Optimum Asphalt Research Articles

Enhancing Porous Asphalt Performance by Adding Waste Mask Fiber: Experimental Analysis of Stiffness, Fatigue, and Creep at Optimum Asphalt Content

Purpose: This study aims to evaluate the impact of incorporating waste mask fibers into porous asphalt mixtures, focusing on stiffness, fatigue, and creep performance at the optimum asphalt content (OAC). Theoretical Reference: The study is based on sustainable construction and materials engineering theories, emphasizing the recycling of waste materials to enhance the performance of construction materials and mitigate environmental impacts. Method: Laboratory experiments were conducted by adding waste mask fibers at varying levels (0%, 1%, 2%, and 3% by weight of asphalt) to the porous asphalt mixtures. Test specimens were designed and evaluated for stability, flow, Marshall Quotient, Voids in Mineral Aggregate (VIM), indirect tensile strength (ITS), stiffness (ITSM), fatigue, and creep performance. Results and Conclusion: The addition of 1% waste mask fibers at the OAC is recommended as it meets the criteria for stability, flow, Marshall Quotient, and VIM. The Cantabro Test showed enhanced resistance, while the ITS Test indicated increased indirect tensile strength. The ITSM Test revealed heightened stiffness of the mixture. Although fatigue testing demonstrated that the porous asphalt mixture could bear loads until collapse at a certain stress level, the creep test confirmed the mixture's resistance to permanent deformation due to traffic loads. Implications of research: The findings suggest that incorporating waste mask fibers into asphalt mixtures can improve mechanical properties and durability, offering a sustainable solution for mask waste disposal. This approach can be adopted by policymakers and engineers to enhance road construction practices while addressing environmental concerns. Originality/value: This study provides novel insights into the recycling of waste mask fibers in asphalt mixtures, demonstrating their potential to improve performance and sustainability in road construction. The research offers a pioneering approach to addressing the environmental challenges.

Performance Characteristics of Nano Palm Shell Ash (NPSA) in Asphalt Mixture

One innovation in creating new materials that have superior properties compared to large-sized materials is to use nanotechnology. The uniqueness of nano materials is that the smaller the size of the material, the greater the surface area and performance characteristics of the material in the asphalt mixture. This research develops nano technology in asphalt pavement construction by making nano material from palm shell ash waste. The aim of this research is to determine the effect of adding palm shell ash nano material as a substitute for asphalt in the AC-WC mixture. The research method was carried out by testing the morphological characterization of the palm shell ash nano material using X-Ray Fluorescence (XRF) testing and Scanning Electron Microscope (SEM) testing, then continuing with testing the characteristics of the mixture using the Marshall testing method. The nano material used is palm shell ash material obtained from palm shell burning waste originating from Riau which is then processed into Nano Palm Shell Ash (NPSA) material using a ball mill. The asphalt used is Pen 60/70 asphalt produced by Pertamina. The use of NPSA material in asphalt modification with NPSA variations of 1%, 2% and 3% can improve the performance of marshal characteristics compared to conventional asphalt mixtures. It can be seen that the stability, flow, VFA and MQ values increase with increasing NPSA percentage in asphalt. Meanwhile, the VIM and VMA values decreased along with the increase in the NPSA percentage in asphalt. In addition, increasing the percentage of NPSA in asphalt can reduce the use of optimum asphalt content compared to conventional asphalt mixtures. Utilizing palm shell ash waste is the best alternative for improving the performance of asphalt in mixtures and is environmentally friendly and economical.

Investigating the Dynamic Creep of Polymer Modified Hot Mix Asphalt

Abstract Jordan's road network continues to deteriorate as a consequence of the continuous increase in traffic and the absence of adequate maintenance work. The primary objective of this study was to enhance HMA performance by using polymer-modified asphalt mixtures. The polymer modifier known commercially as Eastman (EE-2) was mixed with binder penetration grade (60–70) at a ratio of 12%. In order to investigate the performance of polymer, the dynamic creep, the resilient modulus and the stability-flow tests were performed. Marshall Mix design was utilized to prepare a total of 50 samples, of which 20 were used to determine the optimal binder content, and the remaining samples were used to determine the effect of EE-2 modifier on asphalt mixtures. The results showed that the optimal asphalt content was 4.57 percent and revealed that the addition of EE-2 polymer to asphalt cement contributed to the production of a variety of desirable properties. The most important indicator of these developments is increased rutting resistance. For instance, the total permanent deformation has decreased by 87% (8500 to 1000 μm). Conversely, addition of EE-2 has resulted in a threefold increase in the resilience modulus (from 3632 to 10590 MPa). Finally, effect of the EE-2 polymer on the stability was demonstrated by increasing the stability value by about 52%

Penggunaan Serbuk Batu Bata Merah Sebagai Filler Campuran Aspal AC-WC, Pengganti Semen dan Abu Batu dengan Marshall Test

Asphalt concrete as a material for road construction has long been known and widely used in road construction. This study aims to determine the effect of using red brick powder as a filler in the AC-WC asphalt mixture compared to cement and stone ash using the Marshall test with filler variations of 1%, 2%, 3%, and 4%. The determination of the optimum asphalt content was done with trial mixes of 60/70 penetration asphalt starting at asphalt contents of 5.5%, 6%, 6.5%, 7%, and 7.5%. From the initial asphalt mixture tests, an Optimum Asphalt Content (OAC) of 7% was obtained, which meets the Bina Marga 2018 specifications. The results of the Marshall tests on variations of red brick powder, cement, and stone ash fillers at 1% and 2% filler content did not meet the Bina Marga 2018 specifications. However, at 3% and 4% filler content, all Marshall test results met the Bina Marga 2018 specifications. The optimum value of the AC-WC asphalt mixture obtained from the Marshall test was with 4% cement filler, yielding a VIM of 4.239%, VMA of 17.305%, VFA of 79.880%, Marshall stability of 1551 kg, flow of 3.23 mm, and MQ of 480 kg/mm. The use of red brick powder as a filler at 4% filler content was better than stone ash and can be used as it approaches the optimum value, with a VIM of 4.267%, VMA of 17.226%, VFA of 79.637%, Marshall stability of 1529 kg, flow of 3.20 mm, and MQ of 478 kg/mm.

Optimizing the Use of Palm Fiber to Increase Stability and Deformation Resistance in Asphalt Concrete Mixes

Modifying asphalt binder materials with fiber reinforcement is one approach to improving the performance of asphalt concrete mixtures. This research aims to evaluate the effect of optimal palm fiber concentration on strengthening and improving the properties of the mixture and rutting resistance. Test specimens were made with four variations in the composition of a mixture of different palm fiber percentages (0%, 0.4%, 0.6%, and 0.85) with lengths (0.4 cm, 0.6 cm, 0.8 cm, and 1.0 cm) using an optimum asphalt content of 6% to evaluate the properties of the asphalt concrete mixture based on the Marshall Test. In comparison, the rutting indicator was evaluated using a wheel tracking tool with four variations in the percentage of palm fiber to an optimal length of 0.8 cm. The results of the Marshall test research showed that palm fiber increased stability by 6%, with the highest stability at a percentage of palm fiber of 0.6% with a length of 0.8 cm 1210.45 kg, higher than the normal mixture with a stability value of 1142.59 kg, VIM value decreased by 14% compared to the normal mixture and increased the flexibility of the mixture at the optimum percentage composition of palm fiber 0.6% length 8 cm by 4%. Fibre wheel tracking test results show that adding fiber fibers increases the groove and rutting resistance of optimum fiber by 53% with a total deformation value of 0.856 mm, dynamic stability of 5727 passes/mm, and a deformation rate of 0.007/mm/minute. Palm fiber is not strong enough to withstand heat due to a mixing temperature of 150oC and a compaction temperature of 140oC, with a higher risk of fiber damage

Analysis of Optimum Asphalt Content of Lasbutag Mixture (Buton Aggregate Asphalt Coating) Modified by Waste Oil and Diesel as Modifier

Analysis of Optimum Asphalt Content of Lasbutag Mixture (Buton Aggregate Asphalt Coating) Modified by Waste Oil and Diesel as Modifier

Aging Resistance Evaluation of an Asphalt Mixture Modified with Zinc Oxide

The phenomenon of the oxidation and aging of asphalt binders affects the strength and durability of asphalt mixtures in pavements. Several studies are trying to improve the resistance to this phenomenon by modifying the properties of the binders with nano-particles. One material that shows promise in this field is zinc oxide (ZnO), especially in improving ultraviolet (UV) aging resistance. Few studies have evaluated the effect of these nano-particles on the thermo-oxidative resistance of asphalt binders, and, on hot-mix asphalt (HMA), studies are even more scarce and limited. Therefore, in the present study, the resistance to thermo-oxidative aging of an HMA manufactured with an asphalt binder modified with ZnO was evaluated. An asphalt cement (AC 60–70) was initially modified with 0, 1, 3, 5, 7.5, and 10% ZnO (percentage by weight of asphalt binder; ZnO/AC in wt%), and then exposed to aging in Rolling Thin-Film Oven tests (RTFOT) and a Pressure Aging Vessel (PAV). Penetration, viscosity, and softening point tests were performed on these binders, and aging indices were calculated and evaluated. Samples of HMAs were then manufactured using these binders and designed by the Marshall method, determining the optimum asphalt binder content (OAC) and the optimum ZnO/AC ratio. Control (unmodified) and modified HMA were subjected to short-term oven aging (STOA) and long-term oven aging (LTOA) procedures. Marshall, Indirect Tensile Strength (ITS), and resilient modulus (RM) tests were performed on these mixtures. LTOA/STOA results of the parameters measured in these tests were used as aging indices. In this study, ZnO was shown to increase the thermo-oxidative aging resistance of the asphalt binder and HMA. It also contributed to an increase in the resistance under monotonic loading in the Marshall and ITS tests, and under repeated loading in RM test. Likewise, it contributed to a slightly increasing resistance to moisture damage. The best performance is achieved using ZnO/AC = 5 wt%.

The Utilization of Coconut Shell Ash Waste as Filler in Pavement Mixture towards Green Infrastructure

Road is one of the most important land infrastructure in supporting community activities and regional development. The problem with current road construction is the increasingly limited availability of natural materials, so it necessary to innovate materials made from waste. This research utilizes waste material in the form of coconut shell ash as a filler towards the realization of green infrastructure. The purpose of this research was to obtain the characteristics of filler, aggregate, asphalt and their effect on road pavement mixtures. The research method is research in the laboratory. The results obtained are that the physical properties of aggregate, asphalt and coconut shell ash meet the requirements of The General Highway Specification. Utilization of coconut shell ash filler of 3.5% obtained Optimum Asphalt Content (OAC) of 5.5%, 4% obtained OAC of 5.8%. Based on results of the Marshall parameters for the two mixtures meet all the standards of The General Highways Specification. The use of coconut shell ash as filler in a mixture of road pavements can increase the strength and durability of road pavements, as well as support the realization of green infrastructure. It can have an impact on improving environmental quality through the use of waste for road pavement towards the development of environmentally green infrastructure.

Laboratory and Environmental Assessment of Asphalt Mixture Modified with a Compound of Reclaimed Asphalt Pavement and Waste Polyethylene

The use of reclaimed asphalt pavement (RAP) in manufacturing asphalt concrete has become indispensable all over the world. This is due to the limited number of areas that are required to stockpile scraped pavement, as well as a lack of natural aggregate, which is necessary in manufacturing asphalt concrete. Thus, this research aims to evaluate the mechanical characteristics and environmental impact of using RAP and waste polyethylene in hot mix asphalt (HMA). RAP was added to hot mix asphalt in proportions of 25%, 50%, 75%, and 100% instead of the same amount of coarse aggregate. Then, the optimum RAP hot mix asphalt was modified by adding polyethylene in proportions of 1%, 2%, 3%, and 4% into the hot mix asphalt. The Marshall mix design was used to define the optimum asphalt content. As a final point in this experimental work, tests on the loss of stability, indirect tensile strength, and wheel loading tracking were performed to assess the performance of asphalt mixes modified with RAP and polyethylene in different conditions. A life cycle assessment (LCA) was applied using the ReCipe 2016 Endpoint method to evaluate the environmental impacts of these mixtures using the SimaPro software, V9.1. The laboratory tests showed that the mixture containing 50% RAP instead of the same amount of coarse aggregate and 2% polyethylene recorded better Marshall characteristics than the control mixture and the mixture with RAP alone. Finally, the modified hot mix asphalt with added RAP and polyethylene not only achieved superior performance in rutting, water damage resistance, and the stiffness modulus of bituminous mixtures, but it has been verified that there is no serious risk to the environment.

Analysis of the properties of chemical content and the use of local material Kinang Jingkion as coarse aggregate against the characteristics of WC last (AC) mixture in Yalimo Regency

This study aims to analyze the nature of chemical content, analyze abrasion value and optimum asphalt content using local Kinang Jingkion as road pavement material. In this study, XRF and XRD testing methods were used to determine the chemical content of Kinang Jingkion local material, then testing the characteristics of rough aggregate to determine the abrasion value, testing fine aggregate characteristics, and testing asphalt pen 60/70 and marshall test to determine the optimum asphalt content (KAO). The tests obtained the results of comparative data analysis between laboratory tests and literature standards that meet the eligibility requirements. The results showed that: First, the results of XRF and XRD analysis on Wilihingke samples, 0.15 mm granules, 2.36 mm granules, and Kinang Holuwon found that all chemical elements contained in the four samples were solid metal inorganic chemical elements. The results of this analysis prove that the four samples, which are fine aggregates and coarse aggregates, do not contain organic substances. Where the results of this analysis are by the requirements of aggregates which are one of the components in the concrete mixture, where the aggregates used must meet certain conditions, one of which must not contain excess organic matter because it can undergo decay by bacteria using dissolved oxygen; Second, from the test results obtained, the aggregate wear value (abrasion) was 32.69%; Third, based on the test results, the value of the Marshall parameter with Optimum Asphalt Content (KAO) obtained a value of 6.125%.

Mechanical Properties and Performance of Mixtures Containing a High Level of Recycled Materials That Are Designed Using Alternative Approaches

Using recycled asphalt material (RAM) in asphalt mixtures is very common among transportation agencies. With the recent development of balanced mix design methods, it is becoming more important to understand how to optimize mixture performance by offsetting the adverse effects of RAM. In this paper, mixtures from three different sources were adjusted according to the availability adjusted mix design (AAMD) and corrected optimum asphalt content (COAC) methods. Three control mixtures containing RAM, three mixtures containing no RAM, five mixtures designed according to the AAMD method (two of which had 50% reclaimed asphalt pavement content), and two mixtures adjusted using the COAC-based approach were evaluated. Both asphalt mixture performance tester experiments and index tests were used in this study to evaluate material-level indicators of cracking and rutting resistance. Additionally, pavement performance simulations were carried out using AASHTOWare Pavement ME and FlexPAVETM to assess how the observed material-level differences led to differences in structural-level pavement performance. Both the AAMD and COAC methods improved cracking measures. However, the results suggest that the additional virgin binder added through the COAC method without any adjustments to the aggregate structure can have negative consequences for the rutting performance measures. In addition, the mixture and pavement performance results suggest that the AAMD method is a rational approach for including recycled binder availability in mix design procedures to promote improvements in the cracking performance of mixtures by controlling the volumetric properties and the aggregate structure of the mix without having a detrimental effect on rutting resistance.

The Friction-Lubrication Effect and Compaction Characteristics of an SMA Asphalt Mixture under Variable Temperature Conditions.

The aim of this article is to explore the dynamic compaction characteristics of stone mastic asphalt (SMA) and the friction-lubrication effect of internal particles during the superpave gyratory compaction (SGC) process. Firstly, a calculated method for the compaction degree of an asphalt mixture in the gyratory compaction process was defined based on the multiphase granular volume method. Secondly, the gyratory compaction curves of asphalt mixtures were taken based on this calculation method of compaction degree. The dynamic change law of each compaction index (compaction, percentage of air voids, compaction energy index, etc.) during the compaction process was analysed. Finally, the effects of different initial compaction temperatures and different asphalt content on the friction-lubrication effect and compaction characteristics of asphalt mixtures were studied. Research shows that it is reasonable to define the compaction degree by the ratio of the apparent density of the asphalt mixture to the maximum theoretical density of the asphalt mixture during gyratory compaction. The dynamic prediction equations of the compaction degree K and the compaction energy index CEI with the amount of compaction were established, and could effectively predict the compaction degree, percentage of air voids and compaction energy index CEI. The compaction process of the asphalt mixture needed to go through three phases, including periods of rapid growth, slow growth, and stabilisation, and the compaction degree increased by about 10%, 5%, and 1%, in that order, finally tending towards a stable value. The effect of the initial compaction temperature on the forming compaction degree of the asphalt mixture is significant; therefore, it should be controlled strictly in the compaction construction of asphalt mixtures. When the initial compaction temperature of SMA-13 is about 170 °C, the compaction effect is optimal, and the effect of the increase in the amount of compaction at a later stage on the increase in the compaction degree of the asphalt mixture is very low. With the optimal asphalt content, the friction-lubrication effect between the asphalt and aggregate particles is optimal, because it can effectively form an asphalt film, reducing the frictional resistance of the particles moving each other during the compaction process, and the voids will be embedded and filled with each other, finally producing the best compaction result.

Development of Rainwater Filtration System with Porous Asphalt

Rainwater that is not properly collected causes stagnant water, where the water will be polluted by pollutants and contaminants. Thus, it is necessary to innovate to increase the availability of clean water using porous asphalt which is researched to reduce pollutants in polluted water. In this study, filtration of rainwater and stormwater runoff will be carried out using porous asphalt as a filter media with six different filtrate variations. Parameters analysed were pH, Total Dissolved Solids (TDS), and conductivity. The tests carried out were Optimum Asphalt Content (OAC) testing using the Marshall test method with a percentage of asphalt content used was 4-6%, Cantabro Loss testing, porosity, and permeability tests on porous asphalt specimens, as well as testing the filtration effect of porous asphalt. Rainwater and stormwater runoff that flowed through porous asphalt samples without the addition of filter media increased pH, TDS, and conductivity. In rainwater and stormwater runoff filtration, the highest increase in pH occurred in variation 3, namely porous asphalt + aggregate + limestone. The largest reduction in TDS and conductivity values occurred in Variation 7, namely porous asphalt + aggregate + coconut shell activated carbon + sponge + cotton.

Analysis Stability Of Asphalt Concrete Binder Course (AC-BC) With Fly Ash And Bottom Ash Substitution Material

Fly ash and bottom ash are ash produced from the process of burning coal as a source of energy in the steam generating unit of a coal-fired power plant (PLTU). Bottom ash is ash that forms at the bottom of a coal-burning furnace and settles there. In this research, fly ash is used as filler substitution and bottom ash is used as fine aggregate substitution (sand). The purpose of the study was to obtain a suitable Job Mix Design (JMD) for Asphalt Concrete - Binder Course (AC-BC) with fly ash and bottom ash substitution materials. To determine the effect of optimum asphalt content on the values of stability, flow, Marshall Quotient, VMA, VIM and VFB obtained from result of the Masrhall test. Based on the results of Marshall testing, the results show that Analysis Stability Of Binder Course Asphalt Concrete (AC-BC) With Fly Ash And Bottom Ash Substitution Material produces the highest VMA value of 14.462% and the highest VIM value of -1.88%, meaning that there are many gaps in the mixture containing asphalt so that it becomes waterproof and hermetic. The highest stability and MQ values are stability of 1955.55.34 kg and MQ of 1241.13 kg/mm. The appropriate Job Mix Design (JMD) for Asphalt Concrete - Binder Course (AC-BC) with fly ash and bottom ash substitution materials is the composition of Fly Ash at 0%, 50%, and 60% of the total cement while for the use of Bottom Ash from the total sand at 0%, 50%, and 60%.

Poisson's ratio testing method and multi-factor influence quantification model of asphalt pavement materials

The current standard in China does not specify the standard test method for determining Poisson's ratio, and the Poisson's ratio used in pavement design is often roughly fixed, which can result in large errors in the calculations and analysis of road structure. In this paper, the research on different test methods for Poisson's ratio is carried out and the non-linear characteristics of tensile and compressive Poisson's ratio on pavement materials under different influencing factors are analyzed. The results indicate that the absolute value of the ratio between transverse rebound strain and longitudinal rebound strain under 50% of the maximum destructive load can objectively characterize the mechanical properties of Poisson's ratio, and it is the optimal measurement method for Poisson's ratio in asphalt pavement materials. The Poisson's ratio of two pavement materials both decreases with the increase of loading rate and gradually tends to a constant value. Cement dosage and temperature are the most significant factors affecting the tensile and compressive Poisson's ratio of cement stabilized crushed stone and asphalt mixture, respectively. Specifically, when cement dosage increases by 1%, the Poisson's ratio of cement stabilized crushed stone decreases by approximately 10%, and the temperature has a significant influence on the difference in tension and compression for Poisson's ratio of asphalt mixture (up to 40%). The asphalt content corresponding to the minimum Poisson's ratio is basically consistent with the optimal asphalt content obtained by the Marshall volume method. Based on these, a quantification value-taking model is established of the tensile and compressive Poisson's ratios of typical asphalt pavement materials varying with multiple factors. The research results can serve as a reference for the scientific value-taking of pavement structural design parameters considering the different mechanical characteristics of materials in tension and compression.

The effect of Polyethylene Terephthalate (PET) plastic addition to AC-WC in a wet mixture on increase of asphalt stability

PET (Polyethylene Terephthalate) plastic is one of the most common types of plastic used in Indonesia. Its existence has contributed significantly to various sectors, including the food and beverage, cosmetic, pharmaceutical, and other consumer product packaging industries. However, the use of PET plastic also creates a number of impacts that need to be considered. PET (Polyethylene Terephthalate) plastic has become an attractive alternative in the construction industry in Indonesia, particularly in its use as an asphalt mixture in road construction. This study aimed to determine the effect of the addition of PET waste to the asphalt on the value of Marshall characteristics as well as the optimum asphalt content and plastic content in the AC - WC mixture. Basic testing of 4 %, 5 %, and 6 % (by weight of asphalt) PET plastic mixture with wet mixing method where PET plastic is put into hot asphalt and stirred until homogeneous. Marshall test data will go through Formality Test, Homogeneity Test, Two-Way ANOVA, Duncan Test, and Correlation Regression Analysis to get the 3D graph equation. The result is that PET plastic affects the asphalt mixture by increasing the stability value and MQ value, for flow, VFB, and VMA values have decreased. VIM value increased at 4 % level and decreased at 6 % level. From the ribbon graph, the optimum asphalt content for each percentage of PET content is obtained, namely 4 % PET KAO value of 6.2 %, 5 % PET KAO 6.25 %, and 6 % KAO 6.28 %. It can be concluded that the mixing of PET with asphalt in AC-WC mixtures can be maximum if the right percentage combination of asphalt and PET content. From the 3D Graphic Method, it results that the maximum use of plastic PET is at a content of 5.40 %, and an asphalt content of 6.35 %, will produce an asphalt stability of 1714.232 kN

Investigating the Dynamic Creep and the Tensile Performance of Zeolitic Tuff-modified Warm Asphalt Mixtures

Aims This research investigates the effect of adding natural Jordanian Zeolitic tuffs to the SUPERPAVE asphalt mixture at the dynamic creep and the indirect tensile performance. Background Rutting and fatigue are considered the most common types of distress that affect pavements all over the world. Many factors can affect these properties, such as different aggregate properties, asphalt grades, and properties, as well as the type and amount of the mineral filler. Mineral fillers play an important role in enhancing the asphalt mixtures' performance by filling the voids in the mixture besides improving the cohesion of the binder as it has a small weight in addition to a very large surface area. Generally, the powder of limestone is the most used type of filler. However, studies showed that many materials could also be used as mineral fillers successfully. The focus of this study is using natural Jordanian Zeolitic tuff as a mineral filler. Jordanian zeolitic tuff mainly consists of Phillipsite, chabazite, and faujasite, which are considered the most abundant Zeolitic tuff minerals. The pyroclastic material is widely distributed in the Badia region of northeast Jordan. Zeolitic tuffs are located in Jabal Aritayn (30km northeast of Azraq), Tlul AlShahba (20 km east of Al Safawi), Tal Al-Rimah (35 km northeast of Al Mafraq), and other small deposits in central and south Jordan. Objectives The aim of this research was to study the impact of Zeolitic tuffs on overall Superpave asphalt mixture performance. Methods The specimens were prepared using the optimum asphalt content obtained by the SUPERPAVE method. Dynamic Testing System DTS-16 was used to apply both dynamic creep and indirect tensile tests that give a good idea about the rutting and fatigue behavior of asphalt mixtures. Both tests were conducted at 25 °C. Results The Zeolitic tuffs modified asphalt mixtures have lower accumulated strains and higher creep stiffness compared to the control mixture. Subsequently, the indirect tensile test results showed that the modified asphalt mixtures have a higher resilient modulus than the control asphalt mix. Generally, using Zeolitic tuffs as a modifier of asphalt mixtures enhanced the rutting and fatigue resistance. The results showed that asphalt mixtures fortified with 25% Zeolitic tuffs emerged as the best contenders for rutting resistance. Also, mixtures enriched with 50% Zeolitic tuffs stood out in fatigue resistance performance. Conclusion The best dynamic creep performance was by adding 25% Zeolitic tuffs by the mineral filler mass, while the best resilient modulus was by adding 50% Zeolitic tuffs by the mineral filler mass. Other The overarching goals encompass understanding the dynamic creep behavior of Zeolitic tuff-infused asphalt blends, deciphering its indirect tensile performance, pinpointing the ideal replacement ratio for mineral fillers, and drawing a performance comparison between WMA and conventional Hot Mix Asphalt (HMA) compositions.

Foamed waste oil-activated rubberized asphalt binder: A sustainable recycling approach for improving foaming effect and performance

This study prepared foamed waste oil-activated rubberized asphalt (ORA) by activating crumb rubber (CR) with waste vegetable oil (WVO) to address the issue of undesirable foaming effect. Optimal foaming parameters for different rubberized asphalt were determined based on foaming characteristic experiments. Furthermore, rheological properties, fatigue resistance, and adhesion performance of various unfoamed or foamed rubberized asphalt were evaluated through dynamic shear rheometer, bending beam rheometer, pull-out tests. Finally, the analytic hierarchy process was utilized to select the optimum foamed rubberized asphalt. The results show that foaming pressure has a great influence on rubberized asphalt foaming effect, and is recommended at 300 kPa. Compared to conventional rubberized asphalt whether foamed or not, with the increase of activation degree, low-temperature performance, and fatigue resistance of ORA are significantly ameliorated, and the adhesion property of ORA first increases and then decreases, but detrimental to high-temperature performance. The foaming process and foaming agent addition are conducive to low-temperature performance but unfavorable to fatigue resistance and high-temperature property, and have little effect on adhesion performance. ORA (mass ratio of WVO to CR is 1:5) with foaming agent is determined as the optimum selection.

The Effect of Adding Recycled Concrete Aggregates on Asphalt Mixture Modified with Tire Rubber Crumbs -An Experimental and Numerical Study

The accumulation of huge amounts of rubble and the worn-out tires that resulted from the severe damage to Syrian facilities because of the current war in Syria poses a serious environmental problem. In this research, therefore, asphalt mixtures containing recycled concrete aggregates and an asphalt binder modified with tire rubber crumbs were designed. It also determines the loading cycles until failure on fatigue and rutting of these mixtures by following numerical modeling and using the 3D-Move Analysis program. The results showed an increase in the optimal asphalt ratio, the proportion of air voids and flow with the increase in the proportion of recycled concrete aggregates in the asphalt mixture. Contrastingly, it showed a decrease in both volumetric density and stability with the increase in the proportion of these aggregates in the mixture. With modifying these mixtures with tire rubber crumbs, both of the percentage of air voids and stability increase, while the volumetric density and flow decrease. The results also showed an increase in the fatigue strength of the asphalt mixture with an increase in the proportion of recycled concrete aggregates, while the rutting resistance increased when the mixture was modified with tire rubber crumbs.

The Effect of Nano-Hydrated Lime on the Durability of Hot Mix Asphalt

Recently, some of Iraq's newly constructed asphalt concrete pavements showed premature failures with significant negative impacts on roadway safety and the economy. Using Nano hydrated lime (NHL) in pavement construction could be one of the possible steps to improve pavement durability. This article discusses how NHL affects the durability of hot mix asphalt. NHL was added in two methods to the asphalt concrete mixture for the wearing course. The first is the dry method, i.e., on the aggregate, whereas the second is the wet addition method, i.e., to the bitumen. The percentages were tried for each additional method; 1, 2, and 3% by weight of aggregate for the dry method and 0.5, 1, and 1.5% by weight of asphalt concrete for the wet method. The optimum asphalt cement contents were evaluated using the Marshall procedure. Asphalt concrete mixes were prepared at their optimum asphalt content and then tested to evaluate their durability properties, including moisture damage and permanent deformation. These properties have been evaluated using indirect tensile strength and uniaxial repeated loading tests. The results show that the NHL has improved the permanent deformation characteristics and resistance to moisture susceptibility.