Marshall Properties Research Articles

The Influence of Waste Rice Straw Ash as Surrogate Filler for Asphalt Concrete Mixtures

Mineral fillers in asphalt concrete have improved the mix design qualities significantly. However, the high cost, scarcity, adverse impact towards environment and the inability of conventiona filller to enhance mixtures performance due to the increase in traffic loading have necessitated an investigation into viable alternatives in manufacturing asphalt concrete. Thus, researchers have been looking into using agricultural waste in asphalt pavements to improve sustainability and pavement performance. Waste rice straw (WRS) is a high-volume agricultural waste often burnt for electricity or discarded. In this study, WRS ash (WRSA) was sourced locally, incinerated, ball-milled, and sieved to pass BS sieve No.200 to generate fine powder WRSA, which can be utilised as the surrogate mineral filler. This study evaluated the effect of utilising WRSA as a partial substitute of mineral filler on the volumetric and Marshall properties of the WRSA modified asphalt mixtures. The tests were conducted on a series of asphalt concrete specimens prepared based on Marshall's design with the optimal bitumen content for all varying substitution percentages 0 (control), 25, 50, 75, and 100% WRSA and, the engineering properties of the asphalt mixtures were investigated. The study outcomes show that using WRSA as a surrogate filler inmproves asphalt concrete's Marshall stability and quotients value by 33% and 61% at the optimal replacement of 75%. Based on the result, it can be clinched that WRSA can be incorporated as a filler surrogate to promote sustainability.

Experimental Study on Characterization of Bituminous Mixes Containing Recycled Asphalt Pavement Materials for the Construction of Surface Course in Flexible Pavements.

Abstract: In India majority of the road network has a bituminous top surface made of naturally accessible road materials and bitumen. This process has resulted in a faster depletion of road aggregates as well as an increase in gas emissions into the atmosphere, resulting in pollution. The most promising approach for achieving sustainability in road building will be to use low emission bitumen, re-use aggregates obtained from milling, and material reclaimed from the old distressed pavement to create or rehabilitate new roads. In this regard, the current study seeks to evaluate and compare the physical and engineering features of bituminous mixes including RAP material in various percentages for the construction of the surface course in flexible pavements through thorough laboratory investigations. According to the results of laboratory experimental tests, a bituminous mix containing recycled asphaltic pavement (RAP) material exhibits better Marshall Properties, performance properties, and volumetric properties, and meets all of the requirements of the bituminous concrete (BC) layer as per standard specifications. According to the findings of the study, it is possible to create an acceptable grade bituminous mix with a high RAP component that meets the needed volumetric characteristics and performance parameters for the construction of flexible pavements under current traffic and environmental circumstances. Keywords: RAP, Sustainable roads, Volumetric properties, Marshall Properties, ITS.

Experimental Investigation of Flexible Pavement Using Shingles

Abstract: Huge volumes of Shingles are produced from building construction and Asbestos industries. Basically, waste Shingles Aggregates (WSA) are being produced by crushing Shingles during the process of transport and installation of roof, wall and floor. Present society are progressively moving forward to be more environment friendly. To meet up this purposes, recycling and reuse of this material can be the best alternatives than landfill disposal in respect of environment conservation and economy. To increase the usage of Shingles in pavement construction, different percentage of Shingles can be used with the natural aggregate. The technical flexibility of using waste Shingles aggregates as partial replacement of natural aggregates in bituminous mixes can be evaluated. This research work presents some of the laboratory investigation on the possible application of waste Shingles aggregates in bituminous mixes. The physical properties of coarse aggregates, fine aggregates, filler and bitumen are determined according to standard test. Marshall test specimens are prepared for testing to measure the Marshall properties. at optimum bitumen respectively are determined. According to AASHTO, Marshall stability test properties of mixes of waste shingles aggregates are satisfactory. investigated results indicate that the bituminous mixes with waste shingles aggregates give satisfactory results for construction of medium traffic road Keywords: Waste Shingles Aggregates, Marshall Mix Design, Flexible Pavement Construction

Laboratory evaluation of use of areca fibres in SMA mixes

ABSTRACT One of the problems associated with Stone Matrix Asphalt (SMA) mixes is the drain down of binder mortar during production, transportation and placement of the mixes. A commonly adopted method to control the drain down is to add a stabilising additive such as natural, synthetic or mineral fibres to the mixture, which is also known to improve the mechanical and volumetric properties of SMA. The present study evaluates the feasibility of using areca fibres extracted from areca husk in SMA as a stabilising additive. Three SMA mixtures were prepared with Viscosity Grade VG 30 bitumen using areca fibre (SMA-AF), coconut fibre (SMA-CF) and cellulose fibre in pelletised form (SMA-PF) and their performance was compared with a control SMA mixture prepared using Polymer Modified Bitumen (SMA-PMB). The prepared SMA specimens were evaluated for volumetric and Marshall properties, workability characteristics, Indirect Tensile Strength (ITS), fatigue, rutting and moisture susceptibility. The drain down test results indicated that the fibres controlled the drain down, and the optimum fibre content was 0.3% for the mixes with fibres. All the mixtures satisfied the requirements of SMA per IRC:SP 79-2008. The statistical analysis conducted revealed that the fibre type had a significant effect on the properties of SMA mixes. The SMA-PMB and SMA-CF mixes required the least and the highest energy for compaction. Among the mixes with natural fibres, SMA-AF performed better than SMA-CF.

Performance Evaluation of Flexible Pavements with Modified Bitumen Binders

Abstract: In India majority of roads are being constructed by flexible pavements. But the performance of the pavement largely depends on quality and type of materials used, Construction methodology adopted, temperature, climatic conditions etc. Because of these variations in the mentioned parameters, pavements undergo distress/ failure. The different types of failure in flexible pavement are Rutting, Shovelling, Edge breaks, Cracks, Slippage etc. Rutting is a common phenomenon which occurs in flexible pavement surface due to overloading of vehicles and repeated application of wheel load. Rutting is defined as channelized depression in the pavement surface along wheel path due to heavy repetitive traffic load. Design of bituminous paving mixes greatly effects the performance of pavements. In the present laboratory research work, conventional bitumen is used in wearing/ surface course and Modified Bitumen is used in binder course of the layer. Pavement layers are constructed/casted in an Indigenously designed, developed and fabricated equipment called Roller Compactor cum Rut Analyzer (RCRA) and Rutting test was performed. The overall objective is to compare the Marshall properties of the conventional and Modified Bituminous mix and to study the rutting performance of these bituminous mixes. Results shows that bituminous mixes prepared with Modified Bitumen/Binders has a very high Marshall Strength and offers greater resistance to rutting Keywords: Modified Bitumen, Bituminous Concrete (BC), Dense Bituminous Macadam (DBM), Marshall Stability, Roller Compactor cum Rut Analyzer (RCRA), Crumb Rubber Modified Bitumen (CRMB)

Performance Evaluation of Bituminous Mixes with Modified Binders using Roller Compactor cum Rut Analyzer (RCRA)

Abstract: In India majority of roads are being constructed by flexible pavements. But the performance of the pavement largely depends on quality and type of materials used, construction methodology adopted, temperature, climatic conditions etc. Because of these variations in these parameters, pavements undergo distress/ failure. The different types of failure in flexible pavement are Rutting, Shovelling, Edge breaks, Cracks, Slippage etc. Rutting is a common phenomenon which occurs in flexible pavement surface due to overloading of vehicles and repeated application of wheel load. Rutting is defined as channelized depression in the pavement surface along wheel path due to heavy repetitive traffic load. Design of bituminous paving mixes greatly effects the performance of pavements. In the present laboratory research work, conventional bitumen is used in wearing/ surface course and Modified Bitumen is used in binder course of the layer. Pavement layers are constructed/casted in an Indigenously designed, developed and fabricated equipment called Roller Compactor cum Rut Analyzer (RCRA) and Rutting test is performed. The Rutting test is carried out on wearing course of bituminous layer (BC Gr-II with VG-30) and by adopting Binder course layer namely DBM Gr-II prepared with two different types of binders namely VG-30, SBS-70. The overall objective is to compare the Marshall properties of the conventional and Modified Bituminous mix and to study the rutting performance of these bituminous mixes.. Results shows that bituminous mixes prepared with Modified Bitumen/Binders (SBS-70) has a very high Marshall Strength and offers greater resistance to rutting. Keywords: Modified Bitumen, Bituminous Concrete (BC), Dense Bituminous Macadam (DBM) , Marshall Stability, Roller Compactor cum Rut Analyzer (RCRA), Styrene-Butadiene-Styrene (SBS).

A LABORATORY STUDY OF BITUMINOUS MIXES USING A NATURAL FIBRE

Generally, a hydrocarbon mixture could be a mixture of coarse combination, fine combination, filler and binder. A Hot combine Asphalt could be a hydrocarbon mixture wherever all constituents ar mixed, placed and compacted at warm temperature. HMA is Dense ranked mixes (DGM) called Bituminous Concrete (BC) or gap ranked called Stone Matrix Asphalt (SMA). SMA requires stabilising additives composed of polysaccharide fibbers, mineral fibres or polymers to prevent drain down of the combination. within the gift study, an effort has been created to review the consequences of use of a naturally and domestically out there fibre known as SISAL fibre is employed as stabilizer in SMA associated as an additive in BC. For preparation of the mixes combination gradation has been taken as per MORTH specification, binder content has been varied often from fourdimensional to seven-membered and fibre content varied from 1/3 to most zero.5% of total combine. As a district of preliminary study, ash has been found to result satisfactory Marshall Properties and therefore has been used for mixes in subsequent works. victimization Marshall Procedure Optimum Fibre Content (OFC) for each B.C. and SMA mixes was found to be zero.3%. equally Optimum Binder Content (OBC) for B.C. and SMA were found to be five-hitter and five.2% severally. Then the B.C. and SMA mixes ready at OBC and OFC ar subjected to totally different performance checks like Drain down test, Static Indirect strength check and Static Creep check to judge the consequences of fibre addition on combine performance. it's ended that addition of sisal fibre improve the combination properties like Marshall Stability, Drain down characteristics and indirect strength just in case of each BC and SMA mixes. Ii is ascertained that SMA is healthier than B.C. in respect of indirect tensile strength and creep characteristics.

Performance evaluation of coal dust and wood powder ash as alternates of conventional filler in the asphalt concrete

Mineral fillers provide a significant role in the Marshall properties of hot mix asphalt for paving applications. The article's goal is to assess the suitability and effectiveness of two minerals (coal dust and wood powder ash) used as fillers in asphalt concrete. Chemical composition test using X-ray fluorescence indicated a high content of SiO2, Fe2O3, and Al2O3, which encouraged us to select the coal dust and wood powder ash as mineral fillers for further investigation. A total of 90 cylindrical Marshall Specimens, made with different percentages (i.e., 4%-8%) of coal dust, wood powder ash, and conventional stone dust filler were prepared to assess the performance of individual filler within the asphalt concrete mix. And after that, volumetric characteristics such as density, stability-flow test, air void, and voids in mineral aggregates have been analyzed to evaluate the effectiveness of every sample and, afterward, to find out the optimum asphalt content. Finally, the optimum asphalt content for every filler material was ascertained, and subsequently, Marshall properties were checked again to assess the optimum filler content in the mix that satisfy all the standard criteria. The overall Marshall properties for both fillers were within the acceptable limits. Though the optimum asphalt content was higher for coal dust than wood powder ash and stone dust, the wood powder ash showed better durability than coal dust. All mixtures have been found to have better resistance to deformation, fatigue, and moisture-induced damages; however, 4% coal dust and 6% wood powder ash satisfied most of the Marshall criteria than other percentages.

Impact of Crumb Rubber Concentration and Plastic Coated Aggregates on the Rheological Performance of Modified Bitumen Asphalt

The diminution of natural resource exploration, the retrieval of waste, and the structural modification of polymers by additives are the main contributions to sustainable development. The properties of bitumen are enhanced by the crumb rubber through effective bitumen modification techniques, which have environmental and economic advantages. In this study, plastic waste, plastic-coated aggregate (PCA), and bitumen were blended in order to enhance the engineering properties of the flexible pavement. In order to compute the composition of crumb rubber modified bitumen (CRMB), the adopted materials were subjected to the relevant experiments. PCA was a very effective material when compared to the standard bitumen road pavement. The recycling of waste crumb rubber and plastic was tested by adding them into the hot mix asphalt. The Marshall properties of standard (virgin) bituminous mix, CRMB grade 55, and plastic mix asphalt were studied in detail to explore the solutions for a sustainable environment. The comparison was performed between these two materials with the standard bitumen, which resulted in the CRMB and plastics being found as the most effective additions with robust properties such as low-cost material, high strength, long life usage, and un-harmful to nature. The optimal bitumen content was found to be 6.166%, 6.1%, and 5.833% for standard bitumen, crumb rubber modified bitumen, and plastic-coated aggregate, respectively.

Analysis of mixed stiffness modulus of different asphalt levels for AC–BC pavement layer with pertamina 60/70 asphalt and 60/70 esso asphalt material

Asphalt/bitumen is a brownies black material, is viscous so it will soften and melt when it gets enough heating. In general, asphalt is obtained from petroleum refining. Pavement construction in Indonesia, both road rehabilitation project, maintenance and construction of roads, generally. Pertamina 60/70 asphalt is used as a binder for the asphalt mixture. Apart from pertamina asphalt, there are several types of asphalt that ore often used in projects in Indonesia, one of which is esso 60/70 asphalt.Esso asphalt is a type of asphalt produced from foreign companies outside of Indonesia, so it is necessary to do a comparative research test on the Marshall Properties and the stiffness modulus of asphalt. The research was conducted to analyze the stress-strain relationship which show the stiffness and strength of the asphalt material by experimenting with several test objects using the Marshall tool. If the value of the stiffness modulus decreases, asphalt aging will occur which causes the pavement to crack easily when receiving heavy loads. The stiffness modulus analysis of the asphalt mixture is an analytic procedure for planning and evaluating the performance of asphalt mixture. Asphalt mixture is a material that is not perfectly elastic, so the use of the term modulus of elasticity (E) is not suitable, instead the term mixed stiffness modulus is used. The data needed is the value of the stiffness of the asphalt content mixture which was tested by the laboratory to obtain the stiffness modulus and asphalt content characteristic.

Critical review of mineral admixture impregnation in bituminous mixes

The effect of different materials in bituminous mixes, as well as their variance in test parameters, are summarised in this paper. Many studies which were carried out earlier were studied to enhance the sustainable parameters from waste materials. Engaging the proper materials usage with precise can make the bitumen more cost-effective and durable one. For user in order to reduce the cost, the engineers started investigation on the usage of treated waste from different industries as filler in the mix. The use of 4–7 percent Fillers is advised because the amount of ash increases the mix's Marshall Stability. It is concluded that stone dust and limestone sludge, cement, coal ash, zeolite powder, limestone, rice husk ash, date seed Ash, broken brick powder, broken tile powder, cow Bone ash, Broken Glass powder, waste brick powder can be used as a filler. All these materials can be used as the filler and combination of these fillers forms a mastic mix of the bitumen and increases durability. The increase in Marshall Properties can be observed by the addition of filler. This critical review research emphasizes the waste material to serve the purpose of increasing the stability, durability and strengthen the mix and to keep the environment clean using these materials gives satisfactory results. According to abundant study, 25% fly ash by total weight of filler bounces with characteristics comparable to traditional Marshall Stability and Flow value of asphalt mix. Apart from these brick dust or stone dust also produce lot of air voids, but it also provide a lot of stability, so it can be used to replace traditional fillers in almost all cases. The Marshall Stability and flow value of the mix design properties after using the above-mentioned fillers are the focus of this study.

Application of Alternative Filler in Asphalt Mixture: An Overview from Indonesia Perspective

A good quality and proper quantity of filler material is one of the significant factors in producing asphalt mixture. Many studies have been highlighted waste material as an alternative filler to improve asphalt mixture performance. Hence, this paper reviewed the performance of asphalt mixture using rice husk ash (RHA) as filler in terms of the Marshall properties. It shows that 6% RHA by weight of total aggregate was commonly used and depicted better in Marshall properties than the others. This study also found that the RHA can be used to replace up to 100% of the conventional filler. Even though, higher RHA content could significantly reduce the stability yet it still within the acceptable range and could be applied at medium traffic load road. In return, the higher the RHA content the more waste material can be utilized for road construction. Thus, minimized the usage natural source materials.

Experimental study on bituminous concrete pavement using low density polyethylene and sasobit

Since there is a constant increase in high traffic intensity, Bituminous Pavements are predicted to function better these days. Bituminous Pavements perform poorly in moisture-induced conditions. Moisture damage causes stripping or the separation of the binder from the aggregates. According to a thorough literature analysis, adding polymers to asphalt binders helps to enhance the bond between the aggregate and the binder, which may help to improve numerous features of asphalt pavements and aid to meet the aforementioned standards. The widespread usage of plastic in products such as wrappers, carry bags, and cold drink bottles has serious environmental and economic consequences. The safe disposal of these plastic wastes is a major social concern. Also, high temperature mixing of bituminous materials in Hot Mix Plants (HMA) generates toxic gases, affects global warming and reduces the hauling distance of the asphalt concrete pavements. The present study was conducted to investigate the impact of partial replacement of Low-Density Polyethylene (LDPE) waste in bituminous mixes at four different percentages of bitumen contents 4.2%, 4.7%, 5.2% and 5.7%. Furthermore, Sasobit an organic additive of Warm Mix Asphalt Technology at constant percentage of 3% by weight of bitumen was also used with Varying percentages of LDPE, such as 2%, 4% and 6% respectively. This Study examined the effect of above-mentioned types of mixes on Marshall Properties. The inculsion of plastic increased the stability of the mixes. The maximum stability achieved with 4% plastic and 3% sasobit. The addition of sasobit lowers the Tensile Strength Ratio (TSR) value but well under specified limits. Hence, Low-Density Polyethylene with sasobit can be well utilized in bituminous mixes.

Laboratory investigation of bituminous concrete using Reclaimed asphalt pavement and waste Engine oil

The conventional method of preparing bituminous mixes incorporating bitumen and virgin aggregates requires a huge amount of energy to produce along with environmental concerns. In pavement industry, the usage of Reclaimed Asphalt Pavement (RAP) material is growingup dueto financial considerations and the necessity of environmental conservatism. The effective utilisation of reclaimed asphalt pavement waste in bituminous pavement can overcome its disposal issue as well as it is cost effective too. Whereas replacing RAP with virgin aggregates have some drawbacks related to workability and overall quality of the pavement. Reclaimed Asphalt Pavement is subjected to environmental degradation hence affected due to aging. Long term aging effect is very prominent in reclaimed asphalt pavement materials. Hence, it becomes stiff and difficult to employ. To make it workable and its efficacious usage rejuvenators are needed. The addition of oil-containing additives can be useful as rejuvenators. For the present study, Waste Engine Oil (WEO) has been used as a rejuvenating agent. The main objective of this research is to evaluate the effect of RAP with or without rejuvenator in the Hot Mix Asphalt (HMA) mixtures. To assess the performance of the bituminous mixes Marshall properties, Tensile Strength Ratio (TSR) and Indirect Tensile Strength (ITS) for moisture susceptibility were performed. The HMA mixture with 20%, 30%, 40%, 50%, 60%, and 70% of RAP content were prepared and subsequently 1.5% of waste engine oil (by the weight of RAP content) was added to other HMA mixes containing the same RAP proportion. Corresponding result indicates that with the addition of RAP to the HMA mixes showed improved Marshall Properties, Tensile Strength and resistance against moisture susceptibility. Whereas, addition of WEO improves the Marshall Properties but decrement in Tensile Strength was observed.

Rutting prediction of hot mix asphalt mixtures reinforced by ceramic fibers

One of the most severe problems with flexible asphalt pavements is permanent deformation in the form of rutting. Accordingly, the practice of adding fiber elements to asphalt mix to improve performance under dynamic loading has grown significantly in order to prevent rutting distress and ensure a safe and long-lasting road surface. This paper explores the effects of a combination of ceramic fiber (CF), a low-cost, easily available mineral fiber, and thermal insulator fiber reinforced to enhance the Marshall properties and increase the rutting resistance of asphalt mixes at high temperatures. Asphalt mixtures with 0%, 0.75%, 1.5%, and 2.25% CF content were prepared, and Marshall stability and wheel tracking tests were employed to study the effect of added CF on asphalt mixture performance. Scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM) were also used to investigate the morphologies of CF and reinforced asphalt mixtures and to identify the mechanism of improvement .According to the study results, the ideal ceramic fiber content was 1.5%, which yielded an improve in Marshall stability and reduced rut depth by 22.05% and 27.71% at temperatures of 50°C and 60°C, respectively, when compared to asphalt mixtures without CF. Microscopic analyses clearly revealed the surface properties, particle diameter size, and fiber distribution of the reinforced mixture, including the network structure and strength mechanism, which improved the performance of the asphalt mixture by forming a three-dimensional network.

Effectiveness Evaluation of Shredded Waste Expanded Polystyrene on the Properties of Binder and Asphalt Concrete

The disposal of massive amounts of waste, particularly nondecaying waste, is now a major issue for both developed and developing countries. One of the most sustainable solutions to this problem is to recycle garbage into valuable items. Expanded polystyrene, which is manufactured in large quantities, is one of these waste materials. This is being used globally as packaging material, construction material, and household appliances. The waste expanded polystyrene (EPS) is necessary due to its biodegradability, and aesthetically, it has a great negative impact on the environment. The goal of this research would be to see how shredded waste EPS affects the characteristics of asphalt and asphalt concrete. For this, four separate serial asphalt concrete samples were made with varying amounts of shredded expanded polystyrene waste (0.25, 0.50, 0.75, and 1% by the weight of the total aggregate) and five different percentages of asphalt (4.0, 4.5, 5.0, 5.5, and 6.0% by the weight of the total aggregate). In this study, 60/70 grade bitumen was used. Modified asphalt concrete properties were examined and compared with those of the standard specimens. The penetration, ductility, softening point, flash point, and fire point of the asphalt will all be affected by the addition of EPS plastic waste. The optimal asphalt content of the conventional specimen was 5.1 percent, and different percentages of EPS with OAC were applied. The mechanical properties of all specimens were studied in terms of Marshall properties after Marshall specimens were created with regard to OAC by adding EPS. It has been discovered that applying a 0.5% addition produces improved results than other methods. Simultaneously, as the EPS percentage increased, the stability value increased by approximately 82.61% compared to the traditional mix.

Influence of Iron Filing Waste on the Performance of Warm Mix Asphalt

Recently, interest in the use of projectiles in research on recycling waste materials for construction applications has grown. Using recycled materials for the construction of asphalt concrete pavement, in the meantime, has become a topic of research due to its significant benefits, such as cost savings and reduced environmental impacts. This study reports on comprehensive experimental research conducted using a typical mechanical milling waste, iron filing waste (IFW), as an alternative fine aggregate for warm mix asphalt (WMA) for pavement wearing surface applications. A type of IFW from a local machine workshop was used to replace the conventional fine aggregate, fine natural sand (FNS), at percentages of 25%, 50% 75%, and 100% by the weight of FNS of the size passing sieve No. 50. Experimental tests were conducted on the mixes to compare their Marshall properties, resilient moduli, rutting and fatigue resistance, and moisture susceptibility. Finally, a performance analysis was carried out using the VESYS 5W software on the constructed pavement using the IFW mixes. Both the experiment and the modeling work demonstrated that IFW can be an effective alternative resource for replacing natural fine aggregate in WMA concrete and provided details on the optimum rate based on the comprehensive data obtained first hand.

Reducing Environment Pollution by Reusing of Alum Sludge Waste in Stone Mastic Asphalt Mixtures

Globally, a huge quantity of alum sludge waste is produced as a by-product material from drinking water treatment plants that utilize aluminum salts as an essential coagulate and is the most generally produced water treatment remaining sludge around the world, which causes a serious environmental problem. Direct discarding of this substance has ecological effects. Hence, it is important to reuse this alum sludge waste material in such a manner to diminish its detrimental impacts on the environment. This research investigates the possibility of reusing alum sludge waste as a partial replacement of cement filler in stone mastic asphalt (SMA) paving mixtures. For this investigation, the alum sludge was used as a filler material in SMA mixtures in two modes; dried alum sludge at 110°C and burned alum sludge at 700°C. Different percentages of alum sludge were used as a replacement by the total weight of mineral filler at 0, 20, 40, 60, 80, and 100%. The results showed that using alum sludge as a substitution of filler in SMA mixtures reduces the performance of the mixtures in terms of Marshall properties and tensile strength for both dried and burned alum sludge compared with a standard mix. However, the performance of the mixtures containing burned alum sludge gave a better performance than the mixtures containing dried alum sludge.

Performance Studies on Stone Mastic Asphalt Mixes with Reclaimed Asphalt Pavement

Stone mastic asphalt (SMA) is a gap graded mix which is categorised by more quantity of coarse aggregate, high asphalt content and fibre. Due to stone on stone contact and presences of high filler content, it acts as a stiff matrix and reduces the rutting due to heavy traffic load. This research presents a study on fatigue performance RAP replaced SMA mixes using VG 30 as binder along with elastomer as a modifier and results were compared with conventional SMA mix. The specimens prepared were tested using several laboratory test procedures: Marshall mix design, indirect tensile strength, moisture susceptibility, drain down test and Repeated load fatigue test. Test results showed Marshall Properties of the RAP mix improved up to a RAP content of 30% without elastomer modifier and RAP content up to 60% with elastomeric modifier. From the moisture susceptibility test results, the elastomeric modified SMA mix showed high resistance to moisture damage when compared to conventional mix and 30% RAP replacement mix. Repeated load fatigue test was conducted for different stress load and temperature and results showed elastomeric modified SMA mix offered high resistance to deformation across all stress level and temperature when compared to conventional and optimum RAP mix. As a fatigue loading increased resulted in decrease of number of fatigue cycles and increased in the initial tensile strain of the mix. As the percentage of RAP addition increased the initial tensile strain decreased.

Experimental Evaluation of Moisture Damage and Rutting Resistance for SBS Modified Warm Mix Asphalt Incorporating Recycled Asphalt Concrete

The efforts embedded in this paper have been devoted to designing, preparing, and testing warm mix asphalt (WMA) mixtures and comparing their behavior against traditional hot mix asphalt mixtures. For WMA preparation, the Sasobit wax additive has been added to a 40/50 asphalt binder with a concentration of 3%. An experimental evaluation has been performed by conducting the Marshall together with volumetric properties, indirect tensile strength, and wheel tracking tests to acquire the tensile strength ratio (TSR), retained stability index (RSI), and rut depth. It was found that the gained benefit of reduction in mixing and compaction temperatures was reversely associated with a noticeable decline in Marshall properties and moisture susceptibility indices designated by TSR, and RSI, and even the rut resistance was adversely affected. Modification of WMA mixtures by 3% of Styrene-Butadiene-Styrene (SBS) polymer coupled with replacement of virgin ingredient by 50% of recycled asphalt concrete granted a 20% and 15% growth in Marshall stability and tensile strength, respectively. Moreover, both TSR and IRS indices have risen to 87% and 90%, respectively associated with a 39% increase in rutting resistance ability.