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Manufacture of asphalt concrete virtually by physics engine and algorithm generation
Published in Inge Hoff, Helge Mork, Rabbira Garba Saba, Eleventh International Conference on the Bearing Capacity of Roads, Railways and Airfields, Volume 2, 2022
Asphalt concrete is the most commonly used material to build roads. Aggregate and bitumen are two main components. As the primary bearing structure in asphalt concrete, aggregates form the solid skeleton to provide stability. Moreover, the properties of aggregates play an important role in the skid resistance of roads (Bessa et al. 2015), surface stresses and permanent deformations (Pan et al. 2006). Usually, three shape properties of aggregates are considered, form, texture and angularity (Barrett, 1980). Feret diameter, aspect ratio, area, perimeter and chord length can also describe the shape of aggregates. Bitumen coheres and fill gaps in the solid skeleton. Also, its viscosity partly determines the compactability of asphalt concrete (Stimilli er al. 2017).
Improving the performance of Indonesia’s construction industry
Published in Pantaleo D. Rwelamila, Abdul-Rashid Abdul-Aziz, Improving the Performance of Construction Industries for Developing Countries, 2020
The current demand on the construction industry can be reflected by the size of the construction market. The national mid-term development plan for 2015–2019 allocates a budget of 5,519 trillion IDR (~USD 415 bn) for infrastructure development, with funding from the national government (40.1%), local government (9.9%), state-owned enterprises (19.3%) and the private sector (30.7%). In the last five years, civil works were the dominant construction projects in Indonesia. Infrastructure projects usually are financed by both central and local government, as well as state-owned companies such as the National Power Company and Toll Road Company. In the five years 2015–2019, the new government estimates to push infrastructure investments of 4,886 IDR trillion, of which 3,386 IDR trillion is for strategic infrastructure and 1,500 IDR trillion for basic infrastructure.
Cognitive Compatibility
Published in Guy H. Walker, Neville A. Stanton, Paul M. Salmon, Vehicle Feedback and Driver Situation Awareness, 2018
Guy H. Walker, Neville A. Stanton, Paul M. Salmon
The experiment employs the same participants, high-level design, materials and procedure as described in Chapter 6. It is an exploratory study based on a naturalistic on-road driving paradigm in which individuals use their own vehicles around a defined course on public roads. The experimenter travelled in the front passenger seat during the observed runs in the cars, or followed on another motorcycle during the observed runs with the motorcyclists. This controlled for the possible effects of observation upon driving behaviour, as explained previously. Drivers/riders were required to provide a concurrent verbal protocol as they traversed the road course, which was then analysed using a text analysis tool called LeximancerTM (see Smith, 2003). This enabled differences in textual and thematic content to be systematically analysed, and the structure of the verbal protocol to be represented via semantic networks. These outputs were dependent on two independent variables: vehicle type and road type. Vehicle type had two levels: car or motorcycle. Road type had six levels: motorway (freeway), major road, country road, urban road, junction and residential road. Controlling measures were self-report questionnaires of driving style, recordings of average speed and time, and demographic data. All experimental trials took place at defined times to control for traffic density and weather conditions, as noted earlier in Chapter 6.
Pavement performance and modification mechanisms of asphalt binder with nano-Al2O3
Published in International Journal of Pavement Engineering, 2022
Zhiyuan Ji, Lu Sun, Luchuan Chen, Wenjun Gu, Yao Tian, Xuanyu Zhang
Owing to satisfactory engineering performance and riding comfort, asphalt concrete has become the most popular materials used in road construction (Ren et al. 2022). However, under the action of traffic loads and environmental effects, various distresses, such as rutting, crack, and aging, always occur in asphalt pavement (Ren et al. 2020a, 2021a), which affects the quality of the pavement. Considering the asphalt binder’s significance in asphalt concrete, composite modification serves as a commonly employed technology for improving asphalt binder performance (Ren et al. 2019, Wang and Huang 2021). Various modifiers, such as polyethylene (PE), styrene butadiene rubber (SBR), styrene butadiene styrene (SBS), rubber powder, as well as industrial waste, are used to prepare the modified asphalt binder (Sun et al. 2014, Wang et al. 2017, Xiao et al. 2017, Kashi and Saberi 2018). Unfortunately, these common modifiers are difficult to get a balance among performance, economy, and materials compatibility.
The effects of road pricing on transportation and health equity: a scoping review
Published in Transport Reviews, 2021
Kate Hosford, Caislin Firth, Michael Brauer, Meghan Winters
While the aggregate effects of road pricing on health may be positive, these effects may not be distributed equitably. Understanding how the health benefits and burdens are distributed is important for determining whether road pricing will reduce or exacerbate health inequities. For example, while road pricing may reduce air pollution inside the priced area, it could lead to increased pollution in surrounding areas. There are also concerns that people with lower incomes will be disproportionately burdened by tolls, especially those with limited public transit access (Eby, Roskowski, & Puentes, 2020). However, some argue that road pricing has the potential to be progressive in nature if the revenue is redistributed to improve public transit or other ways that benefit people with lower incomes (Eby et al., 2020; Eliasson & Mattsson, 2006). Another argument is that road pricing is more equitable than the status quo (i.e. “unpriced roads”), which essentially subsidises travel for wealthier people (Manville & Goldman, 2018; Taylor, 2010). Roads are typically funded through gas taxes, vehicle registration fees, and income, sales, and property taxes. Aside from gas taxes and vehicle registration fees, all residents pay for the roads regardless of use. Yet lower income households use roads less, as they typically own fewer vehicles and travel less than higher income households (Blumenberg & Pierce, 2014; Manville & Goldman, 2018).
Providing a GIS-based framework for Run-Of-River hydropower site selection: a model based on sustainable development energy approach
Published in Civil Engineering and Environmental Systems, 2021
Mostafa Jafari, Ramin Fazloula, Meysam Effati, Ali Jamali
Hydropower projects may use the vehicle fleets to transfer the workers and materials, most notably during the construction phase. Easy access to hydropower sites is required for construction and maintenance steps, therefore, the alternatives should be adjacent to an access road. Additionally, road construction affects the local environments and can cause serious surface disturbances, vegetation removal, topographical changes, and dust creation. Accordingly, the distance from the access roads is defined as one of the model decision criteria. In the present study, the road layer was classified into major (national and state highways) and minor (district roads, rural roads) roads, followed by evaluating the proximity to each class. The proximity to the network of the railways, along with the road network is highly important for transporting heavy equipment and construction materials (Noorollahi, Yousefi, and Mohammadi 2016).