scholarly journals Performance-Based Asphalt Mix and Pavement Design

2013 ◽  
Vol 2 (1) ◽  
pp. 21-38 ◽  
Author(s):  
Ronald Blab
Keyword(s):  
Low Temperature ◽  
Deformation Behavior ◽  
Elevated Temperatures ◽  
Permanent Deformation ◽  
Flexible Pavements ◽  
Test Methods ◽  
Service Performance ◽  
Triaxial Tests ◽  
Uniaxial Tensile ◽  
Induced Stresses

Abstract Prediction and optimization of in-service performance of road pavements during their live time is one of the main objectives of pavement research these days. For flexible pavements the key performance characteristics are fatigue and low-temperature, as well as permanent deformation behavior at elevated temperatures. The problem facing pavement designers is the need to fully characterize the complex thermo-rheological properties of hot mix asphalt (HMA) over a wide temperature range on the one hand, while on the other also providing a realistic simulation of the traffic- and climate-induced stresses to which pavements are exposed over their design lives of 20 to 30 years. Where heavily trafficked roads are concerned, there is therefore an urgent need for more comprehensive test methods combined with better numerical forecast procedures to improve the economics and extend the service lives of flexible pavements under repair and maintenance programs. This papers therefore focus on performance-based test methods on the basis of existing European standards that address effective mechanical characteristics of bituminous materials and which may be introduced into national requirements within the framework of European HMA specifications. These test methods comprise low temperature tests, i.e. the tensile stress restrained specimen test or the uniaxial tensile strength test, stiffness and fatigue tests, i.e. the four point bending beam test or the uniaxial tension compression test, as well as methods to determine permanent deformation behavior by means of dynamic triaxial tests. These tests are used for the performance-based mix design and subsequently implemented in numerical pavement models for a reliable prediction of in-service performance, which, in combination with performance-based tests, enables a simulation of load-induced stresses and mechanogenic effects on the road structure and thus improved forecasts of the in-service performance of flexible pavements over their entire service lives.

Investigation of Tensile Deformation Behavior of 7075-T6 at Elevated Temperatures

2012 ◽  
Vol 152-154 ◽  
pp. 358-363 ◽  
Author(s):  
Guo Wei Zhou ◽  
Da Yong Li ◽  
Ying Hong Peng
Keyword(s):  
Deformation Behavior ◽  
Elevated Temperatures ◽  
Tensile Deformation ◽  
Total Elongation ◽  
Yield Function ◽  
Uniaxial Tensile ◽  
Tensile Deformation Behavior ◽  
Ductile Mode ◽  
Different Temperatures ◽  
Increasing Temperature

Uniaxial tensile deformation behavior of 7075-T6 under three different strain rates (0.001, 0.004 and 0.03s-1) and five different temperatures (50, 100, 150, 200 and 250°C) is studied. The total elongation in uniaxial tension increases with increasing temperature in range of 50-200°C and decreases with increasing strain rate. But it drops sharply at 250°C. SEM observations of the fracture surface interpret the change of total elongation and show the fracture tends to transit from brittle mode to ductile mode with increasing temperature. The constitutive model and yield function related with temperature are established based on the experiment results.

scholarly journals Assessment of Thermal Stresses in Asphalt Mixtures at Low Temperatures Using the Tensile Creep Test and the Bending Beam Creep Test

2019 ◽  
Author(s):  
Marek Pszczola ◽  
Mariusz Jaczewski ◽  
Cezary Szydlowski
Keyword(s):  
Thermal Stress ◽  
Low Temperature ◽  
Creep Test ◽  
Thermal Stresses ◽  
Test Methods ◽  
Asphalt Mixtures ◽  
Tensile Creep ◽  
Rheological Parameters ◽  
Uniaxial Tensile ◽  
Failure Temperature

Thermal stresses belong to the leading factors that influence low-temperature cracking behavior of asphalt pavements. During winter, when temperature drops to significantly low values, tensile thermal stresses develop as a result of pavement contraction. Creep test methods can be suitable for the assessment of low-temperature properties of asphalt mixtures. To evaluate the influence of creep test methods on the obtained low-temperature properties of asphalt mixtures, three point bending and uniaxial tensile creep tests were applied and the master curves of stiffness modulus were analyzed. On the basis of creep test results, rheological parameters describing elastic and viscous properties of the asphalt mixtures were determined. Thermal stresses were calculated and compared to tensile strength of the material to obtain the failure temperature of the analyzed asphalt mixtures. It was noted that lower strain values of creep curves were obtained for the Tensile Creep Test (TCT) than for the Bending Beam Creep Test (BBCT), especially at lower temperatures. Results of thermal stress calculations indicated that higher reliability was obtained for the viscoelastic Monismith method based on the TCT results than for the simple quasi-elastic solution of Hills and Brien. The highest agreement with the TSRST results was also obtained for the Monismith method based on the TCT results. No clear relationships were noted between the predicted failure temperature and different methods of thermal stress calculations.

scholarly journals Assessment of Thermal Stresses in Asphalt Mixtures at Low Temperatures Using the Tensile Creep Test and the Bending Beam Creep Test

2019 ◽  
Vol 9 (5) ◽  
pp. 846 ◽  
Author(s):  
Marek Pszczola ◽  
Mariusz Jaczewski ◽  
Cezary Szydlowski
Keyword(s):  
Thermal Stress ◽  
Low Temperature ◽  
Creep Test ◽  
Thermal Stresses ◽  
Test Methods ◽  
Asphalt Mixtures ◽  
Tensile Creep ◽  
Rheological Parameters ◽  
Uniaxial Tensile ◽  
Failure Temperature

Thermal stresses are leading factors that influence low-temperature cracking behavior of asphalt pavements. During winter, when the temperature drops to significantly low values, tensile thermal stresses develop as a result of pavement contraction. Creep test methods can be suitable for the assessment of low-temperature properties of asphalt mixtures. To evaluate the influence of creep test methods on the obtained low-temperature properties of asphalt mixtures, three point bending and uniaxial tensile creep tests were applied and the master curves of stiffness modulus were analyzed. On the basis of creep test results, rheological parameters describing elastic and viscous properties of the asphalt mixtures were determined. Thermal stresses were calculated and compared to the tensile strength of the material to obtain the failure temperature of the analyzed asphalt mixtures. It was noted that lower strain values of creep curves were obtained for the Tensile Creep Test (TCT) than for the Bending Beam Creep Test (BBCT), especially at lower temperatures. Results of thermal stress calculations indicated that higher reliability was obtained for the viscoelastic Monismith method based on the TCT results than for the simple quasi-elastic solution of Hills and Brien. The highest agreement with the TSRST results was also obtained for the Monismith method based on the TCT results. No clear relationships were noted between the predicted failure temperature and different methods of thermal stress calculations.

Effect of aggregate gradation on permanent deformation behavior of a warm mix asphalt

2016 ◽  
Vol 58 (7-8) ◽  
pp. 678-688 ◽  
Author(s):  
Ebrahim Sangsefidi ◽  
Ali Mansourkhaki ◽  
Hasan Ziari
Keyword(s):  
Deformation Behavior ◽  
Permanent Deformation ◽  
Warm Mix Asphalt ◽  
Aggregate Gradation

The Application of X-Ray Diffraction at Elevated Temperatures to Study the Mechanism of Formation of Sodium Tripolyphosphate

1961 ◽  
Vol 5 ◽  
pp. 276-284
Author(s):  
E. L. Moore ◽  
J. S. Metcalf
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Amorphous Phase ◽  
Elevated Temperatures ◽  
Sodium Tripolyphosphate ◽  
X Ray Diffraction ◽  
Mechanism Of Formation ◽  
X Ray ◽  
Temperature Form ◽  
High Temperature Form

AbstractHigh-temperature X-ray diffraction techniques were employed to study the condensation reactions which occur when sodium orthophosphates are heated to 380°C. Crystalline Na4P2O7 and an amorphous phase were formed first from an equimolar mixture of Na2HPO4·NaH2PO4 and Na2HPO4 at temperatures above 150°C. Further heating resulted in the formation of Na5P3O10-I (high-temperature form) at the expense of the crystalline Na4P4O7 and amorphous phase. Crystalline Na5P3O10-II (low-temperature form) appears after Na5P3O10-I.Conditions which affect the yield of crystalline Na4P2O7 and amorphous phase as intermediates and their effect on the yield of Na5P3O10 are also presented.

scholarly journals Evaluation of Properties and Micro-Characteristics of Waste Polyurethane/Styrene-Butadiene-Styrene Composite Modified Asphalt

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2249
Author(s):  
Bei Chen ◽  
Fuqiang Dong ◽  
Xin Yu ◽  
Changjiang Zheng
Keyword(s):  
Low Temperature ◽  
Performance Test ◽  
Permanent Deformation ◽  
Modified Asphalt ◽  
Basic Performance ◽  
Styrene Butadiene Styrene ◽  
Styrene Butadiene ◽  
Sbs Modified Asphalt ◽  
And Storage ◽  
Butadiene Styrene

In order to solve the problems caused by asphalt diseases and prolong the life cycle of asphalt pavement, many studies on the properties of modified asphalt have been conducted, especially polyurethane (PU) modified asphalt. This study is to replace part of the styrene-butadiene-styrene (SBS) modifier with waste polyurethane (WP), for preparing WP/SBS composite modified asphalt, as well as exploring its properties and microstructure. On this basis, this paper studied the basic performance of WP/SBS composite modified asphalt with a conventional performance test, to analyze the high- and low-temperature rheological properties, permanent deformation resistance and storage stability of WP/SBS composite modified asphalt by dynamic shear rheometer (DSR) and bending beam rheometer (BBR) tests. The microstructure of WP/SBS composite modified asphalt was also observed by fluorescence microscope (FM) and Fourier transform infrared spectroscopy (FTIR), as well as the reaction between WP and asphalt. According to the results of this study, WP can replace SBS as a modifier to prepare WP/SBS composite modified asphalt with good low-temperature resistance, whose high-temperature performance will be lower than that of SBS modified asphalt. After comprehensive consideration, 4% SBS content and 15% WPU content (4 S/15 W) are determined as the suitable types of WPU/SBS composite modified asphalt.

scholarly journals Analysis of Mechanical Properties and Mechanism of Natural Rubber Waterstop after Aging in Low-Temperature Environment

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2119
Author(s):  
Lin Yu ◽  
Shiman Liu ◽  
Weiwei Yang ◽  
Mengying Liu
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Energy Dispersive Spectrometry ◽  
Permanent Deformation ◽  
Test Chamber ◽  
Accelerate Aging ◽  
Aging Mechanism ◽  
Temperature Environment ◽  
Freezing Test ◽  
Temperature Water

In order to elucidate the aging performance and aging mechanism of a rubber waterstop in low-temperature environments, the rubber waterstops were placed in the freezing test chamber to accelerate aging, and then we tested its tensile strength, elongation, tear strength, compression permanent deformation and hardness at different times. Additionally, the damaged specimens were tested by scanning electron microscope, Fourier transform infrared spectroscopy and energy dispersive spectrometry. The results showed that with the growth of aging time, the mechanical properties of the rubber waterstop are reduced. At the same time, many protrusions appeared on the surface of the rubber waterstop, the C element gradually decreased, and the O element gradually increased. During the period of 72–90 days, the content of the C element in the low-temperature air environment significantly decreased compared with that in low-temperature water, while the content of O element increased significantly.

Permanent Deformation Behavior of Naturally Occurring Bituminous Sands

2008 ◽  
Vol 2059 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Joseph Anochie-Boateng ◽  
Erol Tutumluer ◽  
Samuel H. Carpenter
Keyword(s):  
Deformation Behavior ◽  
Permanent Deformation ◽  
Naturally Occurring

Study on Constitutive Modeling for Large Deformation Behavior of Polyethylene Considering Strain Rate Effect

2013 ◽  
Author(s):  
Sijia Zhong ◽  
Jianfeng Shi ◽  
Jinyang Zheng
Keyword(s):  
Strain Rate ◽  
Large Deformation ◽  
Constitutive Modeling ◽  
Deformation Behavior ◽  
True Strain ◽  
True Stress ◽  
Uniaxial Tensile ◽  
Pipeline System ◽  
Composite Effect ◽  
Time Deformation

Polyethylene (PE) pipes have been applied in transportation of key energy medium such as natural gas in the past decades. The mechanical property of PE is of great importance for better design and safer application of PE pipeline system. The large deformation behavior is a key character of PE, not only for its significant strain rate sensitivity, but also for localized necking process after yielding. In this paper, a new constitutive modeling method was proposed to charaterize the rate-denpendent large deformation behavior of PE, in which the true stress is regarded as a function of true stain and true strain rate alone. Uniaxial tensile tests of PE were conducted under various cross-head speeds, and a digital camera was used to record the real-time deformation of specimens. By separating the composite effect into respective effect of local true strain and strain rate on the local true stress in the necking region, a phenomenological model for describing the rate-dependent deformation behavior under uniaxial tension was ealstablished. Model results were validated and found in good agreement with experimental data.

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