amounts of raw materials for the manufacture of these steel fibres on an industrial scale, resulting in severe environmental issues about the carbon footprint. Sustainability, resource management, and recycling have been one of the key priorities for lawmakers over recent years and have attracted academics to find new ways to resolve environmental problems during the manufacture of industrial steel fibres.
Recent advances in the use of recycled steel fibres have successfully resolved the concerns of high cost, waste disposal and environmental effects of the manufacture of industrial steel fibres [32].
Bamboo Fiber
A cellulosic fibre regenerated from bamboo plants is bamboo fibre. It is a perfect prospective green fibre with excellent textile content that is biodegradable, with strength equal to traditional fibres of glass. In general, bamboo used for fibre preparation is 3-4 years old. By alkaline hydrolysis and multi-phase bleaching of bamboo stems and leaves, fibre is made, followed by chemical treatment of the starchy pulp created during the process [33]. There are various mechanical properties of bamboo fibre-reinforced malleated PP composites with bamboo fibres of varying sizes (< 500μm, 500-
850μm, 850 μm to 1 mm and % lt; 2 mm). Bamboo enhanced MAPP's tensile strength and module raise with a material increase of up to 65 % wt. (as shown in figure 7). For 50 wt. % filled PP, a tensile modulus of 3.4 GPa is obtained, whereas it is about 4 GPa for 50 wt. % MAPP. Similarly, the tensile strength of 50 % bamboo-MAPP composite is 36 MPa, while tensile strength declines marginally for PP composites. Tensile strength and modulus are also enhanced with increased maleic anhydride (MAH) content as a result of improved adhesion between the bamboo fibre and the polymer matrix. Both tensile strength and tensile modulus decrease dramatically with the growing size of bamboo fibres, possibly due to the fact that a smaller fibre has a comparatively greater surface area at the same composition, resulting in stronger interaction between fibre and matrix [34].
Figure 5. (a) raw bamboo fiber, (b) bamboo fiber treated with NaOH 5%, and (c) bamboo fiber treated with NaOH 10%
CONCLUSION
This paper reports the first attempt to enhance the exploration capability of Simulated Kalman filter (SKF) by applying current optimum opposition-based learning (COOBL) technique. In addition, jumping rate is also integrated in the proposed method. Once the jumping rate condition is met, the opposite solution is selected if the solution is better than the current one. The analysis confirmed that the proposed COOBSKF is superior to SKF and better than GA, GWO, PSO and BH. For future research, different OBL techniques shall be considered to enhance further the SKF.
ACKNOWLEDGEMENT
The authors would like to thank UMP for funding this work under an internal grant RDU190387.
REFERENCES
[1] S. Ahmad, “Porous asphalt reduces storm water runoff | Asphalt magazine,” 2006. [Online]. Available:
http://asphaltmagazine.com/porous-asphalt-reduces-storm-water-runoff/. [Accessed: 01-Feb-2021].
[2] R. M. Roseen, T. P. Ballestero, J. J. Houle, J. F. Briggs, and K. M. Houle, “Water Quality and Hydrologic Performance of a Porous Asphalt Pavement as a Storm-Water Treatment Strategy in a Cold Climate,” J. Environ. Eng., vol. 138, no. 1, pp. 81–
89, Jan. 2012, doi: 10.1061/(asce)ee.1943-7870.0000459.
[3] L. Zanoni, A. Boysen, M. Carlson, and J. Harris, “The Benefits of Using Porous Asphalt Pavement in Comparison with Other Forms of Pervious Pavements,” 2019.
[4] J.-S. Chen and C. H. Yang, “Porous asphalt concrete: A review of design, construction, performance and maintenance,” Int. J.
Pavement Res. Technol., vol. 13, no. 6, pp. 601–612, Nov. 2020, doi: 10.1007/s42947-020-0039-7.
[5] D. M. Kusumawardani and Y. D. Wong, “The influence of aggregate shape properties on aggregate packing in porous asphalt mixture (PAM),” Constr. Build. Mater., vol. 255, p. 119379, 2020, doi: 10.1016/j.conbuildmat.2020.119379.
[6] P. Lastra-González, I. Indacoechea-Vega, M. A. Calzada-Pérez, and D. Castro-Fresno, “Recyclability potential of induction- healable porous asphalt mixtures,” Sustain., vol. 12, no. 23, pp. 1–11, Dec. 2020, doi: 10.3390/su12239962.
[7] X. Wang, X. Gu, F. Ni, H. Deng, and Q. Dong, “Rutting resistance of porous asphalt mixture under coupled conditions of high temperature and rainfall,” Constr. Build. Mater., vol. 174, pp. 293–301, 2018, doi: 10.1016/j.conbuildmat.2018.04.104.
[8] G. B. Wright, S. Arthur, G. Bowles, N. Bastien, and D. Unwin, “Urban creep in Scotland: stakeholder perceptions, quantification and cost implications of permeable solutions,” Water Environ. J., vol. 25, no. 4, pp. 513–521, Dec. 2011, doi:
10.1111/j.1747-6593.2010.00247.x.
[9] Fhwa, “Tech Brief: Porous Asphalt Pavements with Stone Reservoirs,” 2015.
[10] B. Xu, M. Li, S. Liu, J. Fang, R. Ding, and D. Cao, “Performance analysis of different type preventive maintenance materials for porous asphalt based on high viscosity modified asphalt,” Constr. Build. Mater., vol. 191, pp. 320–329, 2018, doi:
10.1016/j.conbuildmat.2018.10.004.
[11] L. Gao, Z. Wang, J. Xie, Z. Wang, and H. Li, “Study on the sound absorption coefficient model for porous asphalt pavements based on a CT scanning technique,” Constr. Build. Mater., vol. 230, p. 117019, 2020, doi: 10.1016/j.conbuildmat.2019.117019.
[12] G. Yuan, P. Hao, D. Li, J. Pan, and S. Dong, “Optimization design and verification of Large Stone Porous asphalt Mixes gradation using Compressible Packing Model,” Constr. Build. Mater., vol. 230, p. 116903, 2020, doi:
10.1016/j.conbuildmat.2019.116903.
[13] R. Cao, Y. Zhao, Y. Gao, X. Huang, and L. Zhang, “Effects of flow rates and layer thicknesses for aggregate conveying process on the prediction accuracy of aggregate gradation by image segmentation based on machine vision,” Constr. Build. Mater., vol. 222, pp. 566–578, 2019, doi: 10.1016/j.conbuildmat.2019.06.147.
[14] TRB, “Asphalt Additives and Modifiers | Relationship Between Chemical Makeup of Binders and Engineering Performance | The National Academies Press,” 2017. [Online]. Available: https://www.nap.edu/read/24850/chapter/7. [Accessed: 01-Feb- 2021].
[15] Z. Jiang, C. Hu, S. Easa, X. Zheng, and A. O. A. El Halim, “Identifying optimal polymer type of modified asphalt based on damping characteristics,” Constr. Build. Mater., vol. 173, pp. 308–316, 2018, doi: 10.1016/j.conbuildmat.2018.03.278.
[16] R. tur Rasool, Y. Hongru, A. Hassan, S. Wang, and H. Zhang, “In-field aging process of high content SBS modified asphalt in porous pavement,” Polym. Degrad. Stab., vol. 155, pp. 220–229, 2018, doi: 10.1016/j.polymdegradstab.2018.07.023.
[17] Z. Ding, J. Zhang, P. Li, X. Yue, and H. Bing, “Analysis of viscous flow properties of styrene–butadiene–styrene-modified asphalt,” Constr. Build. Mater., vol. 229, 2019, doi: 10.1016/j.conbuildmat.2019.116881.
[18] H. Zhang, M. Gong, D. Gao, T. Yang, and Y. Huang, “Comparative analysis of mechanical behavior of composite modified asphalt mixture based on PG technology,” Constr. Build. Mater., vol. 259, p. 119771, 2020, doi:
10.1016/j.conbuildmat.2020.119771.
[19] Y. Luo, K. Zhang, P. Li, J. Yang, and X. Xie, “Performance evaluation of stone mastic asphalt mixture with different high viscosity modified asphalt based on laboratory tests,” Constr. Build. Mater., vol. 225, pp. 214–222, 2019, doi:
10.1016/j.conbuildmat.2019.07.119.
[20] J. Jie et al., “Rutting resistance of direct coal liquefaction residue (DCLR) modified asphalt mixture under variable loads over a wide temperature range,” Constr. Build. Mater., vol. 257, p. 119489, 2020, doi: 10.1016/j.conbuildmat.2020.119489.
[21] L. Chu and T. F. Fwa, “Functional sustainability of single- and double-layer porous asphalt pavements,” Constr. Build. Mater., vol. 197, pp. 436–443, 2019, doi: 10.1016/j.conbuildmat.2018.11.162.
[22] Y. Zaika and L. Djakfar, “Gradation Band of Some Types Material for Reservoir Base of Porous Pavement,” Online, 2016.
[23] J. Huang et al., “Investigation on aggregate particles migration characteristics of porous asphalt concrete (PAC) during vibration compaction process,” Constr. Build. Mater., vol. 243, p. 118153, 2020, doi: 10.1016/j.conbuildmat.2020.118153.
[24] C. Zhu, H. Zhang, H. Guo, C. Wu, and C. Wei, “Effect of gradations on the final and long-term performance of asphalt emulsion cold recycled mixture,” J. Clean. Prod., vol. 217, pp. 95–104, 2019, doi: 10.1016/j.jclepro.2019.01.264.
[25] M. Koohmishi and G. Shafabakhsh, “Drainage potential of reservoir course of porous pavement for various particle size distributions of aggregate,” Transp. Geotech., vol. 16, no. March, pp. 63–75, 2018, doi: 10.1016/j.trgeo.2018.07.002.
[26] X. Wu, N. Zheng, and F. Kong, “The analysis of the factors affecting the macrotexture of bauxite clinker aggregate gradation,”
Constr. Build. Mater., vol. 244, p. 118334, 2020, doi: 10.1016/j.conbuildmat.2020.118334.
[27] S. Alber et al., “Investigation of microstructure characteristics of porous asphalt with relevance to acoustic pavement performance,” Int. J. Transp. Sci. Technol., vol. 7, no. 3, pp. 199–207, 2018, doi: 10.1016/j.ijtst.2018.06.001.
[28] Anomin, “Cellulose fiber - Wikipedia,” 2013. [Online]. Available: https://en.wikipedia.org/wiki/Cellulose_fiber. [Accessed:
16-Jan-2021].
[29] A. Gupta, J. Rodriguez-Hernandez, and D. Castro-Fresno, “Incorporation of additives and fibers in porous asphalt mixtures: A review,” Materials, vol. 12, no. 19. MDPI AG, p. 3156, 01-Oct-2019, doi: 10.3390/ma12193156.
[30] A. Gupta, J. Rodriguez-Hernandez, and D. Castro-Fresno, “Incorporation of additives and fibers in porous asphalt mixtures: A review,” Materials, vol. 12, no. 19. MDPI AG, p. 3156, 01-Oct-2019, doi: 10.3390/ma12193156.
[31] B. Han, X. Yu, and J. Ou, “Compositions of Self-Sensing Concrete,” in Self-Sensing Concrete in Smart Structures, Elsevier, 2014, pp. 13–43.
[32] K. M. Liew and A. Akbar, “The recent progress of recycled steel fiber reinforced concrete,” Construction and Building Materials, vol. 232. Elsevier Ltd, p. 117232, 30-Jan-2020, doi: 10.1016/j.conbuildmat.2019.117232.
[33] S. R. Imadi, I. Mahmood, and A. G. Kazi, “Bamboo fiber processing, properties, and applications,” in Biomass and Bioenergy:
Processing and Properties, vol. 9783319076, Springer International Publishing, 2014, pp. 27–46.
[34] Navin Chand and M. Fahim, “Bamboo reinforced polymer composites,” in Tribology of Natural Fiber Polymer Composites, Elsevier, 2008, pp. 162–179.
