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Heavy traffic reduces the strength characteristics of asphalt concrete, causes peeling on the pavement. Crushed stone-mastic asphalt concrete is designed for the device of the upper layers of the coating on roads with high traffic intensity. The use of polymerasfalt concrete on a modified binder can lead to an improvement in the physical and mechanical characteristics of asphalt concrete and increase its re-sistance to climatic influences. The main aspects of improving the quality of crushed stone-mastic as-phalt concrete (SMA) due to the use of a binder modified with sevilen (SEVA) are discussed. The effect of bitumen containing sevilen with 22 and 29 % vinyl acetate groups on the properties of crushed stone-mastic asphalt concrete has been investigated. Analysis of the results showes that the use of modified binders has a positive effect on the entire complex of physical and mechanical parameters of polymer asphalt concrete. An increase in the strength of the samples at 20 and 50 °C, a decrease in this indicator at 0 °C is established. The indicators of water and heat resistance, shear resistance and crack resistance are also improved, which should have a positive effect on the durability of the road surface. Rational concentrations of polymer additives and the amount of vinyl acetate groups in its composition have been established. The adhesion of the binder to the mineral part of the asphalt con-crete mixture is estimated. The index of sensitivity to temperature differences of asphalt concrete sam-ples is considered due to the fact that asphalt concrete is a material that reacts to temperature fluctua-tions in the external environment. The analysis of the results of the tests carried out demonstrates that the use of modified binders has a positive effect on the entire complex of physical and mechanical pa-rameters of polymer asphalt concrete.

Asphalt mastic is known to play an important role when determining the fatigue performance of asphalt mixture. Time sweep test using a Dynamic Shear Rheometer can be used. However, a long testing t...

A laboratory study was done on three bitumen of penetration grade 50/70 from three sources and three corresponding mastics made using these three base bitumen and one filler – Limestone. The tests ...

Rutting is an important problem in Russia today. One of the ways to improve the properties of asphalt concrete mixtures and reduce wear on road surfaces is to modify the binder with polymer additives. The aim of the work was to test the selected compositions of MMAC mixtures containing bitumen modified with the addition of sevilene and rubber for rutting resistance, which make it possible to predict the formation of plastic rut. It was revealed that when using sevilen in its composition, with an increase in the concentration of vinyl acetate, the depth of the track increases in comparison with the industrial polymer-bitumen binder. It is shown that with the introduction of a complex additive based on sevilen and rubber into the binder composition, its rutting decreases and the service life of the road surface increases, which indicates a high elasticity of the complex-modified binder. In this work, the calculation of the service life of the coating before the formation of a critical rut requiring repair of the coating is carried out. It was found that in terms of the slope of the rutting curve and the proportional depth of the rut, the compositions with sevilene and rubber are not inferior to traditional industrial PBB.

Utilisation of recycled construction and demolition waste (CDW) within pavements is a beneficial substitution technique towards sustainability. Following this approach, this research investigates t...

Mastic asphalt is a type of pavement material that has good fluidity and is self-levelling at construction temperature for the bridge deck. There are highly accurate methods and indexes for evaluating fluidity and high-temperature deformation resistance for mastic asphalt-design and construction-control systems. The fatigue cracking is one of the main failure forms of bridge deck pavement. Therefore, the method used to evaluate the fatigue properties of pavement materials is also essential. The anti-deformation capability of the mastic asphalt must be increased, that results in poor fatigue performance and consequent failure of the bridge deck pavement to avoid the rutting of bridge deck pavement. In this study, a simple method is put forward for evaluating mastic asphalt fatigue performance. Impact toughness is defined as the area under the load-displacement curve of a three-point bending beam specimen under impact load to evaluate the fatigue performance of mastic asphalt. The four-point bending beam fatigue test is used to verify the rationality of the impact toughness test method. The results showed that there is a good correlation between the impacts toughness index of mastic asphalt produced under different mixing conditions and the accumulative dissipative energy and fatigue life demonstrated by the four-point bending beam test. Therefore, to evaluate the fatigue performance of mastic asphalt by impact toughness test. Fatigue performance and rut resistance are two ways to evaluate road performance of asphalt mixtures, but they are mutually restrictive. The results show that impact toughness and dynamic stability are inversely correlated. As the impact toughness increases, dynamic stability decreases. Therefore, balancing the fatigue performance and high-temperature rutting resistance of mastic asphalt in the design and quality control is very important.

High-quality and durable asphalt pavement ensures safe and comfortable traffic, optimal logistics costs, territory attractiveness to construction investments, and industrial development. With constantly increasing loads on road pavements, it is necessary to improve the asphalt quality by introducing additives into the mixture, design methodology, scientific justification for the selection and preparation of raw materials. The paper proposes the development algorithm of crushed-stone and mastic asphalt modified by the new stabilizing additive, which consists of 90 % of cellulose fiber from waste paper, 5 % rubber powder, and 5 % bitumen. The optimal particle size distribution of the mineral component in the crushed-stone and mastic asphalt is considered to be 73% of crushed stone with fractions of 15–20, 10–15 and 5–10 mm, 16 % of dolomite sand from crushing screenings, 11 % of mineral powder, 0.4 % of stabilizing additive and 5.5 % of bitumen. The compressive strength of the developed composition is 2.3 times higher than that meeting the requirements of GOST 31015–2002 for the climatic zone II. The research results are confirmed by pilot-industrial tests in constructing the road pavement in Tyumen.

The present study was carried out to evaluate effects of regular sized hydrated lime (RHL) and Nano-sized hydrated lime (NHL) on rutting resistance performance of asphalt mastic related to stiffnes...

The long-term effects of SBS-modified binders and rejuvenators on the properties of high-RAP mixtures, especially the cracking resistance, have not been resolved. Therefore, this paper evaluates th...

Reclaimed asphalt pavement (RAP) arises from the demolition of asphalt road layers. The Optimal Recycling of Reclaimed Asphalt Pavements Project concerns the cold recycling of 100 % RAP without binder addition in base and subbase layers of low-traffic roads. In this context, a test program was performed with Rhine region materials to evaluate the impact of the mastic coating of untreated RAP. A source of reclaimed asphalts with 4.4 % of bitumen is tested before (RAP) and after binder extraction (RAP-BE) and then is compared to an unbound granular material (UGM) with a similar particle-size distribution. Repeated load triaxial tests were conducted at several frequencies to study the permanent and resilient behaviors. The results show that the RAP before binder extraction and the UGM present similar permanent behaviors, while the aggregates without binder reveal low strains. Concerning the resilient phase, the RAP and the RAP-BE show similar levels of strains, but the resilient moduli of the UGM are significantly lower than those of the RAP. From the experimental results, the nonlinear elastic Boyce model was fitted and brings out a highly anisotropic mechanical behavior of the RAP. Finally, the RAP shows a frequency-sensitive viscous behavior because of the bitumen in the mastic, while the effect of the frequency is negligible for the RAP-BE.

Viscoelastic characterisation of asphalt mixtures is an important component for modelling and performance prediction of flexible pavements. In this study, using spherical indentation testing for measuring the viscoelastic properties of asphalt is explored. Indentation testing may provide an interesting alternative to existing experimental techniques, as it is capable of characterising small material volumes. Thus, it may become a useful tool for the characterisation of thin asphalt layers and for the measurement of binder phase properties in-situ in asphalt mixtures. Spherical indentation tests are performed on two mastic asphalt (MA) mixtures, prepared with different mastic types. The shear relaxation moduli obtained from the indentation tests are compared with the ones measured with seismic and SuperPave Indirect Tensile (IDT) tests. A new statistical analysis methodology is proposed for viscoelastic characterisation of the mastic phase with the indentation tests performed on MA mixtures. The accuracy and sensitivity of the developed method are examined. QC 20211110

The present study evaluates effects of regular sized hydrated lime (RHL) and nano sized hydrated lime (NHL) on fatigue and bond strength of asphalt mastic. The asphalt mastics were produced in the laboratory using AC-30 binder with different combinations of basalt–RHL, and basalt–NHL fillers. The dosages of RHL and NHL were selected as 0%, 5%, 10%, 15%, and 20% by weight of asphalt binder, and the percentage of basalt filler was adjusted accordingly. Filler to binder (F/B) ratio was selected as 0.8 (by mass ratio) for all mastic sample preparation. The fatigue damage behavior (number of cycles to fatigue damage/failure) of asphalt mastic was evaluated using a linear amplitude sweep (LAS) test. Further, the interfacial bond strengths of asphalt mastic and aggregate samples were evaluated using the bitumen bond strength (BBS) test. Overall test results indicate that mineralogy, surface area, and interaction properties of RHL and NHL fillers have a significant effect on fatigue, bond strength, and moisture damage performance of asphalt mastic. The results from the LAS test showed that NHL filler predominantly enhanced the fatigue life of asphalt mastic as compared with RHL filler. BBS test results imply that the contribution of NHL filler is significant over RHL filler in improving the bond strength and moisture damage resistance of asphalt mastic. Overall asphalt mastic with 20% NHL filler had better fatigue life, bond strength, and moisture damage performance over mastic with other percentages of RHL or NHL fillers.

In this study, a modified asphalt based trackless tack coat material (TTCM) was prepared by adding styrene–butadiene–styrene, uintaite mastic asphalt, anti-rut asphalt master batch and Sasobit wax to 50# base asphalt (penetration grade). Mehcnaimcal properties like track resistance, shear strength, pull-off strength, and rheological as well as temperature performance of TTCM were studied. Results showed that the adhesive bond strength of TTCM was greater than cohesive forces within hot mix asphalt layer, track-free time was less than 1 min and it did not deteriorate upon contact with tyres at 60 °C. Furthermore, bonding mechanism of TTCM was proposed. Surface morphology and functional group characterization were achieved using SEM and FTIR, respectively. The present approach utilizing routine raw materials and ease of operation for the synthesis of novel modified asphalt based TTCM with enhanced performance can be effectively applied on industrial level production for practical applications.

This paper presents the self-healing results of asphalt mastic by the action of calcium-alginate capsules containing sunflower oil. The morphological, physical, thermal and mechanical properties of the capsules have been evaluated. Additionally, the effect of the capsule oil content and the healing temperature on the self-healing properties of asphalt mastic have been evaluated. It was proven that the capsules can resist the mixing and compaction processes and break inside the asphalt mastic due to mechanical loads, releasing the oil. Healing levels in the asphalt mastic samples with capsules were greater than samples without capsules. The healing level depended on the oil content of the capsules and temperature.

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.

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.

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...

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.

Mastic asphalt (MA) has been recognized as one of the most deformation-resistant and thus durable materials for bridge pavement. The performance properties of MA are highly dependent on the physical and rheological properties of the binder applied in the MA mixture. To modify the binder properties to obtain the expected performance of the MA mixture, Trinidad Lake Asphalt (TLA) is often applied. In this study, the TLA-modified binders to be used in mastic asphalt bridge pavement systems were evaluated to develop the optimum material combination using conventional and performance-related testing. Physical and rheological tests were carried out on TLA-modified binders with the different modifier content in the range of 10–50% on a weight basis. The tests revealed that the TLA modifier addition to the 35/50 base bitumen should be close to the value of 20%. Higher concentrations of TLA may make the binder very stiff and could induce low-temperature cracks in mastic asphalt.

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.

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.

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.

This study evaluated the fatigue performance of Styrene–Butadiene–Styrene (SBS) modified mastic asphalt mixtures used for bridge deck pavements. The effect of the type and content of newly developed SBS modifiers was investigated using typical binder tests. Four-point bending beam fatigue and indirect strength tests were conducted to examine fatigue and fracture behaviors of the SBS modified mastic asphalt mixtures. The SBS modifiers without C C double bonds enhanced the mechanical properties of the mastic asphalt binder and mixtures: lower stiffness after short- and long-term oxidation, significantly greater fatigue resistance at a higher strain level, and higher crack development resistance.

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.

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.

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.

The temperatures of pavement of servicing road reach 60 degrees Celsius in summertime. The stiffness of asphalt mixture is often measured by resilient modulus test or uniaxial compression test at normal temperature. But, measurement method at high temperature is not defined. And shape of specimen also influences measured values in such condition. In this research, the measurement of asphalt mixture at high temperature using uniaxial compression test is investigated. As a result, the measurement method and the shape of specimen are proposed and the stiffness characteristics of dense grade asphalt concrete, porous asphalt concrete, stone matrix asphalt concrete and mastic asphalt concrete are measured.

Temperature reduction of mastic asphalt (MA) mixtures can decrease costs and energy demand, as well as health-relevant emissions of particulate matter throughout the life cycle. A state-of-the-art method for temperature reduction is wax modification of the bituminous binder to reduce its viscosity. In this paper, the results of an extensive study. On mechanical performance, particulate matter emission and life-cycle analysis of temperature-reduced MA are presented. Therefore, a reference MA is compared to three temperature-reduced MAs: a state-of-the-art reduction by modification with amide wax (AW) and an alternative method of substituting crushed aggregates by rounded ones. For both methods, a temperature reduction of 30°C can be realised. In addition, a combination of both methods, wax modification and use of rounded aggregates, is investigated. For this combination a reduction of 50°C is possible. The results show that the resistance to permanent deformation is not decreased by using rounded aggregates and that it can be doubled by employing AW regardless of the aggregate shape. Resistance to low-temperature cracking is not affected by any of the studied methods for temperature reduction. Emission analysis reveals that more than 80% of the emitted particulates are below 2.5 µm a.d. (aerodynamic diameter). From a life-cycle perspective, a main benefit of temperature-reduced MAs is the significant decrease in particulate emissions by up to 80% in case of 50°C temperature reduction. Also, up to 20% of production process energy can be saved when the mixing temperature is reduced by 50°C. Application of a wax additive reduces process energy costs, but increases the total life-cycle costs. Based on the considered scenarios, the application of additives is controversial and the substitution of crushed aggregates by rounded aggregates seems to be beneficial.

Two different types of mineral fillers were mixed with two different grades of asphalt binders to investigate the effect of filler surface on the rheological properties with respect to their long-term aging characteristics. The rheological properties of unaged and aged asphalt-filler systems were studied as a function of aging time. Different modeling techniques were evaluated to construct the aging master curves to investigate the effect of fillers on the long-term aging characteristics of asphalt binders. The results indicate that the generalized power law model can be successfully used to characterize the aging time–temperature effects for asphalt mastics. The results also indicate that the Williams–Landel–Ferry (WLF) model can be used to develop the aging shift factors. In addition, the aging master curves of asphalt-filler systems were also developed to characterize the effect of fillers on the aging kinetic curves of asphalt binders. Furthermore, the results show that stiffness effect of asphalt-fil...

Crumb rubber modified asphalts (CRMA) mastic is an important part of CRMA mixture, however, the testing condition restricts its research in China. In order to study the effect of fillers on the high temperature properties of CRMA mastic, mineral powder, and cement were selected as the fillers and the CRMA mastic were prepared using different filler-to-binder ratios (F/B). The study evaluated the high temperature properties of different CRMA mastic by zero shear viscosity and fail temperature. Test results indicate that with the increase of F/B, fail temperature and zero shear viscosity in the creep recovery phase of CRMA mastic are gradually larger, and the high temperature properties of CRMA mastic has been significantly improved. Compared with the same F/B, the fail temperature and zero shear viscosity in the creep recovery phase of CRMA mastic, which using mineral powder as filler is larger than the one, which using cement as filler. Mineral powder is better than cement in the aspect of improving the high temperature properties of CRMA mastic. The result of this paper can provide a theoretical basis for improving the road performance of CRMA mastic.

The annual road building objects-load increase causes a strengthening requirement for used materials and construction. Therefore, it is necessary to find new compositions satisfying all modern requirements that are nonpolluting and cost effective. One of the main tasks is creating new types of sealing materials; this task can be implemented by using raw materials changing the product damp proof ability. So currently the state-of-the-art sealing materials of the new generation: polymer-bitumen mastics have the lead. The presentational work is focused on developing efficient hydraulic insulating mastic based on a nanomodified polymer-bitumen binder with fine-dispersion filler. Such mastic can be used in constructional engineering in automobile and airport road surface building, in expansion joints making, as a water seal for water supply pipes, and for other artificial structures and is an efficient compound for road composites.

The mechanical performance of asphalt mixture is highly dependent on the viscoelastic property of asphalt mastic, which is usually composed of asphalt binder and fine aggregates with sizes smaller than 2.36 mm. The viscoelastic property of asphalt mastic was analyzed and tested by uniaxial creep tests in the laboratory and fitted using Burgers model in this paper. Three asphalt mastics, dense graded mixture (DGM), stone mastic asphalt (SMA), and open graded friction course (OGFC), were applied and tested at -10 °C and 15 °C separately. Test results show that Burgers can well present the viscoelastic property of asphalt mastic. The viscoelastic property of asphalt mastic was characterized in this paper. The viscoelastic property of asphalt mastic is significantly influenced by its constituents and testing temperature.

The main objective of this study is to predict and interpret the stiffness ratios of sand mastics to asphalt binder at a broad range of temperatures. Both fine and coarse sand mastics were studied using discrete element (DE) method. Twelve samples were prepared in this study, including six fine sand mastics, and six coarse sand mastics. The six fine sand mastics were prepared by blending fine sands (diameters ranging from 0.075mm to 0.3mm) with the 42.15%, 52.4%, 61.8%, 70.8%, 80.3%, 90% of asphalt binders by volume. The six coarse sand mastics were fabricated by blending coarse sands (diameters ranging from 0.3mm to 2.36mm) with the 42.15%, 52.4%, 61.8%, 70.8%, 80.3%, 90% of asphalt binders by volume. The previously developed DE model was employed to consider the interactions in the digital specimens of the 12 sand mastics. The DE simulations were conducted by varying the asphalt binder stiffness values with the constant stiffness value of sands. The stiffness ratios of mineral aggregates to asphalt binders were varied from 1 to 1×1010. The outputs of the simulations were the predicted stiffness of the sand mastics. Finally, the outputs were analyzed to evaluate the impacts of asphalt binder stiffness values and volumetric fractions on the stiffness values of the asphalt sand mastics. Through this study, it was observed that 1) the DE simulation results agreed well with the micromechanical models; 2) the stiffness ratios of sand mastics to asphalt binders ranged from 1 to 1.18×109 for fine sand mastics and from 1 to 3.76×108 for coarse sand mastics.