Permanent deformation and complex modulus: two different characteristics from a unique test

2003 ◽  
Author(s):  
M. Neifar
Keyword(s):  
Complex Modulus ◽  
Permanent Deformation ◽  
Different Characteristics

scholarly journals Deformation Parameters and Fatigue of the Recycled Asphalt Mixtures

2015 ◽  
Vol 11 (2) ◽  
pp. 115-120
Author(s):  
Juraj Šrámek
Keyword(s):  
Complex Modulus ◽  
Permanent Deformation ◽  
Asphalt Mixtures ◽  
Test Method ◽  
Traffic Load ◽  
Bending Test ◽  
Recycled Asphalt ◽  
The Road ◽  
Dynamic Methods ◽  
Deformation Complex

Abstract The deformational properties of asphalt mixtures measured by dynamic methods and fatigue allow a design the road to suit the expected traffic load. Quality of mixtures is also expressed by the resistance to permanent deformation. Complex modulus of stiffness and fatigue can reliably characterize the proposed mixture of asphalt pavement. The complex modulus (E*) measurement of asphalt mixtures are carried out in laboratory of Department of Construction Management at University of Žilina by two-point bending test method on trapezoid-shaped samples. Today, the fatigue is verified on trapezoid-shaped samples and is assessed by proportional strain at 1 million cycles (ε6). The test equipment and software is used to evaluate fatigue and deformation characteristics.

scholarly journals Evaluation of Rheological Behavior, Resistance to Permanent Deformation, and Resistance to Fatigue of Asphalt Mixtures Modified with Nanoclay and SBS Polymer

2019 ◽  
Vol 9 (13) ◽  
pp. 2697
Author(s):  
Gabriela Ceccon Carlesso ◽  
Glicério Trichês ◽  
João Victor Staub de Melo ◽  
Matheus Felipe Marcon ◽  
Liseane Padilha Thives ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Rheological Behavior ◽  
Complex Modulus ◽  
Permanent Deformation ◽  
Asphalt Binder ◽  
Fatigue Cracking ◽  
Fatigue Tests ◽  
Asphalt Mixtures ◽  
The Road ◽  
Styrene Butadiene

Fatigue cracking and rutting are among the main distresses identified in flexible pavements. To reduce these problems and other distresses, modified asphalt mixtures have been designed and studied. In this regard, this paper presents the results of a study on rheological behavior and resistance to permanent deformation and to fatigue of four different asphalt mixtures: (1) with conventional asphalt binder (CAP 50/70); (2) with binder modified by nanoclay (3% NC); (3) with binder modified by styrene–butadiene–styrene polymer (SBS 60/85); and (4) with binder modified by nanoclay and SBS (3% NC + 2% SBS). For this analysis, the mixtures were evaluated based on complex modulus, permanent deformation tests, and fatigue tests (4PB, in the four-point bending apparatus), with the subsequent application of numerical simulations. The results obtained show a better rheological behavior related to greater resistance to permanent deformation for the mixture 3% NC + 2% SBS, which could represent an alternative for roads where a high resistance to rutting is required. Otherwise, on fatigue tests, higher resistance was observed for the SBS 60/85 mixture, followed by the 3% NC + 2% SBS mixture. Nevertheless, based on the results of the numerical simulations and considering the possibility of cost reduction for the use of the 3% NC + 2% SBS mixture, it is concluded that this modified material has potential to provide improvements to the road sector around the world, especially in Brazil.

Performance evaluation of crumb rubber and paraffin modified stone mastic asphalt

2016 ◽  
Vol 43 (5) ◽  
pp. 402-410 ◽  
Author(s):  
Baha Vural Kök ◽  
Mehmet Yilmaz ◽  
Mustafa Akpolat
Keyword(s):  
Fatigue Resistance ◽  
Permanent Deformation ◽  
Crumb Rubber ◽  
Moisture Susceptibility ◽  
Bituminous Mixtures ◽  
Mastic Asphalt ◽  
Stone Mastic Asphalt ◽  
Improved Performance ◽  
The Stability ◽  
Different Characteristics

Recently, crumb rubber (CR) obtained from waste tires and Fischer–Tropsch paraffin are mostly used in bitumen modification to improve the performance of bituminous mixtures. Each of these additives affects the different properties of mixtures. There are limited studies in the literature about the combined usage of additive in the same mixture to utilize the different characteristics. In this study, the stability, stiffness, fatigue resistance, permanent deformation resistance, and moisture susceptibility characteristics of the stone mastic asphalt prepared with the bitumen modified with CR and paraffin were examined and compared with the control mixture. It was determined that CR-modified mixtures showed significantly more elastic characteristics. The mixture in which the 10% CR and 3% paraffin were used together gave better results in terms of moisture susceptibility and fatigue resistance when compared with the control mixture. It was determined that the use of paraffin together with CR contributed to the improved performance, and was in accordance with the CR in terms of mechanical characteristics of stone mastic asphalt.

scholarly journals Evaluation of an Asphalt Mixture Containing a High Content of Reclaimed Asphalt and Different Crumb Rubber Modified Binders

2021 ◽  
Vol 29 (3) ◽  
pp. 22-30
Author(s):  
Majda Belhaj ◽  
Pavla Vacková ◽  
Jan Valentin
Keyword(s):  
Complex Modulus ◽  
Asphalt Pavement ◽  
Permanent Deformation ◽  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Reclaimed Asphalt ◽  
Modified Binders ◽  
Empirical Tests ◽  
And Performance ◽  
Deformation Complex

Abstract Recently, environmental concerns have become a primary driving force in most countries and industries dealing with natural resources. As a part of this category, asphalt pavement industry is trying to implement more green and sustainable features in its products, while maintaining the mechanical and performance-based properties of the resulting asphalt mixtures. Among potential recycled materials, vehicle tires and aged asphalt pavement have been demonstrated to show economic, ecological, and behavioral improvements in the mixtures. However, mixtures with a high content of reclaimed asphalt (RA) and crumb rubber present some limitations. Therefore, using another group of additives, i.e., a warm mix asphalt (WMA) additive, has been considered. The presented paper investigates the use of an elevated content of RA with different crumb rubber modified binders and (in some mixtures) a warm mix additive in an asphalt concrete (AC) binder mix. Regular empirical tests have been conducted and more advanced performance or functional characteristics, i.e., stiffness, thermal induced cracking, resistance to permanent deformation, complex modulus have been determined and evaluated. Selected results are presented in the paper.

scholarly journals Characteristics Buton Natural Asphalt-Rubber (BNA-R) on the Performance Improvement of Warm Mix Asphalt Using Natural Zeolite

2018 ◽  
Vol 34 ◽  
pp. 01032 ◽  
Author(s):  
Nurul Wahjuningsih ◽  
Sigit Pranowo Hadiwardoyo ◽  
R Jachrizal Sumabrata
Keyword(s):  
Natural Zeolite ◽  
Complex Modulus ◽  
Heavy Traffic ◽  
Permanent Deformation ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Warm Mix Asphalt ◽  
Traffic Load ◽  
Test Machine ◽  
Road Maintenance

The decrease in the ability of service of pavement can be caused by the durability factor in the pavement layer in receiving heavy traffic load and the temperature of the pavement. Permanent deformation is one of the criteria of failure of asphalt mixture. Performance assessment of the asphalt mixture can be observed from the rheological properties of asphalt binder. The use of BNA-R in this study is intended to modify the characteristics of bitumen penetration grade 60 / 70 used in warm mix asphalt. Warm mix asphalt with lower temperatures of mixing and compaction than conventional asphalt mixtures was chosen because it is more environmentally friendly. To reduce the temperature in this warm asphalt technology is achieved by using natural zeolite. Both of these materials are local materials that are widely available in Indonesia. The rheology of asphalt 60/70 modified with BNA-R indicates that the addition of BNA-R in the base asphalt increase the complex modulus value and decrease the phase angle value. These values were related to the performance of mixture in the permanent deformation criteria. Reducing the temperature of mixing and compaction should be balanced with modifying the asphalt binder used. Rutting due to permanent deformation can resulted in inconvenience to the passengers and can lead to high costs of road maintenance. To determine the permanent deformation of asphalt mix with material combinations was performed through the wheel tracking test machine with 3,780 cycles for 3 hours. The results shows that after test track over 7 thousand passes have seen permanent deformation characteristics of asphalt concrete mixture with a variation of the characteristics of bitumen.

Analysis of rheological properties of rubberized binders containing warm asphalt additives

2010 ◽  
Vol 37 (5) ◽  
pp. 763-771 ◽  
Author(s):  
Chandra K. Akisetty ◽  
Tejash Gandhi ◽  
Soon-Jae Lee ◽  
Serji N. Amirkhanian
Keyword(s):  
Complex Modulus ◽  
New Technology ◽  
Permanent Deformation ◽  
Crumb Rubber ◽  
Asphalt Binders ◽  
Asphalt Mixes ◽  
High Frequencies ◽  
Warm Mix Additives ◽  
Reduce Emissions ◽  
Different Sources

The main objective of using warm mix asphalt (WMA) is to reduce emissions and improve the workability by lowering the mixing and compaction temperatures of asphalt mixes through different mechanisms. Since warm asphalt is a relatively new technology, not much research has been conducted on various mix compositions. While some of the concerns about WMA have been addressed, the interaction of warm mix additives with modified binders, especially crumb rubber modified (CRM) binder, is not known in great detail. This paper presents the data on rheological tests conducted on rubberized binders containing warm asphalt additives. Binders from five different sources were modified using 10% crumb rubber by weight of the virgin binders. Two of the available warm asphalt technologies, Aspha-min® and Sasobit®, were used to produce the warm asphalt binders. From the tests, it was observed that the addition of the warm asphalt additives significantly reduce the permanent deformation of the binders, increase the viscosity at 60 °C and the complex modulus, G*, and decrease the phase angle, δ, at high frequencies and low temperatures compared with the CRM binders.

scholarly journals Performance Analysis of Compound Rubber and Steel Slag Filler Modified Asphalt Composite

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2588 ◽  
Author(s):  
Yongjie Xue ◽  
Hui Zhao ◽  
Xintong Wei ◽  
Yunya Niu
Keyword(s):  
Complex Modulus ◽  
Permanent Deformation ◽  
Asphalt Binder ◽  
Steel Slag ◽  
Treatment Method ◽  
Crumb Rubber ◽  
Creep Tests ◽  
Shear Creep ◽  
Modified Asphalt ◽  
Slag Powder

A new treatment method of combined crumb rubber and steel slag modifier for asphalt binders was proposed in this work. The viscosity, rheological properties, and thermogravimetric analysis of modified asphalt mortar were then investigated. The modified asphalt composite was prepared in laboratory by two steps. Rubber powder was firstly added into hot asphalt flux to make rubber modified asphalt (RA), and then RA binders were wrapped with steel slag powder by granulation machine to make compound rubber and steel slag filler modified asphalt composite (RSAC). Test results showed that the viscosity–temperature susceptibility of RSAC was superior to that of modified asphalt binder with only one additive. The softening point differences of RSAC was 2.1 °C. The complex modulus and phase angle were significantly influenced by the addition of steel slag fillers. Creep tests show that a better anti-permanent deformation performance of RSAC can be obtained, which means a better low temperature performance could be predictable. The CAM (Christensen-Anderson-Marasteanu) and Burgers models can be used to describe the change of complex modulus and viscous-elasticity performance of RSCA. The lower value of me (0.6344) and R (0.1862) from the CAM model indicated that RSAC was slightly related to the sensibility of frequency. The higher value of λ∞ and E0 of RSAC indicated a better ability of shear-creep resistance.

scholarly journals Investigation of the Effects of Evaporation Methods on the High-Temperature Rheological and Fatigue Performances of Emulsified Asphalt Residues

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Yang Sun ◽  
Jin-Chao Yue ◽  
Ri-Ran Wang ◽  
Rui-Xia Li ◽  
De-Cai Wang
Keyword(s):  
High Temperature ◽  
Complex Modulus ◽  
Asphalt Pavement ◽  
Permanent Deformation ◽  
Fatigue Properties ◽  
Creep Recovery ◽  
Heating Method ◽  
Evaporation Method ◽  
Direct Heating ◽  
Emulsified Asphalt

Cold recycling technology is a widely applied asphalt pavement rehabilitation technology. The properties of emulsified asphalt residues after water evaporates play an important role in the performance of the asphalt pavement. This paper investigates the rheological and fatigue properties of emulsified asphalt residues under different evaporation methods. Two different matrix asphalt binders and emulsifiers were selected to prepare the emulsified asphalt. Moreover, the direct heating method (DHM) and the EN13074 and ASTM D7497-09 evaporation methods were used to obtain emulsified asphalt residues. Furthermore, the linear viscoelasticity, the permanent deformation resistance, and the fatigue resistance were evaluated by the temperature sweep and frequency sweep tests, the multiple stress creep recovery (MSCR) test, and the linear amplitude sweep (LAS) test, respectively. The test results show that under the three evaporation conditions, the growth amplitude order of the rutting factor, recovery percent, complex modulus, and fatigue life of emulsified asphalt residues is ASTM D7497-09 > EN13074 > DHM, and as is the attenuation amplitude order of the nonrecoverable creep compliance and phase angle. The results reveal that the evaporation process leads to oxidation and hardening of the residues. The hardening degree of the ASTM D7497-09 evaporation method is higher than that of the EN13074 evaporation method, and the hardening degree of the EN13074 evaporation method is higher than that of the direct heating method. The rheological and fatigue performances of the emulsified asphalt residues depend on the matrix asphalt. Moreover, the residue that was prepared from 70# asphalt has good high-temperature and fatigue properties, but it has higher temperature sensitivity and stress sensitivity.

Antithrombin Activity of Intact Human Platelets

1975 ◽  
Vol 34 (01) ◽  
pp. 115-126 ◽  
Author(s):  
Kiyoake Watanabe ◽  
Francis C Chao ◽  
James L Tullis
Keyword(s):  
Antithrombin Iii ◽  
Human Platelets ◽  
Significant Loss ◽  
Red Cells ◽  
Antithrombin Activity ◽  
Α2 Macroglobulin ◽  
Rapid Reaction ◽  
Pre Treatment ◽  
Different Characteristics

SummaryAntithrombin activity has been identified in intact washed human platelets. An apparent activity was demonstrated at platelet concentrations above 0.31 × 109/ml, when platelet suspensions were incubated with 2.0 NIH units/ml of thrombin. Neither red cells nor white cells revealed antithrombin activity. No significant loss of the platelet antithrombin activity was observed after ten successive washings or after treatment of platelets with antibodies to antithrombin III or α2-macroglobulin. Almost the same amount of antithrombin activity as normal platelets was demonstrated in the platelets from an afibrinogenemic patient. Pre-treatment of platelets with trypsin, papain, and neuroaminidase reduced the activity significantly, whereas lipase was without effect. The platelet antithrombin reacted with thrombin in less than 3 seconds, and this rapid reaction of platelet antithrombin was different from that of plasma antithrombin III or fibrinogen. The thrombin-like clotting activity of ancrod was inhibited by fibrinogen but not platelets. Also, unlike plasma antithrombin III or fibrinogen, brief exposure to heat (56° C or 60° C) reduced considerable amounts of platelet antithrombin activity. These results suggest that platelets possess a specific antithrombin with different characteristics from other known antithrombins.

MONITORING OF OPERATIONAL LOGISTIC PROCESSES IN GENERAL CARGO WAREHOUSES USING PREDICTIVE ANALYSIS

2019 ◽  
Vol 13 (1) ◽  
pp. 27-36
Author(s):  
Andreas Neubert
Keyword(s):  
Data Mining ◽  
Human Error ◽  
Predictive Analysis ◽  
Data Mining Algorithm ◽  
It Infrastructure ◽  
Monitoring Procedure ◽  
Manual Recording ◽  
Mining Tool ◽  
General Cargo ◽  
Different Characteristics

Due to the different characteristics of the piece goods (e.g. size and weight), they are transported in general cargo warehouses by manually-operated industrial trucks such as forklifts and pallet trucks. Since manual activities are susceptible to possible human error, errors occur in logistical processes in general cargo warehouses. This leads to incorrect loading, stacking and damage to storage equipment and general cargo. It would be possible to reduce costs arising from errors in logistical processes if these errors could be remedied in advance. This paper presents a monitoring procedure for logistical processes in manually-operated general cargo warehouses. This is where predictive analysis is applied. Seven steps are introduced with a view to integrating predictive analysis into the IT infrastructure of general cargo warehouses. These steps are described in detail. The CRISP4BigData model, the SVM data mining algorithm, the data mining tool R, the programming language C++ for the scoring in general cargo warehouses represent the results of this paper. After having created the system and installed it in general cargo warehouses, initial results obtained with this method over a certain time span will be compared with results obtained without this method through manual recording over the same period.

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