scholarly journals Behavior Evaluation of Bituminous Mixtures Reinforced with Nano-Sized Additives: A Review

2020 ◽  
Vol 12 (19) ◽  
pp. 8044
Author(s):  
Raffaella Fusco ◽  
Laura Moretti ◽  
Nicola Fiore ◽  
Antonio D’Andrea
Keyword(s):  
Permanent Deformation ◽  
Particle Type ◽  
Bituminous Mixture ◽  
Bituminous Mixtures ◽  
Physical Mechanisms ◽  
Comparative Review ◽  
Shear Mixing ◽  
Nano Additives ◽  
Potential Improvement ◽  
Nano Titanium Dioxide

This article presents a comparative review of the most commonly used nano-additives for bituminous mixtures: nanoclays (NC), nanosilicates, carbon nanotubes (CNTs), graphene nanoplatelets (GNPs), nano-calcium oxide (CaO), and nano-titanium dioxide (TiO2). In this study, the mechanical behavior of the obtained additive mixture is evaluated. According to the revised literature, the results strongly depend on type, concentration, and dispersal of used nano-additive. In fact, it has been seen that simple shear mixing followed by sonication homogenizes the distribution of the nanoparticles within the bituminous matrix and favors the bonds’ formation. The viscosity of the mixture of bitumen with nanoparticles improves with the increase of the percentage of additive added: it indicates a potential improvement to permanent deformation and rutting. Another benefit is an increased resistance of the binder to aging. Furthermore, it has been shown that the nanoparticles are able to prolong the service life of a bituminous mixture by means of various interdependent chemical–physical mechanisms that can influence the resistance to fatigue failure or the ability to self-heal. However, the effectiveness of these improvements depends on the particle type, added quantity and mixing technique, and the tests carried out.

Pavement Performance Comparison of Bituminous Mixtures at Surface Course

2015 ◽  
Vol 744-746 ◽  
pp. 1273-1276
Author(s):  
Ying Wei Cheng
Keyword(s):  
Surface Layer ◽  
Dynamic Stability ◽  
Test Data ◽  
Hubei Province ◽  
Performance Comparison ◽  
Pavement Performance ◽  
Water Stability ◽  
Performance Study ◽  
Bituminous Mixture ◽  
Bituminous Mixtures

The pavement performance study of bituminous mixture at surface course is very important. This paper focused on comparing the pavement performance of AC-l6C, AC-l6F, Super-12.5 and SMA-16 bituminous mixtures. First the gradations and material we used were illustrated. Then the dynamic stability, water stability and texture depth of these bituminous mixtures was tested. After comparing the test data, we found that the SMA-16 bituminous mixture has the best comprehensive pavement performance and it is most suitable for the surface layer bituminous mixture of freeways in Chinese Hubei Province. Super-12.5 and AC-l6C is applicable too, but AC-l6F is improper in this region.

scholarly journals Preparation of Nanocomposite Alginate Fibers Modified with Titanium Dioxide and Zinc Oxide

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1040
Author(s):  
Dominik Borkowski ◽  
Izabella Krucińska ◽  
Zbigniew Draczyński
Keyword(s):  
Zinc Oxide ◽  
Titanium Dioxide ◽  
Antibacterial Properties ◽  
Natural Polymers ◽  
Nano Zinc Oxide ◽  
Nano Additives ◽  
Alginate Fibers ◽  
Nano Zinc ◽  
Nano Titanium Dioxide ◽  
Selection Of

Active dressings based on natural polymers are becoming increasingly popular on the market. One of such polymers is alginate, which is characterized by biodegradability, resorbability, has no carcinogenic properties, does not have allergenic or hemostatic properties, and has a confirmed lack of toxicity. However, this polymer does not show biocidal and biostatic properties, therefore the purpose of this research was to select the appropriate conditions for the production of calcium alginate fibers modified with nano titanium dioxide and nano zinc oxide. It was assumed that the presence of nano metal oxide fillers will give antibacterial properties to formed fibers, which were used to form nonwovens. The following article presents a comparative analysis of nonwovens made of alginate fibers, without nano additives, with nonwovens made of alginate fibers containing in their structure 7% titanium dioxide and nonwovens made of alginate fibers containing 2% ZnO. The selection of the nano additive content was determined by the spinning ability of the developed polymer solutions. Based on the results contained in the article, it was found that the introduction of modifiers in the structure of fibers increases the diameter of the fiber pores, which improves the sorption and retention properties of the obtained fibers, and also gives differentiated antibacterial properties to the obtained nonwovens depending on the type of nano additive used. Greater activity against Escherichia coli, Staphylococcus aureus strains and Aspergillus Niger molds was shown in nonwovens made of 2% ZnO modified fibers compared to nonwovens made from TiO2 modified fibers.

scholarly journals The influence of binder rheological properties on asphalt mixture permanent deformation

2015 ◽  
Vol 10 (1) ◽  
pp. 54-60 ◽  
Author(s):  
Marcin Gajewski ◽  
Dariusz Sybilski ◽  
Wojciech Bańkowski
Keyword(s):  
Permanent Deformation ◽  
Test Procedure ◽  
Asphalt Mixture ◽  
Design Procedure ◽  
Mix Design ◽  
Creep Recovery ◽  
Quality Prediction ◽  
Simple Test ◽  
Bituminous Mixture ◽  
Shear Creep

The main goal of this paper is to propose the performance parameter for binder which is good for quality prediction of asphalt mixture in frame of resistance to permanent deformation (rutting). Additionally, correlation between, proposed by the authors, repeatable shear creep-recovery test carried out on binder and bituminous mixture rutting test is under evaluation. The results are analysed and correlation between the proposed functional parameter and rut depth is shown. Thanks to that it is possible to claim that expensive rutting test procedure can be assisted with simple test carried out in dynamic shear rheometer at the initial mix design procedure.

scholarly journals The strategic and operational landscape of emergency services in the UK

2019 ◽  
Vol 9 (1) ◽  
pp. 69-88 ◽  
Author(s):  
Peter Murphy ◽  
Paresh Wankhade ◽  
Katarzyna Lakoma
Keyword(s):  
Service Delivery ◽  
Policy Development ◽  
Emergency Services ◽  
Content Type ◽  
Rescue Service ◽  
Comparative Review ◽  
Conceptual Maps ◽  
Potential Improvement ◽  
The Uk ◽  
Development Service

Purpose The organisational and service delivery landscape of the emergency services in the UK has been rapidly changing and is facing further change in the foreseeable future. The purpose of this paper is to examine recent and ongoing organisational changes in the policy development, service delivery and regulatory landscape of the emergency services, in order to capture the overall picture and potential opportunities for improvement or further investigation. Design/methodology/approach This general review utilises the characteristics of the three domains of a national framework, namely, policy development, service delivery and public assurance, and uses these characteristics as lenses to examine the three main blue light emergency services of police, fire and ambulances. Findings What emerges in the organisational landscape and conceptual maps for the police and even more so for the Fire and Rescue Service, is the immaturity of many of the organisations in the policy and the public assurance domains while the service delivery organisations have remained relatively stable. In the relatively neglected ambulance services, we find the NHS’s recent Ambulance Response Programme has considerable potential to improve parts of all three domains. Research limitations/implications The review is limited to the UK and primarily focussed on England. Practical implications The review identifies opportunities for improvement, potential improvement and further research. Originality/value Although the National Audit Office has attempted in the past to provide organisational landscape reviews of individual emergency services, this contemporary comparative review of all three services using a common model is unique. It provides considerable new insights for policy makers, service delivers and regulators.

scholarly journals Evaluation of the Performance of a Warm Mix Asphalt (WMA) Considering Aged and Unaged Specimens

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1241
Author(s):  
Giuseppe Piccone ◽  
Giuseppe Loprencipe ◽  
Arminda Almeida ◽  
Nicola Fiore
Keyword(s):  
Fatigue Behavior ◽  
Permanent Deformation ◽  
Road Construction ◽  
Warm Mix Asphalt ◽  
Environmental Aspects ◽  
Bituminous Mixtures ◽  
Water Sensitivity ◽  
Short And Long Term ◽  
High Level

In the last decades, all technology production sectors reached a high level of development, without neglecting the attention to environmental aspects and safeguarding energy resources. Moreover, in the sector of pavement industry, some alternatives of bituminous mixtures were proposed to reduce the greenhouse gas emissions. One of these is the warm mix asphalt (WMA), a mixture produced and compacted at lower temperatures compared to traditional hot mix asphalt (HMA) (about 40 °C less), to allow a reduction of emissions into the atmosphere and the costs. Other operative benefits concern the health of workers during the whole road construction process, the reduction of distances to which the mixture can be transported, and therefore also the positioning of the plants. However, it is not all benefits, since reduced production temperatures can bring short- and long-term water sensitivity issues, which could threaten the pavement performance. This paper evaluated the performance (water sensitivity, stiffness, fatigue, and permanent deformation) of a WMA produced using a warm mix fabrication bitumen and compared it with an HMA tested in parallel. In general, except for the resistance to permanent deformation, the WMA presented performances comparable to HMA. Regarding the fatigue behavior of asphalt mixtures, the WMA was less affected by ageing conditions, despite it showing lower performance than HMA.

Experimental Study on the Anti-Cracking Performance for Geosynthetics Overlay

2013 ◽  
Vol 838-841 ◽  
pp. 1295-1298
Author(s):  
Ya Zhen Sun ◽  
Li Bao Wang ◽  
Bao Yang Yu
Keyword(s):  
Experimental Study ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Fatigue Test ◽  
Mechanical Performance ◽  
Asphalt Mixture ◽  
Bituminous Mixture ◽  
Bituminous Mixtures ◽  
Cracking Performance

In order to study anti-cracking performance for geosynthetics, the splitting and fatigue test of bituminous mixtures with geosynthetics and without geosythetics are carried out. The mechanical performance for tensile strength and elastic modulus of asphalt mixture are obtained through two tests. The tensile strength and elastic modulus of bituminous mixture are increased by 14.9% and 54.9% respectively. Through adding the geosynthetics overlay to achieve the purpose of retarding the development of cracks in the pavement.

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