High Temperature Performance Of Asphalt Research Articles

Influence Mechanism of Epoxy Resin and Curing Agent on High-Temperature Performance of Asphalt

To deeply show the internal reasons for the effects of epoxy resin and curing agent on the high-temperature performance of asphalt, nine kinds of asphalt with different content of epoxy resin and curing agent were prepared. On the premise of ensuring that the softening point, penetration and ductility of epoxy asphalt no attenuation, the dynamic shear rheology test and Saybolt viscosity test were used to examine the rutting factor (G*/sin δ), complex shear modulus (G*), phase angle (δ), and viscosity of asphalt with different epoxy resin and curing agent contents. With the help of fluorescence microscopy, microscopic morphology was analyzed, and the micro-image was further analyzed quantitatively by using 3Dsurface and particle statistics. The results show that adding epoxy resin and curing agent into asphalt can significantly improve the rutting factor and complex shear modulus of asphalt and reduce the phase angle and the viscosity growth rate of asphalt changed from fast to slow. Fluorescence and 3Dsurface imaging results indicate when the epoxy resin and the curing agent are uniformly distributed and forms microflocculent structures, the epoxy resin can fully swell in asphalt, and the fluorescence intensity is uniform. The statistical analysis of particles shows that the improvement in high-temperature performance of asphalt by epoxy resin and curing agent results from the distribution of particle area above 26.7346 μm2. The high-temperature performance of epoxy asphalt is optimal when the content of epoxy resin and curing agent is 6 %.

Performance and optimization of castor beans-based bio-asphalt and European rock-asphalt modified asphalt binder

This study aims at investigating the composite modification effect of castor beans-based bio-asphalt and European rock asphalt on the properties of asphalt binders and optimizing the blending ratio of composite modified asphalt for specific properties by D-optimal mixture design (DMD). Penetration, softening point, ductility, rotary viscosity and dynamic shear rheometer (DSR) tests results revealed the addition of rock asphalt could compensate the adverse effect of bio-asphalt on the high-temperature performance of asphalt, and bio-asphalt could promote the swelling of rock asphalt by increasing complex modulus (G*) and decreased phase angle (δ). Fourier transform infrared spectroscopy (FTIR) results indicated that there no true chemical reaction occurred between bio-asphalt, rock asphalt and base asphalt. Additive bio-asphalt could effectively reduce the cost of asphalt binders. The optimal blending ratio of alternative AH-70 and AH-50 asphalt is obtained aiming at the requirement of penetration, softening point, ductility and viscosity by DMD: for AH-70, the optimal replacement ratio is 2.9% bio-asphalt, 16.7% rock asphalt, and 80.4% base asphalt; the optimal replacement ratio of AH-50 is 7.9% bio-asphalt, 6.3% rock asphalt, and 85.8% base asphalt. The application of DMD made the analysis of experimental data more intuitive and helped in composition optimization of bio-asphalt and rock-asphalt composite modified asphalt which meets specific properties, which provides a reference for the selection of other composite modified asphalt.

Utilization of wax residue as compatibilizer for asphalt with ground tire rubber/recycled polyethylene blends

Wax residue (WR) is a by-product of Fischer-tropsch synthesis (FTS), which is currently disposed as common solid waste and utilized with low value-added. Meanwhile, ground tire rubber (GTR) and recycled polyethylene (RPE) as low-cost modifiers for asphalt modification have been focused. This study attempts to evaluate the feasibility of utilization of WR as compatibilizer for asphalt modified with GTR/RPE. To that end, GTR, RPE and WR were mixed through a direct melt compounding in a co-rotating twin screw extruder, which were further used to modify asphalt. The effects of GTR/RPE ratio and WR were assessed by evaluating performance of the modified asphalt. The results indicated that GTR/RPE blends contribute to improving high-temperature performance of the modified asphalt. Decreasing ratio of RPE to GTR leads to the reduced high temperature performance but enhanced low temperature performance. The incorporation of WR impairs the high temperature performance of asphalt with GTR/RPE, but the resulting asphalt shows better high temperature performance than commercial SBS modified asphalt. The proper amount of WR improves the low temperature behavior of the modified asphalt. WR improves the fatigue performance of asphalt with GTR/RPE. More importantly, WR enhances storage stability and compatibility of asphalt with GTR/RPE. The degree of dispersion of the modifier is improved with the increase of WR, which verifies the enhancement of compatibility. These results demonstrated that WR is a good stabilizer for asphalt modified with GTR/RPE. Moreover, GTR/RPE/WR additive is effective for the reduction of energy consumption, CO2 emissions and cost in asphalt production.

High temperature performance of asphalt modified with Sasobit and Deurex

Warm Mix Asphalt (WMA) is a valued and effective technology to decrease asphalt binder’s viscosity in order to save energy and to reduce the release of carbon dioxide (CO2). Sasobit (an organic additive) is a widely used warm mix additive, which has been studied in several aspects by some researchers such as the increase of physical properties as well as the increase of rheological properties of asphalt binder. Deurex (natural sugar cane wax or free of paraffins), which is similar to the Sasobit, can be seen as a new warm mix additive. The study aims to assess the high temperature rheological properties and viscosity reduction of asphalt which is modified with the two additives: Sasobit and Deurex. During the study, Deurex was added into the base asphalt in same proportion as the Sasobit as 0%, 1%, 2% and 3%, so 16 different binders could be obtained. Above all, the study conducted the Rotational viscometer test (RV), which separately and together measured the two additives’ effects for the viscosity of the binders. The conventional tests results reveal that adding Deurex to the Sasobit can improve the cracking properties of binders as compared to the Sasobit at low temperature. And the viscometer test results reveal that both Sasobit and Deurex can reduce the viscosity and the Sasobit can be more effective than Deurex when the content of additive is low. Furthermore, the decrease of asphalt binders’ viscosities is more obvious at lower temperature. Then the study conducted the Dynamic shear rheometer (DSR) test including the Performance grade, frequency sweep and temperature sweep tests. G∗(complex shear modulus) and δ (phase angle) can be measured in the test, and the results reveal that the Sasobit and Deurex increase the value of G∗ and decrease the value of δ. Therefore, the rutting factor G∗/sinδ is improved. In other words, the high temperature properties of modified asphalt binders are increased, particularly the ability of resistance to deformation. The test also found that the 2%Deurex play a relatively big efficacy with Sasobit. Finally, the Fourier transform infrared spectroscopy (FTIR) test was used to analyze the modification mechanism of the modified binders. All in all, the Sasobit and Deurex modified asphalt do have a good performance in high temperature. And 2%Deurex with 2% or 3%Sasobit is recommend.

回收碳粉改性沥青制备及其技术性能

打复印机回收碳粉的积累已经成为一个潜在的环境风险，必须回收利用。采用回收碳粉作为沥青改性剂，按不同掺量制备改性沥青。通过对同掺量下不同温度、剪切速率、剪切时间的改性沥青进行针入度、软化点、延度等室内试验，得出最佳室内制备工艺参数。试验结果表明：1) 回收碳粉改性沥青室内最佳工艺参数为剪切温度150℃~160℃，剪切时间30 min，剪切速率3500~4500 r/min；2) 回收碳粉能改善基质沥青的高温性能，增强抵抗变形的能力，并降低感温性，但低温性能有小幅度降低；3) 为保证在提高沥青高温性能的同时而减小对低温性能的影响，建议回收碳粉添加量不应超过10%。 Accumulation of waste powder of printer has become a potential environmental risk; it must be recycled. In carbon powder as an asphalt modifier, different doses of content preparing modified asphalt are used. The influence of different processing technique parameters and different modifier sorts on modified asphalt’s properties is studied, thus to direct modified asphalt production. Theoretical research combined experimental methods is carried out. The result shows that: 1) carbon powder modified asphalt’s best cutting temperature is from 150˚C to 160˚C, cutting time is 30 minutes, and cutting rate is 3500 - 4500 r/min; 2) recycled carbon powder can improve the high temperature performance of asphalt, thus enhance the ability of resistance to deformation, and reduce the temperature sensitivity, but the low temperature performance of asphalt has fallen slightly; 3) as the guarantee to improve the high temperature performance of asphalt and at the same time reduce the effect on the properties of low temperature, the recycled carbon powder added amount shall not exceed 10%.

Performance Characteristics of Silane Silica Modified Asphalt

At present there are many kinds of fillers and modifier used for modified asphalt, but the effect of modifier differs in thousands of ways; most of them can increase the high temperature performance of asphalt, but the modified effect of low-temperature crack resistance, water stability, and antifatigue performance is different. Aiming at the subsistent problems, this paper innovatively puts forward the idea of taking the silane silica (nanosilica modified with silane coupling agent) as filler to develop one kind of modified asphalt concrete which has excellent comprehensive performance based on the idea of enhance the whole performance of asphalt concrete and interface consolidation strength between aggregate and asphalt at the same time. The best mixing amount of silane silica and the production process of modified asphalt were conducted by contrasting the test date as penetration, viscosity, and softening point; the aging of asphalt and modified asphalt was analyzed by TG test, the superiority of silane silica modified asphalt is more clearly understandable by chemical analysis results. Meanwhile it is proved that silane silica has positive effect to improve the mixture of high and low temperature performance, water stability, and aging resistance through a series of road performance tests.

Studies of High Temperature Performance of Asphalt Based on Repeated Creep and Recovery Test

The high temperature characteristic of asphalt is closely associated with the performance of asphalt pavement. In this paper, repeated creep and recovery experiments are conducted for 2 kinds of base asphalt and 4 different kinds of modified asphalt. According to the pavement situation of China, two temperature levels (i.e., 60 °C and 70 °C) and two stress levels (120Pa and 300Pa) are selected in the test. We observe improved performance of the modified asphalt than the base asphalt, owing to the fact that the modified asphalt is a linear viscoelastic material, with special delayed elastic deformation and recovery properties. The high temperature performance of the modified asphalt is vulnerable to changes in temperature, stress and loads. We further perform rutting test and find that result is highly correlated with the viscous composition of creep stiffness (Gv), with the correlation coefficient being 0.9838 and 0.9813, respectively, indicating that Gv can well judge the merits of high temperature performance of different asphalt.

The Influence of Nano-Montmorillonite on High Temperature Performance of Asphalt

In order to increase the life of bituminous pavement, quality of bitumen needs to be enhanced and modified. Different dosages of nano-organic montmorillonite (nano-OMMT) were used as modifier for base asphalt. The effect of the contents of nano-OMMT on high temperature performance of asphalt was investigated. Experimental results showed that with the increase of nano-OMMT of content, the high temperature performance of asphalt was gradually improved. And the high temperature sensitivity of asphalt is also enhanced. The nano-OMMT modified asphalt is expected to possess superior rutting resistance to the base asphalt.

The Study of High Temperature Performance of Asphalt Modified by Trinidad Lake Asphalt

In this paper, the relationships between the high temperature performance of two different kinds of asphalt modified by Trinidad Lake Asphalt and the different amounts of the Trinidad Lake Asphalt were investigated,The results showed that: Trinidad Lake Asphalt could increase the-softening points of the modified asphalts, reduce penetration and enhance the viscosity. However, the variation trends of each index in two modified asphalts were different; among the high-temperature dynamic rheological performance indexes, complex modulus became larger, phase angle became smaller, and rut factor increased. These results indicated that Trinidad Lake Asphalt can effectively improve the high temperature stability and the modified asphalt had higher resistance stability to rutting. The complex modulus of modified asphalt with different amount of the Trinidad Lake Asphalt had the similar variation trends with frequency, The asphalt modified by Trinidad Lake Asphalt should be delayed elastic body, and its sensitivity to the frequency had no obvious improvement.

Optimization of technical measures for improving high-temperature performance of asphalt–rubber mixture

Asphalt–rubber pavements often become damaged in high-temperature regions and appear rutted or wavy, and experience slippage. To improve the high-temperature performance of the asphalt–rubber mixture, technical measurements, such as, the optimal adjustment of gradation, technique of composite modification, and control of compaction were investigated. An optimal adjustment of aggregate gradation based on stone matrix asphalt improves the high-temperature stability of the asphalt–rubber mixture significantly. Through composite modification, the effect of asphalt–rubber modification was enhanced, and the dynamic stability and relative deformation indices of the asphalt–rubber mixture were improved significantly. Furthermore, compaction parameters had a significant influence on the high-temperature stability of the asphalt–rubber mixture. The rolling times for compacting the asphalt–rubber mixture should be controlled to within 18–20 round-trips at a molding temperature at 180 °C; if the rolling time is a 12 round-trip, the compaction temperature of the asphalt–rubber mixture should be controlled between 180 and 190 °C.

Influence of Rubber Powder Content on High-Temperature Performance of TOR Rubber Asphalt

Six kinds of TOR rubber asphalts with 5%-30% rubber powder contents of were selected to carry out conventional high-temperature tests and dynamic shear rheological tests to obtain some parameters reflecting the high-temperature performance of asphalt binders, such as softening point, dynamic viscosity at 60°C, rutting factor (G*/sinδ) at 60°C and critical temperature of rutting factor (TG*/sinδ). The results show that the changing tendency of two rheological parameters of TOR rubber asphalts, G*/sinδ at 60°C and TG*/sinδ, is ascend in first and descend at last with the increase of rubber powder content proportion. The high-temperature performance of TOR rubber asphalt with the rubber powder content about 20% is the best. Softening point and dynamic viscosity at 60°C, as two conventional high-temperature parameters of asphalt binders, can describe the high-temperature performance of TOR rubber asphalt with the rubber powder content below 20%, but cannot evaluate accurately the high-temperature performance of TOR rubber asphalt with the rubber powder content above 20%, because TOR rubber asphalt has formed a network structure at this moment.

Research on Perfomance of Vulcanized Eucommia Ulmoides Gum Blending with Asphalt

Asphalt modifier is traditionally obtained from petroleum byproduct, which has a high price and can not regenerate. This makes the traditional asphalt modifier not able to satisfy the economic requirement of increasing highway construction. Therefore, it is necessary to find a new modifier, which is economically efficient and also has good engineering performance. This paper introduces a recent development on the vulcanizing process of eucommia ulmoides gum（EUG） and the physical mechanics function of vulcanized gum, and explains its desirable engineering characteristic as well as its engineering application foreground. In this study, based on the characteristic of rubber-plastic unified material chart, vulcanized EUG is blended with asphalt binder as a modifier. The analysis of infrared spectrum and scan electricity mirror and asphalt basic index experiment are made. The result indicates that vulcanized EUG can improve both low temperature performance and high temperature performance of asphalt, which means that it is a feasible and desired choice for asphalt modifying.

The Resarch for Asphalt Modified with Phosphorus Trichloride/SBS

Abstract The high-temperature storage stability of styrene-butadiene-styrene triblock copolymer (SBS) modified asphalt can be improved to some extent with the addition of phosphorus trichloride. The dynamic mechanical and physical properties of SBS-modified asphalts before and after adding phosphorus trichloride were studied respectively. The addition of phosphorus trichloride to asphalt improved the high-temperature performance of asphalt and reduced its temperature susceptibility to a great extent with unfavourable effect on low-temperature ductility. The addition of SBS to phosphorus trichloride modified asphalt increased the low-temperature ductility, viscosity of asphalt and improved its high-temperature performance further. Different SBS structures influenced the rheological and physical properties of asphalt before and after adding phosphorous trichloride.

Asphalt Modified with Nonmetals Separated from Pulverized Waste Printed Circuit Boards

Nonmetals separated from pulverized waste printed circuit boards (PCBs) were reused as a new modifier to improve the performance of asphalt. The classical and rheological properties of unmodified asphalt and non-metal-modified asphalt (NMA) were determined. Specifically, the influence of nonmetals content and particle size on these properties has been studied. When the nonmetals content was 25 wt% and the particle size group was 0.07-0.09 mm, the NMA had a viscosity of 1225 cP at 135 degrees C, a penetration of 53.7 dmm at 15 degrees C, a ring and ball softening point of 54 degrees C, a ductility of 43.5 cm at 15 degrees C, a G*/sin delta of 3995.27 Pa at 60 degrees C, and an upper limit temperature (G*/sin delta = 1 kPa) of 69.4 degrees C, all of which showed that the high temperature performance of asphalt was improved significantly. Therefore, this study gives a fundamental understanding of NMA and represents a novel attempt to deal with the fast increasing quantities of nonmetals from waste PCBs, which is significant from an environmental and economic standpoint.