The urban heat island effect, its causes, and mitigation, with reference to the thermal properties of asphalt concrete.

Municipal solid waste incineration (MSWI) bottom ash has gained increasing attentions for its friendly application worldwide, due to promotion of waste recycling One of the biggest concerns for incineration bottom ash (IBA) utilization lies in its elevated metal concentrations and leaching potential While challenges faced by the user are miscellaneous based on several aspects—regulations and rules, the heterogeneity of IBA sources, specific risks arisen from individual applications and/or mixed public views, etc Extensive knowledge on IBA characterization, existing treatment and application contributes to optimize life cycle of the bottom ash, herein enhancing the IBA management practices On the understanding that both feedstock and the process for incineration are various, properties, treatments and applications of the IBA are accordingly different Nevertheless, literature reviewed data indicate evidently that IBA, varying in its original resources and treatment facilities though, shares common geotechnical and chemical properties As the technology development on the IBA is dominated by these common properties, through which the proper treatment and application could be well determined In this review three perspectives were concentrated First, general properties of IBA eg heavy metals and their leaching potential, bulk components, particle size distribution and pH were investigated, whereby the general trends were indicated with collective plots Secondly, the existing status quo on IBA treatment methods and applications were investigated, suggesting a highest potential as low-strength aggregates Thirdly, toxicity studies and LCA on IBA as emerging research topics were also investigated, to further justify its application feasibility

Review of MSWI bottom ash utilization from perspectives of collective characterization, treatment and existing application

The characteristics of municipal incinerated bottom ash (MIBA) and its performance in road pavement applications is assessed through systematic analysis and evaluation of the global experimental data. MIBA has been used in unbound, hydraulically and bitumen bound forms. As unbound material, after processing, MIBA exhibits suitable mechanical properties for use as capping, fill and sub-base material, which has been successfully demonstrated in field testing. In hydraulically bound form, MIBA can be a viable aggregate component in subbase and roadbase layers at low to moderate contents, depending on the performance requirements and binder content. As bituminous bound aggregate in roads, the material can be fit for use at low contents, which is reinforced by a number of completed case studies, with the allowable MIBA fraction controlled by the voids contents, abrasion resistance and bitumen content requirements.

https://cyberleninka.org/article/n/1475938.pdf

Municipal incinerated bottom ash (MIBA) characteristics and potential for use in road pavements

Reclaimed asphalt pavement (RAP) is harder than virgin bitumen due to ageing and it needs to be rejuvenated. Three bio-based rejuvenators are used and the rejuvenating effects are evaluated. Rheological tests show how the rejuvenators may restore the mechanical properties of RAP binder. An ageing index is proposed to show that the rejuvenators are affected differently by ageing. Despite their addition, physio-chemical oxidation did not reverse. Mechanical changes were not caused by chemical changes at functional groups level but a rearrangement of polar/nonpolar components. The results show that considering the effect of aging is vital in identifying how rejuvenators affect the RAP binder chemically and mechanically.

Effect of ageing on the mechanical and chemical properties of binder from RAP treated with bio-based rejuvenators

Construction and demolition waste (CDW) accounts for at least 30% of the total solid waste produced around the world. At around 924 million tons in the European Union in 2016 and 2.36 billion tons in China in 2018, the amount is expected to increase over the next few years. Dumping these wastes in sanitary landfills has always been the traditional approach to waste management but this will not be feasible in the years to come. To significantly reduce or eliminate the amount of CDW being dumped, circular economy is a possible solution to the increasing amounts of CDW. Circular economy is an economic system based on business models which replaces the end-of-life concept with reducing, reusing, recycling, and recovering materials. This paper discusses circular economy (CE) frameworks-specifically material recovery and production highlighting the reuse and recycling of CDW and reprocessing into new construction applications. Likewise, a literature review into recent studies of reuse and recycling of CDW and its feasibility is also discussed to possibly prove the effectivity of CE in reducing CDW. Findings such as effectivity of recycling CDW into new construction applications and its limitations in effective usage are discussed and research gaps such as reuse of construction materials are also undertaken. CE and recycling were also found to be emerging topics. Observed trends in published articles as well as the use of latent Dirichlet allocation in creating topic models have shown a rising awareness and increasing research in CE which focuses on recycling and reusing CDW.

Circular Economy on Construction and Demolition Waste: A Literature Review on Material Recovery and Production

Use of stabilized bottom ash for bound layers of road pavements

The experimental investigation herein described is aimed at understanding the effects of cellulose-based fibers on the mechanical properties of bituminous mastics for paving applications. Three bitumen (two of which modified with SBS polymers), a calcareous filler and four different types of fiber with varying content were used to prepare the investigated mastics. The filler to bitumen ratio was maintained constant. The laboratory investigations were focused on empirical tests (Needle Penetration and Ring and Ball – R&B – Temperature) and dynamic-mechanical tests, the latter performed in a wide range of temperatures. Results suggest that fibers improve the behavior of mastics for hot mix asphalts, particularly with respect to the prevention of rutting phenomena at high service temperatures.

/pdf/the-effects-of-fibers-on-the-performance-of-bituminous-171cf40qen.pdf

The effects of fibers on the performance of bituminous mastics for road pavements

Both the design and the construction of airfield pavements have to be consistent with strict requirements and constraints and also higher safety standards due to their particular setting. In addition, maintenance and construction times must be minimized in order to avoid delays and limitations on airport capacity. Maintaining or constructing airfield pavements also entails working during all-weather conditions (e.g. winter time and heavy cold conditions); materials adopted therefore play a major role in the success of the maintenance or construction activity.

Environmental management plans and eco-friendly policies and strategies are increasingly being adopted by airport directors. Noise reduction plans through improved air traffic management techniques, emissions control for aircraft engines and ground maneuvering vehicles, reuse of water for washing airfield pavements, use of renewable energies, and use of photocatalytic materials are only some of the numerous ways of achieving a sustainable airport.

The paper focuses on construction techniques and the development of innovative materials for the achievement of environmental sustainability on airfield pavements. In particular, the authors present how a long lasting and well performing airport pavement can be built if more than 85% of the materials used are recycled materials. The environmental analysis of a case study on a major Italian airport shows that the release of almost 35% of emissions could be avoided if recycling practices are taken into account. Furthermore, pavement performance is analyzed and monitored as well in order to show that recycling does not necessarily result in lower performance.

Outcomes clearly suggest that the recycled airport pavement has a comparable performance and less of an environmental impact on standard airfield pavements. Moreover, results can be implemented into an Airport Pavement Management System to assess the best strategy, considering the environmental footprint in addition to the traditional performance analysis and cost effectiveness.

Recycled airport pavements for achieving environmental sustainability: An Italian case study

Use of recycled fillers in bituminous mixtures for road pavements

The global desire to move toward sustainable transportation systems encouraged road authorities to adopt warm-mix asphalt technologies and to increase the amount of reclaimed asphalt pavement (RAP) in asphalt mixtures. The reduction of mixing and compaction temperatures through the adoption of specific additives has exhibited several downsides, including low resistance to high temperatures (rutting), incomplete drying of the aggregates, moisture damage, and low durability. However, high RAP percentages provided aging of the asphalt binder, variability in the aggregate gradation and asphalt binder content, and some limitations during plant production. The authors conducted a comprehensive laboratory investigation on several warm-asphalt mixes, including those with high RAP percentages, to evaluate volumetric, mechanical, and long-term performance. A new compound of a polymer-modified and fiber-reinforced system was added to provide comparable performance with respect to polymer-modified hot mixes. The labo...

Mix Design of Polymer-Modified and Fiber-Reinforced Warm-Mix Asphalts with High Amount of Reclaimed Asphalt Pavement: Achieving Sustainable and High-Performing Pavements

Emanuele Toraldo

Papers

Use of stabilized bottom ash for bound layers of road pavements

The effects of fibers on the performance of bituminous mastics for road pavements

Recycled airport pavements for achieving environmental sustainability: An Italian case study

Use of recycled fillers in bituminous mixtures for road pavements

Mix Design of Polymer-Modified and Fiber-Reinforced Warm-Mix Asphalts with High Amount of Reclaimed Asphalt Pavement: Achieving Sustainable and High-Performing Pavements