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In order to evaluate the influence of rock asphalt on the self-healing behavior of asphalt mastics, this study carried out the frequency sweep test, fatigue-healing test and complete process monitoring test of self-healing behavior for four different asphalt mastics. In addition, this study examined a proposed mechanism of self-healing from literatures. The results show that the optimum self-healing temperature of control asphalt mastic is identified as its near-Newtonian fluid transition temperature (slightly higher than softening point), while the optimum self-healing temperature of rock asphalt mastic is lower than its near-Newtonian fluid transition temperature and softening point, which indicates that rock asphalt mastic maximizes its self-healing potential before the near-Newtonian fluid state. This study models the self-healing behavior of the asphalt mastic considering the effect of healing temperature and time to verify the applicability of the capillary diffusion theory that explains the self-healing in asphalt mastics. The proposed model determined the rest times for full healing of asphalt mastics, and results indicate that the self-healing rate of asphalt mastic can be significantly increased by rock asphalt. The results of the self-healing behavior monitoring test and the parameters obtained from the proposed model both indicate that rock asphalt has some adverse effects on the self-healing behavior in the initial stage, but will promote the development of self-healing after a period of time. Overall, the addition of rock asphalt can improve the self-healing properties of asphalt mastic. Based on the aforementioned macroscopic results and the capillary diffusion theory, it can be concluded that the addition of rock asphalt negatively affects the wetting mechanism of self-healing, but positively influences the strength and efficiency of diffusive cohesive healing, thus effectively enhancing the self-healing behavior of asphalt mastic.

To accurately describe the linear viscoelastic properties of asphalt and asphalt mastic, the authors proposed a fractional differential constitutive model called the generalized fractional differential Zener (GFDZ) model. Then, by means of the GFDZ model, the dynamic and static viscoelastic properties of two kinds of asphalt and two kinds of asphalt mastic were described and predicted. Finally, the GFDZ model was compared with the modified CAM (mCAM) model and 2S2P1D model. The results show that the GFDZ model can simultaneously and accurately characterize the dynamic and static viscoelastic properties of asphalt or asphalt mastic using a set of model parameters. The GFDZ model overcomes the deficiencies of the mCAM model and 2S2P1D model, and provides a reference for the characterization and constitutive description of the linear viscoelastic properties of asphalt and asphalt mastic.

Subject: a rapid increase in the traffic intensity and freight traffic on motor roads leads to premature destruction of road surfaces. At the same time, the actual service life of asphalt-concrete pavements rarely exceeds 4-5 years and in most cases is only 2-3 years. Most intensively defects and fractures appear on asphalt-concrete pavements in the early spring. Nowadays the overhaul intervals for the road surface coverings are significantly lower than those given by the regulatory requirements. One of the main reasons for this phenomenon is the use of obsolete technologies based on traditional materials whose properties are inadequate to resist stresses and deformations arising in the coating. This is especially evident in the climatic conditions of the south of the European part of Russia, where the upper layers of the roadway experience a much wider range of temperatures. Tighter requirements for the initial road-building materials and timely repair of the coatings allow us to increase the service life of motor roads. Research objectives: the aim of the study is to develop a new type of asphalt-concrete, such as porous-mastic one. Materials and methods: the work was carried out based on observations and published sources, a method of theoretical study and analysis. Results: the domestic and foreign experience of using the given asphalt concrete for the top layer of the coating was considered. The technology of preparation and laying of a porous-mastic asphalt-concrete mixture is presented and its advantages and disadvantages are shown. Conclusions: increasing the longevity of highways is an important and urgent task and it can be solved, in particular, due to the wide use of new technologies and non-traditional building materials that allow us to improve the quality of asphalt-concrete pavement and prolong its overhaul intervals.

The microstructures of asphalt mastic have been considered as an important micromechanical mixture property related to the macro performance of asphalt mixtures based on the multi-scale analysis me...

Bitumen of VG-30 grade is a common satisfactory binder for flexible pavement in tropics. Bitumen when mixed with other additives exhibits poor performances under moist and temperate conditions. Under varying temperature, traffic loads and volume and wet conditions, the pavement becomes less durable. The addition of polymers to bitumen has shown increased performances in interfacial properties of flexible pavements and also become cost effective. The local milk pouches used by Odisha State Cooperative Milk Producers’ Federation’s (OMFED) are of low-density polyethylene display excellent additive properties of bitumen as a good stabilizer for flexible roads made of bituminous concrete, bituminous macadam roads and mastic asphalt for stones. Present study envisages the optimization of polythene percentage in bituminous concrete using Marshall’s technique applying 5, 10 and 15% replacement with shredded OMFED pouches. The tests conducted are to find maximum specific gravity, penetration, ductility, softening point and flash and fire tests. It is observed at 10% replacement of the shredded OMFED polythene pouches give the optimum result. The search also stresses upon logical and advanced method for augmenting the use of the OMFED polythene garbages, reduces polythene waste and helps in maintaining a sustainable environment.

Mastic asphalt (MA) has been particularly popular in recent years for bridge pavements due to many advantages such as easy application, good waterproofing properties, and high durability. However, the drawback of mastic asphalt in comparison to other asphalt mixtures is its lower resistance to permanent deformation. Trinidad Lake Asphalt (TLA) is often applied to make mastic asphalt resistant to permanent deformation. Practical experience demonstrates that serious failures may occur if MA pavement design and materials selection is not taken into account sufficiently. Therefore in this study, the influence of two parameters: zero shear viscosity (ZSV) of TLA-modified binder and mastic composition described by the filler–binder ratio, on the permanent deformation resistance of the MA mixture was evaluated. The primary purpose of determining the ZSV of the TLA-modified binders was to evaluate the rutting potential of the binders. The permanent deformation (rutting) resistance of the MA mixtures was evaluated based on static and dynamic indentation tests. The optimum content of TLA in the base bitumen and the optimum filler–binder ratio in the MA mixture were obtained based on multiple performance evaluations for modified binder, mastic and MA mixtures, i.e., 20% and 4.0, respectively.

Problem. The temperature of mastic as-phalts mixing is significantly higher than the one for hot asphalt mixtures. It is due using of high viscous bitumens as a mixture component and realizing the main advantage of mastic asphalt – its ability to flow and compact with its own weight at high tempera-ture. There is no uniform way to assign the process temperatures for mastic asphalt. Goal. To find the process temperatures for mastic asphalt with bitumen binders differ by viscosity as a researching on tem-perature influence and influence of binder concentra-tion on properties of mastic asphalt is a goal of this research work. Methodology. The mastic asphalt mixtures and asphalt concrete with conventional pavement bitumen 70/100 (penetration is 85 dmm) and high viscous bitumen (penetration is 38 dmm) are chosen for research. The mineral aggregates contain 42 % of crushed granite 5-10 mm, 33 % of granite screening and 33 % of limestone powder. The properties of mastic asphalts are evaluated with EN 12697-20:2003, SOU 42.1-37641918-106:2013 and DSTU EN 13108-6:2018. Results. It was found a significant influence of amount and viscosity of bitu-men and a temperature on workability of mastic as-phalt mixture and on properties of mastic asphalt concrete. Originality. The comparative analysis of workability of mastic asphalt mixture and properties of mastic asphalt concrete with bitumens differ in viscosity is a scientific originality of presented re-search. Practical value. Due to research results it is not reasonable to assign the temperature that sup-plies viscosity of 0.5 Pa•s as a temperature of mixing of mastic asphalt. The temperature conditions of mastic asphalt mixing are much higher (200 – 240 °C). To evaluate workability and find a minimal acceptable temperature of mixture it is possible to use the thickness of the mixture layer after spreading as an indicator. With this the acceptable workability of the mastic asphalt mixture can be characterized by thickness of its layer 30 mm or less after spreading.

This study aims to determine the effect of latex addition to the durability of the Split Mastic Asphalt (SMA) pavement mixture in order to increase its durability when the road is flooded. Durability test conducted where the sample was immersed in water for 0, 24, 48, 72, 96 hours, with latex variations of 1.5%, 2%, 2.5%, 3%, 3.5%. From the results of the study it was found that the durability of asphalt mixture without latex was higher than that of SMA with latex. The durability indexes were 6.740%, 10.648, 11.717, 13.884, 14.766 and 9.991 for 0%, 1.5%, 2%, 2.5%, 3%, 3.5% latex in the mixture respectively. The higher the index the lower the strength. In addition, the longer the soaking time the lower the strength. However, as the latex in the mixture increases, the stability was also increase achieved at 3% latex. The SMA pavement mixture with the addition of latex does not increase its durability but can increase its stability value. So, it is recommended that SMA pavement mixture with latex is only for pavement where the water level is not high.

The article shows the results of fatigue life tests of macadam and mastic asphalt concrete made with use of a bituminous binder of various PG marks. The optimal compositions of the samples of macadam and mastic asphalt concrete characterized by close residual porosity to exclude its effect on the physical and mechanical properties and indicators of fatigue life are selected. A Cooper CRT-SA4PT-BB-16 testing machine was used to evaluate the fatigue life of macadam and mastic asphalt concrete, testing beam specimens for four-point bending. The following test protocol was used in the work: a loading frequency of 10 Hz, a test temperature of + 20 ° C, a decrease in the rigidity of the samples to 50% of the initial value and the number of cycles was recorded. Based on the analysis of the obtained dependences: strength indicators, mixture stiffness and fatigue life, it is shown that there is no linear relationship between the mark of bitumen binder and the fatigue life of a road composite made on its basis, therefore, focus on PG mark of bitumen to design the composites of durable asphalt concrete with predetermined properties is not enough.

Ülkemiz dalgalı ve dağlık topografik bir yapıya sahip olmasından dolayı; vadi kesimlerinde iki yükselti arası ve su geçişlerinde ulaşımın sağlanması için viyadük ve köprüler gibi yapılar önemli role sahiptir. Karayolu projelerinde amaç; yüksek maliyetli sanat yapılarının özellikle çelik köprülerin hizmet ömrünün verimli olması, kaplama tabakasında oluşacak kalıcı ve elastik deformasyonlara karşı en uygun kaplama tipinin seçilmesi ile sürüş kalitesinin ve trafik güvenliğinin en üst seviyede tutulmasıdır. Çelik köprülerde, trafik yüklerinin aşındırıcı etkileri ve tabliyedeki korozyona karşı korumak üzere genellikle mastik asfalt (harç) tipi kaplama tabakası kullanılmaktadır. Bu çalışmada; çelik köprülerde kullanılan üstyapı tiplerinin performanslarının değerlendirilmesi amacıyla; mastik asfalt kaplamalı, mastik asfalt üzeri taş mastik asfalt kaplamalı ve mastik asfalt üzeri modifiye bitümlü aşınma tabakası kaplamalı 3 farklı üstyapı tipinin performansları ölçülmüştür. Çelik tabliyeli köprü üstyapılarında kullanılan karışımlar, taş mastik ve modifiye aşınma tipi karışımlar için Marshall yöntemi ve mastik asfalt için ise ZTV Asphalt StB 07 yöntemi ile hazırlanmış ve karışımlara tekerlek izinde oturma ve yorulma deneyleri yapılarak performansları karşılaştırılmıştır. Our country has a rolling and mountainous terrain as topographicaly. The construction of viaduct and bridges play a significant role with regards to transportation for the route passing through two ridges and sea passages. The main purpose of road and bridge construction projects are to maximize the life expectancy of these high-cost structures and to ensure that the most suitable materials with high resistance against permanent deformations are chosen to improve quality of riding comfort and safety. Steel deck bridge, the mastic asphalt (mortar) type coating layer is used to protect the bridge deck against corrosion by both the corrosive effects of the traffic loads and the corrosion. In this study, the design of the mastic asphalt, stone mastic asphalt and modified bituminous asphalt mixture types used as coating layer in steel bridges. This asphalt mixture were prepared by Marshall and ZTV Asphalt methods and the performances of different bituminous binder types were evaluated by using the wheel traction and fatigue tests.

The cracking behavior of asphalt mixtures in the shape of angled edge crack semi-circular bend (SCB) specimens created by the generation and packing algorithm was investigated numerically. Using extensive two-dimensional finite element analyses, the effects of crack length and crack inclination angle, elastic modulus of aggregates and mastic parts, Poisson’s ratios of aggregates and mastic parts, shape of aggregates, distribution pattern for the aggregates inside the asphalt mastic, crack tip location, and air void distribution on geometry factors (YI and YII) were investigated. It was shown that the crack tip location has a significant effect on the magnitude and sign of geometry factors but the shape of aggregates had no sound influence on both modes I and II stress intensity factors. Geometry factors obtained from heterogeneous modeling (i.e. two-phase aggregate/mastic asphalt mixture) when the crack tip is located inside the aggregates were greater than those obtained from homogeneous model. On the other hand, if the crack tip is located inside the mastic part, the geometry factors will be smaller than the homogeneous SCB model. The crack growth path was predicted using the maximum tensile stress criterion. It was shown that the aggregates could change the crack growth path locally; however, the general direction of crack growth in heterogeneous and homogeneous modeling is the same.

The technological properties of mastic and sulfur-mastic asphalt concrete mixtures have been evaluated. The hypothesis has been confirmed that the compositions of mastic asphalt concrete mixtures with crystallization-coagulation structure have increased fracture resistance. Optimal technological modes of producing and paving are recommended.

The paper considers the use of crushed stone-mastic asphalt mixtures laid with a small thickness as protective layers of wear of roads. The General characteristics of mixtures and their components are given, the pros and cons, as well as the possibility of their application are given. As a mineral powder, it is recommended to use lime-containing waste (calcium oxide hydrate) of the chemical industry. The effective increase of shear resistance of the protective wear layer with the subsequent prevention of the formation of a track on the coating due to the use of lime-containing waste, which has a highly active structuring effect on bitumen with a slowdown in its aging in the asphalt binder, subject to the principles of sufficient water resistance and crack resistance of asphalt concrete. The replacement of mineral powder with lime-containing waste in the composition of crushed-mastic asphalt concrete with the same mass amount of other mineral components and bitumen indicates a significant increase in quality indicators.

U radu se analizira mogućnost upotrebe reciklirane poliuretanske pjene kao veziva/modifikatora za lijevani asfalt. Rezultati pokazuju da se tvrđi bitumen dobiva s povećanjem poliuretanske pjene do 5 % kada obradivost mješavine postaje nepovoljna. Proizvedena je mješavina lijevanog asfalta s 4 % poliuretanske pjene u bitumenu. Zabilježena je manja vrijednost dubine utiskivanja u usporedbi s uzorkom bez dodataka te je ustanovljeno da se modificirani lijevani asfalt može koristiti na cestama s teškim prometnim opterećenjem. Dobiveni rezultati pokazuju da postoje dobri izgledi za širu primjenu ovog otpadnog polimera., The aim of this paper is to analyse the suitability of recycled polyurethane (PU) foam as a binder modifier in mastic asphalts (MA). The results show that harder bitumen is achieved with an increasing percentage of PU, up to 5 %, when the workability of the sample becomes poor. A MA mix with a 4 % of PU in bitumen was manufactured. A lower indentation was observed when compared to a virgin sample, and it was established that the modified MA can be used on heavy-traffic roads. These results suggest a promising use of this waste polymer.

Aging of asphalt binders is induced by chemical or physicochemical changes during production of pavement and throughout its service life. Although binder aging in pavement always occurs while binders are in contact with aggregates and mineral filler, in most laboratory aging studies and in current specifications, asphalt binders are individually aged without accounting for aggregate induced interactions. Past research has had conflicting findings, as it attributes mitigating or catalytic effects to the presence of mineral fillers in asphalt binders with oxidative aging. Thus, in the present study it was hypothesized that evaluation of asphalt oxidative aging without taking into account the interactive effect of the presence of mineral fillers was inadequate as a specification tool. The effect of mineral fillers on oxidative aging of asphalt was investigated with accelerated aging of mastics (asphalt and fillers) in a pressure aging vessel (PAV) and by measuring the changes in stiffness and glass transition temperature ( Tg). The testing matrix included an aging evaluation of mastics containing different fillers, mineralogy, and surface area. The results showed that the low-temperature behavior of aged mastic could be modified by controlling filler concentration and type. The fillers acted as an agent adsorbing heavy fractions of asphalt binder and therefore reduced stiffness and changing Tg. During oxidative aging of asphalt binders and mastics, diffusion and adsorption mechanisms played a role in the rate of aging of asphaltic material. The results provided insight on the potential for selecting a mineral filler concentration and mineralogy type to reduce the impact of oxidative aging and possibly improve the service life of pavement.

The first thin surfacing system was introduced into the United Kingdom from France in 1991 with others quickly following, whilst surfacing with stone mastic asphalt from Germany commenced in 1995. The Highways Agency accepted the use of the first two proprietary systems on English trunk roads following road trials monitored by TRL Limited. Thereafter other systems had to demonstrate equivalent performance to gain similar approval. Advantages such as ease of laying and noise reduction have meant that they have rapidly grown in use to become the most common surfacing laid in many parts of the country. In order to provide the required texture depth for use on UK trunk roads, the gradings of the systems tended to be modified from those used elsewhere in Europe. As a result, data on durability from the continent could not be relied upon. The current HA approval system is based on two-year monitored road trials, so the short- to medium-term durability of each of these products has been demonstrated. The paper reviews the data used to assess the medium-term durability of the 21 thin asphalt surfacing systems currently approved by the Highways Agency on a total of 69 sites. The data reviewed includes the traffic loading, the initial and two-year retained texture and the skid-resistance for all systems together with other information, such as the wheel-tracking rate and the fatigue characteristics, on those systems for which the properties were measured. The report also gives details of the first year results from a three-year review into the longer-term durability of the systems on the original road trial sites. (A)

Due to their technical advantages, waterproofing systems with Gussasphalt mastic asphalt, polymer-bitumen waterproofing membranes and asphaltic plug joints are widely used for bridges and tunnels in Switzerland. Experience shows that type of solution is very successful and durable if planning, selection of material quality and application are conducted professionally and with special care regarding the interaction between the different components of the system. This article focuses firstly on the interaction between polymer-bitumen asphaltic plug joints and the adjacent pavement, especially on the de-bonding which may occur due to incorrect planning or construction. Secondly, the practical aspects of the compatibility between the mastic asphalt and the polymer-bitumen waterproofing membranes, as well as the application of mastic asphalt, are explained and discussed. For the covering abstract see ITRD E117840.

Pavement rutting is one of the peculiar and far impacting pavement distresses which being observed in flexible pavements. At present, the pavement surface at the bus shelter area appears to be challenging problem and requires maximum attention due to its severe distress, categorized as higher severity rutting. In order to ponder upon such high severity distress, some of the alternative solutions could stand as: Mastic Asphalt (MA), Use of Modified Bitumen, Stone Matrix Asphalt (SMA), White-topping, Glass Fiber Grid, Rigid Pavements and paver-blocks. Thus the overall objective of this study is to explore various alternatives of similar environments and arrive at optimum kind of alternative for Urban Flexible Pavements and also for BRTS Bus Shelters and to evaluate the damage analysis by the use of KENPAVE software of each alternative and compare the cost analysis.

Excessive sole horn wear in cattle due to abrasive floors, such as new concrete and mastic asphalt, and excessive sole trimming, are the leading causes of thin soles. This study compared prevalence of thin soles in Austrian dairy cows in six herds housed on fully-floored mastic asphalt (FMA) or partially-floored mastic asphalt (PMA). All cows had last received hoof trimming at least 5 months before the study commenced. Sole horn thickness of the hind claws was measured ultrasonographically in 97 cows at two points on each claw: (1) point 1 exactly at the tip of the pedal bone surface; and (2) point 2 approximately 3 cm caudally. Locomotion was scored in all cows and claw lesions were categorised using a computerized claw trimming database program and evaluated at cow- and claw-level. An ANCOVA-model was applied to calculate the effects of different factors (breed, age, farm, days in milk) and covariates on sole horn thickness. The cut-off measurement for thin soles was defined as ≤4.5 mm, in accordance with a recent study. Regarding claw health, FMA areas were inferior to PMA areas in barn installations. In cows on FMA, the prevalence of thin soles was significantly higher (P = 0.01) and mean sole horn thickness at point 1 was significantly lower (P = 0.01) than cows on PMA (59.7% vs. 12.5%; 5.35 mm vs. 6.63 mm, respectively). There were also significantly more lame cows on FMA than on PMA (P = 0.01). The FMA group had higher prevalences of white-line disease (59.6% vs. 25%; P = 0.01) and toe ulcers (12.3% vs. 0%; P = 0.02) than the PMA group.

This study aimed at investigating the effect of the floor type used in the walking area of cubicle housing systems and of access to pasture on claw dimensions and claw shape in dairy cows. Data were collected on 36 farms, 12 farms each fitted with mastic asphalt, slatted concrete or solid rubber flooring. With each floor type, cows on half of the farms had access to pasture in summer. The farms were visited three times at intervals of about 6 months and data were collected from 10 cows during each visit. Net growth of the claw horn was highest on rubber flooring and lowest on mastic asphalt. On all floor types, claw angles were larger after the winter period and smaller after the summer period. With regard to claw shape, floor type had an effect on the occurrence of flat, concave and overgrown claw soles. In conclusion, none of the investigated floor types was clearly superior to the others with regard to claw dimensions and claw shape, and access to pasture during summer (median 4 h per day) had only little influence on the investigated claw characteristics.

On 18 October 2011, the International Agency for Research on Cancer (IARC) revealed its conclusions of an eight-day comprehensive review of bitumen (asphalt) and bitumen emissions (fumes). The working group concluded that occupational exposures to oxidized bitumens and their emissions during roofing are ‘probably carcinogenic to humans’ (Group 2A); occupational exposures to hard bitumens and their emissions during mastic asphalt work are ‘possibly carcinogenic to humans’ (Group 2B); and occupational exposures to straight-run bitumens and their emissions during road paving are ‘possibly carcinogenic to humans’ (Group 2B) These evaluations and supporting data have been published as Volume 103 of the IARC Monographs. The IARC process is described, as well as details of the conclusions, hazard versus risk, prominent human, animal and mechanistic studies, routes of exposures and ways to reduce exposures. Implications for the asphalt pavement industry include communication to workers and product users, and pote...

Multiscale modeling is becoming an increasingly useful method of evaluating the behaviors of asphalt concrete. Reasons for this increased interest include the fact that many of the critical behaviors of this material are affected by localized behaviors that cannot be completely captured using more traditional continuum approaches. Computational methods are popular for this type of evaluation because in principle they can directly account for many of the localized mechanisms. However, computational expense can be excessive, particularly if all of these localized mechanisms are accounted for rigorously. An alternative method of multiscale modeling relying on analytical models is developed and presented in this paper. The model is referred to as the microstructure association model because it accounts for the ways that the multiple scales within asphalt concrete associate together to yield the gross behaviors of the finished composite, asphalt concrete. This model is formed from the hypothesis that a...

The asphaltic cement and mastic asphalt are respectively carried on Brookfield rotary viscometer and Lueer tester. The results show that: the thixotropic properties of mastic asphalt lags behind the asphaltic cement; as the stirring temperature is high, the thixotropic effect of mastic asphalt is not obvious, but the construction time range is large. With high stirring speed, the thixotropic effect of mastic asphalt is obvious, but the construction time range is small. The thixotropic effects of mastic asphalt are also analyzed to provide reference for the improvement of the construction process and quality of the construction.

During compaction of asphalt mixtures, aggregate structure starts building up by proximity and direct contact of aggregates. In the previous studies, it has been shown that the aggregate structure directly affects the service performance. However, the mechanisms of the aggregate structure formation are not clearly understood. This study is focused on the mechanisms affecting aggregate mobility during compaction and the effect of material properties on the aggregate structure formation. At the initial stages of compaction, there is a relatively thick layer of mastic (i.e. mix of binder and filler) between aggregates, which allows for a shearing mobility in the mix, if the mastic viscosity is sufficiently low. However, as compaction proceeds, the mastic layer at proximity zone of aggregates becomes thinner due to high stress intensity and the higher viscosity of thin mastic film or the aggregates dry contact effect increases the shearing resistance against compaction (i.e. mix becomes locked). In this study...

This study quantifies moisture damage at the asphalt mastic–aggregate interfaces using finite element method modelling technique in ABAQUS. A model aggregate surrounded by a layer of mastic is subjected to static loads of varying magnitudes and patterns. Using dynamic shear and elastic moduli of wet and dry mastic and aggregate as model inputs, moisture-induced damage is quantified through parameters such as contact stresses at interface, load to initiate damage and de-bonding at the interface. Results show that contact stresses are significantly higher in dry samples than wet samples. It is revealed that damage initiates at a smaller magnitude of deformation (0.0508 mm) in the wet sample than that (0.508 mm) in the dry sample. That is, a stiffer dry sample carries more loads and deforms less before damage initiation than a softer wet sample. In addition, approximately 6.8% interface de-bonding occurs in the dry sample, whereas 49.1% de-bonding occurs in the wet sample.

Bituminous mastics influence many other important asphalt mixture properties in addition to their own allowance for the load transfer in the aggregate skeleton. The influence of bituminous mastics extends to the overall stability of a mixture, air void distribution, bitumen draindown during transport, a mixture's workability during the laying process, and the overall in-time performance of the pavement. To understand the properties of asphalt mixtures and their resistance to environmentally induced failure mechanisms, it is paramount to study not only bitumen and the asphalt mixture but also the mastic itself. Current asphalt design procedures do not take mastic behavior into account, however; this omission leads to a significant flaw in the ability to design and predict asphalt concrete response. This paper presents the results of an ongoing research project to enhance the understanding of the mastic phase as well as to develop a new test protocol to characterize mastics. A description is given of the measurements of mastic viscosity for different types of mastics in which the bitumen source is kept as a constant but with varying fillers as well as concentrations. Environmental susceptibility was investigated by subjecting the samples to aging and moisture conditioning. Biomass fillers were included in some of the mastics, in addition to some of the traditional fillers, to show their impact on the viscosity under varying conditions. Results showed that the developed test protocol was able to identify clearly the impact of filler properties on the mastic viscosity. A critical filler concentration was identified beyond which the viscosity behavior became nonlinear. The results also showed that moisture and aging had significant effects on the viscosity of mastics.

V diplomski nalogi so predstavljena področja vgrajevanje lito asfaltne zmesi, ki se danes porablja v tujini in v Sloveniji in kakšna je njegova uporabnost, spremembe v daljšem časovnem obdobju in morebitne napake oziroma poškodbe, ki lahko nastanejo tekom let, in vzroki zanje. Na podlagi zbrane literature s tega področja sem v prvem delu naloge predstavila, kje se liti asfalt vgrajuje v tujini. Ker menim, da se v Sloveniji ne uporablja v tako širokem spektru, bodo v nadaljevanju predstavljena področja vgradnje in izkušenj pri nas. V osrednjem delu sem opisala izkušnje s postopkom proizvodnje in vgrajevanja, vključno s prevozom lito asfaltne zmesi. Vse to zahteva usklajeno oziroma povezano skupino ljudi. Tako delo poteka neprekinjeno, kar je zelo pomembno za kakovost izdelka, je hitro in nenazadnje tudi ekonomično. Na koncu naloge je na konkretnih primerih preverjen kakšen je izgled litega asfalta danes. The thesis presents the areas of installation of mastic asphalt mixture, which nowadays is used in Slovenia and abroad. It describes what is its utility, changes over time, any failure or damage that may arise over the years and the reasons for the changes. In the first part of the thesis subject I present where the mastic asphalt is installed abroad based on the collected literature. Because I believe that in Slovenia it is not applied in such a wide spectrum, I will present the areas of installation and experience in our country in the chapters that follow. In the central part I describe the experience of the production process and the installation, including transport of mastic asphalt mixture. All this requires a coordinated and integrated group of people. Such work is carried out continuously, which is very important for product quality. Such work is also fast and last but not least it is also economical. At the end of the thesis I describe specific cases on the terrain, which show the appearance of asphalt today.

This study assessed the slip resistance of different types of solid flooring in cattle housing using a range of technical tests and gait analysis. Dynamic and static coefficient of friction, skid resistance, and abrasiveness were tested on concrete flooring with a smooth finish, a grooved pattern, or a tamped pattern, acid-resistant mastic asphalt, soft rubber mats, and a worn slatted concrete floor. Coefficients of friction and skid resistance were tested under clean and slurry-soiled conditions. Linear kinematic variables were assessed in 40 cows with trackway measurements after the cows passed over the floors in a straight walk. All gait variables were assessed as deviations from those obtained on the slatted concrete floor, which was used as a baseline. The coefficient of friction tests divided the floors into 3 categories: concrete flooring, which had a low coefficient of friction (0.29-0.41); mastic asphalt flooring, which had medium values (0.38-0.45); and rubber mats, which had high values (0.49-0.57). The highest abrasion (g/10 m) was on the asphalt flooring (4.48), and the concrete flooring with a tamped pattern had significantly higher abrasiveness (2.77) than the other concrete floors (1.26-1.60). Lowest values on the skid-resistance tests (dry/wet) were for smooth concrete (79/35) and mastic asphalt (65/47), especially with a slurry layer on the surface. Gait analysis mainly differentiated floors with higher friction and abrasion by longer strides and better tracking. Step asymmetry was lower on floors with high skid-resistance values. The most secure cow gait, in almost every aspect, was observed on soft rubber mats. Relationships between gait variables and physical floor characteristics ranged from average to weak (partial correlations 0.54-0.16). Thus, none of the physical characteristics alone was informative enough to characterize slip resistance. With reference to gait analysis, the abrasiveness of the hard surfaces was more informative than the coefficient of friction, but the effect of pattern was better detected by skid-resistance measurements. Consequently, several physical characteristics are needed to objectively describe the slip resistance of cattle floors. Soft rubber mats gave better tracking than hard, solid floors, even with a grooved surface or a tamped pattern.

In this study, the effects on the claw health of dairy cows of three different floor types and access to pasture were investigated on 35 farms. The farms were fitted with a given floor type in the indoor walking area of a cubicle housing system: a solid rubber, mastic asphalt or slatted concrete floor. Because we chose farms on which the given floor type was in good condition, the data presented show what can be achieved on these types of floors under ideal circumstances. Cows on half of the farms per floor type had access to pasture during the grazing period. Each farm was visited three times at approx. 6-month intervals at the end of the winter indoor-housing period and at the end of the summer period, i.e. after the period with access to pasture on half of the farms. During each visit, the claw health of the same 10 cows per farm was assessed on the occasion of routine claw trimming. The proportion of cows with haemorrhages increased from mastic asphalt to rubber and slatted concrete floors. A lower proportion of cows kept on mastic asphalt was affected by white-line fissures and needed intermittent claw-trimming, an indicator for lameness. Cows housed in cubicle systems with slatted concrete floors were at the lowest risk of having heel-horn erosions. Access to pasture was associated with a lower incidence of slight white-line fissures and dermatitis digitalis. A higher proportion of cows with sole haemorrhages and sole ulcers were found on all floor types at the end of the summer period than at the end of the winter indoor-housing period. Floor type did not influence the presence of sole ulcers and deep white-line fissures. In conclusion, the effect of floor type on claw health was slight, and none of the investigated floor types was clearly superior to the others. Access to pasture was not effective in reducing the presence of most types of claw lesions associated with the floor type used in the indoor walking area.

Bitumen has attracted attention from the scientific community and regulating agencies. The debate on health effects of exposure to vapours and aerosols of bitumen during the hot application of bitumen ranges from respiratory and neurological effects to carcinogenicity. In 2000, the German Hazardous Substances Committee (AGS), in collaboration with the German Bitumen Forum, initiated the examination of a group of mastic asphalt workers and a same number of construction workers without exposure bitumen using a cross-shift design. The study was then extended to the Human Bitumen Study, and the recruitment was finished in 2008 after examination of 500 workers on 80 construction sites. Three hundred and twenty workers exposed to vapours and aerosols of bitumen at high processing temperatures and 118 workers at outdoor construction sites were included. In the Human Bitumen Study external exposure to vapours and aerosols of bitumen, internal exposure to PAH by analysing urinary 1-hydroxypyrene, the sum of hydroxyphenanthrenes and the sum of 1- and 2-hydroxynaphthalenes, irritative effects in the upper and lower airways and genotoxic effects in blood cells were investigated. The study turned out to be one of the largest investigations of workers exposed to vapours and aerosols of bitumen under current exposure conditions. The present paper summarizes its background and main topics.

The chemical complexity of emissions from bitumen applications is a challenge in the assessment of exposure. Personal sampling of vapours and aerosols of bitumen was organized in 320 bitumen-exposed workers and 69 non-exposed construction workers during 2001-2008. Area sampling was conducted at 44 construction sites. Area and personal sampling of vapours and aerosols of bitumen showed similar concentrations between 5 and 10 mg/m(3), while area sampling yielded higher concentrations above the former occupational exposure limit (OEL) of 10 mg/m(3). The median concentration of personal bitumen exposure was 3.46 mg/m(3) (inter-quartile range 1.80-5.90 mg/m(3)). Only few workers were exposed above the former OEL. The specificity of the method measuring C-H stretch vibration is limited. This accounts for a median background level of 0.20 mg/m³ in non-exposed workers which is likely due to ubiquitous aliphatic hydrocarbons. Further, area measurements of polycyclic aromatic hydrocarbons (PAHs) were taken at 25 construction sites. U.S. EPA PAHs were determined with GC/MS, with the result of a median concentration of 2.47 μg/m(3) at 15 mastic asphalt worksites associated with vapours and aerosols of bitumen, with a Spearman correlation coefficient of 0.45 (95% CI -0.13 to 0.78). PAH exposure at mastic-asphalt works was higher than at reference worksites (median 0.21 μg/m(3)), but about one order of magnitude lower compared to coke-oven works. For a comparison of concentrations of vapours and aerosols of bitumen and PAHs in asphalt works, differences in sampling and analytical methods must to be taken into account.

A laboratory investigation of the interactions between granites and asphalts based on rheology is described. In this study of asphalt-filler interactions, the rheological properties of asphalt mastics using different granite powders and different filler-asphalt ratios were measured using a dynamic shear rheometer. Statistically significant relations between the rheological properties of the granite-asphalt mastics and the moisture stability of granite-asphalt mixtures were found. Aggregate factors that influence the moisture stability of asphalt-aggregate mixtures were obtained, and the selection criteria for selecting granite aggregates for use in roads were developed; these could be useful as a reference for practical application.

The objective of this study was to compare the behaviour of dairy cows in cubicle housing systems with different floor types (mastic asphalt, slatted concrete floor and rubber floor) in the walking area. From a total number of 18 farms, 6 farms each were equipped with one of the given floor types, and stride length and self-grooming behaviour (self-grooming caudal to the costal arch standing on three or four legs) as well as the general activity of the cows (standing and lying) was observed directly. Stride length was measured both in winter during the indoor housing period and in summer during the pasture period. The cows’ stride length was longest on rubber floor, followed by mastic asphalt and slatted concrete floor, and increased from winter to summer on all floor types (interaction of floor type and season: F2,101 = 4.30, p = 0.02). Self-grooming behaviour and general activity of the cows were observed during summer, autumn and winter. No significant differences in self-grooming behaviour were found between the three floor types. Cows stood for longer in the walking area on rubber floor than on mastic asphalt or slatted concrete floor, with an interaction between floor type and season (F4,47 = 4.55, p = 0.0035). It is concluded that rubber floor is more suitable and slatted concrete floor less suitable than mastic asphalt in the walking area of cubicle housing systems for dairy cows.

In our research project entitled "Chemical irritative and/or genotoxic effect of fumes of bitumen under high processing temperatures on the airways," 73 mastic asphalt workers exposed to fumes of bitumen and 49 construction nonexposed workers were analyzed and compared with respect to polycyclic aromatic hydrocarbons (PAHs) exposure and exposure-related health effects. In order to assess the internal exposure the monohydroxylated metabolites of pyrene, 1- hydroxypyrene (1-OHP), and phenanthrene, 1-, 2- and 9-, and 3- and 4-hydroxyphenanthrene (OHPH) were determined in pre- and post-shift urinary samples. Significantly higher concentrations 1-OHP and OHPH were detected in the post-shift urine samples of 7 mastic asphalt workers working on the same construction site compared to the reference workers and all other 66 mastic asphalt workers. The adjusted mean OHPH in the reference, 66 mastic worker, and 7 worker subgroups was 1022, 1544, and 12919 ng/g creatinine (crn) respectively, indicating a marked rise in the 7 worker subgroup. In addition, there was a more than 12-fold increase of PAH metabolites from pre- to post-shift in these 7 workers, whereas in the other mastic asphalt workers there was only a twofold rise in PAH-metabolite concentration between pre- and post-shift values. The analysis of a drilling core from the construction site of the seven workers led to the detection of the source for this marked PAH exposure during the working shift as being coal tar plates, which were, without knowledge of the workers and coordinators, the underground material of the mastic asphalt layer. The evaluation of the stationary workplace concentration showed enhanced levels of phenanthrene, pyrene, fluorene, anthracene, and acenaphthene during working shifts at the construction site of these seven workers. Our study shows that biological monitoring is also a useful tool for the detection of unrecognized sources with high PAH concentrations.

Weight and pressure distribution on the claw were studied in Swedish Holsteins housed in different flooring systems. A total of 127 cows housed in different sections of the experimental barn were used. Each section had different flooring in the walking and standing areas. There were rubber mats or abrasive mastic asphalt flooring on the alleys or a low-abrasive slatted concrete floor. Some sections had feed-stalls equipped with rubber mats; other sections did not. The vertical ground reaction force, contact area, and average contact pressure were determined on the left hind foot using the I-Scan system and analyzed with the F-scan system. These determinations were made in each of the following 3 zones of the claw: bulb, wall, and sole. Most of the weight on claws exposed to concrete floors was carried by the bulb (37.4 +/- 3.5 and 18.3 +/- 2.9% of weight exerted on the foot in the lateral and medial claw, respectively) and the wall zone (20.0 +/- 2.6 and 13.4 +/- 2.4% on lateral and medial claw, respectively). The weight and pressure distribution in cows kept on sections with rubber covered alleys but passing daily over the asphalt floor on their way to the milking parlor did not differ in any zones, except for lateral bulbs, compared with those exposed to slatted concrete alone. Still, the weight bearing of the sole zone in cows kept on rubber mats without access to asphalt was less than that of cows kept on concrete slatted floors (5.1 +/- 0.7 vs. 12.7 +/- 1.1% and 1.1 +/- 0.5 vs. 8.7 +/- 0.7% in lateral and medial claws, respectively). In cows kept on asphalt flooring without feed-stalls, most weight was exerted to the sole zone (36.2 +/- 2.9 and 22.2 +/- 1.8% in lateral and medial claws, respectively). Feed-stalls in combination with asphalt flooring yielded a decreased total contact area (30.1 +/- 1.2 cm(2)) compared with asphalt floors without feed-stalls (35.7 +/- 1.2 cm(2)). The largest total contact area was obtained on the asphalt floor without feed-stalls, resulting in a lower contact pressure (39.8 +/- 2.3 N/cm(2)) than in claws exposed to concrete (66.0 +/- 2.7 N/ cm(2)) or rubber mats (56.7 +/- 1.7 N/cm(2)). In conclusion, housing with abrasive floors resulted in claws with increased contact area at the sole surface and therefore, decreased contact pressure, but reduced the weight-bearing role of the strongest part of the claw capsule, the claw wall.