Marshall Stability Value Research Articles

Effect of Using Fine Volcanic Ash Instead of Crushed Basalt Filler in Hot Mix Asphalt

Numerous studies over the years have demonstrated the significance and impact of filler in influencing the physical and mechanical properties of Hot Mix Asphalts (HMAs). To overcome such issues, as environmentally friendly alternatives, several different materials for construction have been proposed. This led to an investigation into the potential use of fine volcanic ash (FVA) as a hot mix asphalt filler alternative. In order to prepare bituminous concrete mix sample with conventional basalt filler (BF) as control mix. The Marshall Mix design approach was used to calculate the effective bitumen content. A total of 15 bituminous concrete mix specimens with bitumen content of 4%, 4.5%, 5%, 5.5%, and 6% were created, and the optimum asphalt content was 5.24 %. The impacts of five different (FVA) samples with filler contents of 15%, 30%, 45%, and 60% by weight were compared with respect to bituminous concrete performance. The Marshall stability of a total of 30 samples with varying amounts of (FVA) were investigated. The outcomes were compared with a conventional bituminous concrete mixture. The results showed that fine volcanic ash may substitute 30% of the basalt filler at a bitumen content of 5.24%, 13.84 KN Marshall stability value, 4.0% air voids, 74.77% VFB, 2.380 g/cm3 bulk density and 3.54 mm flow. Therefore, the combination of 30% Fine Volcanic Ash by weight of Basalt Filler satisfies the ASTM Specifications, while the remaining VA content satisfies the basic requirements of the ASTM Specifications.

Pengaruh Penambahan Zat Aditif Anti Striping (WETFIX-BE) Pada Kinerja Campuran Aspal Beton (AC-WC)

The asphalt concrete layer is the top layer of road pavement construction which is in direct contact with vehicle wheel loads and the influence of weather. One type of asphalt concrete layer is Asphalt Concrete – Wearing Course (AC–WC). Asphalt functions as an aggregate adhesive. In asphalt concrete mixtures it is very important to maintain its characteristics. During the maintenance period, the mixture will easily experience striping or peeling of the asphalt from the aggregate. To maintain and improve the properties of asphalt, one way is to use an anti-striping additive, this additive is Wetfix-Be, which is a compound that contains chemicals. Anti-peeling materials are only used if the residual Marshall stability value (IRS-Index of Retained Stability) or the Indirect Tensile Strength Ratio (ITSR) value of the asphalt mixture before adding the anti-peeling agent is less than required. If an anti-flaking agent must be used then before the anti-flaking agent is added to the mixture, the residual marshall stability (after 24 hour immersion, 60 °C) must be at least 75%.

Performance assessment of sustainable asphalt concrete using steel slag, with an artificial neural network prediction of asphalt concrete behavior

This research evaluated the possibility of using Moroccan steelworks slag as a substitute for natural aggregates in asphalt mixtures, using chemical and mechanical analyses to demonstrate its compatibility with this application. Two granular mixtures, M1 and M2, were developed, incorporating respectively 15% and 25% natural sand (0/1.25) with slag aggregates to obtain granular mixtures complying with local standards. These mixtures were then tested with three different asphalt contents (4.7%, 5.2%, and 5.7%). Mechanical tests, including a gyratory compactor, Marshall stability, and Duriez strength, were carried out. In particular, the M1:5.2 and M2:5.2 mixtures met compaction criteria and showed remarkable Marshall Stability values, reaching 23.49 kN and 21.81 kN respectively. In comparison, the control mixtures only achieved a maximum stability of 11 kN. Thermal properties were also assessed, showing that the maximum thermal conductivity was achieved at an asphalt content of 5.2%. The slag-based mixtures, M1 and M2, showed higher thermal conductivity than the control mix M0, with maximum values of 0.74W/mK for M1 and 0.86W/mK for M2, compared with 0.56W/mK for M0. The overall results show that the M1 and M2 mixtures had improved thermal and mechanical properties compared with the M0 control mix. Artificial neural network (ANN) modelling was carried out using Marshall Test data. It showed excellent performance in predicting the stability and flow properties of asphalt mixtures. These results suggest that incorporating steelmaking slag into asphalt concrete mixtures was an effective strategy for simultaneously improving their thermal and mechanical properties.

Identifying the effect of adding coconut coir on the characteristics of the top layer of pure natural buton asphalt concrete wearing course (AC-WC)

Buton Asphalt is natural asphalt originating from Buton Island (Indonesia), with the potential deposit amount reaching up to 662 million tons. This substantial domestic mining potential must be utilized for domestic road needs and to boost the country's economy. However, Buton asphalt's utilization is minimal compared with imported oil asphalt, which reached a usage rate of up to 94 % in 2022. Therefore, as a form of a solution-oriented policy, Buton asphalt is included as one of the 21 commodities in the Strategic Roadmap for Downstream Investment in Indonesia, followed by various supportive regulations for developing this Buton asphalt product. One of the leading products the government targets is natural pure Buton asphalt. This product consists of >99 % bitumen content after extraction, also called Pure Buton Asphalt. The idea was to modify pure Buton asphalt with coconut coir to increase the Marshall Stability and Dynamic Stability values to make the asphalt mixture more resistant to vehicle loads and rutting. The tests were conducted to determine the optimum asphalt content (OAC) of the mixtures, Marshall's Stability comparison, and the dynamic stability test using a Wheel Tracking Machine to identify the comparison of permanent deformation. This study analyzed the Marshall characteristics and dynamic stability characteristics with variations in coconut coir content of 0.5 %, 0.75 %, and 1 % by weight of asphalt and variations in coconut coir length of 0.5 cm, 1 cm, and 1.5 cm. Based on the results of this study, the optimum asphalt content in this study is 6.76 %, where pure Buton Asphalt modified with coconut coir has an increase in Marshall's stability value and dynamic stability value compared to pure Buton asphalt without additional coconut coir

Analysis of the Use of Waste Plastics Low-Density Polyethylene (LDPE) along with Bitumen in the Construction of Asphalt Pavement using the Marshall Test

Plastic disposal is a significant problem as it is non-biodegradable and causes air pollution if burned. The utilization of waste plastics in road construction has gained attention due to environmental concerns and the need for sustainable development of infrastructure. This research investigates the performance waste plastics, low-density polyethylene (LDPE) and, in the asphalt road along with the bitumen based on the Marshall Stability Test. The Optimum bitumen content (OBC) is found to be 5.2%. Different concentrations of LDPE (8% and 10% by weight of bitumen) were used. The use of LDPE on the asphalt pavement has Marshall Stability and Marshall flow values in the usable range as specified in the specification criteria of the Standard Specification for Road and Bridge Works (SSRBW). Also, the use of waste plastics in the pavement reduces the cost and helps to promote an environmentally friendly approach to infrastructure development.

Evaluation of soft computing techniques for predicting Marshall Stability of waste plastic-reinforced asphalt concrete

ABSTRACT Pavement engineering has long prioritized enhancing the quality and durability of asphalt concrete, a foundational material in road construction. This study employs advanced soft computing techniques to predict the Marshall Stability (MS) of asphalt concrete reinforced with waste plastic. Techniques such as Artificial Neural Network (ANN), Random Forest (RF), Random Tree (RT), Support Vector Machine (SVM), and Bagging RT are utilized. Evaluation of model effectiveness is conducted using seven statistical metrics: coefficient of correlation (CC), root mean square error (RMSE), mean absolute error (MAE), relative absolute error (RAE), root relative squared error (RRSE), mean absolute percentage error (MAPE), scatter index (SI), and comprehensive measure (COM). Among the applied models, the Bagging RT model emerges as the top performer, exhibiting superior performance across multiple metrics. Specifically, the Bagging RT model achieves impressive CC values of 0.921 and 0.834, indicating strong correlations between predicted and actual MS values. Additionally, it demonstrates low error metrics, with RMSE values of 1.632 and 2.869, and MAE values of 1.207 and 2.081, respectively. A sensitivity analysis conducted for the Bagging RT-based model underscores the significant influence of aggregate size on MS prediction, highlighting the model’s capability to elucidate critical factors shaping material stability.

Use of Domestic Waste Polyethylene as a Bitumen Modifier in Bituminous Pavement Applications

The present study evaluated the use of domestic waste polyethylene (PE) in the applications of bituminous pavement. This study investigates the performance of the mixes using different waste PE percentages, i.e., 1%, 2%, 3%, 4% and 5%. It is observed that the softening point and elastic recovery value increase with PE content increases. The penetration index (PI) and temperature susceptibility of binders were evaluated. Adding PE to bitumen shows an improvement in the temperature susceptibility of the modified binders. The Marshall Stability value of bitumen containing 3% PE is higher at 69.65% than virgin binder stability. When 3% PE modified bitumen to the mixes, its indirect tensile strength (ITS) is 70.44 % higher than the conventional mix. The tensile strength ratio (TSR) value improved from 62% (unmodified binder) to 91.18% (modified binder) at 3% PE content, which is 47% higher than the conventional mixture. It indicates that the moisture susceptibility of mixes using PE is higher than conventional mix. Additionally, the mix deformation resistance with 3% PE was found to be 68.75% higher than the mix made with the unmodified binder. The study found that the bituminous mixes using PE have shown higher effectiveness in the properties such as stability, indirect tensile strength, rutting resistance, etc. of the mixes. It indicates that bituminous mixes with modified binders with PE provide higher resistance to permanent deformation.

Investigation of Performance Properties of Milled Carbon Fiber Reinforced Hot Mix Asphalt

In this study, the mechanical behavior and resistance to moisture damage of hot mix asphalt (HMA) concrete with the addition of Milled Carbon Fiber (MCF) were experimentally investigated. For this purpose, the gradation curve within the boundaries of the Turkish highway construction specifications (HTS) has been determined. By keeping the determined gradation constant, MCF was added at different rates (1 %, 1.5 %, 2 %, 2.5 %, 3 %) by weight of the mixture. In the study, first, optimum bitumen ratios (OBR) of pure control samples (0 %-Control) without MCF and mixtures with MCF additives were determined by using the Marshall design method. To determine the OBR, samples were prepared with bitumen content of 3.5 %, 4 %, 4.5 %, 5 %, 5.5 %, and 6 % at each carbon additive ratio. The mixture samples prepared using the specified OBRs were subjected to Marshall stability (MS) and flow, as well as to retained Marshall stability (RMS), indirect tensile strength (ITS), and moisture damage resistance tests. According to the test results, it was observed that the MS values of the asphalt concrete with MCF additives increased at certain carbon additive ratios, while the flow values decreased compared to the witness sample. It was determined that the RMS and indirect tensile strength ratio (TSR) values of hot mixes with MCF-added bitumen increased and the moisture damage resistance of the mixes increased. As a result, when the optimum MCF ratio determined for the wearing course is used, it is thought that the engineering properties of HMA will improve.

Marshall Performance Analysis Of Eggshells And Cement As Filler In Asphalt Concrete Mixtures (AC - WC)

Roads are transportation infrastructure whose needs in Indonesia continue to increase, along with the increasing number of vehicles. Road construction is a construction that receives traffic loads, therefore it is expected that a road pavement layer must have a strong pavement construction and be able to receive loads from traffic users. AC-WC (Black-top Concrete - Wearing Course) asphalt layer is a road pavement construction consisting of asphalt composition, coarse aggregate, fine aggregate and filler. Fillers in asphalt mixtures function to increase the binding power of AC-WC asphalt, so as to improve mixture stability and fillers can fill the voids between aggregate particles, filler commonly used is stone ash. This research will be conducted with the addition of broiler eggshell filler and porland cement in the Asphalt Concrete wearing Course (AC-WC) mixture. The research was conducted with an experimental method conducted in the Civil Engineering laboratory of Abdurrab University. The specification used in this study is Public Road Revision 2 Year 2018, The optimum asphalt content (KAO) used was 6.5%. Based on the results of the study, the largest marshall stability and melting value is found in the 100% cement filler variation, which is 1772.7 Kg and the value of flow value (melting) 3.77 mm while the largest marshall quotient (MQ) value is found in the 25% eggshell filler variation, 75% cement, which is 529.2 Kg/mm.

Assessing recycled asphalt pavement: Impact of waste cooking oil and waste engine oil as rejuvenators on mechanical properties

Sustainable pavement construction is an extensively researched subject within the field of pavement engineering. Due to its environmental and commercial advantages, the construction of pavements utilizing recycled asphalt pavement (RAP) is progressively gaining popularity worldwide. Owing to the aging process, binder extracted from RAP is inherently harder than virgin binder and requires rejuvenation for application in high RAP blends. This paper investigates the performance characteristics of Waste Cooking Oil (WCO) and Waste Engine Oil (WEO) as rejuvenators in RAP-incorporated asphalt mixtures to assess their suitability for pavement use. The optimal rejuvenator content is determined based on the performance of physical properties. The study indicates that asphalt mixes rejuvenated with Waste Cooking Oil (WCO) demonstrate higher Marshall Stability values compared to mixes rejuvenated with Waste Engine Oil (WEO) at both 30% and 60% Recycled Asphalt Pavement (RAP) levels. Additionally, mixes incorporating WCO exhibit increased flow values. Furthermore, WCO outperforms WEO in Tensile Strength Ratio (TSR) at 30% RAP, with a slight decrease at 60% RAP. Results from Marshall and Indirect Tensile Strength (ITS) tests suggest that both WEO and WCO are effective rejuvenators, playing a critical role in aligning the properties of RAP-inclusive asphalt mixes with those of virgin mixes.

Study and valorization of a new bituminous concrete based on natural dune sand for hot and arid environments

The trans-desert road network is exposed to enormous degradation of asphalt concrete pavements due to the high temperatures of these arid regions, which considerably accelerate asphalt ageing. Common bituminous mixes generally use quarry sand fillers, the proportions of which are poorly controlled due to the diversity of rock deposits and their manufacturing conditions. This article responds to this problem by proposing dune sand as a source of filler by grinding it and then introducing it into pure bitumen to obtain the bitumen-filler mix. In this paper, two types of analysis were carried out, one thermal and the other mechanical to study the influence of the substitution of quarry sand filler by dune sand filler in asphalt concrete. In the thermal analysis, the study evaluates the stiffening power (?TBA) of three types of fillers incorporated into a pure bitumen, namely quarry sand, dune sand and standardized filler. The results of these analyses reveal that at a normative percentage of 57% filler with 43% pure bitumen, the stiffening power (?TBA) of dune sand filler and normalized filler comply with established standards (between 8 and 16°C), unlike quarry sand filler, which does not meet standards. The mechanical analysis carried out on quarry sand filler and dune sand filler revealed an improvement in mechanical performance when dune sand filler was used, with MARSHALL stability values indicating an average increase from 3.9 to 4.9, and better resistance to water with a greater than 99% ratio for the DURIEZ test well above the 75% threshold. These results offer the potential to optimize bituminous mixes by incorporating dune sand fillers, thereby enabling Saharan roads to be built more quickly, at lower cost and, above all, to extend their lifespan, making a positive contribution to the development of road infrastructure in hot, arid environments.

Study of Crumb Rubber as Binder Material in Asphalt

Asphalt is a mixture of aggregates, bitumen, quarry dust, and cement. As an addition in hot mix asphalt mixtures, recycled tire rubber known as "crumb rubber" is regarded as an environmentally friendly building practice. The laboratory hot mix asphalt design tests were conducted according to Marshall method procedure. In this study, three different crumb rubber contents (10%, 15%, and 20% by weight of bitumen), and three different bitumen contents (4%, 5%, and 6%) with a penetration grade 60/70 were investigated. The Marshall stability value and durability properties were taken into account in a comparison study between the standard and modified asphalt concrete mixtures. The strength and performance of asphalt mixtures tended to improve with the addition of crumb rubber. As some of the test results were within the acceptable range, the findings indicated that crumb rubber is advised for use as an addition in asphalt mixtures. Besides, the durability of asphalt mixtures also needed to be concerned.

Evaluation of the Stability and Flow of Asphalt Concrete Produced with Waste Brick Tile Powder as a Filler

The utilization of recycled brick tile powder as a replacement for conventional filler in the asphalt concrete mix has been studied in this research. This research evaluates the effectiveness of recycled brick tile powder and determines its optimum replacement level. Using recycled brick tile powder is significant from an environmental standpoint as it is a waste product from construction activities. Sixteen asphalt concrete samples were produced, and eight were soaked for a day. Samples contained 5% Bitumen, 2% to 5% brick tile powder, and conventional stone dust filler. The properties of samples were evaluated using the Marshall test. It was observed that the resistance to stiffness and deformation of asphalt concrete was increased by 99% when the conventional filler was replaced with brick tile powder. The resistance to deformation decreases as the percentage of brick tile powder increases while Marshall stability values increase significantly. At an optimum content of 4% recycled brick tile powder as filler, the Marshall stability is increased by 123%. Based on this investigation, it is established that brick tile powder can be effectively used in asphaltic concrete as a filler. This presents a sustainable solution to waste utilization and pavement performance.

Performance of Hybrid Asphalt Mixture through the Stability and Tensile Strength

Introduction: The stability and tensile strength of asphalt mixtures play a crucial role in pavement durability, primarily due to the challenges associated with cracking. This study investigates the utilization of a hybrid asphalt mixture comprising hybrid materials: Palm Oil Fuel Ash (POFA), garnet waste and sawdust to enhance the modified asphalt performance. Aims: The objective is to examine the hybrid materials’ influence towards the mechanical properties of the hybrid asphalt mixture, specifically focusing on the Indirect Tensile Strength (ITS) as well as the Marshall stability test. Methods: To achieve this, hybrid materials were finely ground and sieved to 25µm before being incorporated into the mixture. The Marshall mix design procedure was conducted, utilizing hybrid binders at concentrations of 0% (control), 3% 6%, and 9%. The effects of the hybrid asphalt mixture on stability, flow, stiffness, and ITS were assessed at the optimal binder content. Results: The findings indicate that the hybrid asphalt mixture reveals enhanced Marshall stability, stiffness, flow, and ITS values compared to conventional asphalt mixtures. Notably, hybrid asphalt mixtures with 6% binder concentration demonstrate the most significant enhancement in terms of Marshall stability and ITS. Conclusion: This correlation suggests that the incorporation of POFA, garnet waste, and sawdust as hybrid materials in the hybrid asphalt mixture possesses a positive effect on the overall mechanical properties of the pavement. Highlights: • POFA, garnet waste, and sawdust increased the stability of the hybrid asphalt mixture. • POFA, garnet waste, and sawdust increased the tensile strength of the hybrid asphalt mixture. • Hybrid asphalt mixture performs positively towards flow and stiffness.

Improvement of pavement engineering properties with calcium carbide residue (CCR) as filler in Stone Mastic Asphalt

Characteristics of pavement material are crucial factors in improving the stability and durability of asphalt pavement due to the poor performance of traditional asphalts. Reusing industrial waste in asphalt concrete production can address these concerns, reduce environmental problems and preserve resources. There have been few studies on the effects of using industrial waste materials on Stone Mastic Asphalt (SMA) properties. This paper examines the impact of Calcium Carbide Residue (CCR) as a filler in SMA. The study evaluates control samples, those with Rock Powder (RP) and Ordinary Portland Cement (OPC) filler, and those with CCR using Marshall stability (MS) and Indirect Tensile Strength (ITSdry and ITSsat) tests. Results show positive effects of CCR and RP on asphalt sample strength. The highest MS, MQ, and TSR values were observed in samples containing CCR80 %+RP20 %. These indices increased 45 %, 35 %, and 51 %, respectively, compared to control samples. The alkaline CCR material forms strong bonds with acidic bitumen, producing asphalt more resistant by 97 % compared to control samples. SMA modified with CCR + RP was also found to be less sensitive to water damage than traditional SMA with RP or OPC filler. The rough texture of CCR may positively affect the strength and durability of asphalt mixtures against moisture damage. Using CCR as a filler in SMA can enhance pavement engineering properties, reduce production costs and environmental problems, and develop sustainable asphalt mixtures for practical application. The main novelty of this research is the use of CCR and RP combination in SMA mixtures.

Innovative Use of Waste PET-Derived Additive to Enhance Application Potentials of Recycled Concrete Aggregates in Asphalt Rubber.

Polyethylene terephthalate (PET) drinking bottles, rubber tires, and concrete are the very common municipal solid wastes, which are usually disposed of at landfills and stockpiles and cause continuous damage to the environment. Some studies have indicated that waste PET can be chemically converted into an additive for improving the overall properties of asphalt pavement incorporating natural aggregates, especially the moisture-induced damage resistance. However, it is not clear whether this PET additive still works for asphalt rubber containing recycled concrete aggregates (RCA). To well reveal this issue, this study first adopted a similar way to chemically recycle waste PET into the additive for modifying crumb rubber modified asphalt (CRMA) binder and then mixed the binder with the 13 mm maximum aggregate stone matrix asphalt containing 100% coarse RCA for preparing the mixtures. After a series of physicochemical characterizations of the PET additive, the moisture resistance, rutting resistance, low-temperature cracking resistance, and fatigue resistance of the mixture were systematically evaluated. The results showed that the PET additive is capable of improving the resistance to moisture and high-temperature deformation of asphalt rubber and helps greatly reduce the moisture-induced damage to the interfacial bonding layer. To be more detailed, the residual Marshall stability (RMS) value of RCA-CRMAM/1PET after 72 h of immersion is higher than 85% by contrast to that of RCA-CRMAM (77.1%), while the tensile strength ratio (TSR) value of RCA-CRMAM/1PET shows more than 80% compared to that of 65.2%. In addition, only 1% PET additive can enhance the high-temperature resistance of asphalt rubber containing RCA to rut and allow it to maintain higher resistance to rut after moisture-induced damage. 1% PET additive can help improve the bearing capacity of RCA-CRMAM under a low-temperature environment and delay its fatigue life at small stresses. Generally, with the successful introduction of PET additives to asphalt rubber containing RCA, more durable and sustainable highway pavement can be produced and applied in practice to alleviate the negative impacts caused by waste PET, waste tire rubber, and waste concrete.

Asphalt concrete mix analysis using volcanic ash filler

Asphalt mixture is a combination of a mixture of aggregate and asphalt. Sinabung eruption volcanic ash produced many negative impact on health and the environment. So that needs to be done in order to study the volcanic ash can be used in road pavement, especially on Asphalt Concrete pavement, the purpose of this study to determine the effect comparison of volcanic ash filler sinabung on Asphalt Concrete - Binder Course. This research was laboratory experimental in nature with asphalt level variation of 5%, 5.5%, 6%, 6.5%, 7% and volcanic filler level of 1, 2 and 3% in each asphalt level variation. There were 5 samples used the examination was done using marshall test instrument. The test used to determine the graph of asphalt content with value stability, flow, bulk density, VIM, VMA, VFB. The results of the over all addition of volcanic ash in the petroleum asphalt. Asphalt Concrete Binder Course Marshall stability values indicate that the better that showed that a mixture of aggregate is very good. If the flow value is lower, the VIM value is getting lower, then the VMA value and VFB value have a value that is more than the minimum value.

A Review on Correlation between Marshall Stability and ITS values for Bituminous Mixes with RAP

Abstract: Utilization of recycled materials in DBM mixes is gaining popularity due to environmental concerns and the potential for cost savings. The performance of DBM is influenced by several factors, including the choice of binder grade and the incorporation of recycled materials. However, the impact of recycled materials on the mechanical properties of the mix, as measured by Marshall stability and indirect tensile strength, needs to be thoroughly understood. Although the effect of RAP addition in DBM has been studied in relation to the Marshall test but not much is known about its effect on Indirect Tensile Strength. Marshall Stability and ITS have alone been the subject of several research investigations, but their combination has received far less attention. The correlation between Marshall Stability and ITS was researched to some extent for virgin mixes but not with recycled material. An effort has been made to examine their correlation in this study. This study aims to explore the potential benefits of incorporating RAP in DBM mixes and how it affects the correlation between the two parameters.

Use of Waste Material as Filler in Bituminous Mix Design

Abstract: Bituminous concrete is a costlier and highest payment flexible payment layer. For satisfy the design requirements of stability and durability the bituminous mixes should be designed effectively. The ingredients of the mixture include dense grading of coarse aggregates, fine aggregates, fillers and bitumen binder. In this Study an attempt was made to find the effect of filler on the behavior of bituminous mixes. Fillers play an important role in the filling of voids and hence change the physical and chemical properties. Thus their effect is of utter importance. Bitumen in combination with filler forms mastic. This mastic can be seen as a constituent of mixture of asphalt that holds the aggregates together. An important role is played by the fillers that pass through 0.075mm sieve. With the increase in the amount of filler, Marshall Stability of the bitumen mix increases directly. Use of 4-8% filler in asphalt concrete is recommended by the Asphalt Institute. In India, waste concrete dust and brick dust are considered to be cheaper and are available in plenty. In this study an attempt was made to find the effect of fillers on the bitumen mixes. In this study, concrete dust and brick dust was used as filler. The properties of bituminous mixes containing these fillers were studied and compared with each other. For the purpose of comparison Marshall Method of mix design was used. In this study various tests were also conducted on aggregates and bitumen and the results were compared with the specifications. The study revealed that use of concrete dust and brick dust as filler improves the physical characteristics of bitumen. Marshall Stability and flow value of bitumen mix also improved.

Appraising the synergistic use of recycled asphalt pavement and recycled concrete aggregate for the production of sustainable asphalt concrete

Material obtained from the demolition of concrete structures and milling of flexible pavements has the highest potential for recyclability. This study aimed to evaluate the performance of hot mix asphalt with the concurrent use of recycled asphalt pavement (RAP) and recycled concrete aggregate (RCA). Contents of RAP and RCA were varied from 0% to 50% by fixing the total recycling materials percentage to 50%. Penetration grade 40/50 virgin binder and waste engine oil (WEO) as rejuvenator were used in the present study. A series of tests, such as Scanning electron microscopy (SEM), Marshall stability, indirect tensile strength test, IDEAL CT, uniaxial compression test, and resilient modulus test, were carried out to assess the performance of the prepared recycled asphalt mixtures. SEM images revealed the presence of the medium to fine particles on RCA indicating the rough surface texture. Except RAP10 (10% RAP plus 40% RCA) and RAP50 (50% RAP) mixes, all mixes had Marshall stability value greater than the control mix, the highest for RAP40 (40% RAP plus 10% RCA) mix followed by RAP0 (50% RCA) mix. In the case of resilient modulus, the effect of RAP is more pronounced till 40% resulting in an almost linear increase in values. Also, RAP40 exhibited the highest rutting and fatigue resistance. As far as moisture sensitivity is concerned, all the mixes performed satisfactorily as the tensile strength ratio (TSR) was greater than 80%. Overall, the major factors affecting the performance of recycled mixes were surface roughness, stiffness of the aged binder and rejuvenator.