Effect Of Bitumen Research Articles

Use of polyethylene terephthalate as an Anti-stripping agent in GLASSPHALT

This study evaluates the use of polyethylene terephthalate (PET) in Glassphalt aimed at increased bonding effect of bitumen, reduced stripping and increased in stability and strength. Control mix were prepared with bitumen content of 5.0, 5.5, 6, 6.5 and 7% to determine the optimum bitumen content (OBC). Optimum glass content (OGC) was obtained from samples prepared with glass content of 5, 10, 15, 20, and 25% replacement by weight of fine aggregates. The OBC and OGC were used prepare samples with PET content of 2, 4, 6, 8, and 10% by weight of the OBC. The optimum PET content had a higher stability value of 5.8kN and higher air void of 3.8% when compared to the control mix. Stripping value tests showed that PET modified glassphalt had 0% stripping after a period of 48 hours. Waste PET of 6.6% in 16% glassphalt is recommended for use as an anti-stripping agent.

ЩЕБЕНОЧНО-МАСТИЧНЫЙ АСФАЛЬТОБЕТОН С ИСПОЛЬЗОВАНИЕМ БИТУМА, МОДИФИЦИРОВАННОГО СЭВИЛЕНОМ

Heavy traffic reduces the strength characteristics of asphalt concrete, causes peeling on the pavement. Crushed stone-mastic asphalt concrete is designed for the device of the upper layers of the coating on roads with high traffic intensity. The use of polymerasfalt concrete on a modified binder can lead to an improvement in the physical and mechanical characteristics of asphalt concrete and increase its re-sistance to climatic influences. The main aspects of improving the quality of crushed stone-mastic as-phalt concrete (SMA) due to the use of a binder modified with sevilen (SEVA) are discussed. The effect of bitumen containing sevilen with 22 and 29 % vinyl acetate groups on the properties of crushed stone-mastic asphalt concrete has been investigated. Analysis of the results showes that the use of modified binders has a positive effect on the entire complex of physical and mechanical parameters of polymer asphalt concrete. An increase in the strength of the samples at 20 and 50 °C, a decrease in this indicator at 0 °C is established. The indicators of water and heat resistance, shear resistance and crack resistance are also improved, which should have a positive effect on the durability of the road surface. Rational concentrations of polymer additives and the amount of vinyl acetate groups in its composition have been established. The adhesion of the binder to the mineral part of the asphalt con-crete mixture is estimated. The index of sensitivity to temperature differences of asphalt concrete sam-ples is considered due to the fact that asphalt concrete is a material that reacts to temperature fluctua-tions in the external environment. The analysis of the results of the tests carried out demonstrates that the use of modified binders has a positive effect on the entire complex of physical and mechanical pa-rameters of polymer asphalt concrete.

Shale rock core analysis using NMR: Effect of bitumen and water content

Hydrocarbon production from unconventional shale reservoirs has gained increasing worldwide focus, spurred largely by improvements in production techniques. Nuclear magnetic resonance (NMR) is increasingly being explored as a means of characterizing such shale rock. Compared to conventional sandstone and carbonate rocks, shales present a much lower porosity and permeability with NMR signal arising from both producible hydrocarbon fluid content as well as semi-solid organic solids and bitumen. Interpretation of the resultant NMR signal from shales is consequently comparatively more complex. To this end we apply combined NMR free induction decay (FID) and Carr-Purcell-Meilboom-Gill (CPMG) measurements and interpret the spliced data using a combined Gaussian and exponential inversion method. This was applied to a range of shale samples with variable moisture content in an attempt to assess the accuracy of such an approach to delineate the inherent predominantly bitumen signal from that of the added water. The analysis was performed at a range of frequencies (20, 40 and 60 MHz), which are applicable to more widely accessible bench-top NMR spectrometers. Consistently, the Gaussian component of the resultant T2*|T2 distribution was found to be independent of moisture content, scaling rather with the total organic content of the respective shale cores. In contrast, the exponential component of the resultant T2*|T2 distribution was found to scale linearly with the moisture content of the cores.

The effect of rock frame on elastic properties of bitumen sands

Elastic properties of bitumen reservoir change dramatically during thermal production, due to varying temperature and pressure conditions, which affect both the pore fluid and the rock frame. The effect of bitumen on the elastic properties of bitumen sands is widely studied, while the frame effect is commonly ignored. The influence of frame under different pressure and temperature conditions is investigated through laboratory measurements. Natural and artificial samples are compared to investigate the role of rock frame in their elastic properties. Samples with the same bitumen but different porosities are also compared, which reveals that the distinctions between the samples vary with temperature. Theoretical models are also applied to inspect the influence of rock frame, indicating the weak frame. In the end, two samples from Alaska and Alberta are compared, justifying the roles of bitumen and rock frame during the heating process. Our results reveal that rock frame of bitumen sands is quite loose, which may even damage during the heating process; and its influence on the rock elastic property is temperature dependent: at low temperature, its influence is insignificant, while at high temperature, its contribution is more important. These results suggest that for seismic monitoring of bitumen reservoir production, we should emphasize the temperature effect at the early stage and pay more attention to the pressure effect at the later stage of thermal production.

Effect of bitumen and migrated oil on hydrocarbon generation kinetic parameters derived from Rock-Eval pyrolysis

Thermally immature whole rock and related bitumen-extracted samples were pyrolyzed. Investigating the influence of high molecular weight hydrocarbons and degradation products of non-hydrocarbon constituents of bitumen and associated migrated oil (i.e. resins and asphaltenes) on petroleum generation kinetic parameters derived from Rock-Eval pyrolysis is the main aim of this study. Based on the optimized kinetic parameters, frequency factor values of the bitumen-free samples show an obvious increase compared to whole rocks, while the range of activation energies for them is narrower. On the other hand, the predicted geological temperatures of the onset (TR 10%) and the peak hydrocarbon generation (geological Tmax) from the whole rocks are generally lower than the corresponding extracted samples. In other words, the whole rock samples underestimate the petroleum formation temperatures. Thus, the results of this study suggest the extraction of bitumen prior to Rock-Eval pyrolysis in order to obtain precise kinetic parameters for the source rocks bearing a large amounts of heavy bitumen or migrated oil.

Compatibility of poly(dimethylsiloxane) microfluidic systems with high viscosity hydrocarbons

In this work, the compatibility of poly(dimethylsiloxane) (PDMS) with high viscosity petroleum liquids (bitumen) was evaluated to study the possibility of using PDMS microchannels in heavy oil and bitumen extraction research using solvent based methods such as Vapor Extraction. Three curing agent to base ratios (1:2, 1:10, and 1:20) were used to fabricate PDMS. Swelling ratio of these three samples in the vicinity of different organic solvents and diluted bitumen were evaluated by measuring the weight of sample every 15 min. It was found that 1:10 ratio PDMS was preferential ratio for minimizing absorption. We were particularly interested in the kinetic of swelling, deformation, and discoloration of PDMS. The hypothesis was that a PDMS microchip can still be used for experiments with heavy oil and bitumen if the experiment time is much shorter than the time it takes for PDMS discoloration, swelling, and deformation. The coating of PDMS slabs with trichloro (1 h 1 h 2 h 2 h-perfluorooctyl) silane was also tested and swelling ratios were again measured to evaluate the effect of surface coating. Swelling ratios were at the same order for uncoated PDMS which shows silane coating is not able to improve the solvent compatibility of PDMS. Moreover, solubility parameter was used to predict the swelling ratio of 1:10 PDMS sample in organic solvents. It predicts that hexane and toluene have the highest solubility that was in great agreement with experimental results. It seems that solubility parameter is a reliable factor to qualitatively predict the swelling ratio of PDMS. The effect of bitumen on transparency of PDMS was also studied using Ultraviolet–Visible spectrophotometer.

Moisture sensitivity examination of asphalt mixtures using thermodynamic, direct adhesion peel and compacted mixture mechanical tests

Moisture damage in asphalt mixtures is a complicated mode of pavement distress that results in the loss of stiffness and structural strength of the asphalt pavement layers. This paper evaluated the moisture sensitivity of different aggregate–bitumen combinations through three different approaches: surface energy, peel adhesion and the Saturation Ageing Tensile Stiffness (SATS) tests. In addition, the results obtained from these three tests were compared so as to characterise the relationship between the thermodynamic and the mechanical tests. The surface energy tests showed that the work of adhesion in dry conditions was bitumen type dependent, which is in agreement with the peel test. After moisture damage, all of these three tests found that the moisture sensitivity of aggregate–bitumen combinations were mainly aggregate type dependent. Based on the peel test, the moisture absorption and mineralogical compositions of aggregate were considered as two important factors to moisture sensitivity. This phenomenon suggests that in a susceptible asphalt mixture, the effect of aggregate may be more influential than the effect of bitumen. The SATS test and the peel test showed similar moisture sensitivity results demonstrating the good correlation between these two mechanical tests. However, the surface energy tests and the mechanical tests cannot correlate in terms of moisture sensitivity evaluation.

Total Internal Reflection Fluorescence Microscopy To Investigate the Distribution of Residual Bitumen in Oil Sands Tailings

A major waste byproduct of oil sands in situ extraction is oil sands tailings, which are a mixture of water, clay, and residual bitumen. These tailings represent a huge ecological footprint in the form of tailings ponds, which not only render large land areas unusable but also prevent reuse of water. The slow dewatering of the tailings ponds poses a major challenge to the industry. The presence of complex inorganic–organic bitumen–clay mixtures in these tailings contributes to this problem. Hence, understanding the nature of the bitumen–clay association and the effect of bitumen on clay particle–particle interactions is important for the development of more effective chemicals or processes to accelerate particle aggregation and sedimentation during dewatering. Previous studies that investigate these interactions used techniques that are sensitive only toward inorganic clay but not sensitive towards organic bitumen. Here, we use a high-resolution total internal reflection fluorescence (TIRF) microscopy to ...

Development of a composite substrate peel test to assess moisture sensitivity of aggregate–bitumen bonds

This paper presents the development of a suitable procedure to prepare peel test specimens using coarse aggregates and compare the results with the established standard peel test. The newly developed composite substrate peel test (CSPT) was found to be effective in characterising the moisture sensitivity of the aggregate–bitumen bond and the results correlated well with the results from a standard peel test. The results from the CSPT and the standard peel test showed that the fracture energy after moisture damage was found to be aggregate type dependent. Limestone tends to have better resistance to moisture damage than granite when moisture adsorptions are similar. Furthermore, in terms of similar aggregates, lower moisture adsorption results in better moisture resistance. This phenomenon suggests that in a moisture susceptible asphalt mixture, the effect of aggregate may be more influential than the effect of bitumen. Strong correlations were found between the standard peel test and the CSPT in terms of moisture damage evaluation and suggest that the CSPT maybe a more practical procedure to test the aggregate–bitumen bond for actual aggregates used in asphalt mixtures.

Biological effects and toxicity of diluted bitumen and its constituents in freshwater systems.

Approximately 50 billion cubic meters of bitumen resides within the oil sands region of Alberta, Canada. To facilitate the transport of bitumen from where it is extracted to where it is processed, the bitumen is diluted with natural gas condensate ('dilbit'), synthetic crude from hydrocracking bitumen ('synbit'), or a mixture of both ('dilsynbit'). A primary consideration for the effects of diluted bitumen products on freshwater organisms and ecosystems is whether it will float on the water surface or sink and interact with the stream or lake sediments. Evidence from a spill near Kalamazoo, MI, in 2010 and laboratory testing demonstrate that the nature of the spill and weathering of the dilbit, synbit or dilsynbit prior to and during contact with water will dictate whether the product floats or sinks. Subsequent toxicological data on the effects of dilbit and other diluted bitumen products on freshwater organisms and ecosystems are scarce. However, the current literature indicates that dilbit or bitumen can have significant effects on a wide variety of toxicological endpoints. This review synthesizes the currently available literature concerning the fate and effects of dilbit and synbit spilled into freshwater, and the effects of bitumen and bitumen products on aquatic organisms and ecosystems. Dilbit is likely to provide ecological impacts that are similar to and extend from those that follow from exposure to lighter crude oil, but the prospect of bitumen settling after binding to suspended sediments elevates the risk for benthic impacts in streams and lakes.

Influence of aggregate mineralogical composition on water resistance of aggregate–bitumen adhesion

The effects of aggregate mineralogical composition on moisture sensitivity of aggregate–bitumen bonds were investigated using four aggregate types (two limestone and two granite) and two bitumen grades (40/60 pen and 70/100 pen). Moisture sensitivity (or water resistance) of the aggregate–bitumen bonds were characterized using retained strength obtained from three different tensile tests (peel, PATTI and pull-off). The results showed significant differences in the amount of moisture absorbed by a given aggregate which suggested strong correlations between aggregate mineral composition and moisture absorption. For most of the aggregate–bitumen bonds, failure surfaces transformed from cohesive to adhesive with conditioning time thereby confirming the strong influence of moisture on aggregate bonds. The three tensile tests used in this study showed similar rankings in terms of moisture sensitivity but the pull-off test was found to be the most sensitive. The effect of bitumen on moisture sensitivity was found to be lower than the effect of aggregates, with the moisture absorption properties of the aggregates depending strongly on certain key minerals including clay, anorthite and calcite. Strong correlations were also found between mineral compositions and moisture sensitivity with clay and anorthite having strong negative influence while calcite showed positive effect on moisture sensitivity. Previous studies have identified various mineral phases like albite, quartz, and k-feldspar, as detrimental in terms of moisture sensitivity. The results appear to support the extension of the existing list of detrimental aggregate minerals to include anorthite and clay while supporting the case of calcite as a moisture resistant mineral.

Effect of Bitumen on the Mechanical Properties of Medium Carbon Steel

The effect of austempering of 0.45% carbon steel in hot bitumen on the hardness, impact strength, tensile properties and microstructure were investigated. The hardness values, impact strengths and tensile strengths of the austempered samples increased almost linearly from the austempering time of 1 hour to 3 hours after which they all dropped. At the austempering time of 3 hours the maximum values of hardness, impact strength and tensile strength of 496.2HV, 149J and 706.2 N/mm2respectively were attained. These values are 24.5%, 4.9% and 25.8% higher than the hardness values, impact strength and tensile strength respectively of the as-received steel. The high impact strength and tensile strength recorded despite the high hardness value was probably due to the formation of bainite structure and the diffusion of carbon from the bitumen into the steel samples.

Cellular alterations and modulation of protein expression in bitumen-challenged human osteoblast cells

There are many arguments on the carcinogenic potential of bitumen extract. The mechanism of bitumen-induced damage is not well understood at the molecular level. Therefore, in the present study, cell-transforming and tumor-inducing potential of bitumen extract was studied using in vitro [human osteosarcoma (HOS) cells] and in vivo [nude and severe combined immunodeficiency (SCID) mice] models. Gas chromatography/mass spectrometry (GC/MS) analysis was carried out to find out the existence of carcinogenic compounds in the bitumen extract. Cell transformation test, anchorage independence assay, karyotyping assay, tumorigenicity assay, and 2-DE analysis were used to find out the effect of bitumen using the in vitro and in vivo models. GC/MS analysis showed the existence of carcinogenic compounds in the bitumen extract. HOS cells were treated with different concentrations (25, 50, and 100μl/ml) of bitumen extract. Compared to the parental HOS cells, bitumen transformants (HOS T1 and HOS T2) showed the characteristics of anchorage independency, chromosomal anomaly, and cellular transformation. Interestingly, bitumen transformants were not able to form tumor in nude/SCID mice. Proteomic analysis revealed the existence of 19 differentially expressed proteins involved in progression of cancer, angiogenesis, cell adhesion, etc. Exposure of bitumen extract to HOS cells results in the cellular transformation similar to cancer cells and can modulate proteins involved in the progression of cancer. We state that the non-tumorogenic potential of bitumen transformant in nude/SCID mice can be attributed to the downregulation of galectin-1, chromodomain helicase DNA-binding protein 1-like gene, and membrane-associated guanylate kinase 2 protein.

IMPROVEMENT OF SOME UPPER EUPHRATES SOIL RESISTANCE TO WATER EROSION BY USING TWO CONDITIONERS

This study was conducted to know the effect of rainfall intensity and slope on the amount of soillsses under simulated rain, and the effect of Bitumen and wheat straw on soils losses conditioners on soil losses. Soil samples have been taken from the (0 - 30 cm) depth to four soils which are: Zangora, Mhammadi, Madheek and Heet whose erodibility classes are, high, moderate – high, moderate and low respectively, soil samples were air dried and sieved with a (4 mm) diameter sieve and put them in special flumes, two types of conditioners were used with control treatment. Bitumen sprayed with (1%) Concentration and wheat straw which was added in alevel of (6 mg. ha-1) mixed with soil to 5 cm depth. The containers were fixed on four slopes ( 0, 3, 5 ) and 7 % treatments are distributed randomly in three replicates for each treatment by using complete randomized design (CRD) with afactorial experiment. All the flumes are exposed to simulated rain with two intensities 30 an 53 mm. h-1 for 30 min. The scattered soil splash, soil losses by runoff and volume of surface runoff were measured. The results showed that increasing rainfall intensity and slope has asignificant effect on amount of soil losses by the scattered splash and runoff and volume of surface runoff. Adding the two Conditioners (Bitumen, wheat straw) had ahigh significant effect in decreasing soil Losses but Bitumen showed abetter effect than wheat in decreasing soil losses by splash, where as wheat straw showed abetter effect than Bitumen indecreasing soil losses by runoff. The wheat straw has better effect than Bitumen in decreasing runoff volume.

Use of the Distinct Element Method to Model the Deformation Behavior of an Idealized Asphalt Mixture

This paper investigates the use of distinct element modelling to simulate the behavior of a highly idealized bituminous mixture in an uniaxial compressive creep test. The effect of bitumen is represented as shear and normal contact stiffnesses. Elastic contact properties have been used to investigate the effect of sample size and the effect of the values of the shear and normal contact stiffnesses on bulk material properties. It was found that a sample containing at least 4,500 particles is required for Young's modulus and Poisson's ratio to be within 2% of the values calculated using a much larger number of particles. The bulk modulus was found to be linearly dependent on the normal contact stiffness and independent of the shear contact stiffness. Poisson's ratio was found to be dependent on only the ratio of the shear contact stiffness to the normal contact stiffness. A simple elasto-visco-plastic Burger's model was introduced to give time dependent shear and normal contact stiffnesses.

Impact of fines content on a warm slurry extraction process using model oilsands ☆

Natural oilsands deposits are composed of a complex mixture of sand, silt, clay, water and bitumen. The bitumen content and silt fraction, or fines (<44 μm), have traditionally been used as primary measures of ore processability. However, it is now known that this rule of thumb is not always applicable. In fact, the variability of oilsands, in terms of both quality and composition, makes it difficult to determine the unbiased effect of any individual component on bitumen extraction from mined ore. To address this problem, a model oilsands (MOS) system has been devised to determine how the interactions of oilsands components affect bitumen recovery. In this preliminary work, the effects of bitumen and fines contents, connate water pH and sodium hydroxide (NaOH) dosages on primary bitumen recovery were determined under the conditions extant in the warm slurry extraction process (WSEP). A three-factor Box–Behnken experimental design was used to quantify the effects. Prior to incorporation into the model oilsands system, each component was characterized to ensure quality control between tests. For the simple model studied in this work, the fines content and sodium hydroxide addition were the most important parameters affecting primary bitumen recovery. Although a small amount of fines was required to recover bitumen in the absence of process aids, an excess of fines was always detrimental to bitumen recovery.

Enhancement of DNA damage and involvement of reactive oxygen species after exposure to bitumen with UVA irradiation

This study was carried out to evaluate whether bitumen cytotoxicity is enhanced when bitumen treatment is combined with UVA exposure. We also evaluated the oxidative processes in bitumen-induced DNA damage, and attempted to identify the DNA damage caused by bitumen and UVA exposures, either alone or in combination. The effects of bitumen and UVA on cell proliferation were examined using HL 60 cells. DNA–protein crosslinks (DPCs) were assessed using a K-SDS assay, and reactive oxygen species formation was detected by 8-OH-dG formation. We evaluated the formations of double-strand breaks (DSB) using λDNA/ HindIII and single-strand breaks (SSB) using PM2 DNA. The cytotoxicity assay showed enhanced suppression of cell proliferation when bitumen exposure and UVA exposure were combined. Combined exposure caused significant increases in DPCs over either exposure alone. Incubation of deoxyguanosine (dG) with bitumen or UVA showed an increase in 8-hydroxy-2′-deoxyguanosine (8-OH-dG) levels when compared with controls, and combined exposure enhanced this effect. An evaluation of agarose gel bands showed that DSB and SSB were not formed following exposure to bitumen and UVA. This fact indicates that bitumen and UVA may be involved in genotoxic processes by producing oxygen free radicals and that combined exposure enhances these effects.

Direct seeding of native trees and shrubs in low rainfall areas and on non-wetting sands in South Australia

Seeds of common endemic species of Acacia, Callitris, Eucalyptus and Melaleuca were sown at 12 sites in Southern Australia in 1994 and 1995 to determine the role of soil stabilisers, fertilisers, time of seeding, herbicides, ripping and soil preparation with a V-blade or a disc in improving the reliability of direct seeding in Mediterranean type climates with low rainfall. Rainfall in 1994 was below average with 140 mm at the northern sites (55% of the average) and 300 mm at the southern sites (74% of the average) and only Acacia was successful with at least 3 plants/10 m present at the end of spring at eight sites and a survival rate after the first summer of 43%. In 1995 at least 3 plants/10 m of Acacia and Eucalyptus spp. were present at the end of spring at eight sites, with at least 3 plants/10 m of Melaleuca at six sites and at least 3 plants/10 m of Callitris at only three sites. Melaleuca had the highest overall survival rate at the end of summer with 52% compared to Acacia 42%, Eucalyptus 41% and Callitris 29%. Sowing two to three weeks after the opening rains (May at most sites) with good weed control gave the best results. Plant survival over the summer was reduced by 40% where weeds were not controlled by a herbicide. Ripping or fertiliser did not improve success. Ground preparation with an 80 cm wide V-blade generally produced better results than using a 25 cm wide disc except for Melaleuca. The effect of bitumen was variable in the trials, but appeared to be beneficial on wind eroded sites. The results indicate that direct seeding of trees and shrubs can be carried out in Mediterranean type climates with 250 to 425 mm average annual rainfall including on soils that are water repellent. This technology could be used for large scale revegetation in areas of the world with low rainfall Mediterranean type climates that have been largely denuded of trees and shrubs.

Development of negative skin friction on driven piles in soft Bangkok clay: Reply

This paper describes the results of short-term pullout tests and long-term full-scale measurements of negative skin friction on driven piles in Bangkok subsoils. Two instrumented cylindrical (hollow) prestressed concrete piles were fully equipped with two independent load-measurement systems, load cells, and telltale rods. Pore pressures and ground movements in the vicinity of the piles were monitored throughout the period of investigation. The effect of bitumen coating on negative skin friction was also studied. The long-term behaviour of driven piles was compared with the estimated values obtained from short-term pullout tests and soil strength data. It was found that the negative skin friction can be predicted well by the effective stress approach using values of β between 0.1 and 0.2. The load–settlement and load–transfer behaviour were numerically modelled to acquire a more comprehensive understanding of negative skin friction developed on driven piles. A settlement-controlled concept is also introdu...

Effect of bitumen on the thermal depolymerization of kerogens and coals

Effect of bitumen on the thermal depolymerization of kerogens and coals