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Francesco Canestrari - One of the best experts on this subject based on the ideXlab platform.
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influence of different fillers and sbs modified bituminous blends on fatigue self healing and thixotropic performance of Mastics
Road Materials and Pavement Design, 2019Co-Authors: Giorgia Mazzoni, Amedeo Virgili, Francesco CanestrariAbstract:The prediction of asphalt pavement performance is closely linked to the behaviour of mastic, consisting of filler and bitumen, which can be modelled as viscoelastic material. The purpose of this study is to investigate the effect of different fillers and bituminous blends on mastic fatigue response, considering recoverable phenomena in viscoelastic materials (thixotropy and self-healing) that concurrently occur. Three fillers (limestone, basalt and Portland cement) and three aged polymer modified bitumen contents (0%, 45% and 100%) were blended with a virgin polymer modified bitumen obtaining nine Mastics characterised in terms of fatigue, self-healing and thixotropy using a Dynamic Shear Rheometer. Data obtained are analysed through a model previously adopted for polymer modified bitumens and Mastics, allowing the determination of the fatigue endurance limit. Results show that the presence of filler with increasing particle density and/or Rigden voids causes a higher mastic stiffness without a clear tren...
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fatigue self healing and thixotropy of bituminous Mastics including aged modified bitumens and different filler contents
Construction and Building Materials, 2017Co-Authors: Giorgia Mazzoni, Fabrizio Cardone, Arianna Stimilli, Francesco CanestrariAbstract:Abstract Bituminous mastic is a self-healing viscoelastic material. Recoverable phenomena, such as thixotropy and self-healing capability, are recognised as an important resource for the development of sound road pavements. The experimental investigation described in this paper and carried out through a Dynamic Shear Rheometer (DSR) provides a comparison among Mastics blended with different percentages of aged polymer modified bitumen, new virgin polymer modified bitumen and filler in terms of fatigue, self-healing and thixotropy. Data analysis is based on a model adopted in previous studies for polymer modified bitumens in order to calculate the fatigue endurance limit. Results show that the presence of increasing percentages of filler causes detrimental effects on mastic fatigue performance which can be offset by the addition of a certain amount of aged polymer modified bitumen. In fact, regardless of the filler content considered, a percentage of aged polymer modified bitumen (up to 45%) added to Mastics enhances the fatigue endurance limit suggesting significant benefits when dealing with sustainable recycled mixtures containing Reclaimed Asphalt (RA) aggregates.
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self healing capability and thixotropy of bituminous Mastics
International Journal of Fatigue, 2016Co-Authors: Giorgia Mazzoni, Arianna Stimilli, Francesco CanestrariAbstract:Abstract Fatigue resistance of bituminous materials is related to time-dependent phenomena, such as damage accumulation, hardening, viscoelasticity, thixotropy and healing. In bituminous mixtures, damage related to fatigue processes mainly involves bitumen and its combination with filler (i.e. mastic). Currently, there is no consolidated method for the determination of the fatigue endurance limit of bitumens that takes into account also the above-mentioned phenomena, while limited work has been done on Mastics. To bridge this gap, the experimental investigation described in this paper provides a comparison between bitumens and corresponding Mastics in terms of fatigue, self-healing and thixotropy. Long term aged materials were also taken into consideration in order to identify potential detrimental effects on self-healing due to oxidation phenomena, evaluating the possible inclusion of Reclaimed Asphalt (RA) for the production of bituminous mixtures. The data analysis was based on an innovative test method which had previously been implemented for bitumens and was carried out using a Dynamic Shear Rheometer (DSR). Moreover, the influence of morphological properties of filler on filler-bitumen interactions was assessed by means of a Scanning Electron Microscope (SEM). Results show that the above-mentioned analysis method is also suitable for analysing bituminous Mastics and is able to identify the role of filler as well as the influence of ageing on the self-healing process of bituminous materials. The investigation confirms that a certain amount of aged bitumen added to a virgin bitumen/mastic is able to considerably improve the overall fatigue performance suggesting significant benefits when dealing with recycled mixtures including RA aggregates.
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influence of mineral fillers on the rheological response of polymer modified bitumens and Mastics
Journal of Traffic and Transportation Engineering, 2015Co-Authors: Fabrizio Cardone, F Frigio, Gilda Ferrotti, Francesco CanestrariAbstract:The rheological properties of the bituminous components (bitumen and bituminous mastic) within asphalt mixtures contribute significantly to the major distresses of flexible pavements (i.e. rutting, fatigue and low temperature cracking). Asphalt mixtures are usually composed of mastic-coated aggregates rather than pure bitumen-coated aggregates. The purpose of this study is to investigate the effects of mineral fillers on the rheological behaviour of several polymer-modified bitumens (PMBs) through laboratory mixing. A neat bitumen and two types of polymers (elastomeric and plastomeric) were used to produce PMBs, and two fillers with different minerals (limestone and basalt) were selected to obtain Mastics. The dynamic shear rheometer (DSR) and bending beam rheometer (BBR) were used to characterize the rheological properties of PMBs and Mastics. In particular, multiple stress creep recovery (MSCR) tests were performed to evaluate the rutting potential at high temperatures, whereas BBR tests were carried out to investigate the low temperature behaviour of these materials. BBR results for unmodified Mastics show that the increase of stiffness is similar regardless of the filler type, whereas results for polymer-modified Mastics indicate that the degree of stiffening depends on the combination of filler/polymer types. MSCR results show that adding filler leads to a reduced susceptibility of permanent deformation and an enhanced elastic response, depending on the combination of filler/polymer types. Overall results suggest that a physical–chemical interaction between the filler and bitumen occurs, and that the interaction level is highly dependent on the type of polymer modification.
Linlin Zou - One of the best experts on this subject based on the ideXlab platform.
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Effects of Filler⁻Bitumen Ratio and Mineral Filler Characteristics on the Low-Temperature Performance of Bitumen Mastics.
Materials (Basel Switzerland), 2018Co-Authors: Chuanfeng Zheng, Linlin ZouAbstract:This study analyzed the effects of the filler–bitumen interaction of the content and the meso powder characteristics of the mineral filler on the low-temperature performance of bitumen Mastics. Control strategies for the mineral filler content (filler–bitumen ratio (RFB)) were also determined. Panjin #90 bitumen and styrene–butadiene–styrene polymer-modified bitumen were used in the experiment. Four kinds of limestone powder were used, all of which satisfy the Chinese standard for powder particle size but exhibit different meso characteristics. Each kind of limestone powder was used to prepare bitumen mastic samples under five different RFBs. The meso voids in the unit mass (Vg) of the four kinds of mineral filler were tested on the basis of the principle of the Rigden void ratio. The fixed bitumen–free bitumen ratio in the bitumen mastic samples was determined using Vg, bitumen density, and RFB. The low-temperature cohesive strength of the bitumen Mastics was used as the control index for critical failure, whereas variation rates of bending creep stiffness at low temperature were used as the control index for fatigue failure. Results showed that the effects of the filler–bitumen interaction of the content and the meso characteristics of the mineral filler are significant and such effects are determined by the fixed bitumen–free bitumen ratio. The optimal fixed bitumen–free bitumen ratio in the bitumen Mastics under two low-temperature conditions (−30 °C and −10 °C) can be determined on the basis of the influence of the fixed bitumen–free bitumen ratio on the critical and the failure control indices. Moreover, RFB can be obtained through reverse calculation. The mineral filler content can therefore be precisely controlled, which is crucial for the rational use of mineral filler and for the improvement of the pavement performance of bitumen Mastics at low temperatures.
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effects of filler bitumen ratio and mineral filler characteristics on the low temperature performance of bitumen Mastics
Materials, 2018Co-Authors: Chuanfeng Zheng, Linlin ZouAbstract:This study analyzed the effects of the filler–bitumen interaction of the content and the meso powder characteristics of the mineral filler on the low-temperature performance of bitumen Mastics. Control strategies for the mineral filler content (filler–bitumen ratio (RFB)) were also determined. Panjin #90 bitumen and styrene–butadiene–styrene polymer-modified bitumen were used in the experiment. Four kinds of limestone powder were used, all of which satisfy the Chinese standard for powder particle size but exhibit different meso characteristics. Each kind of limestone powder was used to prepare bitumen mastic samples under five different RFBs. The meso voids in the unit mass (Vg) of the four kinds of mineral filler were tested on the basis of the principle of the Rigden void ratio. The fixed bitumen–free bitumen ratio in the bitumen mastic samples was determined using Vg, bitumen density, and RFB. The low-temperature cohesive strength of the bitumen Mastics was used as the control index for critical failure, whereas variation rates of bending creep stiffness at low temperature were used as the control index for fatigue failure. Results showed that the effects of the filler–bitumen interaction of the content and the meso characteristics of the mineral filler are significant and such effects are determined by the fixed bitumen–free bitumen ratio. The optimal fixed bitumen–free bitumen ratio in the bitumen Mastics under two low-temperature conditions (−30 °C and −10 °C) can be determined on the basis of the influence of the fixed bitumen–free bitumen ratio on the critical and the failure control indices. Moreover, RFB can be obtained through reverse calculation. The mineral filler content can therefore be precisely controlled, which is crucial for the rational use of mineral filler and for the improvement of the pavement performance of bitumen Mastics at low temperatures.
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Effects of Filler–Bitumen Ratio and Mineral Filler Characteristics on the Low-Temperature Performance of Bitumen Mastics
MDPI AG, 2018Co-Authors: Chuanfeng Zheng, Linlin ZouAbstract:This study analyzed the effects of the filler–bitumen interaction of the content and the meso powder characteristics of the mineral filler on the low-temperature performance of bitumen Mastics. Control strategies for the mineral filler content (filler–bitumen ratio (RFB)) were also determined. Panjin #90 bitumen and styrene–butadiene–styrene polymer-modified bitumen were used in the experiment. Four kinds of limestone powder were used, all of which satisfy the Chinese standard for powder particle size but exhibit different meso characteristics. Each kind of limestone powder was used to prepare bitumen mastic samples under five different RFBs. The meso voids in the unit mass (Vg) of the four kinds of mineral filler were tested on the basis of the principle of the Rigden void ratio. The fixed bitumen–free bitumen ratio in the bitumen mastic samples was determined using Vg, bitumen density, and RFB. The low-temperature cohesive strength of the bitumen Mastics was used as the control index for critical failure, whereas variation rates of bending creep stiffness at low temperature were used as the control index for fatigue failure. Results showed that the effects of the filler–bitumen interaction of the content and the meso characteristics of the mineral filler are significant and such effects are determined by the fixed bitumen–free bitumen ratio. The optimal fixed bitumen–free bitumen ratio in the bitumen Mastics under two low-temperature conditions (−30 °C and −10 °C) can be determined on the basis of the influence of the fixed bitumen–free bitumen ratio on the critical and the failure control indices. Moreover, RFB can be obtained through reverse calculation. The mineral filler content can therefore be precisely controlled, which is crucial for the rational use of mineral filler and for the improvement of the pavement performance of bitumen Mastics at low temperatures
Amir Modarres - One of the best experts on this subject based on the ideXlab platform.
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rheological and micro structural properties of bituminous Mastics containing chemical and wax warm additives
Construction and Building Materials, 2020Co-Authors: Saeed Mansoori, Amir ModarresAbstract:Abstract This research investigates the rheological and micro-structural characteristics of warm bitumens and bituminous Mastics containing a newly introduced chemical warm additive namely PAWMA® in comparison with Zycotherm® as a chemical additive and Sasobit® as a conventional wax additive. A 60/70 penetration grade bitumen was used as the reference binder in producing bitumen and mastic specimens. In preparing Mastics, limestone powder was added to the base bitumen as much as 60% by weight of bitumen. Three warm additive contents including 1, 3 and 5% for Sasobit, 0.2, 0.4, and 0.6% for PAWMA and 0.07, 0.10 and 0.15% for Zycotherm were added to Mastics, by weight of bitumen. Dynamic shear rheometer was perfromed on bitumens and Mastics after short and long-term aging processes. Also, the micro-structural properties were examined by atomic force microscopy (AFM) procedure. Based on the results, despite reducing the mixing temperature for warm Mastics, PAWMA® showed similar rheological and micro-structural properties to reference mastic. Sasobit® evidently changed the micro-structural properties in terms of topography roughness and the catana-phase structure while the use of different chemical additives percentages had no significant effects on nano-scale structure and AFM topography in comparison with reference mastic.
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rheological properties of bituminous Mastics containing chemical warm additive at medium temperatures and its relationship to warm mix asphalt fatigue behavior
Construction and Building Materials, 2019Co-Authors: Erisa Mirzaaghaeian, Amir ModarresAbstract:Abstract Previous research studies have proved the beneficial effects of Zycotherm on durability and moisture resistance of asphalt mixes. This study was performed to investigate the long-term performance of bituminous mastic and asphalt mix containing this additive in terms of fatigue behavior. The shear modulus and phase angle master curves of bituminous Mastics were developed at 20 °C using the results of frequency sweep DSR test at four temperatures of 13, 19, 25 and 31 °C. Then, the time sweep test was accomplished at 20 °C to examine the fatigue resistance of asphalt Mastics. The micro-structural behavior of Mastics were analyzed by atomic force microscopy test. The fatigue behavior of asphalt mixes designed with the same additive contents to Mastics were performed by indirect tensile fatigue test at 20 °C. The results of time sweep test demonstrated that the addition of Zycotherm up to 0.14% by weight of bitumen, had no detrimental effects on mastic fatigue resistance. It has been recognized from topographical analysis that the micro-structural behavior of Zycotherm containing mastic was highly similar to that of the base one. The variations were came from the difference in the mixing temperature during the preparation of conventional and Zycotherm containing mixtures.
M Garciamorales - One of the best experts on this subject based on the ideXlab platform.
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comparative assessment of the effect of micro and nano fillers on the microstructure and linear viscoelasticity of polyethylene bitumen Mastics
Construction and Building Materials, 2018Co-Authors: Claudia Roman, M GarciamoralesAbstract:Abstract In order to minimize permanent deformation in bitumen Mastics, the combined addition of traditional mineral filler and an organo-modified nano montmorillonite to different bitumen/polymer matrices was evaluated by dynamic shear/torsional tests and microscopy techniques. Individual addition of microfiller or nanoclay was also studied. The most remarkable result corresponded to a polymer modified mastic containing a mix of 40 wt% microfiller and 5 wt% nanoclay. As compared to a reference mastic with 45 wt% microfiller, the complex modulus at 65 °C increased more than two decades. The nanoclay has thereby shown high reinforcing potential if combined to standard mineral filler in bitumen Mastics.
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linear rheology of bituminous Mastics modified with various polyolefins a comparative study with their source binders
Materials and Structures, 2017Co-Authors: Claudia Roman, M GarciamoralesAbstract:The effect of bituminous Mastics on controlling the mechanical properties of the asphalt mixtures has been largely claimed. Theoretical models often fail to predict the rheological behavior of highly concentrated Mastics because of the various interaction forces involved. This situation becomes much more complex when dealing with biphasic polymer modified bitumens (PMBs). This investigation explores the influence of various recycled polyolefins (LDPE, HDPE and PP) on the linear rheological behavior of modified Mastics with a fixed filler/binder ratio of 65/35 (by weight). The filler was of siliceous-type, and all the PMBs contained 4 wt.% polymer. Oscillatory torsion/shear tests were carried out between 25 and 65 °C. It was found that the rheology of the HDPE-binder very much resembles its polymer-rich phase (PRP), which behaves like a concentrated polymer solution. In contrast, the LDPE-binder proved to have a bitumen-rich phase (BRP) still playing a large part in the PMB rheology. This result had a strong effect on the mastic rheology, as the filler shows more affinity for the bitumen. In consequence, the G′ plateau observed in the HDPE-mastic was similar to that found in its parent PMB. In contrast, if compared to its source binder, the LDPE-mastic manifested a rheological behavior better described by the filler acting as bridging points of PRP domains.
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linear and non linear viscoelastic behavior of sbs and ldpe modified bituminous Mastics
Construction and Building Materials, 2016Co-Authors: Claudia Roman, M Garciamorales, A A Cuadri, Ievgenii Liashenko, P PartalAbstract:Abstract This article compares bituminous Mastics modified by either the tri-block copolymer styrene-butadiene-styrene (SBS) or low density polyethylene (LDPE). Linear and non-linear oscillatory measurements were conducted at 25 and 55 °C, taken as representative of the medium and high in-service temperatures, respectively. For 3 wt.% polymer, distinct rheological responses were found. The LDPE-mastic showed enhanced linear complex shear modulus and elasticity at 55 °C. Conversely, if subjected to deformations beyond the linear viscoelasticity (LVE) limit, the SBS-mastic presented an improved capacity of complex modulus recovery, at 25 °C, when it returned to the LVE regime.
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rheological behaviour of polymer modified bituminous Mastics a comparative analysis between physical and chemical modification
Construction and Building Materials, 2012Co-Authors: Maksim E Shivokhin, M Garciamorales, P Partal, A A Cuadri, C GallegosAbstract:Abstract Lack of experimental data concerning the behaviour of Mastics and, above all, polymer-modified Mastics has been lately claimed. Thus, this work presents a comparative analysis between the effect that “physical” and “chemical” modification by polymers exert on Mastics prepared by blending modified binders with different contents of calcium carbonate (filler/bitumen ratios ranging from 65/35 to 80/20). Tri-block copolymer SBS and a “reactive” isocyanate-based prepolymer were used as modifying agents in the preparation of the binders. Linear viscoelasticy tests revealed that polymer type exerts, at high temperatures, a significant influence on the binder contribution to the overall rheological properties of the mastic.
Chengduo Qian - One of the best experts on this subject based on the ideXlab platform.
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Effects of filler particle size and ageing on the fatigue behaviour of bituminous Mastics
Construction and Building Materials, 2020Co-Authors: Baodong Xing, Weiyu Fan, Ling Han, Chuanyi Zhuang, Chengduo QianAbstract:Abstract Fatigue cracking is caused by repeated traffic loads and environmental conditions (temperature, ageing, etc.); it predominantly initiates within the mastic phase in the form of micro-cracks. In this sense, bituminous Mastics (comprised of a binder, filler and entrapped air) play a significant role in the anti-fatigue performance of asphalt mixes. In this paper, the effects of filler particle size and ageing on the fatigue behaviour of bituminous Mastics were evaluated. Prior to this, the rheological properties of the studied samples were evaluated using physical tests and frequency sweep tests. Moreover, the mastic morphology and filler distribution inside a bituminous matrix were characterized by Scan Electronic Microscope (SEM). The results revealed that ageing had a greater effect than filler particle size on the rheological behaviour of SBS-modified bituminous Mastics, especially for Mastics containing coarse filler particles. According to the ageing responses derived from log-log fatigue law plots, aged Mastics containing coarse filler particles had higher slopes (represented by coefficient B) and lower intercepts (identified by coefficient A) than un-aged Mastics. However, opposite fatigue behaviour was observed with fine filler granules, where coefficient B slightly decreased while coefficient A slightly increased after ageing. In addition, mastic morphology and filler dispersion inside a bituminous matrix were characterized by SEM, providing insight to possible relationships between morphological characteristics and fatigue performance.