Percentage Of Bitumen Research Articles

The Effects of Animal Bone Ash on Asphalt Pavement Mixtures

This study focuses on alternative raw material sources to meet the demand for sustainable construction materials. Particularly, it is suggested that waste materials, such as animal by-products, could provide a solution for enhancing the mechanical properties and durability of asphalt concrete. The research aims to improve the physical and mechanical properties of asphalt concrete by utilizing bone powder obtained from Category 3 animal by-products through a hydrolysis procedure. Experiments conducted showed that the addition of 5% bone powder increased maximum stability when used in conjunction with different percentages of bitumen. Overall, some positive developments were observed in the physical and mechanical properties of asphalt concrete containing animal bone ash, possibly due to strengthening the bond between aggregate particles and bitumen material. This study highlights the potential of animal bone ash in improving the mechanical properties of asphalt concrete and recommends a 5% bone powder addition for optimum stability and durability. However, further research and field tests are needed to better understand the long-term effects of animal bone ash and its performance under different road conditions.

Reclamation and recycling of plastic waste in road construction: Design of a bituminous mix from plastic waste

The purpose of this work is the recovery and recycling of plastic waste as additives in asphalt concrete (AC) in order to make a comparison with the conventional mix. The plastic waste used in this study is recycled plastic bottles made of Polyethylene Terephthalate (PET). The objectives also include the study of the effect of the addition of different percentages of shredded plastic on the properties of the asphalt mix and the comparison with the properties of the conventional mix. The results indicated that recycled plastics can be conveniently used as an additive for bituminous mixes to participate in the sustainable management of plastic waste and the improvement of the performance of the mix. After carrying out a comparative study between the classic mix and the mix modified with recycled plastic, we obtained an optimal bitumen content of 5.33 % to be mixed with an optimal quantity of plastic of 6 % to obtain a mix with better quality. Subsequently, we proposed to carry out a study trying to reduce the quantity of bitumen while maintaining the optimum quantity of plastic (6 %) in order to evaluate the percentage of bitumen that could be substituted with plastic to approach values obtained at the optimum at the level of conventional asphalt concrete. With 6 % of plastic, it is possible to reduce the optimal amount of bitumen from 5.33 % to 5 %, leading to a reduction in the cost per km of road.

Effect of Coated Aggregates by Plastic Bottles on Bituminous Concrete for Road Pavement

The amount of waste plastics which are released by factories and human activities day to day becomes big problem to human being health as days ahead. The major impact of waste plastics is the environmental pollution, as they do not decompose. This current study, was about to use those waste plastics as Partial replacement of bitumen in bituminous concrete production for road pavement. Different materials like plastics, coarse aggregate, fine aggregate, filler materials and bitumen were used. The plastics used in this research were shredded into small pieces of 5 to 10 mm size and mixed with aggregates in hot state. Tests on aggregates and bitumen for strength and specific gravity were carried out respectively. To examine the behavior of plastics, test specimens were prepared without plastic contents with different bitumen percentage of 4.5%, 5%, 5.5%, 6%, 6.5% for the purpose of finding optimum bitumen binder for normal mix. The optimum bitumen percent for normal bituminous mix is 5.7% and the maximum stability of 9.2875 KN is reported, which is above 8.2 KN as minimum stability accepted. The quantity of bitumen was partially replaced with 3%, 10%, 15% and 20% by plastics. High stability value of 10.89 KN was found at optimum 14.3% plastics. This paper reports that waste plastics produce a good result compare to normal mix.

Effects of Long-Term Soaking on the Load-Bearing Capacity of Bitumen-Treated Saline Sabkha Soil Subgrade

This study delves into the potential of using modified sabkha soil, a low-quality material, as a cost-effective solution for road construction in Kuwait, a country grappling with resource limitations. The research evaluates the effects of adding different percentages of bitumen (0%, 4%, 8%, and 10%) to sabkha soil samples, specifically looking at their load-bearing capacity under long-term soaking conditions. The findings indicate that adding up to 8% bitumen enhances the soil's geotechnical properties and its load-bearing capacity. However, any further addition leads to a decline in these properties. Importantly, the soil's load capacity shows significant improvement under soaked conditions. These encouraging laboratory results suggest that utilizing waste sabkha soil could pave the way for effective soil waste management techniques, thereby addressing environmental concerns related to sabkha soil disposal.

Hierarchical automated machine learning (AutoML) for advanced unconventional reservoir characterization

Recent advances in machine learning (ML) have transformed the landscape of energy exploration, including hydrocarbon, CO2 storage, and hydrogen. However, building competent ML models for reservoir characterization necessitates specific in-depth knowledge in order to fine-tune the models and achieve the best predictions, limiting the accessibility of machine learning in geosciences. To mitigate this issue, we implemented the recently emerged automated machine learning (AutoML) approach to perform an algorithm search for conducting an unconventional reservoir characterization with a more optimized and accessible workflow than traditional ML approaches. In this study, over 1000 wells from Alberta’s Athabasca Oil Sands were analyzed to predict various key reservoir properties such as lithofacies, porosity, volume of shale, and bitumen mass percentage. Our proposed workflow consists of two stages of AutoML predictions, including (1) the first stage focuses on predicting the volume of shale and porosity by using conventional well log data, and (2) the second stage combines the predicted outputs with well log data to predict the lithofacies and bitumen percentage. The findings show that out of the ten different models tested for predicting the porosity (78% in accuracy), the volume of shale (80.5%), bitumen percentage (67.3%), and lithofacies classification (98%), distributed random forest, and gradient boosting machine emerged as the best models. When compared to the manually fine-tuned conventional machine learning algorithms, the AutoML-based algorithms provide a notable improvement on reservoir property predictions, with higher weighted average f1-scores of up to 15–20% in the classification problem and 5–10% in the adjusted-R2 score for the regression problems in the blind test dataset, and it is achieved only after ~ 400 s of training and testing processes. In addition, from the feature ranking extraction technique, there is a good agreement with domain experts regarding the most significant input parameters in each prediction. Therefore, it is evidence that the AutoML workflow has proven powerful in performing advanced petrophysical analysis and reservoir characterization with minimal time and human intervention, allowing more accessibility to domain experts while maintaining the model’s explainability. Integration of AutoML and subject matter experts could advance artificial intelligence technology implementation in optimizing data-driven energy geosciences.

Performance analysis of non-conventional Stone Mastic asphalt (SMA) elaborated with crumb rubber bitumen or by mean of glass macrofibers addition

Stone Mastic Asphalt (SMA) are high performance mixes that are widely used throughout the world. Originally designed in Germany, they are identified as mixtures with high percentages of coarse aggregates, lower quantities of fine materials, high filler content and higher bitumen contents than a conventional asphalt. To achieve these higher bitumen percentages, it is necessary to incorporate fibres, generally cellulose fibres, to prevent binder draindown during mixing, transport and compaction. There are currently studies, at research level, to eliminate or reduce the dosage of fibres using high-viscosity bitumen’s. One way to achieve this kind of bitumen is through high rates of Crumb rubber (CR) from end-of-life tyres. This allows the use of high bitumen percentages without draindown and dispense with the use of fibres. Another alternative is to replace cellulose fibres with synthetic or glass macrofibre’s, these latter being considered structural. The macrofibre acts improving rutting and cracking resistance, providing performance improvements, especially in extreme weather conditions. This work focuses on the study of a 19 mm maximum size SMA analysing its performance to rutting, cracking, dynamic modulus, and moisture damage. Alternatives to the traditional SMA with cellulose fibres were studied here; one through the addition of glass macrofibres maintaining the commercial polymer modified asphalt and other alternative was a fibreless SMA elaborated with a high-viscosity modified asphalt with Crumb rubber (CR) from end-of-life tyres. It was found it is possible to produce SMA with high viscosity crumb rubber bitumen binder without fibres (SMA CR) and met all the volumetric characteristics specified for SMAs, specifically the draindown. The SMA CR and Glass addition in SMA showed improvements in dynamic modulus behaviour. The addition of glass macrofibres provide improvements with higher cracking resistance at low temperatures.

Performance of hot-mix asphalt using polymer-modified bitumen and marble dust as a filler

Marble dust waste powder generated by the marble cutting industry has a high alkalinity. In this research, the use of marble dust (MD) as a mineral filler substitute in hot mixed asphalt (HMA) was evaluated. The Marshall mix design was used to determine the optimum bitumen content (OBC) for all of the mixtures. For each of the four MD contents, i.e., 0, 2%, 4%, and 6% by weight of the total aggregates, four different bitumen percentages were used. The results of the Marshall stability test showed that the optimum filler content was 4% MD. Samples were prepared with 0 MD in the control mix and varying percentages of MD as an alternate filler. In addition, MD aided in increasing the Marshall stability, rutting resistance, and permanent deformation and reduced the fatigue life of asphalt mixtures. As the percentage of MD increases, the rutting resistance and stiffness at high temperatures both increase. As the percentage of MD increases, the fatigue life reduces. Rut resistance in high-temperature conditions can be improved by using MD in HMA as a partial substitute for stone dust (SD). In areas where extensive MD waste is present, MD can be incorporated into HMA mixtures instead of conventional fillers.

Mechanical and environmental performance comparisons of improved asphalt pavement wearing courses with high quality aggregates, steel slags, and polymeric compound

The use of waste materials in the construction of hot mix asphalt (HMA) pavements is an important opportunity for environmental sustainability. When properly designed, the alternative mixtures may also guarantee excellent mechanical performance.In this study, the results of an experimental analysis carried out on dense-graded HMAs are presented. In particular, the performance of a “traditional” surface mixture with limestone aggregate (designed with neat bitumen or a polymer-modified bitumen within the typical acceptance requirements for intended use in wearing courses) was compared with two alternative mixtures. The research investigated a surface mixture including coarse basaltic aggregates (a high-quality non-renewable resource) and one in which the coarse aggregate is substituted by a waste material, i.e. steel slags, in a high percentage. Both the improved mixtures included neat bitumen and a polymeric compound too, for advanced performance. Finally, for a more comprehensive comparison, a Life Cycle Assessment - LCA (cradle-to-gate approach) was carried out on the different mixtures, to compare the environmental impacts related to their production in asphalt plants, considering the features of the materials and fuels involved. The laboratory results showed comparable structural performance for the two mixtures with basalt aggregates and steel slag. In addition, other positive aspects concerned the higher crushing resistance of metal slag compared to basalt aggregates and the lower percentage of bitumen required by the proposed mixture with slags, with evident practical benefits. Furthermore, the LCA provided useful information about the environmental sustainability of the different mixtures, so that the feasibility of use of these recycled materials may be evaluated considering not only the technical and cost perspectives but the environmental ones too. The numerical results evidenced remarkable benefits for several impact categories for the mixtures with recovered waste materials, with promising advantages with their growing wide adoption.

Pengaruh Proses N-Hexane Solvent Extraction pada Ekstraksi Bitumen dari Aspal Buton sebagai Bahan Baku Minyak Bumi Nonkonvensional

Buton tar sand or commonly known as asbuton is a natural tar sand deposit found in Buton Island, Southeast Sulawesi. The reserve of asbuton is approximately 179.1 million tons with a hypothetical resource of oil amounting to 10,577,646,000 liters. Asbuton is potentially used as an alternative raw material for non-conventional oil. Non-conventional oil from asbuton could be used as a substitute to the depleted resources of conventional oil in Indonesia. Asbuton non-conventional oil could be prepared by extracted bitumen, a heavy hydrocarbon material in asbuton tar sand from its mineral. The bitumen then could be further processed to produce non-conventional oil. Various studies have been carried out to extract bitumen with various solvents. This study uses direct extraction and soxhlet extraction methods with n-hexane solvent to obtain the most optimum percentage of bitumen. Direct extraction method is done by varying the temperature (40, 45, 50, 55, 60oC) and the weight ratio of asphalt and n-hexane solvent (1:20; 1: 30; 1:40; 1:50). Based on the results of research that has been done, the highest percentage of bitumen yield is formed at 40oC and at a ratio of 1:20 that is 88.60% for the direct extraction method. The 1:40 ratio of soxhlet solvent extraction has the highest bitumen yield of 90.97%. After that, a characteristic analysis was carried out using FTIR with a strong absorbance in the area of 1423.47; 1033.85; 873.75; 709.80 cm-1 representing the C-H and C = H groups.

A Study on Frequency Response Functions in Pavement Engineering

Mechanical impedance (MI) defines the ability of a system to vibrate as a consequence of force application. In the recent years, the correlation of this parameter with tire-road noise and other characteristics has gained certain attention. Nevertheless, the information about this topic is still insufficient. Usually, the force is set through an impulse hammer as a master and the acceleration is measured through an accelerometer as a response in order to measure the corresponding Frequency Response Function (FRF). The objectives of the study presented in this paper are i) to analyse the differences between the axial mechanical impedance (complex ratio of force and velocity referred to the same point, named driving-point impedance) and the non-axial mechanical impedance (complex ratio of the force at the point i and velocity at the point j, named transfer impedance); ii) to analyse the effect of adding crumb rubber (2% by mixture weight) and of the percentage of bitumen on the mechanical impedance for the bituminous samples. Therefore, laboratory tests on asphalt concrete specimens have been performed, using an instrumentation system composed of i) an impact hammer reporting the impact force value; ii) an impedance head measuring the direct impact force and the direct acceleration at the hitting point location; iii) a piezoelectric accelerometer measuring the transfer acceleration at a certain distance from the hitting point location. Results demonstrate that the ratio between the repeatability and the average is quite constant, while for heights higher than 10 cm, also MI tends to be independent on the height. A number of recommendations have been made based on the results of the present research.

Hydrocarbon Generation Mechanism of Mixed Siliciclastic–Carbonate Shale: Implications from Semi–Closed Hydrous Pyrolysis

Affected by the complex mechanism of organic–inorganic interactions, the generation–retention–expulsion model of mixed siliciclastic–carbonate sediments is more complicated than that of common siliciclastic and carbonate shale deposited in lacustrine and marine environments. In this study, mixed siliciclastic–carbonate shale from Lucaogou Formation in Junggar Basin was selected for semi–closed hydrous pyrolysis experiments, and seven experiments were conducted from room temperature to 300, 325, 350, 375, 400, 450, and 500 °C, respectively. The quantities and chemical composition of oil, gases, and bitumen were comprehensively analyzed. The results show that the hydrocarbon generation stage of shale in Lucaogou Formation can be divided into kerogen cracking stage (300–350 °C), peak oil generation stage (350–400 °C), wet gas generation stage (400–450 °C), and gas secondary cracking stage (450–500 °C). The liquid hydrocarbon yield (oil + bitumen) reached the peak of 720.42 mg/g TOC at 400 °C. The saturate, aromatic, resin, and asphaltine percentages of bitumen were similar to those of crude oil collected from Lucaogou Formation, indicating that semi–closed pyrolysis could stimulate the natural hydrocarbon generation process. Lucaogou shale does not strictly follow the “sequential” reaction model of kerogen, which is described as kerogen firstly generating the intermediate products of heavy hydrocarbon compounds (NSOs) and NSOs then cracking to generate oil and gas. Indeed, the results of this study show that the generation of oil and gas was synchronous with that of NSOs and followed the “alternate pathway” mechanism during the initial pyrolysis stage. The hydrocarbon expulsion efficiency sharply increased from an average of 27% to 97% at 450 °C, meaning that the shale retained considerable amounts of oil below 450 °C. The producible oil reached the peak yield of 515.45 mg/g TOC at 400 °C and was synchronous with liquid hydrocarbons. Therefore, 400 °C is considered the most suitable temperature for fracturing technology.

Investigation of Cold Recycling of Bituminous Surface Treatment with Foam Bitumen

The course of turned of bituminous pavement layers into hot mix asphalt (HMA) layers has been increasing day by day all over the world. Bituminous surface treatment that contains consirable amount of aggregate and bitumen, is an important source of recycling that offers a great amount of pavement materials intead of virgin material usage on pavement consruction. In the study, it was aimed to investigate the usability of bituminous surface layer treatment in the base layers of the HMA roads by mixing with foam bitumen and active filler materials in order to eliminate the potential performance degradation that will be encountered when it is recycled due to the low bitumen percentage compared to hot mix asphalt and the wear of the aggregate due to climatic conditions and traffic loads over time. The study conducted that intends to technically evaluate the cold recycling of bituminous surface treatment of roads with foam bitumen and active filler materials; for 70/100 bitumen grade, 5 different bitumen mixes were prepared and ideal bitumen percentage was investigated for this bitumen grade. The effect of bitumen percentage on mixture performance was evaluated with 50/70-100/150-160/220 bitumen grades and mixtures were prepared in single bitumen ratio (2.5%). It was investigated that active fillers will give suitable results for foam bituminous mixtures by preparing mixtures for three different active fillers; cement, hydrated lime and fly ash. To evaluate all these productions, ITS, unconfined compressive strenght, triaxial resilient modulus and asphalt permanent deformation tests were performed. The results obtained showed that production made using 2% foam bitumen and 1% was found suitable for moisture sensitivity and structural stability. Recycling of bituminous surface treatment using foam bitumen and cement is an environmentally and economically beneficial method by reducing both waste and raw material consumption.

Experimental Investigation of Bitumen by Using E-Waste Plastic as Filler

Electronic waste or simply e-waste management is one of the various challenges due to the unexpected surge in the electronic products. In our day-to-day life, the electronic components plays the predominant role in every human being. Peoples activities are daily determined by the personal computers, mobile phones, and gadgets etc., All these issues are drastically affect the human health and environment. The disposal of these e-wastes creates the huge environmental loss and harmful to use for the any purpose. For these improper disposals, the solution for these electronic products is in the usage of the concrete.This research paper is to examine the strength of bitumen by using E-Waste plastic as filler. In this experiment, Polyethylene plastic is used which is thermoplastic polymer and it is the most widely produced plastic in the world. Marshall Stability test is taken to analyze the strength of bitumen. The stability and flow value of bitumen is tested for various bitumen percentage with constant 5% E-Waste plastic filler. From the test values the stability and flow value of bitumen is optimum in 5% in addition to the strength of bitumen is increased to 10% than the conventional bitumen.

Investigation of Mechanical Properties of Quicksand Stabilized with Bitumen Emulsion and Reinforced with Waste Polypropylene Fibers and The Effect of Freeze and Thaw on Its Performance

The existing quicksands in the desert are among the problematic soils whose stabilization has been considered by experts. Emulsion bitumen is one of the environmentally friendly stabilizers of these sands. Also, the method of reinforcement with (fibers) has many advantages due to the increase in soilstrength in the same way and the formation of thickness in the soil mass. The aim of this study was to investigate the effect of polypropylene fibers and emulsion bitumen on improving sandy soil properties and the effect of freeze-thaw cycles on the behavior of soils stabilized by these two substances; For this purpose, samples of aeolian sand soil with 0%, 0.25%, 0.5%, 0.75% and 1% waste polypropylene fibers of 0, 5, 10, 15% bitumen emulsion were made and tested for California load-bearing capacity and uniaxial compressive strength. Also, to evaluate the effect of freeze-thaw cycle, the samples were subjected to uniaxial resistance test after enduring 3 and 7 freeze-thaw cycle. The results show that the addition of fibers and bitumen to the sand first increases the specific gravity and CBR and decreases from one percent onwards by increasing the fibers of these two parameters; It has compressive strength and ultimate strain with increasing fiber percentage; In general, increasing the percentage of fibers from 0to 1% on average increases the compressive strength by 91% and the final strain by 54% and increasing the percentage of bitumen from 5 to 15% on average increases the compressive strength by 4% and the final strain by 13%. In addition, the results show that the compressive strength of the samples decreases by an average of 15% and 19% after withstanding 3 and 7 freeze-thaw cycle, respectively; However, after enduring 3 and 7 freeze-thaw cycle, the compressive strength increases with increasing the percentage of fibers to 75%.

IMPROVING THE CONSOLIDATION CHARACTERISTICS OF SALINE SABKHA SOIL BY ADDING BITUMEN

The rapid economic and population growth, increase in constructions, and a small selection of appropriate soil resources in Kuwait have made it necessary to research soil stabilization methods because the existing soils are currently unsuitable in their natural conditions. In this study, the consolidation characteristics of sabkha soil samples in southern Kuwait mixed with 0%, 4%, 8%, and 10% bitumen with respect to soil dry weight were investigated. For this purpose, an experimental program, including soil characterization tests, modified Proctor compaction test, one-dimensional consolidation test, and collapsibility test, was executed. Results indicate that increasing the bitumen percentage improves the compressibility characteristics of sabkha soil. Upon the addition of 10% bitumen, the yield stress increased from 25 to 34 kPa, compression index slightly increased from 0.02774 to 0.03145, and swelling index decreased from 0.0119 to 0003. Further, there was a considerable reduction in the collapse potential from 1.192 to 0.301 upon the addition of 10% bitumen. Thus, it is evident that the disadvantageous characteristics of sabkha soil can be mitigated. The results support the possibility of recycling the sabkha soil, thereby contributing toward addressing the environmental issues associated with the disposal of excavated sabkha soil.

Modification of Aggregate Gradation for Simultaneous Optimization of Evaporation and Permeability of Porous Asphalt Mixtures

Today, with the expaansion of cities and the growth of urbanization, followed by climate change, it is crucial to prevent the occurrence of floods and control it in cities. Porous pavement, including porous asphalt, is known as one of the best methods for urban flood control due to its two properties of evaporation and permeability. The purpose of this study is to modify the gradation of porous asphalt in order to optimize its permeability and evaporation for low-traffic urban passages. For this purpose, permeability, evaporation, and Cantabro tests were performed on samples with different gradations and percentages of bitumen; then, using Design Expert software, the gradation and percentage of optimal bitumen were determined. Finally, the performance of the asphalt gradation and optimal bitumen percentage were evaluated by performing empty space percentage, modified Latman, Marshall, and psychological strength tests and Cantabro tests. The results show that with finer gradation, the permeability, evaporation, and minimum bitumen percentage are reduced by about 55%, 82%, and 60%, respectively. Also, the gradation is medium with 4% bitumen gradation and the percentage of bitumen is optimal, which has a good performance in low-traffic urban passages.

Using response surface methodology to optimize rubber and LDPE contents in bitumen at low-temperature performance

Selecting the optimum amount of modifiers added to bitumen to modify its characteristics has always been one of the most important steps of such researches. In this study, the response surface method is used to design the experiments and to determine the optimal combination of different percentages of waste LDPE and crumb rubber. Waste LDPE in the amounts of 3%, 5%, and 7% and crumb rubber in the amounts of 1%, 3%, and 5% are used as the modifiers. In addition, the central composite design method is used to select the optimal combination of waste LDPE and crumb rubber. Polymer percentage is the most effective parameter in this research. The results show an optimum point of approximately 3% waste LDPE and 3% rubber powder. It can be the optimal point and has the best performance at low temperatures in this combination of modified bitumen percentages. However, the exact optimal point is obtained as 3% recycled plastic and 2.02% rubber powder after the optimization process.

Experimental study of the role of interface element in earth dams with asphalt concrete core - Case study: Mijran dam

In recent years, the tendency to use asphalt concrete cores in earth dams is very common and is increasing. In such dams, the interaction between asphalt concrete core and soil materials has an important role in dam stability. The present study, as a case study of Mijran Dam located in Ramsar area in Iran, has evaluated experimentally the mechanical behavior of the interface between the filter soil material and the asphalt concrete core in the laboratory. In this regard, the samples were tested using large-scale direct shear machine in different normal stresses and in dry and saturation conditions. Also, tests have been performed on samples with different percentages of bitumen and relative density of filter materials at different shear rates and under different freeze-thaw cycles. In all the above conditions, the shear surface has been considered as the interface and the shear rate used in different tests varied in the amounts of 0.5, 1, 1.5 and 3 mm/min. The results of this study show that different percentages of bitumen used do not have such an effect on the shear strength parameters of interface. As the relative density increases, the values of the shear parameters increase. If the sample is dry or saturated, parameters such as dilation angle and shear stiffness increase with increasing density, but the interaction ratio increases in the dry state and decreases in the saturated state. As the shearing rate increases, the dilation angle and interaction ratio in the interface materials increase by about 2–3%. On the contrary, increasing the freeze-thaw cycles reduces the mentioned strength parameters.

Utilization of Bitumen, Aggregate and Wax with Rubber Tyre in a Flexible Pavement

With continuous wear and tear actions of rubber tyre on roads, a pile of waste rubber gets accumulated every year and it is posing severe threats to the environment. Due to high temperature in the summers, the road tends to become brittle, which may cause separation of binder in the bituminous road causing heavy cracks, so usage of wax tends to reduce the formation of cracks and improve the flexibility of road. This study aims to examine the effects on properties of the bitumen-aggregate mixture when the aggregates are partially replaced by similar sizes of waste rubber tyre particles and bitumen in the mix are partially replaced by a crumb waste rubber tyre, with partial addition of wax content in the bituminous samples. For this purpose of testing the suitability of using rubber waste in road pavement, Marshall Stability test is conducted on several bituminous mixtures. Varying percentages of rubber tyre, such as 0%, 5%, 10% and 15%, are used with different percentages of bitumen content (4.0, 4.2, 4.4, and 4.6), and varying percentages of paraffin wax (0-5%) is also added in the specimen with rubber and bitumen. This is utilized in obtaining the optimum content of bitumen required for best suitability of flexible pavement as well as to assess the durability and strength of a pavement. This study is performed on various mixtures, for the values of bulk density, air voids, stability value and flow value. The studies show that bitumen content corresponding to the maximum stability value and maximum bulk specific gravity in bituminous mixture, indicating the optimum bitumen percentage that can be replaced with crumb rubber tyre. This paper discusses the partial replacement of both aggregate and bitumen in the bituminous mixture, containing some percentages of paraffin, which can help in improving the serviceability level and assists in enhancing the flexibility and cohesion of road to resist heavy loadings of vehicle.

Calculation of the gamma radiation shielding efficiency of cement-bitumen portable container using MCNPX code

In the current study, the shielding characteristics of Portland cement combined with various percentages of bitumen (from 10% to 50%) materials were investigated. The MCNPX code was used to calculate the linear and mass attenuation coefficients, half and tenth value layers, and the mean free path for gamma rays. For the calculations, gamma sources (137Cs with 0.662 MeV and cobalt 60Co with an average energy of 1.25 MeV) were employed. In comparison to the cement paste solely, the cement-bitumen composites have a greater photon attenuation coefficient. It is suggested that new compositions can be used as shielding material for dual photon protection and would be recommended in casting containers of thickness 6 cm for embedding the cesium (137Cs) and cobalt (60Co) as a mobile container during transportation and long storage.