In order to study the application of gyratory compaction molding method in emulsified asphalt cold recycled mixture and optimize the relevant technical parameters, the study was carried out according to splitting stre...In order to study the application of gyratory compaction molding method in emulsified asphalt cold recycled mixture and optimize the relevant technical parameters, the study was carried out according to splitting strength, stability and water stability test;the design of the experiment involved changing gyration number, emulsified asphalt and water content, molded specimen temperature and other factors to analyze the volume parameters, mechanical properties and water stability. The results show that both the maximum dry density and dry and wet splitting strength ratio(DWSSR) of emulsified asphalt cold reclaimed mixture are improved by the rotary compacting method, while the porosity and the optimal dosage of water are reduced. Furthermore, with the increase of compaction times, the porosity and splitting strength index both change exponentially. DWSSR and porosity are consistent with quadratic functions. The use of gyratory compaction for 70 times at 25 °C and the optimum dosage of emulsified asphalt can be determined based on the splitting strength ratio. The high-temperature stability and water damage resistance of the pavement can be improved by the use of rotary compacting method effectively, and the early strength and road performance are higher than the regulatory requirements.展开更多
Under repeated train-induced loads, cement and emulsified asphalt mortar(CA mortar) as a viscoelastic material has a time-dependent deformation, part of which is irreversible. This could lead to debonding between the ...Under repeated train-induced loads, cement and emulsified asphalt mortar(CA mortar) as a viscoelastic material has a time-dependent deformation, part of which is irreversible. This could lead to debonding between the mortar layer and the track slab. Based on the theory of viscoelasticity and the analytical method of the time hardening law(THL), the viscoelastic deformation behavior of CA mortar was studied. Using ABAQUS, we established a solid model of China railway track system(CRTS) Ⅰ prefabricated slab track, with CA mortar at different initial Young’s moduli under cyclic loading corresponding to the influence of actual train loads. The results reveal that the fitted parameters of the THL for CA mortar are suitable for describing its viscoelastic deformation. As the initial Young’s modulus increases, the strain difference before and after cyclic loading gradually decreases, and the displacement difference increases from 0.2 mm to 0.6 mm. The deformation mainly occurs at the end of a mortar layer with longitudinal distribution of about 2.5 times the fasteners’ spacing. It follows that the viscoelastic performance of CA mortar is one of the most important reasons that cause debonding underneath the track slab. Therefore, we suggest that the adverse effects of viscoelastic behavior of CA mortar should be considered when researching such deformation and damage.展开更多
In recent years,with the improvement of the requirements of road performance,modified emulsified asphalts with better performance has gradually replaced the emulsified asphalt and become the primary material for road ...In recent years,with the improvement of the requirements of road performance,modified emulsified asphalts with better performance has gradually replaced the emulsified asphalt and become the primary material for road maintenance.This paper introduces the modified emulsified asphalt materials commonly used in pavement maintenance projects,definitions and modified mechanisms of polymerized styrene butadiene rubber(SBR)modified emulsified asphalt,styrene butadiene styrene block polymer(SBS)modified emulsified asphalt and waterborne epoxy resin(WER)modified emulsified asphalt are summarized.The analysis focused on comparing the effects of modifiers,preparation process,auxiliary additives,and other factors on the performance of modified emulsified asphalt.In this paper,it is considered that the greatest impact on the performance of emulsified asphalt is the modifier,emulsifier mainly affects the speed of breaking the emulsion,stabilizers on the basic performance of emulsified asphalt evaporative residue is small;and when the modifier is distributed in the asphalt in a network,the dosage at this time is the recommended optimum dosage.Finally,this study recommends that in the future,the polymer-asphalt compatibility can be improved through composite modification,chemical grafting and other methods to continue to develop broader applicability and better performance of modified emulsified asphalt.展开更多
Emulsified asphalt/polymer is one of the most applied composite materials in pavement industry,which is also defined as emulsified polymer modified asphalt(PMA).PMA exhibits the transition behavior of multi-physical s...Emulsified asphalt/polymer is one of the most applied composite materials in pavement industry,which is also defined as emulsified polymer modified asphalt(PMA).PMA exhibits the transition behavior of multi-physical states with corresponding viscoelastic characteristics,and studies had focused on the application performances of PMA.However,few had paid proper attention to the morphological compatibility of PMA,which dominated its viscoelastic transition and failure probability directly.This paper aims to establish a graylevel co-occurrence matrix(GLCM)model with morphology theory to quantitatively describe the morphological compatibility of PMA,combined with fluorescent microscope.Furthermore,waterborne polymers with self-crosslinking characteristics are introduced to modify emulsified asphalt,including acrylate,epoxy resin,polyurethane and liquid rubber.The rheological characteristics of PMA are comprehensively evaluated through performance grade,steady shear viscosity,and master curve tests.Finally,a statistical analysis is conducted to establish the relationship between morphological compatibility and rheological characteristics of PMA.The approach introduced in this study could be a promising method to investigate the multi-physical transition behaviors and morphological compatibility of emulsified asphalt/polymer composite material.展开更多
In this work,C@Fe_(3)O_(4) composites were prepared through a typical template method with emulsified asphalt as carbon source,ammonium ferric citrate as transition metal oxide precursor,and NaCl as template.As an ano...In this work,C@Fe_(3)O_(4) composites were prepared through a typical template method with emulsified asphalt as carbon source,ammonium ferric citrate as transition metal oxide precursor,and NaCl as template.As an anode for lithium-ion batteries,the optimized C@Fe_(3)O_(4)-1:2 composite exhibits an excellent reversible capacity of 856.6 mA·h·g^(-1)after 100 cycles at 0.1A·g^(-1)and a high capacity of 531.1mA·h·g^(-1)after 300 cycles at 1 A·g^(-1),much better than those of bulk carbon/Fe_(3)O_(4) prepared without NaCl.Such remarkable cycling performance mainly benefits from its well-designed structure:Fe_(3)O_(4) nanoparticles generated from ammonium ferric citrate during pyrolysis are homogenously encapsulated in graphitized and in-plane porous carbon nanocages derived from petroleum asphalt.The carbon nanocages not only improve the conductivity of Fe_(3)O_(4),but also suppress the volume expansion of FesO4 effectively during the charge discharge cycle,thus delivering a robust electrochemical stability.This work realizes the high value-added utilization of low-cost petroleum asphalt,and can be extended to application of other transition-metal oxides-based anodes.展开更多
Emulsified asphalt is the primary material for preventive maintenance and cold-mix paving,but its low cohesive strength and poor mechanical properties limit its wide application,even with polymer modification.In this ...Emulsified asphalt is the primary material for preventive maintenance and cold-mix paving,but its low cohesive strength and poor mechanical properties limit its wide application,even with polymer modification.In this study,Styrene-Butadiene Rubber(SBR)emulsified asphalt was modified with nano-cellulose materials,namely nano paper-cellulose(NPC)and wood-derived nano-cellulose(WDC),to improve its properties.A novel preparation method of nano-cellulose solution was developed,including blending,ultrasonic stirring,and centrifugal treatment.Four types of nano-cellulose solution(0.5%NPC,0.5%,1.0%,and 1.5%WDC by weight of water)were selected.The microscopy analysis indicated that 0.5%WDC emulsion had a smaller particle size than 1.5%WDC emulsion.The rheology test indicated that WDC modified residue improved rutting resistance with the increased solution dosage due to the cross-linking effect,but its creep-and-recovery performance was worse than that of SBR emulsion residue.The NPC modified binder had a higher rutting factor than WDC modified binder at the same dosage after short-term aging.In addition,1.0%WDC could be regarded as the optimal dosage in terms of fatigue and low-temperature performance.Furthermore,Fourier Transform Infrared Spectroscopy(FTIR)results showed that 0.5%NPC modified residue performed better in long-term aging resistance compared with 0.5%WDC modified asphalt.展开更多
The slurry scaling with cationic emulsified asphalt, which is a new technique in highway construction, is rapidly extended at home and abroad. The technique should apply an excellent slow set cationic cmulsincr. Now, ...The slurry scaling with cationic emulsified asphalt, which is a new technique in highway construction, is rapidly extended at home and abroad. The technique should apply an excellent slow set cationic cmulsincr. Now, slow set emulsificrs are ligninamines which are synthesized by trimethylamine-epichlorohydrin route. Owing to high price and unstable quality, the extending of slurry sealing technique is affected seriously. We prepare the ligninaminc by a novel synthetic method. By the novel method, the cost of production is reduced by more than 30%, and the products have stable quality, high emulsifying function and broad adaptability for various asphalts. The novel synthetic method uses soda lignin, secondary amines and inexpensive aminating assistants as raw materials. The technological process of the method may use either one or two-step process, and the technological condition arc uncomplicated and easy to master.展开更多
This paper describes the research achievement in manufacturing the cation asphalt emulsifier for micro-surfacing using an eco-friendly material which is rich in resources and low in production cost. This material is a...This paper describes the research achievement in manufacturing the cation asphalt emulsifier for micro-surfacing using an eco-friendly material which is rich in resources and low in production cost. This material is alkali lignin which used to be treated as wastes during the processing of wood and the cation asphalt emulsifier for micro-surfacing made from this is sulfomethylated lignin quaternary ammonium salt cation emulsifier. This emulsifier is synthesized through sulfomethylation and quaternary-ammonization of alkali lignin so as to allow the emulsifier molecule to contain two hydrophilic groups inside it. Newly developed cation emulsifier is widely used for micro-surfacing for its high emulsifying power and slowly-disintegrable and fast-setting ability.展开更多
Fluidized catalytic cracking slurry oil-in-water emulsion(FCCSE)was prepared by using interfacial complexes generation method that was simple and versatile.The critical factors influencing the sample preparation proce...Fluidized catalytic cracking slurry oil-in-water emulsion(FCCSE)was prepared by using interfacial complexes generation method that was simple and versatile.The critical factors influencing the sample preparation process were optimized,for instance,the optimum value of the mixed hydrophile-lipophile balance of compound emulsifier was 11.36,the content of compound emulsifier was 4 wt%,the emulsification temperature was 75C,the agitation speed was 200 rpm,and the emulsification time was 30e45 min.The performance as a drilling fluid additive was also investigated with respect to rheological properties,filtration loss and inhibition of FCCSE.Experimental results showed that FCCSE was favorable to inhibiting clay expansion and dispersion and reducing fluid loss.Furthermore,it had good compatibility with other additives and did not affect the rheological properties of drilling fluids.FCCSE exhibited better performance than the available emulsified asphalt.It has a promising application as anti-collapse agent in petroleum and natural gas drilling.展开更多
基金Projects(51708048,51704040)supported by the National Natural Science Foundation of ChinaProject(17C0050)supported by the Scientific Research Project of Hunan Provincial Department of Education for General Scholars,China+1 种基金Project(kfj160103)supported by the Open Fund of State Engineering Laboratory of Highway Maintenance Technology(Changsha University of Science&Technology),ChinaProject supported by the Open Fund of Guangxi Key Lab of Road Structure and Materials,China
文摘In order to study the application of gyratory compaction molding method in emulsified asphalt cold recycled mixture and optimize the relevant technical parameters, the study was carried out according to splitting strength, stability and water stability test;the design of the experiment involved changing gyration number, emulsified asphalt and water content, molded specimen temperature and other factors to analyze the volume parameters, mechanical properties and water stability. The results show that both the maximum dry density and dry and wet splitting strength ratio(DWSSR) of emulsified asphalt cold reclaimed mixture are improved by the rotary compacting method, while the porosity and the optimal dosage of water are reduced. Furthermore, with the increase of compaction times, the porosity and splitting strength index both change exponentially. DWSSR and porosity are consistent with quadratic functions. The use of gyratory compaction for 70 times at 25 °C and the optimum dosage of emulsified asphalt can be determined based on the splitting strength ratio. The high-temperature stability and water damage resistance of the pavement can be improved by the use of rotary compacting method effectively, and the early strength and road performance are higher than the regulatory requirements.
基金Project supported by the National Natural Science Foundation of China(No.51578472)。
文摘Under repeated train-induced loads, cement and emulsified asphalt mortar(CA mortar) as a viscoelastic material has a time-dependent deformation, part of which is irreversible. This could lead to debonding between the mortar layer and the track slab. Based on the theory of viscoelasticity and the analytical method of the time hardening law(THL), the viscoelastic deformation behavior of CA mortar was studied. Using ABAQUS, we established a solid model of China railway track system(CRTS) Ⅰ prefabricated slab track, with CA mortar at different initial Young’s moduli under cyclic loading corresponding to the influence of actual train loads. The results reveal that the fitted parameters of the THL for CA mortar are suitable for describing its viscoelastic deformation. As the initial Young’s modulus increases, the strain difference before and after cyclic loading gradually decreases, and the displacement difference increases from 0.2 mm to 0.6 mm. The deformation mainly occurs at the end of a mortar layer with longitudinal distribution of about 2.5 times the fasteners’ spacing. It follows that the viscoelastic performance of CA mortar is one of the most important reasons that cause debonding underneath the track slab. Therefore, we suggest that the adverse effects of viscoelastic behavior of CA mortar should be considered when researching such deformation and damage.
基金The authors acknowledge the financial support from National Natural Science Foundation of China(No.51968006).
文摘In recent years,with the improvement of the requirements of road performance,modified emulsified asphalts with better performance has gradually replaced the emulsified asphalt and become the primary material for road maintenance.This paper introduces the modified emulsified asphalt materials commonly used in pavement maintenance projects,definitions and modified mechanisms of polymerized styrene butadiene rubber(SBR)modified emulsified asphalt,styrene butadiene styrene block polymer(SBS)modified emulsified asphalt and waterborne epoxy resin(WER)modified emulsified asphalt are summarized.The analysis focused on comparing the effects of modifiers,preparation process,auxiliary additives,and other factors on the performance of modified emulsified asphalt.In this paper,it is considered that the greatest impact on the performance of emulsified asphalt is the modifier,emulsifier mainly affects the speed of breaking the emulsion,stabilizers on the basic performance of emulsified asphalt evaporative residue is small;and when the modifier is distributed in the asphalt in a network,the dosage at this time is the recommended optimum dosage.Finally,this study recommends that in the future,the polymer-asphalt compatibility can be improved through composite modification,chemical grafting and other methods to continue to develop broader applicability and better performance of modified emulsified asphalt.
基金supported by the National Natural Science Foundation of China under the project number of 51861145402.
文摘Emulsified asphalt/polymer is one of the most applied composite materials in pavement industry,which is also defined as emulsified polymer modified asphalt(PMA).PMA exhibits the transition behavior of multi-physical states with corresponding viscoelastic characteristics,and studies had focused on the application performances of PMA.However,few had paid proper attention to the morphological compatibility of PMA,which dominated its viscoelastic transition and failure probability directly.This paper aims to establish a graylevel co-occurrence matrix(GLCM)model with morphology theory to quantitatively describe the morphological compatibility of PMA,combined with fluorescent microscope.Furthermore,waterborne polymers with self-crosslinking characteristics are introduced to modify emulsified asphalt,including acrylate,epoxy resin,polyurethane and liquid rubber.The rheological characteristics of PMA are comprehensively evaluated through performance grade,steady shear viscosity,and master curve tests.Finally,a statistical analysis is conducted to establish the relationship between morphological compatibility and rheological characteristics of PMA.The approach introduced in this study could be a promising method to investigate the multi-physical transition behaviors and morphological compatibility of emulsified asphalt/polymer composite material.
基金supported by the National Natural Science Foundation of China(51402030)the Chongqing Special Key Project of Technological Innovation and Application Development(CSTB2022TIAD-KPX0031)+2 种基金the Team Building Project for Graduate Tutors in Chongqing(JDDSTD2022006)the Research and Innovation Program for Graduate Students in Chongqing(2023S0090)the National Innovation and Entrepreneurship Projects for College Students(202310618015).
文摘In this work,C@Fe_(3)O_(4) composites were prepared through a typical template method with emulsified asphalt as carbon source,ammonium ferric citrate as transition metal oxide precursor,and NaCl as template.As an anode for lithium-ion batteries,the optimized C@Fe_(3)O_(4)-1:2 composite exhibits an excellent reversible capacity of 856.6 mA·h·g^(-1)after 100 cycles at 0.1A·g^(-1)and a high capacity of 531.1mA·h·g^(-1)after 300 cycles at 1 A·g^(-1),much better than those of bulk carbon/Fe_(3)O_(4) prepared without NaCl.Such remarkable cycling performance mainly benefits from its well-designed structure:Fe_(3)O_(4) nanoparticles generated from ammonium ferric citrate during pyrolysis are homogenously encapsulated in graphitized and in-plane porous carbon nanocages derived from petroleum asphalt.The carbon nanocages not only improve the conductivity of Fe_(3)O_(4),but also suppress the volume expansion of FesO4 effectively during the charge discharge cycle,thus delivering a robust electrochemical stability.This work realizes the high value-added utilization of low-cost petroleum asphalt,and can be extended to application of other transition-metal oxides-based anodes.
基金This study was supported by the National Natural Science Foundation of China(Grant No.51778478).
文摘Emulsified asphalt is the primary material for preventive maintenance and cold-mix paving,but its low cohesive strength and poor mechanical properties limit its wide application,even with polymer modification.In this study,Styrene-Butadiene Rubber(SBR)emulsified asphalt was modified with nano-cellulose materials,namely nano paper-cellulose(NPC)and wood-derived nano-cellulose(WDC),to improve its properties.A novel preparation method of nano-cellulose solution was developed,including blending,ultrasonic stirring,and centrifugal treatment.Four types of nano-cellulose solution(0.5%NPC,0.5%,1.0%,and 1.5%WDC by weight of water)were selected.The microscopy analysis indicated that 0.5%WDC emulsion had a smaller particle size than 1.5%WDC emulsion.The rheology test indicated that WDC modified residue improved rutting resistance with the increased solution dosage due to the cross-linking effect,but its creep-and-recovery performance was worse than that of SBR emulsion residue.The NPC modified binder had a higher rutting factor than WDC modified binder at the same dosage after short-term aging.In addition,1.0%WDC could be regarded as the optimal dosage in terms of fatigue and low-temperature performance.Furthermore,Fourier Transform Infrared Spectroscopy(FTIR)results showed that 0.5%NPC modified residue performed better in long-term aging resistance compared with 0.5%WDC modified asphalt.
文摘The slurry scaling with cationic emulsified asphalt, which is a new technique in highway construction, is rapidly extended at home and abroad. The technique should apply an excellent slow set cationic cmulsincr. Now, slow set emulsificrs are ligninamines which are synthesized by trimethylamine-epichlorohydrin route. Owing to high price and unstable quality, the extending of slurry sealing technique is affected seriously. We prepare the ligninaminc by a novel synthetic method. By the novel method, the cost of production is reduced by more than 30%, and the products have stable quality, high emulsifying function and broad adaptability for various asphalts. The novel synthetic method uses soda lignin, secondary amines and inexpensive aminating assistants as raw materials. The technological process of the method may use either one or two-step process, and the technological condition arc uncomplicated and easy to master.
文摘This paper describes the research achievement in manufacturing the cation asphalt emulsifier for micro-surfacing using an eco-friendly material which is rich in resources and low in production cost. This material is alkali lignin which used to be treated as wastes during the processing of wood and the cation asphalt emulsifier for micro-surfacing made from this is sulfomethylated lignin quaternary ammonium salt cation emulsifier. This emulsifier is synthesized through sulfomethylation and quaternary-ammonization of alkali lignin so as to allow the emulsifier molecule to contain two hydrophilic groups inside it. Newly developed cation emulsifier is widely used for micro-surfacing for its high emulsifying power and slowly-disintegrable and fast-setting ability.
基金the financial support of Geological Survey project of Ministry of Land and Resources(NO.12120113097400).
文摘Fluidized catalytic cracking slurry oil-in-water emulsion(FCCSE)was prepared by using interfacial complexes generation method that was simple and versatile.The critical factors influencing the sample preparation process were optimized,for instance,the optimum value of the mixed hydrophile-lipophile balance of compound emulsifier was 11.36,the content of compound emulsifier was 4 wt%,the emulsification temperature was 75C,the agitation speed was 200 rpm,and the emulsification time was 30e45 min.The performance as a drilling fluid additive was also investigated with respect to rheological properties,filtration loss and inhibition of FCCSE.Experimental results showed that FCCSE was favorable to inhibiting clay expansion and dispersion and reducing fluid loss.Furthermore,it had good compatibility with other additives and did not affect the rheological properties of drilling fluids.FCCSE exhibited better performance than the available emulsified asphalt.It has a promising application as anti-collapse agent in petroleum and natural gas drilling.
