Estimation and uncertainty analysis on carbon dioxide emissions from construction phase of real highway projects in China

Controlling non-point source pollutants (NPSPs) is critical in achieving good surface water quality; the contribution of road runoff has recently received increased attention. This study monitored the runoff characteristics of NPSPs, including suspended solids, particle size distribution, heavy metals, organic matter, and nutrients, from asphalt and concrete roads. Water quality parameters, including biochemical oxygen demand (BOD), chemical oxygen demand (COD), and nutrients of the receiving reservoir, were also investigated. During the first flush, the changes in pollutant concentrations over time were higher on concrete roads than asphalt roads. Concentrations peaked over a short period, while an increased pollutant concentration may be present several days after rain. The runoff concentration and particle size distribution were higher on concrete roads, whereas the concentrations of heavy metals were similar in asphalt and concrete roads. The organic matter concentration of asphalt roads was higher, or identical, to that in the first flush from concrete roads; this may be associated with the road location. Water quality analysis of the reservoir showed relatively good results for BOD, COD, and nutrient concentrations. Road construction was a factor that determined the characteristics of NPSPs in road runoff.

Integrated Life Cycle Cost Comparison and Environment Impact Analysis of the Concrete and Asphalt Roads

Carbon footprint comparison of innovative techniques in the construction and maintenance of road infrastructure in The Netherlands

The paper considers a possibility to use sand asphalt concrete as a material for protection of asphalt concrete and cement concrete road pavements against affection of external destructive factors. Advantages and disadvantages of sand asphalt concrete road pavements have been determined in the paper. The paper provides recommendations on improvement of sand asphalt concrete properties and contains an analysis of possible variants for usage of complex-modified sand asphalt concrete in the road construction. It has been noted that according to its potentially possible physical and mechanical properties activated quartz sand being micro-reinforced by dispersive industrial wastes is considered as an efficient component for creation of constructive layers in road asphalt concrete pavements. The paper reveals only specific aspects of the efficient application of quartz sand in road asphalt concrete. The subject of the paper loоks rather interesting for regions where there are no rock deposits for obtaining broken-stone ballast but there is rather significant spreading of local quarts sand. Its successful application is connected with the necessity to develop special equipment for physical and chemical activation of sand grain surface that permits strongly to increase an adhesive strength in the area of phase separation within the “bitumen–SiO2” system. The considered problem is a topical one and its solution will make it possible to local sand in a maximum way and partially to exclude application of broken stone in road construction.

Use of Recycled Material in WMA- Future of Greener Road Construction

Introduction. Increasing the load on highways and constantly increasing the intensity of traffic requires the use of road construction materials with improved physical and mechanical properties. Asphalt concrete is one of the most common and effective materials, which allows to provide the necessary strength and durability of the pavement structure. However, the use of traditional materials for its preparation - mineral material and road bitumen has a limited resource, which does not always meet traffic conditions. Modern scientific research in materials science allows to use mixtures of asphalt concrete and asphalt concrete road with the use of basalt fiber.Apply mixtures of asphalt concrete and asphalt concrete road with the use of basalt fiber, allows to increase the mechanical characteristics - tensile strength and resistance to fatigue from repeated loads, which increases the crack resistance of asphalt concrete layers of pavement structures, as well as increases resistance to shape change. accumulation of residual deformations.Problem Statement. From the literature analysis it is established that the coating of non-rigid pavement is in difficult operating conditions, which is confirmed by the intensive growth of defects in the form of tracks, landslides, inflows, cracks, due to increasing parameters of transport loads and high summer temperatures, so there is a need new materials.Purpose. Is to study the impact of the effectiveness of asphalt concrete reinforced with basalt fiber.Results. The results of physical and mechanical properties of asphalt concretes with the use of basalt fiber are obtained. The results of formation of residual deformations in the form of track in asphalt concrete with the use of basalt fiber are obtained. As a result of the conducted researches the analysis of efficiency of application of basalt fiber in asphalt concrete mix is executed.On the basis of the carried-out researches the basic requirements to asphalt concrete mix with use of basalt fiber are establishedConclusions. The research results were used in the development of regulations for the design, construction and repair of asphalt layers of roads in Ukraine.Keywords: asphalt concrete road with basalt fiber, asphalt concrete mixes with basalt fiber, loading, covering, stability, temperature.

The article is devoted to the preliminary national standard 184-2016 “Public roads. Asphalt concrete road mixes and asphalt concrete. Technical conditions”. The purpose of the work is to identify incorrect and unsubstantiated data of the preliminary national standard in comparison with the current interstate standard 9128-2009 “Asphalt concrete road, airfield and asphalt concrete mixtures. Technical conditions”. The following are ideas, some comments and suggestions that should be taken into account when developing and approving the preliminary national standard for asphalt concrete. The comparative analysis is aimed at identifying unsubstantiated technical characteristics, physical and mechanical parameters and criteria for testing asphalt concrete. The topics covered include “Grain compositions”, “Road classification”, “Voids”, “Dust”, “Sample preparation for testing”. The feasibility of using the new system was evaluated. The results are presented in the form of a comparative analysis of the requirements of current standards with the requirements of preliminary standards for the general characteristics of asphalt concrete mixtures. Proposals have been developed to adjust the physical and mechanical properties of asphalt concrete in accordance with the performance indicators of St. Petersburg roads.

Asphalt concrete pavement, as the main form of high-grade roads today, occupies an important place in modern road construction due to its advantages such as low noise level, ease of repair and short construction period. This road type is widely adopted worldwide and provides a reliable foundation for road networks in cities and villages. In cold regions, snowy weather tends to cause ice on the road surface, posing a serious safety hazard for vehicle travel. The problem of road accidents in winter is relevant both for regions with extremely cold climatic conditions and for the temperate continental climate that prevails almost throughout Ukraine. To solve this problem, deicing agents are widely used to improve the safety of road travel. The application of deicing agents effectively reduces the impact of snow and ice on roads and ensures the safe passage of vehicles in adverse weather conditions. However, while deicing agents play an important role in improving traffic flow, their widespread use has also brought some problems that should not be ignored. The chemicals in deicing agents may have adverse effects on pavement materials, especially on asphalt concrete roads. For studying the effect of deicing agents on asphalt concrete, this paper presents an experimental investigation of the effect of deicing agents on the water stability of asphalt concrete under the conditions of freeze-thaw cycle test. The impact of deicing agents and freeze-thaw cycles on asphalt concrete was investigated by evaluating the variation patterns of three key parameters: stability, residual stability and air void content. The experimental results showed that the stability and residual stability of asphalt concrete showed an overall decreasing trend with the increase of the number of freeze-thaw cycles, indicating that the asphalt concrete was damaged or degraded under the conditions of freeze-thaw cycles. The higher concentration of the deicer solution corresponded to the more pronounced changes in the test parameters, indicating a significant effect of the deicer on the asphalt concrete. At the end of 27 cycles, the average loss of stability, residual stability and void ratio were 29%, 22% and 73%, respectively. This indicates that the combined effect of freeze-thaw cycles and deicing agent is more significant for air void content.

The transportation sector is considered one of the driving forces behind the increased release of greenhouse gases (GHGs), with road transport being this sector’s main emissions contributor. In turn, efforts should be devoted to reducing emitted GHGs from this sector, and many such opportunities lie in the road transport life cycle. This paper investigated fourteen emission reduction scenarios based on the green initiatives issued by the Abu Dhabi Government. The explored measures are either related to road works and road municipal services or to traffic movement. The proposed measures were evaluated with reference to a baseline study previously reported by the authors for three different road projects in Abu Dhabi city. Findings reveal that normalized GHG emission reduction could be significantly reduced by (i) replacing 30% of internal combustion engine passenger cars with battery electric vehicles where the power demand is covered almost equally from nuclear and liquified natural gas (LNG) sources, (ii) reducing the number of passenger cars by 10%, and (iii) having one-fifth of passenger cars powered by LNG. A lesser significant reduction could be achieved by replacing conventional lamps with light-emitting diode (LED) lamps or by having one-fourth of lighting powered by solar energy. Even lesser reduction could be achieved by (i) replacing a portion of Portland cement with ground granulated blast furnace slag in concrete structures, (ii) fully utilizing treated sewage effluent for roadside-plant irrigation, (iii) reducing desalinated water used for roadside-plant irrigation by 20%, and (iv) increasing the number of higher efficiency passenger cars by 10%. Replacing hot-mix asphalt with warm-mix asphalt and using asphalt with a high stiffness modulus in the base layer results in low emission reduction. The use of 15% recycled asphalt or the use of 50% recycled aggregate in road construction has the least impact on emission reduction. When all explored scenarios were combined, an overall normalized GHG emissions reduction of 9–17% during the road project life cycle could be achieved.

Methods of road surface durability improvement

Purpose This study aims to identify the key barriers and enablers within a developing country context (Sri Lanka) to tackle the public health impacts during road construction projects. The current impact assessment process of the country and the better ways of integrating public health impacts into the road construction projects are discussed in this study. Design/methodology/approach The first phase of empirical investigations on barriers and enablers to address public health impacts during road construction projects was conducted via expert interviews. Semi-structured interviews were conducted with 32 academic and industry experts with at least two years of experience in road construction, public health and environmental management. Data collection for the case studies followed the initial expert interview guidelines to identify the barriers and enablers to integrating public health impacts and vulnerabilities during road construction projects. Multiple case studies were selected to better understand the barriers and enablers in Sri Lanka to consider public health during road construction projects. Four road construction projects in Sri Lanka were selected as the cases for this research. Findings This study identified four main categories of barriers and enablers, including knowledge, partnerships, management and the appraisal process. Research findings show that partnership, resource and management-related barriers are the most perceived issues in tackling public health in Sri Lankan road projects. Among them, the lack of institutional collaboration and funds and resources were frequently expressed as the main barriers to addressing public health during road construction projects. These findings provided lessons on the governance and policy framework regarding integrating public health impacts into road construction projects, including the potential to integrate health into other forms of impact assessment of road constructions, such as EIAs and SIAs. Research limitations/implications This study was limited to four case studies in Sri Lanka. The empirical evidence is limited to the expert’s opinion on a particular subject. Public health data was not gathered or analysed in this research. Practical implications These findings provided lessons on the governance and policy framework regarding integrating public health impacts into road construction projects, including the potential to integrate health into other forms of impact assessment of road constructions, such as EIAs and SIAs. They can also aid decision-makers and project managers in more comprehensive impact assessment and monitoring during road construction activities while mitigating public health impacts. Originality/value A lack of empirical evidence in the public health impacts and vulnerability literature in road construction and a shortage of public health impact assessment in the current EIA process in the global and Sri Lankan context highlighted the need for public health-related research in road construction projects. This study contributes to the theory by identifying key barriers and enablers during the construction process of road projects to tackle public health impacts.

The development of transportation, especially the use of motorcycles has contributed significantly to increasing community mobility. However, along with the increasing number of vehicles, the risk of traffic accidents has also increased. One of the main factors causing accidents is the failure of the braking system, which most often occurs in two-wheeled vehicles. Automatic motorcycles, which generally still use conventional braking systems, have a higher level of vulnerability to brake failure compared to other types of vehicles. The ease of use of automatic motorcycles makes this vehicle the main choice for people in their daily activities. One of the braking system technologies developed by motorcycle manufacturers in Indonesia is the Combi Brake System (CBS), which aims to improve the safety of motorcycle riders. This study aims to analyze the comparison of braking efficiency between the CBS and Non-CBS systems by considering variations in load and type of road pavement construction. The research method uses an experimental approach with the road brake test method at speeds of 40 km/h and 60 km/h. The test results showed that the highest brake efficiency of 56.76% occurred on asphalt roads with active CBS brakes and a load of 65 kg at a speed of 60 km/h, while the lowest efficiency of 23.28% occurred on concrete roads with inactive CBS brakes and a load of 125 kg at a speed of 40 km/h. . While the brake temperature analysis showed the highest value of 79.34 °C on asphalt roads with CBS brakes off and 125 kg load at 60 km/h speed, while the lowest temperature of 48.36 °C occurred on concrete roads with CBS brakes on and 65 kg load at 40 km/h speed.

Greenhouse gas emissions from road construction: An assessment of alternative staging approaches

Warm mix asphalt (WMA) is a sustainable innovation in road construction that enables bituminous mixtures to be produced and compacted at lower temperatures than traditional hot mix asphalt (HMA). This reduction in temperature significantly decreases greenhouse gas (GHG) emissions and other pollutants, supporting global climate change mitigation efforts. WMA technology enhances energy efficiency while maintaining the performance and durability of road surfaces, offering an environmentally responsible alternative for the construction industry. Its adoption reflects a commitment to reducing the carbon footprint of infrastructure projects. These innovations are anchored in three primary techniques, chemical additives, organic additives, and foaming processes, each of which contributes uniquely to reducing energy consumption while improving pavement performance. Extensive research has revealed the multifaceted advantages of WMA. Mechanically, WMA demonstrates exceptional properties, including enhanced resistance to stripping, fatigue, thermal cracking, and rutting, which collectively contribute to the longevity and resilience of asphalt pavements. Environmentally, the reduced energy demands of WMA production not only reduce emissions but also provide an opportunity to integrate recycled materials and industrial byproducts, further reinforcing its eco-friendly credentials. Economically, the lower production temperatures translate into operational cost savings, although a detailed analysis of long-term cost implications is essential to fully understand its financial viability. This review highlights the historical development, material innovations, and advanced techniques underpinning WMA, providing a thorough evaluation of its rheological and fractured properties. This research aims to support the widespread implementation of WMA in pavement applications. This study also emphasized the critical role of life cycle assessment (LCA) in quantifying the sustainability benefits of WMA mixtures. Moreover, the study explores the emerging trends and challenges in the widespread adoption of WMA, emphasizing the need for robust evaluations of its economic, environmental, and safety aspects. Ultimately, WMA technologies represent a pivotal innovation, offering an integrative solution to modernize the road construction industry while addressing pressing environmental concerns.

The U.S. transportation section contributed a third of the national Greenhouse Gas (GHG) emissions in 2022. As such, the Louisiana Department of Transportation and Development (DOTD) initiated federally funded efforts to create Life Cycle Assessment (LCA) models for pavement systems. The objective of this study was to quantify the holistic, cradle-to-grave environmental impacts of asphalt pavements containing Reclaimed Asphalt Pavement (RAP) and Warm Mix Asphalt (WMA) technologies using a closed-loop recycling assumption based on 100% RAP recovery at the end-of-life stage, consistent with current practice in Louisiana. Five field sections in service for up to 16 years were collected from DOTD’s LaPave database. The LCA framework followed ISO 14040 and included definition of cradle-to-grave system boundaries, a functional unit based on in-service pavement sections, inventory data derived from public databases and field performance records, and use-phase modeling based on pavement–vehicle interaction. Public datasets were used to quantify GHG emissions across all life cycle phases. Results indicated WMA additives reduced production and construction GHG emissions by 5%. An RAP increase by 1% decreased material/construction GHG emissions by approximately 0.9%; however, it potentially increased use-phase emissions due to roughness. Mixtures combining WMA and RAP emitted the lowest GHG among the studied mixtures, which promotes integrating sustainable pavement strategies.