Construction materials are the most widely used materials for civil infrastructure in our daily lives. However, from an environmental point of view, they consume a huge amount of natural resources ...and generate the majority of greenhouse gasses. Therefore, many new and novel technologies for designing environmentally friendly construction materials have been developed recently. This Special Issue, “Environment-Friendly Construction Materials”, has been proposed and organized as a means to present recent developments in the field of construction materials. It covers a wide range of selected topics on construction materials.
Construction materials are the most widely used materials for civil infrastructure in our daily lives. However, from an environmental point of view, they consume a huge amount of natural resources ...and generate the majority of greenhouse gasses. Therefore, many new and novel technologies for designing environmentally friendly construction materials have been developed recently. This Special Issue, “Environment-Friendly Construction Materials”, has been proposed and organized as a means to present recent developments in the field of construction materials. It covers a wide range of selected topics on construction materials.
Construction materials are the most widely used materials for civil infrastructure in our daily lives. However, from an environmental point of view, they consume a huge amount of natural resources ...and generate the majority of greenhouse gasses. Therefore, many new and novel technologies for designing environmentally friendly construction materials have been developed recently. This Special Issue, “Environment-Friendly Construction Materials”, has been proposed and organized as a means to present recent developments in the field of construction materials. It covers a wide range of selected topics on construction materials.
The demand for alternative bitumen which could fully/partially replace Petroleum sourced bitumen for pavement construction is globally increasing. The increase in demand can be associated with ...several factors: depletion in crude oil resources, advances in crude oil refining processes, increased demand for highway infrastructure, and regional transportation-environmental policies. Since the production of Petroleum bitumen consumes energy and generates emissions, there is an effort to decrease harmful emissions which has inspired researchers to look for so-called "green alternatives". Natural bitumen could be considered a green alternative as it is a mixture of bitumen and mineral matter present naturally on earth, mainly if the Natural bitumen can be transported easily to the construction site. This paper reviews the state-of-the-art information on pavement construction using Natural bitumen from laboratory and field perspectives. The Physico-chemical properties, rheological properties and field behaviour of asphalts pavements containing Natural bitumen were assessed. Many road authorities would hesitate to utilise Natural bitumen for pavement applications due to a lack of available data, knowledge and a systematic research study. To the best of the authors’ knowledge, there is no comprehensive literature review article on Natural bitumen. Thus, the presented article aims to comprehensively review Natural bitumen resources and their types, Physico-chemical properties, application in pavement constructions, and reported field performances. At the end of the paper, future research challenges, future recommendations and a methodological framework is proposed.
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•A comprehensive review of various types of Natural bitumen available is presented.•Past literature shows that Natural bitumen has the potential to replace petroleum bitumen for pavement construction (fully or partially).•Petroleum bitumen modified using 50% Natural bitumen results in improved performance of Asphalt mixes.•As presented in past literature utilisation of Natural bitumen would lower energy consumption.
► We describe the rheological properties of binders using the 2S2P1D Model. ► The model can be used over a wide range of temperatures and frequencies. ► Most of the samples show good agreement ...between the measured and descriptive data.
This study evaluates the suitability of the 2S2P1D Model to describe the rheological properties of a large database of bituminous binders held by the Nottingham Transportation Engineering Centre. This database includes more than 60 different combinations of unmodified bitumen, polymer-modified bitumen and bitumen–filler mastics, unaged and aged samples. The 2S2P1D Model is found to be able to satisfactorily describe the linear viscoelastic rheological (LVE) properties of binders over a wide range of temperatures and frequencies. A comparison between measured and descriptive complex modulus and phase angle data was done using a graphical method and goodness-of-fit statistics. Except for the unaged polymer-modified bitumens, all tested samples show good agreement between the measured and descriptive data.
Oil road bitumen was modified by a copolymer of ethylene with vinyl acetate (EVA) and 3-glycidyloxypropyltrimethoxysilane (epoxysilane). These modifiers were simultaneously introduced into the BND ...90/130 oil bitumen at a temperature of 165 °C. The components were mixed up during two hours with further isothermal holding at the same temperature during the required period. Epoxysilane crosslinks bitumen with EVA making it possible to obtain an immiscible bitumen polymer binder. The optimal content of EVA is 12 mph, epoxysilane -3 mph with a mixing time of 4 hours. The optimal bitumen polymer binder is characterized by the following properties: softening point of 66 °C, penetration at 25 °C = 50, penetration index of 2.15, brittleness temperature of -22 ° C. Separation is significantly reduced. NMR spectroscopy has revealed that the introduction of the binding agent to the bitumen-polymer binder does not create low-mobile structures. It allows forecasting the high binder stability during storage and transportation.
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•The effects of bitumen on the filtration of aqueous clay suspensions were studied.•Bulk bitumen did not have significant detrimental effect on the filtration.•Emulsified bitumen ...facilitated filtration possibly by mopping the ultrafine particles.•The effect of adsorbed bitumen depended on the bitumen content on the mineral surface.•Thin bitumen coating facilitated filtration; thick bitumen coating impeded filtration.
Typical mine tailings can be dewatered by filter press to filter cakes containing >=85 wt% solids that are ready for reclamation, but Alberta oil sands tailings could only reach about 60 wt% solids using the same technology, even when the dominant particle sizes are similar. In this work, the effects of residual bitumen, one of the distinguishing features of oil sands tailings, were investigated. The residual bitumen in the oil sands tailings exists in the forms of bulk bitumen, emulsified bitumen, and adsorbed bitumen. The roles of the three forms of bitumen were investigated in the filtration of primarily a model mineral kaolinite mineral slurry supplemented by rutile, quartz and montmorillonite slurries. Generally, bulk bitumen was found not to affect filtration significantly, emulsified bitumen facilitated filtration possibly by mopping the ultrafine particles, while bitumen adsorbed on mineral surfaces had more complex effects: a thin bitumen coating improved filtration because of the induced surface hydrophobicity, while a thick bitumen coating impeded filtration due to its mobile and deformable nature. The poor filterability of oil sands tailings may be partly caused by the mobile and deformable bitumen coating on the sands/clay mineral surfaces. This study elucidated the effects of a third deformable organic phase on the filtration of an aqueous mineral slurry, providing insights for solid–liquid separation in the presence of a mobile third phase.
This study explores the influence of intrinsic bitumen properties on foam characteristics, considering physical properties (penetration, softening point, viscosity), chemical compositions (SARA ...components, FTIR indices), and physico-chemical characteristics surface free energy (SFE). Ten distinct bitumen samples from two different sources were analyzed. The results reveal that physical properties alone do not sufficiently account for variations in foaming potential among bitumen types. However, chemical compositions and SFE proved to be more informative, explaining the differences in maximum expansion ratio and foam index, specifically for bitumen from the same source. In contrast, when bitumen originates from different sources, none of these intrinsic properties can clarify foaming potential. Notably, intrinsic bitumen properties fail to elucidate the variability in the half-life of foamed bitumen, even when the bitumen types share the same source. These findings underscore the significance of considering multiple factors when assessing bitumen's foam characteristics, particularly when evaluating materials from diverse sources.
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