Asphalt Research Articles

Predicting creep deformation of asphalts modified with polymer using artificial neural networks

Predicting creep deformation of asphalts modified with polymer using artificial neural networks

“Sumak KawsayIs Harmful for All of Us”: Oil Roads and Well-being among the Waorani in Ecuadorian Amazonia

Exploration of the notion of waponi kewemonipa (living well) among Waorani people living near oil camps suggests that the extractivist developmental model delivered by the Ecuadorian government in the name of buen vivir (living well) is harmful to their experience of well-being. For Waorani living well is related to peace, collective happiness, and certain ecological experiences. The forest, a socio-biological ecological milieu, is the ideal locus of the Waorani conception of living well, but environmental changes related to oil camps and roads challenge their health and vitality.La exploración de la noción de waponi kewemonipa (o buen vivir) entre los waorani que viven cerca de los campamentos petroleros sugiere que el modelo de desarrollo extractivista fomentado por el gobierno ecuatoriano en nombre del “buen vivir” es perjudicial para la experiencia indígena del bienestar. Para los Waorani, vivir bien se relaciona con la paz, la felicidad colectiva y ciertas experiencias de índole ecológico. El bosque, un ambiente socio-biológico, es el locus ideal de la concepción waorani del buen vivir, pero los cambios ecológicos relacionados con los campos petroleros y las carreteras dificulta la experiencia de su salud y vitalidad.

Cast-in-situ piles encasements based on oil-bituminous rocks (kirs) in saline soils

A technology of building a pile foundation in saline soils with a protective and load-bearing shell based on bituminous rocks (kirs) is proposed that makes it possible to eliminate water permeability, to increase suffusion resistance and bearing capacity of the soil, as well as durability. The method of extracting natural bitumen from bituminous rocks (kirs) is based on the ability of kirs to self-grind or disintegrate into small parts at elevated temperatures in aqueous salt solutions. The proposed method excludes mechanical grinding and allows reducing the consumption of reagents and improving the quality of extracted natural bitumen. The compositions of the obtained mastics based on natural bitumen are not inferior in their properties to the known compositions of waterproofing cold mastics based on industrial bitumen at a lower cost.

A comparative study on direct liquefaction of two coals and hydrogen efficiency to the main products

To improve the performance of megaton direct coal liquefaction (DCL) technology that has been practiced in China since 2008 and to develop a better technology that can be operated at milder conditions with high efficiency, this work studies coal conversion (XC), products yield (Yi) and hydrogen consumption (RH) of SW coal (H/C = 0.75) used in the megaton plant and NMH coal of a higher H/C ratio (0.97) in tetralin and a temperature range of 380–455 °C. The experiments were carried out in fast heating high-throughput micro reactors and the dependencies of XC and Yi on temperature, time, and RH are studied. The results show that the XC-RH and Yi-RH relations are coal dependent but not temperature dependent in the temperature range of 380–440 °C. The kinetics modeling indicates that NMH contains more mobile fractions than SW and appreciable amounts of coals react in the 1 min heating-up period. The rate constants of coal to each product follows the order of asphalt (AS) > oil (O) > organic gas (OG), while the activation energy and H consumption to each product follows a reverse order.

Understanding the nature of bio-asphaltenes produced during hydrothermal liquefaction

Asphaltenes, the heaviest and most polar components of crudes, are generally associated with considerable operational issues in refineries. In order to understand potential operational issues during upgrading/processing of bio-crudes, structural and thermal behaviour of asphaltenes derived from bio-crude (bio-asphaltenes) from hydrothermal liquefaction of food-waste and wood residues were compared with petroleum derived asphaltenes derived from bitumen. Structural analysis using nuclear magnetic resonance and elemental analysis revealed 7 aromatic rings per unit structure for bitumen asphaltenes, 4 for food-waste asphaltenes, and 3 for wood asphaltenes. The calculated molecular weight per unit structure followed the order: bitumen asphaltenes (589–636 g mol−1) > food-waste derived asphaltenes (338–358 g mol−1)> wood residue derived asphaltenes (268–274 g mol−1). The carbon residues using thermal gravimetric analysis (bitumen asphaltenes = 40%, bio-asphaltenes = 19–25%) and glass transition temperature (bitumen asphaltenes = 80 °C, bio-asphaltenes = 4–64 °C) followed the same order. These results indicate a very different structural and thermal behaviour for petroleum and bio-asphaltenes.

Use of expanded polystyrene from disposable food pack as a modifier for bitumen in hot mix asphalt

This study evaluate the use of Disposable Food Pack (DFP) as a modifier for bitumen for an improved Hot Mix Asphalt (HMA). The bitumen was modified with 2%, 4%, 6%, 8% and 10% DFP obtained from domestic waste. The penetration, ductility and specific gravity of DFP modified bitumen decreased from 68mm to 59.5mm, 110cm to 101cm and 1.025 to 1.012 respectively with increase in DFP, while softening point increased from 49.5 oC to 54.5 oC with increase in DFP. The Marshal Stability results revealed that the DFP modified bitumen increased the stability values of the compacted mixes to a maximum of 9.33kN at 8% DFP content. The flow showed decrease from 3.18mm at 2% DFP to 2.94mm at 10% DFP, whereas the density of the compacted mixes increased to a maximum of 2.293g/cm3 with increased modifier. An Optimum DFP Content of 6.7% by weight of the Optimum Bitumen Content (OBC) isrecommended.
 Keywords: Bitumen, Disposable Food Pack, Expanded Polystyrene, Hot Mix Asphalt, Modified bitumen

Characterization of naphthenic acid fraction compounds in water from Athabasca oil sands wetlands by Orbitrap high-resolution mass spectrometry.

Classical naphthenic acids (NAs) are known to be primary aquatic toxicants of concern in the Athabasca oil sands region (AOSR), and are a component of naphthenic acid fraction compounds (NAFCs). Recent studies conducted in the AOSR have examined metals and polycyclic aromatic hydrocarbons in regional wetlands. However, few studies have described NAs and/or NAFCs in AOSR wetlands. To address this gap, we examined NAFC profiles in the water of different wetlands in the AOSR, including naturalized borrow pits (i.e., abandoned pits created by excavation of road-building materials), and opportunistically-formed wetlands associated with reclamation activities. For comparison, NAFC profiles from these wetlands were compared to an opportunistic wetland formed from tailings pond dyke seepage. Samples were prepared using solid-phase extraction and analyzed using negative-ion high-resolution Orbitrap mass spectrometry. Principal component analyses (PCA) revealed patterns to the NAFC profiles in the wetlands. The first distinct grouping of wetlands included water bodies associated with reclamation activities that are located on and/or adjacent to mining overburden. One other wetland, HATS5w, separated from all other wetlands during PCA, and had a unique NAFC profile; detailed examination of NAFCs revealed HATS5w contained the heaviest (i.e., high m/z components) and most unsaturated NAFCs among study locations, demonstrating the usefulness of high-resolution mass spectrometry for characterizing individual wetlands. The NAFCs of HATS5w are also substantially different from bitumen-derived inputs in overburden-adjacent opportunistic wetlands. Collectively, the NAFC profiles presented provide new information on background levels of polar bitumen-derived organics in AOSR wetlands.

Extractive deasphalting as a method of obtaining asphalt binders and low-viscosity deasphalted hydrocarbon feedstock from natural bitumen

The peculiarities of the composition of natural bitumen from Russian Federation deposits give rise to further processing and transportation problems due to necessity of construction of processing units close to their production areas. In order to solve this problem, a method of pretreatment of natural bitumen was proposed, as a result, potential asphalt binders and low-viscosity deasphalted oil suitable for transportation to refineries are produced. Based on experimental data, the optimal conditions for the process were selected. It was recommended to carry out the first stage of crude preparation, namely thermomechanical dehydration of bitumen, with an end-point for distillation of 150 °C. This solved the problem of stable water-hydrocarbon emulsions and further dewatering of bitumen, and excluded the possibility of destruction reactions resulting in more unstable hydrocarbon compounds. At the next stage, it was proposed to carry out the process of deasphalting of bitumen with acetone at a solvent:crude ratio of 3:1. Therefore, production of deasphalted oil, with viscosity close to that of natural crude oil, and asphalt, as a feedstock for the production of universal road bitumen, intended for both summer and winter operating conditions, was shown.

Preparative isolation, fractionation and chemical characterization of dissolved organics from natural and industrially derived bitumen-influenced groundwaters from the Athabasca River watershed

Recent analytical advances have provided evidence that groundwater affected by oil sands process-affected water (OSPW) is reaching the Athabasca River at one location. To understand and discriminate the toxicological risks posed by OSPW-influenced groundwater relative to groundwaters associated with natural oil sands deposits, these highly complex mixtures of soluble organics were subjected to toxicological characterization through effects directed analysis. A recently-developed preparative fractionation methodology was applied to bitumen-influenced groundwaters and successfully isolated dissolved organics from both industrial and natural sources into three chemically distinct fractions (F1, F2, F3), enabling multiple toxicological assessments. Analytical techniques included electrospray ionization high resolution mass spectrometry (ESI-HRMS), liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QToF/MS), gas chromatography mass spectrometry (GC–MS), and synchronous fluorescence spectroscopy (SFS) methods, which did not reveal obvious differences between sources. Comparisons between fractions within each source consistently demonstrated that F3 contained compounds with greater polarity than F2, which in turn was more polar than F1. The abundance of O2 species was confined to F1, including naphthenic acids often cited for being the primary toxicants within bitumen-influenced waters. This result is consistent with earlier work on aged OSPW, as well as with other extraction methods, suggesting that additional factors other than molecular weight and the presence of acid functionalities play a prominent role in defining compound polarities and toxicities within complex bitumen-derived organic mixtures. The similarities in organic abundances, chemical speciation, aromaticity, and double bond equivalents, concomitant with inorganic mixture similarities, demonstrate the resemblances of bitumen-influenced groundwaters regardless of the source, and reinforce the need for more advanced targeted analyses for source differentiation. • Method for extraction and fractionation of dissolved organics was applied to bitumen-influenced groundwater samples • Dissolved organics are considered principal toxic components in OSPW • Three large volume organic fractions were generated and characterized by complement of methodologies • Isolated fractions increased in polarity and degree of aromaticity • Chemical composition was similar between groundwaters influenced by OSPW and/or natural bitumen sources

Application of Mid-surface Layer in Asphalt Pavement Tunnel Paving Based on Foam Warm Mix Technology

With the deepening of the national green transportation policy, the constructi on of environmental protection and energy-saving highway has become the focus of th e industry. Based on the problem of flue gas emission from asphalt pavement tunnel pa vement, the mechanical foaming warm mixing technology is introduced. The foaming characteristics of modified asphalt, the performance of foam warm mix mixture, and th e evaluation of energy consumption and emission reduction of foam warm mix mixtur e are studied and analyzed. The results show that the energy consumption of foam asph alt production is significantly reduced, which has positive demonstration significance f or energy saving and emission reduction in highway construction.

Adesione Additives for the Production of Asphalt Concrete with the Use of Waste in Building Ceramics

The possibility of using industrial waste is theoretically justified porcelain stoneware as an asphalt concrete filler. The influence of adhesive additives for bitumen bond BND (oil road bitumen) 60/90 with porcelain stoneware of various fractional composition has been established.

Experimental Investigation on the Use of Selenice Natural Bitumen as an Additive for Pavement Materials.

As a good asphalt modifier, natural asphalt has been the focus of more attention because of its low price and ability to improve the performance of modified asphalt. In this paper, the incorporation of a natural asphalt binder in the production of bituminous materials for pavement application in China was experimentally investigated to evaluate the feasibility of such a process and its potential benefits in terms of performance. For this purpose, an asphalt binder conventionally used in the south of China was blended with various percentages of a hard natural binder obtained from the region of Selenice in Albania. The content of Selenice natural bitumen (SNB) was 80.5%, having high molecular weight and the advantages of good stability and compatibility with virgin asphalt. The physical, rheological, and mechanical properties, as well as the modification mechanism of the binder and corresponding asphalt mixture, were evaluated in the laboratory. It was observed that the hard binder improved the response of the binder blend at high and intermediate temperature; this reflected a better stability, improved moisture susceptibility, and enhanced rutting resistance of the mixture. Fluorescence microscopy showed that after dissolving, the size of the SNB modifier became smaller and its distribution was uneven, presenting three forms, granular, agglomerated, and flocculent properties. Chemical test results showed that the modification mechanism of SNB was mainly related to the enhancement of hydrogen bonds and Van der Waals forces caused by sulfoxide and carbonyl along with the stress concentration caused by silica particles. Molecular composition revealed that the proportion of middle molecules has reduced while the proportion of large molecules has increased. It is considered that SNB is a promising low-priced natural modifier with excellent rutting resistance properties. Future research will be focused on the economic analysis, pavement life cycle assessment of SNB modified asphalt, and its application in perpetual pavements.

Effect of Binary Basicity (CaO/SiO2) on Selective Reduction of Lateritic Nickel Ore

Selective reduction methods are being developed to process lateritic nickel ore to produce nickel with high content with low temperature or energy consumption. This research was carried out to study the effect of binary basicity (CaO/SiO 2 ) in the lateritic nickel ore's selective reduction process. The lateritic nickel ore with 1.38% Ni and 38.2% Fe content was used in this study. The reduction was conducted at 1150°C for 60 minutes in a muffle furnace with 10 wt.% additives of sodium sulfate, bituminous coal as reductant, and calcium oxide addition to modify its binary basicity. The results showed that the nickel grades generates from the 0,1 basicity due to the breakage of magnesium, iron, and nickel silicate into metallic iron and nickel. However, the next increase of basicities decreased the nickel grade due to the formation of a high melting point compound. lateritic nickel ore, selective reduction, binary basicity, reductant, additive.

Development of Roughness Prediction Models for Laos National Road Network

The International Roughness Index (IRI) has been accepted globally as an essential indicator for assessing pavement condition. The Laos Road Management System (RMS) utilizes a default Highway Development and Management (HDM-4) IRI prediction model. However, developed IRI values have shown the need to calibrate the IRI prediction model. Data records are not fully available for Laos yet, making it difficult to calibrate IRI for the local conditions. This paper aims to develop an IRI prediction model for the National Road Network (NRN) based on the available Laos RMS database. The Multiple Linear Regression (MLR) analysis technique was applied to develop two new IRI prediction models for Double Bituminous Surface Treatment (DBST) and Asphalt Concrete (AC) pavement sections. The final database consisted of 83 sections with 269 observations over a 1850 km length of DBST NRN and 29 sections with 122 observations over a 718 km length of AC NRN. The proposed models predict IRI as a function of pavement age and Cumulative Equivalent Single-Axle Load (CESAL). The model’s parameter analysis confirmed their significance, and R2 values were 0.89 and 0.84 for DBST and AC models, respectively. It can be concluded that the developed models can serve as a useful tool for engineers maintaining paved NRN.

Approach for Predicting Cracking Deterioration in Sprayed Seals from Subjective Condition Ratings

Cracking is the most influential distress on the performance of bituminous surfaces of granular pavements and ultimately that of underlying layers. The purpose of the study reported here is to describe the modeling approach adopted in developing cracking deterioration models of bituminous sprayed seals from historical time series subjective condition ratings. In this approach, a multilevel analysis has been applied to capture the variations between observations, segments, and highways. Further, it involved considering all possible contributing factors that affect cracking deterioration of in-service sprayed seals. Factors considered here include surface age, temperature, traffic volume, rainfall, shoulder seal width, and subgrade soil reactivity. The modeling approach has been applied to condition data from five rural highway networks separately then collectively. In the latter, only significant contributing factors from the individual networks’ models are considered. These networks have spray sealed granular pavements with different operating and environmental conditions. Predictions of the overall model have been compared with the currently used model. The latter has been developed for the same networks from two years of subjective condition data, using Markov chains (MC) and surface age as the only predictor. The overall model developed here using multilevel analysis and incorporating the significantly contributing factors predicts earlier deterioration than the MC model currently used. The latter predicts 70% of segments to be in good condition at the age of 5 years, whereas the first predicts only 49%.

High Performance Asphalt for Airfield Pavement

Due to the expected increase in air traffic movements around the world and its impact on the environment, the requirement to build more sustainable and low maintenance airfield infrastructures has become very important. One solution consists in using high performance asphalt materials in order to provide a better sustainable whole life cost solution for these pavements. Performances of binder play a key role in the performances of the asphalt pavement as the properties of both are linked. Using Polymer Modified Bitumen Asphalt materials for runway and taxiway represents an alternative solution to traditional Marshall Asphalt (MA). This type of products for wearing course and binder can improve considerably the airfield pavement performances regarding the Rutting resistance, thermal susceptibility or even Fuel resistance. Due to new generation of aircraft more and more aggressive, use of rut resistance asphalt base course is also mandatory. Asphalt Concrete manufactured with Hard Grade bitumen like “High Modulus Asphalt” with improved mechanical characteristics can lead to longer service life, by preserving resources and bringing also cost savings as maintenance is reduced. This type of Asphalt Concrete showed on major airport projects his potential as a viable alternative to the traditional airfield pavement materials for base course such as Crushed Rocks or Dense Bitumen Macadam.

Feasibility study of low density polyethylene modified bituminous mix in DBM layer of flexible pavement

An efficient and adequate system of transportation is inevitable for the development of any country. A high traffic intensity in terms of overloaded commercial vehicle, introduction of new axle configuration, significant variations of daily and seasonal temperature of the pavement are significant factors contributing to early development of distress symptoms like ravelling, rutting, cracking, bleeding, shoving and pot holing of bituminous surfacing, which demand a proper strengthening of pavements. The early development of distress in the pavement with the conventional mixes revealed the need of design specification based on performance tests. To overcome such kind of distress, properties of bitumen and bituminous mixes can be improved to meet the requirement of pavement with the incorporation of certain modifiers. The present study evaluates the Low-Density polyethylene (waste milk pouches) modified bituminous mix properties corresponding to the optimum binder content by conducting different performance test. Experimental studies demonstrated that waste milk pouches (6% by weight of the binder) modified bituminous mix gives the best result in terms of stability and durability. Experimental results indicated that using the waste milk pouches in bitumen is not only a cost-effective mix but also a very good solution in terms of improving bitumen pavement mix properties. The present paper aims to highlight the change in properties by addition of modifiers in bitumen and develop a procedure to estimate the reliability of a particular mix design. By considering these aspects, statistically it has been proved that the bituminous mix obtained experimentally, is also reliable to be used in real life scenario.

The Method of Integral Assessment of the Quality of Oil Oxidized Bitumen as a Method for Selecting the Parameters of the Two-Stage Oxidation Process

Based on previous research, we used a multicriteria (integral) quality assessment to determine the priority oxidation temperatures for obtaining oil road bitumen. This method allows one to select the process parameters and ensure the production of high-quality products from paraffin raw materials. Moreover, the method allows for evaluating the effectiveness of the two-stage process at different temperatures. The paper shows the results of calculating standardized coefficients and weight coefficients for each quality indicator, as well as the integral quality indicators showing the quality of road bitumen samples. The research results showed that the priority in quality is given to a bitumen sample obtained at the oxidation temperature of 200 °C at the first stage and 260 °C at the second stage. This bitumen showed the best quality compared to other samples corresponding to GOST 33133-2014, which further confirms the previously obtained results. It is established that the multicriteria integral method of quality assessment can be used in bituminous production to identify the priority quality of bitumen and determine the process parameters depending on the quality of raw materials.

Influence of hydrophilic nanosilica premixing method on the property of isocyanate-based polymer modified bitumen

Bitumen/PEG (polyethylene glycol)/MDI (4,4′-diphenylmethane diisocyanate)/SiO2 (nanosilica) composites were prepared by simple mixing, during which polyurethane reaction occurs between MDI and polar groups provided by either hydrophilic SiO2, PEG or asphaltenes in bitumen. To induce different sequence of polyurethane reaction between MDI and other three matters, SiO2 nanoparticles were premixed with PEG, MDI, or base bitumen. The content of SiO2 was kept as 0.08 wt% of base bitumen, and this tiny loading of SiO2 could significantly influence the performance of modified bitumen under different premixing methods. Rutting resistance under high temperature of modified bitumen was studied by dynamic shear rheometer with oscillatory frequency sweep and multiple stress creep recovery (MSCR) tests. Crack resistance under low temperature was explored by bending beam rheometer. When SiO2 premixed with base bitumen, the modified bitumen has the worst rutting and crack resistance, even worse than bitumen/PEG/MDI system without SiO2 addition. However, the rutting resistance could be obviously improved when the SiO2 premixed with PEG or MDI. Microstructure evolution was observed for estimation of phase separation, which also could be an indication of thermal stability.

Impact of loading rate on asphalt concrete deformation and failure

Impact of loading rate on asphalt concrete deformation and failure