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31 pages, 26063 KiB

Open AccessArticle

Design and Construction Aspects of Concrete Block Paved Vertical Traffic-Calming Devices Located in Home Zone Areas

by Stanisław Majer, Alicja Sołowczuk and Marek Kurnatowski

Sustainability 2024, 16(7), 2982; https://doi.org/10.3390/su16072982 - 03 Apr 2024

Viewed by 461

In recent years, speed reduction measures have been increasingly used, especially in heavily urbanised areas. If local conditions allow, traffic-calming schemes are implemented, which include a variety of traffic-calming measures (TCM). Some of the most common traffic-calming measures are concrete block paved vertical [...] Read more.

In recent years, speed reduction measures have been increasingly used, especially in heavily urbanised areas. If local conditions allow, traffic-calming schemes are implemented, which include a variety of traffic-calming measures (TCM). Some of the most common traffic-calming measures are concrete block paved vertical traffic-calming devices (VTCDs), including speed tables, speed humps, speed bumps and raised pedestrian crossings. Different design and construction recommendations apply to the respective VTCD types. The aim of this article is to examine the effectiveness of VTCDs in speed reduction and the impact of horizontal forces on pavement conditions, both within and beyond VTCDs, after over a dozen years of exposure to traffic. For this purpose, speed surveys were carried out on selected two-way streets running through home zones in Poland. The pavements on selected VTCDs were identified and visually assessed for damage, and subsidence areas were estimated using the terrestrial laser scanning (TSL) technique. The analysis resulted in the development of the Deviation Model 3D (DM3D), showing local deviations from the theoretical surface, obtained by superimposing the two models, the Real Surface Digital Terrain Model (RS DTM) and the Theoretical Surface Digital Terrain Model (TS DTM). A comparative analysis of the pavement surface condition and the magnitudes of horizontal forces allowed us to identify the locations of critical spots in VTCDs. The results were used as the basis for developing recommended pavement structures and deriving engineering recommendations for concrete block paving in VTCDs. Full article

(This article belongs to the Special Issue Sustainability in Pavement Materials and Design)

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25 pages, 11997 KiB

Open AccessArticle

Design of Concrete Block Paving in Home Zone Traffic Circle Areas

by Stanisław Majer, Alicja Sołowczuk and Marek Kurnatowski

Sustainability 2024, 16(5), 1973; https://doi.org/10.3390/su16051973 - 27 Feb 2024

Viewed by 473

Abstract

Contemporary street space upgrade or regeneration projects tend to include setting up home zones that are located in large city suburbs, smaller towns or spas. These home zones feature one-way streets, merging of a pavement and carriageway into one level surface and various [...] Read more.

Contemporary street space upgrade or regeneration projects tend to include setting up home zones that are located in large city suburbs, smaller towns or spas. These home zones feature one-way streets, merging of a pavement and carriageway into one level surface and various traffic calming measures (TCM), including speed tables and traffic circles (TC). Concrete paving blocks are the preferred surfacing material. As part of this study, traffic surveys were carried out in a small seaside spa in Poland to determine the accelerations and decelerations of vehicles passing through four traffic circles that have different central island heights and different streetscape characteristics. A visual assessment of the pavement condition was also carried out. The pavement deformation changes were analysed using 3D models derived on the basis of the terrestrial laser scanning data obtained with the Trimble SX10 scanning total station. The existing pavement structure was analysed as part of this study. Next, the areas that require strengthening were identified based on subsidence and horizontal forces analyses, with the latter calculated from the observed decelerations and accelerations of the passing vehicles. Finally, design guidelines are given for concrete block surfacing in high traffic impact locations. Full article

(This article belongs to the Special Issue Sustainability in Pavement Materials and Design)

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16 pages, 3273 KiB

Open AccessArticle

Characterization of Cold Recycled Asphalt Mixtures including Reinforcing Fibers

by Carlo Carpani, Edoardo Bocci and Maurizio Bocci

Sustainability 2023, 15(23), 16209; https://doi.org/10.3390/su152316209 - 22 Nov 2023

Viewed by 729

Abstract

In recent years, cold recycling techniques have been widely used all over the world thanks to their huge environmental advantages. However, their performances are lower than the traditional hot-mix asphalt, both for the longer time to develop the final mechanical properties, which leads [...] Read more.

In recent years, cold recycling techniques have been widely used all over the world thanks to their huge environmental advantages. However, their performances are lower than the traditional hot-mix asphalt, both for the longer time to develop the final mechanical properties, which leads to delays in the reopening to road traffic, and for the lower fatigue resistance. The present paper deals with the characterization of cold recycled asphalt mixtures (CRAM), made with 100% reclaimed asphalt pavement, where synthetic fibers were included to improve the fatigue performance. The investigation involved the analysis of the curing time, volumetric properties, stiffness, strength, rheological behavior and resistance to cyclic loading. The results showed that the use of synthetic fiber, with the optimum dosage, determined a higher CRAM performance, especially in terms of fatigue resistance. Full article

(This article belongs to the Special Issue Sustainability in Pavement Materials and Design)

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21 pages, 6827 KiB

Open AccessArticle

Plastic Deformation Characteristics and Calculation Models of Unbound Granular Materials under Repeated Load and Water Infiltration

by Ning Li, Xueyan Zhou, Dongxia Hu and Jie Wang

Sustainability 2023, 15(19), 14516; https://doi.org/10.3390/su151914516 - 06 Oct 2023

Viewed by 616

Abstract

Unbound granular materials (UGMs) have advantages in their water storage and drainage capabilities in permeable pavement, which is a benefit for urban sustainable development. The plastic strain of UGM is a crucial mechanical property that affects its design and construction. During its service [...] Read more.

Unbound granular materials (UGMs) have advantages in their water storage and drainage capabilities in permeable pavement, which is a benefit for urban sustainable development. The plastic strain of UGM is a crucial mechanical property that affects its design and construction. During its service life, repeated load only, repeated load after infiltration, and simultaneous action with load and infiltration are the three inevitable working conditions that will impact plastic strain, especially dynamic water infiltration. How these working conditions influence plastic strain needs to be focused on and solved. This study conducted laboratory tests to investigate plastic strain considering factors such as loading strength and repetitions, as well as infiltration number and duration. The results showed that the plastic strain and plastic strain rate exhibited similar variations during the repeated load only test and repeated load after infiltration test. The plastic strain changed significantly with different infiltration numbers but had relatively small variations in terms of the plastic strain rate. Longer infiltration duration led to greater plastic strain. With the simultaneous action, the plastic strain presented different variation to the other two conditions. The first and second infiltrations had a more obvious influence on the plastic strain when infiltration was applied. Calculation models were established to predict the effects of loading strength and repetitions as well as infiltration number and duration on plastic strains. For the repeated load only test, an error of 4.6% was observed. In terms of the infiltration number and duration, the errors were found to be 18.5% and 8.5%, respectively. The power function and Sigmoidal Logistic model were used to establish calculation models under the simultaneous action test with a maximum error of 11.5% ranging from 100 to 60,000 repetitions. The proposed calculation models can characterize plastic strain under the three working conditions very well, which can help in the design and construction of fully permeable pavement. Full article

(This article belongs to the Special Issue Sustainability in Pavement Materials and Design)

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22 pages, 9768 KiB

Open AccessArticle

Investigating Asphalt Self-Healing with Colorless Binder and Pigmented Rejuvenator

by Tiago Ribeiro, Ana Cristina Freire, Margarida Sá-da-Costa, João Canejo, Vinicius Cordeiro and Rui Micaelo

Sustainability 2023, 15(5), 4556; https://doi.org/10.3390/su15054556 - 03 Mar 2023

Cited by 4 | Viewed by 1397

Abstract

Despite asphalt self-healing with encapsulated rejuvenators having been intensively researched over the last decade, there is still uncertainty about the performance advantages granted by this technology. As a way of adding to the existing set of research methodologies, this study aimed to test [...] Read more.

Despite asphalt self-healing with encapsulated rejuvenators having been intensively researched over the last decade, there is still uncertainty about the performance advantages granted by this technology. As a way of adding to the existing set of research methodologies, this study aimed to test the feasibility of a visual method to investigate the working mechanism of encapsulated rejuvenators in the bituminous mixture. For this purpose, clear bituminous mixtures were produced using a colorless synthetic binder and a pigment was added to the rejuvenator incorporated in the calcium alginate capsules. The internal structure of the bituminous mixtures containing these capsules was inspected both on loaded and unloaded specimens. The colored rejuvenator was also directly added to cracked specimens and its distribution was studied, along with the interaction between the rejuvenator and the synthetic binder. The results show that the rejuvenator could modify the binder to a limited extent, and the bituminous mixtures containing capsules showed evidence of rejuvenator release. It is demonstrated that the aggregate gradation of mixtures has a significant effect on capsule damage and rejuvenator release. However, the pigment can be filtrated from the rejuvenator by the capsule polymer structure and the asphalt. Even though the methodology presented some constraints, it has been proven to be capable of achieving the initial goal, while also acting as an important first step in the visual study of rejuvenator release in asphalt. Full article

(This article belongs to the Special Issue Sustainability in Pavement Materials and Design)

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13 pages, 1399 KiB

Open AccessArticle

Life Cycle Assessment (LCA) of Alternative Pavement Rehabilitation Solutions: A Case Study

by Christina Plati and Maria Tsakoumaki

Sustainability 2023, 15(3), 2129; https://doi.org/10.3390/su15032129 - 23 Jan 2023

Cited by 1 | Viewed by 2262

Abstract

In the context of sustainability, the pavement construction industry is taking a more holistic approach to environmental, economic, and social issues. In particular, pavements are believed to be responsible for up to 24% of total greenhouse gas emissions over the last century. Therefore, [...] Read more.

In the context of sustainability, the pavement construction industry is taking a more holistic approach to environmental, economic, and social issues. In particular, pavements are believed to be responsible for up to 24% of total greenhouse gas emissions over the last century. Therefore, it is critical to include a tool to assess the environmental and health impacts of pavement construction or rehabilitation in the related design studies. This tool is called Life Cycle Assessment (LCA). With this in mind, this case study examines two alternative solutions for the rehabilitation of an existing highway pavement: one using conventional materials and processes and one using conventional recycled materials and recycling processes. These two alternatives are ecologically evaluated using an LCA method to increase the importance of quantifying environmental and health impacts. By comparing the corresponding results, this study aims to quantitatively demonstrate how recycled materials and recycling processes contribute to the sustainability of pavements. As a final result, it is shown that the environmental and human health benefits are significant, even though the use of recycled materials and processes for pavements may be limited. Full article

(This article belongs to the Special Issue Sustainability in Pavement Materials and Design)

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16 pages, 2190 KiB

Open AccessArticle

Assessing RAP Multi-Recycling Capacity by the Characterization of Recovered Bitumen Using DSR

by Vítor Antunes, Fernando Moreno, Maria Rubio-Gámez, Ana Cristina Freire and José Neves

Sustainability 2022, 14(16), 10171; https://doi.org/10.3390/su141610171 - 16 Aug 2022

Cited by 3 | Viewed by 1172

Abstract

This paper addresses the changes in bitumen properties during multi-recycling cycles, both before and after ageing. The rheology of recovered bitumen was characterized using the dynamic shear rheometer. The softening point and penetration value were also determined. The analysis showed that the bitumen’s [...] Read more.

This paper addresses the changes in bitumen properties during multi-recycling cycles, both before and after ageing. The rheology of recovered bitumen was characterized using the dynamic shear rheometer. The softening point and penetration value were also determined. The analysis showed that the bitumen’s properties could be recovered even after more than one recycling cycle. The bitumen recovered from the second recycling cycle presented an average reduction of 45% in terms of complex modulus when compared with the first recycling cycle. The bitumen from the RAP mixtures presented a similar susceptibility to ageing. The analysis clearly showed that RAP has the potential to be multi-recycled. Full article

(This article belongs to the Special Issue Sustainability in Pavement Materials and Design)

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19 pages, 8227 KiB

Open AccessArticle

Erodibility of Nanocomposite-Improved Unsaturated Soil Using Genetic Programming, Artificial Neural Networks, and Evolutionary Polynomial Regression Techniques

by Kennedy C. Onyelowe, Ahmed M. Ebid, Uchenna Egwu, Michael E. Onyia, Hyginus N. Onah, Light I. Nwobia, Izuchukwu Onwughara and Ali Akbar Firoozi

Sustainability 2022, 14(12), 7403; https://doi.org/10.3390/su14127403 - 16 Jun 2022

Cited by 4 | Viewed by 1555

Abstract

Genetic programming (GP) of four levels of complexity, including artificial neural networks of the hyper-tanh activation function (ANN-Hyper-Tanh), artificial neural networks of the sigmoid activation function (ANN-Sigmoid), evolutionary polynomial regression (optimized with genetic algorithm) (EPR), and intelligent techniques have been used to predict [...] Read more.

Genetic programming (GP) of four levels of complexity, including artificial neural networks of the hyper-tanh activation function (ANN-Hyper-Tanh), artificial neural networks of the sigmoid activation function (ANN-Sigmoid), evolutionary polynomial regression (optimized with genetic algorithm) (EPR), and intelligent techniques have been used to predict the erodibility of lateritic soil collected from an erosion site and treated with hybrid cement. Southeastern Nigeria and specifically Abia State is being destroyed by gully erosion, the solution of which demands continuous laboratory examinations to determine the parameters needed to design sustainable solutions. Furthermore, complicated equipment setups are required to achieve reliable results. To overcome constant laboratory works and equipment needs, intelligent prediction becomes necessary. This present research work adopted four different metaheuristic techniques to predict the erodibility of the soil; classified as A-7-6, weak, unsaturated, highly plastic, high swelling and high clay content treated with HC utilized in the proportions of 0.1–12% at the rate of 0.1%. The results of the geotechnics aspect of the work shows that the HC, which is a cementitious composite formulated from blending nanotextured quarry fines (NQF) and hydrated lime activated nanotextured rice husk ash (HANRHA), improves the erodibility of the treated soil substantially and consistently. The outcome of the prediction models shows that EPR with SSE of 1.6% and R² of 0.996 outclassed the other techniques, though all four techniques showed their robustness and ability to predict the target (Er) with high performance accuracy. Full article

(This article belongs to the Special Issue Sustainability in Pavement Materials and Design)

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