Surface Dressing Research Articles

ОДНОСТАДИЙНЫЙ СПОСОБ ПОЛУЧЕНИЯ СУПЕРГИДРОФОБНЫХ ПОКРЫТИЙ, СОДЕРЖАЩИХ ЧАСТИЦЫ НАПОЛНИТЕЛЯ

The paper proposes an approach for obtaining composite coatings based on copolymers of alkylmethacrylates and glycidylmethacrylate with appreted kaolin and aerosil particles. The formation of coatings on the surface is carried out by aerosol application and subsequent temperature curing. The influence of the filler surface dressing, concentration and particle shape on the formed topology of the surface layer and the stability of superhydrophobic properties has been studied.

Life cycle assessment of energy consumption and carbon emissions of a green maintenance material for asphalt pavement: Warm mix OUFC-5

The warm mix (WM) 4.75 mm nominal maximum aggregate size (NMAS) Open-Graded Ultra-thin Friction Course (WM OUFC-5) represents an innovative green preventive maintenance material boasting commendable road performance. Its potential to address carbon peak and neutrality goals objectives has garnered significant interest. This study aims to quantify the energy-saving and carbon reduction benefits of WM OUFC-5. Three commonly used preventive maintenance materials, including thin overlay (TO), synchronous surface dressing (SSD), and micro-surfacing (MS) in Hubei province, China, were selected as a control group. Employing the process-based life cycle assessment (PLCA), an evaluation framework and computational model was devised to gauge the energy and carbon footprints of each maintenance material. A comparative analysis was then conducted to identify the primary energy and emission contributors of WM OUFC-5 across different life-cycle phases. The results indicate that WM OUFC-5 is a highly sustainable material with low energy consumption and carbon emissions, with its energy consumption being merely 47.2% of TO and 50.7% of MS. And its carbon emissions are 64.3% lower than TO, 26.9% lower than MS, and 49.8% lower than SSD. Throughout the maintenance life cycle, the raw materials production and processing phase and the mixture production phase emerged as the predominant contributors to energy consumption and carbon emissions. The study also provided actionable recommendations to curtail energy and carbon footprints across all phases of the asphalt pavement maintenance life cycle. This study provides support for the low-carbon development of asphalt pavement maintenance in China.

Size-Controlled Ammonium-Based Homopolymers as Broad-Spectrum Antibacterials.

Ammonium group containing polymers possess inherent antimicrobial properties, effectively eliminating or preventing infections caused by harmful microorganisms. Here, homopolymers based on monomers containing ammonium groups were synthesized via Reversible Addition Fragmentation Chain Transfer Polymerization (RAFT) and evaluated as potential antibacterial agents. The antimicrobial activity was evaluated against Gram-positive (M. luteus and B. subtilis) and Gram-negative bacteria (E. coli and S. typhimurium). Three polymers, poly(diallyl dimethyl ammonium chloride), poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride), and poly(vinyl benzyl trimethylammonium chloride), were examined to explore the effect of molecular weight (10 kDa, 20 kDa, and 40 kDa) on their antimicrobial activity and toxicity to mammalian cells. The mechanisms of action of the polymers were investigated with dye-based assays, while Scanning Electron Microscopy (SEM) showed collapsed and fused bacterial morphologies due to the interactions between the polymers and components of the bacterial cell envelope, with some polymers proving to be bactericidal and others bacteriostatic, while being non-hemolytic. Among all the homopolymers, the most active, non-Gram-specific polymer was poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride), with a molecular weight of 40 kDa, with minimum inhibitory concentrations between 16 and 64 µg/mL, showing a bactericidal mode of action mediated by disruption of the cytoplasmic membrane. This homopolymer could be useful in biomedical applications such as surface dressings and in areas such as eye infections.

Use of antimicrobial Dialkyl Carbamoyl Chloride (DACC) surface dressings for the treatment of infected post-surgical complications in neonates with low risk of adverse reactions: case series in the AOU Meyer NICU

The skin of the child presents significant differences compared to that of the adult; this diversity is even more marked if the skin of the newborn is taken into consideration. In fact, this is immature, as is its immune response. This results in weak responses to microorganisms. Therefore, the use of antibacterial dressings is necessary to manage the microbial load at the skin surface level. To this end, international consensus documents suggest that the use of products with a physical and mechanical action to remove bacteria is indicated. Bacterial uptake dressings that exploit DACC technology are bacteriostatic and non-bactericidal dressings; this "passive" control of the bacterial load avoids the rupture of the bacterial cell wall and the consequent release of endotoxins, which worsen the inflammatory state and prevent the healing of the lesion. Thanks to its purely physical principle, it also does not release any antimicrobial agent, which could create the risk of bacterial resistance and allergies. This treatment proposal aims to highlight the advantage and benefit of advanced dressings with DACC technology, for the prevention and treatment of pediatric and neonatal infected wounds.

ЄВРОПЕЙСЬКА ПРАКТИКА ВИРІШЕННЯ ПРОБЛЕМ ЕФЕКТИВНОГО ФУНКЦІОНУВАННЯ ПОВЕРХНЕВОЇ ОБРОБКИ ПОКРИТТЯ. ЧАСТИНА 2. УПРОВАДЖЕННЯ ДСТУ EN 12272-1:2021 (EN 12272-1:2002, IDT) ПОВЕРХНЕВА ОБРОБКА. МЕТОДИ ВИПРОБУВАНЬ. ЧАСТИНА 1. НОРМИ І ТОЧНІСТЬ РОЗПОДІЛЕННЯ В’ЯЖУЧОГО

Introduction. Decision the tasks of effective functioning of surface dressing of roads of Ukraine with the use of modern methods carried out in European countries, in particular tests in accordance with EN 12272-1: 2021 (EN 12272-1: 2002, IDT) Surface dressing — Test methods — Part 1: Rate of spread and accuracy of spread of binder and chippings. Problem statement. One of the prerequisites for the effective functioning of the road network of Ukraine is, first of all, the introduction of the road industry the requirements of the Association Agreement between Ukraine and the EU. In order to implement the requirements of this Agreement, which are the key principles of economic modernization and sustainable development of the country, «DerzhdorNDI» SE has prepared a comprehensive set of national standards with an identical degree of compliance with European requirements in the direction of solving the problems of effective functioning of the surface dressing of the pavement. Purpose. The purpose of this work is to promote the implementation in the road industry of Ukraine of the requirements of the national standard DSTU EN 12272-1:2021 (EN 12272-1: 2002, IDT) «Surface dressing — Test methods — Part 1: Rate of spread and accuracy of spread of binder and chippings» which is being prepared for publication by the National Standardization Body of Ukraine and enter into force with 01.07.2022. The related requirements of this standard DSTU EN 12271:2021 (EN 12271:2006, IDT) «Surface dressing. Specifications» discussed in the article «European practice of solving the problems of effective functioning of surface dressing. Part 1. Materials and methods. Analysis of the national standard DSTU EN 12272-1:2021 (EN 12272-1:2002, IDT) Surface dressing - Test methods - Part 1: Rate of spread and accuracy of spread of binder and chippings with an identical degree of compliance with EN 12272-1:2002 (version en) «Surface dressing — Test methods — Part 1: Rate of spread and accuracy of spread of binder and chippings». Results The requirements of the national standard for the effective functioning of the surface dressing of roads in Ukraine are considered, further use of which provides an opportunity to improve the performance of works for its arrangement. Conclusion. The use of this standard will be promote the introduction of various on test methods used to rate of spread and accuracy of spread of binder and chippings, as well as indirect assessment of the quality of equipment for their distribution in the case of surface treatment. Requirements provide an opportunity to use quite simple toolkit, under consideration in this article, and which should be used in the road industry of the country. Based on the provisions of the standard, practical recommendations can be developed in order to implement test methods for the installation of surface dressing. The introduction of these principles will promote the competitiveness of products of national producers, who have to produce samples or ancillary equipment, the use of which is given in the standard, given the needs and priorities of national customers

Polymicrobial Colonization of Prosthetic Joint Infections Treated With Open Wound Management.

Open wound management in prosthetic joint infection (PJI) patients has been used in problematic dehisced wounds hoping to stimulate granulation tissue and closure. However, infections that start as a monomicrobial PJI can become polymicrobial with resultant worse outcomes following open wound management. This study assessed the relationship between open wound management and the development of polymicrobial periprosthetic joint infections. We reviewed patients referred with a synovial cutaneous fistula. Patients with an open wound measuring less than 2 cm and less than two weeks of open wound management were excluded. Variables included original organisms cultured, type and length of open wound management, and organisms cultured at the time of revision infection surgery. Of the 65 patients with a previous monomicrobial infection treated with open wound management, 22/65 (34%) progressed to a polymicrobial infection. Thirty (46%) wounds were packed open with gauze, 20 (31%) were managed with negative pressure wound therapy, and 15 (23%) had surface dressings only. Of the 22 patients who converted to a polymicrobial infection, only 10 (45%) were infection free at follow-up. In contrast, 30 of 43 patients (70%) whose infections remained monomicrobial were infection free at follow-up. Open wound management can lead to conversion from a monomicrobial to a polymicrobial PJI, a rate of 34% in this series. Open prosthetic wound management should be discontinued for a fear of converting a monomicrobial infection to a difficult to treat polymicrobial infection. Surgeons must be prudent in the use of open wound management. Level IV, Retrospective Case Series.

Planar polishing process method based on real-time dressing of a polishing pad surface.

Planar polishing is an important manufacturing process for high-precision planar components. In this study, a real-time dresser and a planar polishing process based on real-time dressing for large-aperture optical plane components were developed. Efficient dressing of a polishing pad surface can be achieved with the real-time dresser. Compared with the conventional method, real-time correction for the surface shape of the polishing pad was realized via the temperature parameter t in the real-time dresser, and this parameter can be optimized through optimization experiments. Finally, a series of experiments was carried out to verify the effectiveness of the real-time dresser on surface dressing. Through the real-time dressing of the polishing pad surface, the flatness peak-valley deviation and the root-mean-square deviation of the flat optical element surface (430×430mm) can reach 3λ and 0.9λ, which is improved by 25% and 33%, respectively.

ЄВРОПЕЙСЬКА ПРАКТИКА ВИРІШЕННЯ ПРОБЛЕМ ЕФЕКТИВНОГО ФУНКЦІОНУВАННЯ ПОВЕРХНЕВОЇ ОБРОБКИ ПОКРИТТЯ. ВІДПОВІДНІСТЬ ХАРАКТЕРИСТИК ПОВЕРХНЕВОЇ ОБРОБКИ ТЕХНІЧНИМ УМОВАМ ДСТУ EN 12271:2021 (EN 12271:2006, IDT)

Introduction. The wearing course of a road pavement is in complicated operational conditions in combination with adverse weather and climatic factors that are characteristic of the country for most of the year. These factors make high demands on the wearing course, in particular arranged by the method of a surface dressing. European practice of solving these issues is based on the provisions of a set of standards that can serve to solve the problems of effective functioning of a surface dressing on roads in Ukraine. Problem statement. The introduction of the requirements of the Association Agreement between Ukraine and the EU [1] into the road sector on a new favorable regime for economic relations, improvement of trade and investment are key factors in economic modernization and sustainable development of the country. European realities indicate that one of the prerequisites for the effective functioning of the road network is, first of all, implementation of modern standards. Actually, in our country there is an urgent need for their updating, in particular for the modern practice of solving the issues for the arrangement of surface dressing of the pavement, especially its design and quality control of work. Therefore, for implementation of the requirements of this Agreement, “DerzhdorNDI” SE has prepared a comprehensive set of national standards in this area with an identical degree of compliance with European requirements. Purpose. The purpose of the work is to promote the implementation of national standards with an identical degree of compliance with European requirements for the efficient operation of layers, arranged by the method of surface dressing on the roads in Ukraine. In this regard, at the present stage, only those requirements are considered, which are set out in the DSTU EN 12271: 2021 (EN 12271: 2006, IDT) «Surface dressing. Specifications» which is being prepared for publication by the National Standardization Body of Ukraine. The related standards, which are applied as a whole, will be updated and presented after their entry into force in the following parts of the article for the acquaintance of the road community. These standards are: –– DSTU EN 12272-1:2021 (EN 12272-1:2002, IDT) Surface dressing - Test methods - Part 1: Rate of spread and accuracy of spread of binder and chippings [2]; –– DSTU EN 12272-2:2020 (EN 12272-2:2003, IDT) Surface dressing - Test methods - Part 2: Visual assessment of defects [3]; –– DSTU EN 12272-3:2020 (EN 12272-3:2003, IDT) Surface dressing. – Test method - Part 3: Determination of binder aggregate bonding by Vialit plate shock test method [4]. Materials and methods Analysis of the national standard DSTU EN 12271: 2021_ (EN 12271: 2006, IDT) Surface dressing - Requirements with identical degree of conformity EN 12271: 2006 (version en) Surface dressing - Requirements[5]. Results The requirements of the national standard for the effective functioning of the surface dressing of roads in Ukraine are considered, further use of which provides an opportunity to improve the performance of works for its arrangement. Conclusion.The implementation of the requirements of the standard will contribute to the establishment of scientifically sound standards for surface dressing. The priority approaches proposed in it regarding requirements, design process and quality control can be approved as modern, requiring application in the road industry. In particular, it is appropriate to introduce requirements for the mandatory arrangement of the test site to confirm surface dressing performance (Type Approval Installation Trial (TAIT)), or measures taking into account the specifics of Factory Production Control (FPC). The use of the requirements of the standard will be facilitated by the development of country regulations or practical recommendations based on regional local conditions, and their implementation in order to create the most relevant areas of effective forms of improving the quality of surface dressing.

Surface rehabilitation of Portland cement concrete (PCC) pavements using single or double surface dressings with soft bitumen, conventional or modified emulsions

Surface dressings are a sustainable maintenance alternative for pavements with surface distresses, due to the low amount of resources involved. This paper aims to analyze the viability of using twelve different surface dressing solutions, including three binders (conventional and modified emulsions, and a soft 160/220 bitumen) and a covering with diluted emulsion, for surface treatment of Portland cement concrete (PCC) pavements. Several test methods were used to evaluate the macrotexture, skid resistance, adhesion, and resistance to wearing on a large scale prototype. In general, single surface dressings increased further the macrotexture of the concrete pavement surface. The skid resistance of single and double surface dressings was similar. The best surface dressing in the pull-off test was that with the 160/220 bitumen. The conventional and modified emulsions presented similar mechanical adhesion in the Vialit plate test. Concerning the prototype wearing test, the best result was obtained for the double surface dressing with bitumen covered with diluted emulsion. Based on this work’s results, the surface dressings are a potential surface rehabilitation alternative for concrete pavements.

Non-autoclaved foam concrete for layers of highways surface dressing

The article is devoted to the problems associated freeze with the calculated estimation of the parameters of the structural and heat-insulating antifreeze layer in the subgrade of non-rigid roads on various soil bases. The main physical, technical and deformation characteristics of monolithic dispersed non-autoclaved foam concrete reinforced with polypropylene fiber of grades of density from 600 to 1000 kg/m3 are investigated. Freezing of subsoil waters directly under the roadway pavement and, as a result, its increase in volume, leads to significant deformations of the road surface. Under such conditions, the period of defectfree operation of the roadway pavement is significantly reduced, which in turn leads to the need to repair it in a more intensive mode. One of the ways to reduce the operating cost and maintenance costs of the road transport infrastructure is to introduce into the design and construction practice new structural concepts for road surface dressing that ensure high quality pavement during the normative operational period. This can be achieved by introducing an effective heat-insulating material into the pavement structure as an anti-frost layer in order to elimi-nate the effect of frost lift of the roadway pavement of non-rigid roads. Since domestic and foreign experience freeze in the road construction has proven the effectiveness of the use of heatinsulating materials in the road surface dressing construction, in recent years in Ukraine there has been increased interest in the use of non-autoclaved foam concrete as a modern and highly effective heat-insulating material in road construction. The installation of a heat-insulating layer made of non-autoclaved foam concrete allows us to completely or partially prevent freezing or overheating of the surface dressing base, reduce the influence of periodic variations in environmental temperature, which in turn will increase the durability of the pavement structure. The publication presents nomograms for determining the optimal thickness of the heat-insulating anti-frost heavy course (layer) of road surface dressing (based on sand, loamy sand, clay and loam) done at the street and road network for all climatic and geographical regions of Ukraine.

Assessment of Skid Resistance of Road Pavements

The quality of the paved road depends not only on the decisions of the road designer and the work carried out but also on the materials used. Most of the aggregates used are imported from other countries. However, the usage of domestic materials reduces the cost of the road pavement and the use of aggregates produced by a special production technology in Lithuania, i.e., dolomite aggregates instead of granite aggregates. Experimental studies were carried out on the skid resistance of the road surface. It was found that the coefficient of skid resistance met the requirements for surface dressing with dolomite aggregate, and the results were analysed with 95% probability. This coefficient partially met the requirements for asphalt concrete, while it did not meet the requirements at all for stone mastic asphalt. The surface roughness, however, met the requirements for road sections where granite aggregates were used instead of dolomite in mixes of surface dressing and asphalt concrete. The analysis was carried out considering the volume of traffic and the service life of the individual road sections. It was determined that it was suitable for a 5-year guarantee period to perform the surface dressing, wearing course of asphalt concrete and stone mastic asphalt with dolomite aggregate where part of heavy vehicles is less than 20% of traffic flow. The use of granite aggregates was justified only in the road where heavy vehicles dominated.

Introduction of Computer Aided Test Analysis Program for Civil Engineering

The Computer Aided Test Analysis for Civil Engineering (CATACE) is made based on International standards, regulations and specifications. It includes test analysis for aggregates, bitumen, soil, asphalt concrete and its mixtures. It includes the technical requirements for nuclear gauge, selection parameter for surface dressing, blending for prime coat and tack coat. It provides the unit conversion between American to international system. It provided over 40 kinds of test analysis, and it will be increase working efficiency for the Material Testing Engineer who is working oversea project and follows International Standards. The paper introduces the functions and application of the program.

Сonceptual Fundamentals for Technology of Sand Disperse-Reinforced Asphalt Concrete

A problem of efficient resource usage in road branch continues to be one of the most complicated issues and requires an intensification in investigation process pertaining to possibilities for production of road construction materials of low resource intensity with high physical and mechanical properties. Technogenic wastes of the Belarusian enterprises are rather various and they need a detailed investigation. Application of such methods as IR spectrometry, probe microscopy, study of of geometric characteristics of particles and fibers make it possible to determine more active centres and reveal micro-defects that influence on strength of adhesion bond at the boundary of “fiber – binder” and physical and mechanical properties of ready-mixed asphalt concrete. Nature of basalt fiber presupposes mainly physical character of adhesion interaction at the boundary of phase separation. An increase of technogenic waste activity to enhance adhesion contacts up to chemisorption level is possible only due to preliminary fiber processing which includes cleaning, removal of foreign inclusions, etching, drying, probable sorting-out and fluffing. Industrial approbation of such technological process is not possible without development of a corresponding module or a plant. Disperse reinforment causes changes in composition and technology of sand asphalt concrete. An increase in specific surface of an aggregate, necessity of uniform distribution of fiber in terms of volume determine the required need in a binder, procedure and regimes for component mixing. Grain composition of the aggregate can be represented by crush screening and natural sand of mixture of these materials. Requirements to properties of sand disperse-reinforced asphalt concrete are formed on the basis of operational conditions and layer arrangement of the material in the design of a surface dressing. The disperse-reinforced sand asphalt concrete can perform functions of a superfine protective layer, a levelling layer or a crack stopping layer which is resistant to fatigue crack formation.

Environmental impact of biogenic oils as raw materials in road construction

ABSTRACTReplacing fossil with biogenic raw materials is an approach to slowing the consumption of fossil resources and to reducing climate change. However, the use of biogenic raw materials can cause other considerable environmental impacts. This study evaluates the overall environmental impact of the use of biogenic oil in the five main road construction applications in Europe today. In hot spray surface dressing and cold asphalt for repairs, biogenic oils of food crop origin are used to replace solvents. In colourless binders, surface treatment emulsions and rejuvenating agents, biogenic oils of food crop origin are used to replace fossil oils. Based on literature review and expert interviews, the products with biogenic additives could be assumed to have equivalent quality and behaviour in the construction, use and end-of-life phases, so the LCA was restricted to the production of raw materials and the emissions of those materials during the construction phase. In general, binders supplemented with vegetable food crop oils are not advisable from an environmental point of view. The use of food crop oils could only make sense if they are produced from waste oils (recycling) or if a better quality in the construction or use phases is achieved, such as reduced emissions or increased service life. Such improved quality can be achieved not only with biogenic raw materials, but also with those of fossil origin. Based on the literature analysis, it is also recomobilanzen: Methode de “system” as a whole be optimised, i.e. not only its materials but also its use.

The influence of the mould cooling temperature on the surface appearance and the internal quality of ESR ingots

One of the main benefits of the ESR process is to obtain an ingot surface which is smooth and allows a subsequent forging operation without any surface dressing. The main influencing factor on surface quality is the precise controlling of the process such as melt rate and electrode immersion depth. However, the relatively strong cooling effect of water as a cooling medium can result in the solidification of the meniscus of the liquid steel on the boundary liquid steel and slag which is most likely the origin of surface defects. The usage of different cooling media like ionic liquids, a salt solution which can be heated up to 250°C operating temperature might diminish the meniscus solidification phenomenon. This paper shows the first results of the usage of an ionic liquid as a mould cooling medium. In doing so, 210mm diameter ESR ingots were produced with the laboratory scale ESR furnace at the university of applied science using an ionic liquid cooling device developed by the company METTOP. For each trial melt different inlet and outlet temperatures of the ionic liquid were chosen and the impact on the surface appearance and internal quality were analyzed. Furthermore the influence on the energy balance is also briefly highlighted. Ultimately, an effect of the usage of ionic liquids as a cooling medium could be determined and these results will be described in detail within the scope of this paper.

The Influence of the Mould Cooling Temperature on the Surface Appearance and the Internal Quality of ESR Ingots

One of the main benefits of the ESR process is to obtain an ingot surface which is smooth and allows a subsequent forging operation without any surface dressing. The main influencing factor on surface quality is the precise controlling of the process such as melt rate and electrode immersion depth. However, the relatively strong cooling effect of water as a cooling medium can result in the solidification of the meniscus of the liquid steel on the boundary liquid steel and slag which is most likely the origin of surface defects. The usage of different cooling media like ionic liquids, a salt solution which can be heated up to 250 °C operating temperature, might diminish the meniscus solidification phenomenon. This paper shows the first results of the usage of an ionic liquid as a mould cooling medium. In doing so, 210 mm dia. ESR ingots were produced with the laboratory scale ESR furnace at the University of Applied Sciences Upper Austria using an ionic liquid cooling device developed by the company METTOP. For each trial melt, different inlet and outlet temperatures of the ionic liquid were chosen and the impact on the surface appearance and internal quality were analyzed. Ultimately, an effect of the usage of ionic liquids as a cooling medium could be determined and these results will be described in detail within the scope of this paper.

Performance Evaluation of Gravel Road Sections Sealed with Surface Dressing

The rural population of India lack adequate transport infrastructure to access the nearby towns/headquarters. The Ministry of Rural Development (MoRD), Government of India (GoI) decided to develop various rural roads under Pradhan Mantri Gram Sadak Yojna (PMGSY). The main objective of PMGSY is to achieve all weather connectivity to all habitations. Hence, a pilot study was initiated over a 7 km gravel road stretch from “Ghanapur-Palakurthy Public Works Department (PWD) Road to Komatigudem via Ippagudem, and Rangaraigudem” in the Warangal district of Telangana State, India. There are various disadvantages associated with construction using gravel like dust generation and gravel loss over a period of time due to passage of vehicles. The best solution to minimize these problems is to seal the gravel roads. The pilot road considered in this study was constructed using locally available gravel up to the surface course and then sealed using surface dressing. The performance of the road sections were evaluated in terms of roughness, skid resistance, and texture depth. The initial set of data was collected immediately after construction and one month after construction. Later, four sets of pavement performance data was collected after seven months of construction of the surface dressing layer in November 2013, January 2014, April 2014, and June 2014. Altogether, six sets of data were collected. The data was analyzed and important observations are reported in this paper. There is a considerable change in surface texture and skid resistance values after the first one month of construction whereas no significant changes were observed in the roughness values. Further, there is no significant difference in the results of surface texture, skid resistance and roughness values when the pavement sub-sections were evaluated for four times even after seven months of construction of the sealing layer.

An extensive laboratory investigation of the use of bio-oil modified bitumen in road construction

Several roads in Iceland with bio-oil modified surface dressings exhibited severe distresses such as bleeding, binder drain down, and eventually as surface dressing sticking to tires. Samples from six road sections were evaluated in the laboratory to determine the causes of the failure. Binders with and without bio-oil, rapeseed oil and fish oil, were evaluated through a comprehensive rheological and chemical characterization. Both oils, exhibited solubility issues with the bitumen; consequently, the oils covered the aggregates, preventing bonding between binder and stones. It appears that fish oil worked a little better than rapeseed oil for binder modification.

Implementation of Preventive Maintenance in Network-Level Optimization

Application of appropriate preventive maintenance treatments, at the right time, extends the service life of pavements, resulting in benefits to road users through increased ride comfort and safety and to road agencies through the reduction of future maintenance costs and improvement of the network condition. Preventive maintenance treatments usually have been applied on the highly trafficked sections of the Serbian national road network, but they have not been applied on the low-volume part of the network. This study used the Serbian low-volume roads network as a case study to identify appropriate preventive maintenance treatments for low-volume roads, model these into a pavement management system, and assess the potential benefits of their application compared with the current practice. The World Bank's RONET (road network evaluation tools) model, designed to assess the current characteristics of road networks and their future performance according to various levels of interventions (and budgets), was selected for this study. The model was modified for the study to incorporate use of preventive maintenance treatments. Modifications included adjustment of the pavement deterioration curves to incorporate a slower deterioration rate resulting from the application of crack sealing and pothole patching and surface dressings or thin overlays while the pavement was still in good condition. The results indicate that the use of preventive maintenance treatments would result in increased net benefits and a substantial reduction in future road agency costs compared with the maintenance scenario without preventive maintenance.

Influence of road pavement macrotexture on tyre/road noise of vehicles

Noise level in the surroundings of traffic routes mainly depends from traffic volume, flow composition, speed of the vehicles as well as from the cross-section and road longitudinal gradient. Under higher speeds significant influence on the noise level has also tyre/road noise. Tyre/road noise depends on type and pavement condition state, specifically from the surface macrotexture. The influence of macrotexture is varying and strictly connected with the type of vehicles, tyres characteristics, frequencies of emitted noise. On the base of investigations of the rolling noise applying Statistical Pass-By method along the Polish roads the paper presents elaborated dependences and fixed values of differences between maximum noise levels under passing multiple-axle heavy vehicle and passenger car on the asphalt concrete surface, stone mastic asphalt and the surface dressing. The functional dependences between maximum rolling noise levels in the range of complete level and in the octave band spectra: 250 Hz, 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz and between the surface macrotexture described by mean profile depth, and logarithm of vehicle speed and adequate nomograms were evaluated in the paper. On this base the values of differences in the levels of emitted noise from passing heavy vehicle and passenger car in function of speed and surface macrotexture were computed. The manuscript also presents how surface macrotexture and traffic flow composition have influence on equivalent noise level in the road vicinity under equal traffic volume.