Asphalt Concrete Stiffness Modulus Estimation Utilizing an Algorithm Approach

2013 ◽  
Author(s):  
C. Plati ◽  
K. Georgouli ◽  
A. Loizos
Keyword(s):  
Asphalt Concrete ◽  
Stiffness Modulus

The Viscoelastic Characteristics of the Asphalt Concrete Modified with Different Synthetic Waxes Using a Modified Huet- Sayegh Model

2017 ◽  
Author(s):  
Grzegorz Mazurek
Keyword(s):  
Asphalt Concrete ◽  
Dynamic Modulus ◽  
Complex Modulus ◽  
Model Parameters ◽  
Fischer Tropsch ◽  
Stiffness Modulus ◽  
Molecular Weights ◽  
Cole Diagram ◽  
Sinusoidal Load ◽  
Viscoelastic Characteristics

The article presents the results of dynamic modulus tests carried on the asphalt concrete (AC16W). The sinusoidal load was applied to the samples in accordance with DTC-CY method. The neat bituminous binder (penetration grade 35/50) was modified by means two synthetic waxes, coming from the Fischer-Tropsch raction, with various molecular weights and softening point temperature results (hard and softer). The relaxation phenomenon in terms of changes in complex modulus and phase angle was evaluated using the modified Huet-Sayegh (2S2P1D). Estimated model parameters pointed out that the addition of the synthetic wax with the high (hard wax) and the low (softer wax) molecular weight raised the stiffness of the bituminous binder in relation to the reference bitumen 35/50. The application of the modified Huet-Sayegh model showed that the presence of the synthetic wax in the bitumen significantly affected the stiffness modulus of considered asphalt concretes. Basing analysis on Cole-Cole diagram it was found significant differences in the viscoelastic behaviour between the reference asphalt concrete and the asphalt concretes with synthetic waxes. In contrast, there were no significant differences between viscoelastic properties of tested asphalt concretes modified, used in the experiment, synthetic waxes. Furthermore, the sensitivity to the loading time of asphalt concretes containing both synthetic waxes was marginal.

scholarly journals Effect of Hydrated Lime on Indirect Tensile Stiffness Modulus of Asphalt Concrete Produced in Half-Warm Mix Technology

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4731
Author(s):  
Mateusz M. Iwański
Keyword(s):  
Asphalt Concrete ◽  
Permanent Deformation ◽  
Active Agent ◽  
Hydrated Lime ◽  
Partial Replacement ◽  
Stiffness Modulus ◽  
Limestone Filler ◽  
Tensile Stiffness ◽  
Lime Content ◽  
Indirect Tensile

Half-warm mix asphalt (HWMA) mixtures can be produced at temperatures ranging from 100 °C to 130 °C, depending on the production methods used. The lowest mixing temperature can be achieved by using water-foamed bitumen. The mixture should be characterized by a long service life, defined by the resistance to permanent deformation and high stiffness modulus at temperatures above zero. It is therefore important to ensure the adequately high quality of the bitumen binder. Bitumen 50/70 was provided with appropriate quality foaming characteristics (expansion ratio, ER, half-life, t1/2) by adding a surface-active agent (SAA) at 0.6 wt % before foaming. Then asphalt concrete (AC) 8 S was designed and produced with the recommended water-foamed binder. Hydrated lime, an additive substantially affecting asphalt concrete mechanical parameters, was used at 0, 15, 30, and 45 wt % as a partial replacement for the limestone filler. The influence of the amount of hydrated lime on the content of voids, indirect tensile stiffness modulus at −10 °C, 0 °C, +10 °C, +20 °C, and +30 °C, and the resistance to permanent deformation was investigated. Statistical analysis of the test results showed the quantity of 30% to be the optimum hydrated lime content. The AC 8 S resistance to permanent deformation was determined at the optimum hydrated lime content. The comprehensive evaluation revealed a synergistic effect between bitumen 50/70, modified before foaming with 0.6 wt % SAA and 30 wt % hydrated lime as the limestone filler replacement, and the half warm mixture AC 8 S, in terms of the standard requirements and durability of the HWMA concrete in pavement applications.

Influences of Aging History on Low Temperature Performance of Asphalt Concrete

2008 ◽  
Vol 385-387 ◽  
pp. 493-496 ◽  
Author(s):  
Shao Peng Wu ◽  
Guo Jun Zhu ◽  
Ling Pang ◽  
Cong Hui Liu
Keyword(s):  
Low Temperature ◽  
Flexural Strength ◽  
Asphalt Concrete ◽  
Tensile Strain ◽  
Natural Aging ◽  
Bending Stiffness ◽  
Bending Test ◽  
Stiffness Modulus ◽  
Stone Mastic Asphalt ◽  
High And Low Temperatures

According to three-point bending test, this paper explores the influence of low temperature on the flexural strength, the tensile strain and bending stiffness modulus of the aged Stone Mastic Asphalt (SMA-13) concrete. The asphalt mixtures are aged according to the short-term aging (at 135°C, 4 hours), and long-term aging (asphalt concrete at 85°C, 120 hours) and natural aging (3 months, 6 months and 9 months). The result shows that, with the same loading rate, the tensile strain of specimens at -30°C are smaller than those at -10°C; but when temperature is certain, the tensile strain of specimens lager than those of aged specimens. The longer the aging time lasts, the more flexural strength differences between high and low temperatures can be found. A pretty well index variation can be found between the tensile strain and temperature. The same trend also appears between the bending stiffness modulus and temperature of SMA-13 asphalt concrete.

scholarly journals Potential of Using Imidazoline in Recycled Asphalt Pavement

2019 ◽  
Vol 14 (4) ◽  
pp. 521-542
Author(s):  
Robert Jurczak ◽  
Paweł Mieczkowski ◽  
Bartosz Budziński
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Pavement ◽  
Asphalt Mixtures ◽  
Fatigue Performance ◽  
Recycled Asphalt Pavement ◽  
Recycled Asphalt ◽  
Stiffness Modulus ◽  
Optimum Content ◽  
Environmental Considerations ◽  
Freezing Temperatures

The environmental considerations need to be taken into account in any road resurfacing and upgrading project, for example, by reusing asphalt rubble for production of new pavement courses. Mixtures containing larger amounts of recycled asphalt pavement are improved by adding rejuvenator additives. The tests performed on the recycled asphalt mixtures containing lard imidazoline confirm the suitability of this agent for paving applications. Lard imidazoline was found to improve the stiffness modulus, fatigue performance and resistance to the action of water and freezing temperatures. The parameters obtained at the optimum content of additive complied with the criteria defined for virgin asphalt concrete and other mixtures of that kind.

scholarly journals Performance Evaluation of Conventional and High Modulus Asphalt Concrete with Novolac Polymer Modifier Using Aashtoware Software

2018 ◽  
Vol 7 (4.20) ◽  
pp. 386 ◽  
Author(s):  
Basim H. Al-Humeidawi ◽  
Abbas F. Jasim ◽  
Huda A. Kadhim
Keyword(s):  
Asphalt Concrete ◽  
Permanent Deformation ◽  
Asphalt Binder ◽  
Pavement Performance ◽  
High Modulus ◽  
Construction Costs ◽  
Stiffness Modulus ◽  
Polymer Modifier ◽  
Pavement Thickness ◽  
First Time

In order to changes the original asphalt characteristics, there are many additives have been used to produce or modify the High Modulus Asphalt Binder (HMAB). Even though the hard grade asphalt binder has some disadvantages, such as the aging process due to high mixing and compacting temperature, which can negatively affect the pavement performance, some other advantages include increasing stiffness modulus of asphalt binder and high resistance to permanent deformation. Also, using the hard grade asphalt binder will save construction costs by reducing the asphalt pavement thickness due to its high stiffness modulus. In Iraq, the Novolac modifier and its Cross-linking Agent (Hexamine) was used for the first time as a modifier for asphalt which can significantly improve the rheological properties of asphalt and its role in HMA. This study focuses on estimating the thickness reduction of flexible pavement due to using High Modulus Asphalt Concrete (HMAC). The reduction in permanent deformation and thickness of pavement were estimated for suggested pavement structure sections implemented HMAC mixture compared with the pavement section implemented conventional mixtures using AASHTOWare software version 2.3. The analytical results indicate that adding 4% of Novolac modifier and 15 % of Hexamine (form weigth of Novolac) is reduced the permanent deformation and bottom up cracking by 30% and 46 % compared to conventional mix, respectively. However, it can be concluded that adding Novolac polymer modifier enhanced the pavement performance.  

scholarly journals Rutting Resistance of Hot Mix Asphalt Containing Coarse Recycled Concrete Aggregates Coated with Waste Plastic Bottles

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Alireza Azarhoosh ◽  
Mehdi Koohmishi ◽  
Gholam Hossein Hamedi
Keyword(s):  
Asphalt Concrete ◽  
Cement Mortar ◽  
Permanent Deformation ◽  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Creep Tests ◽  
Stiffness Modulus ◽  
Waste Plastic ◽  
Rutting Resistance ◽  
Dynamic Creep

The use of recycled concrete aggregate (RCA) as a part of coarse aggregates in asphalt pavements confers economic and environmental benefits. Coarse RCA (CRCA) has inferior mechanical and physical properties compared to natural aggregates due to very porous and weakly adhered cement mortar. In this study, CRCA surfaces were coated with waste plastic bottles (WPB) and used at 15%, 30%, and 50% in the asphalt concrete. The Marshall, stiffness modulus, and dynamic creep tests were performed to determine the strength of hot mix asphalts against rutting. The results revealed that the use of untreated CRCA reduced the Marshall quotient and the rutting resistance of the asphalt concrete. The results of the stiffness modulus and dynamic creep tests indicated that CRCA incorporation increased permanent deformation in the tested specimens due to the reduction of asphalt concrete stiffness. However, the asphalt concrete containing treated CRCA had lower permanent deformation because WPB promotes CRCA stability by penetrating its void and reinforcing cement mortar. Furthermore, by raising the temperature, the strength of all asphalt concretes decreased against rutting, and the reduction rate was higher in the modified specimens.

scholarly journals Influence of F-T Synthetic Wax on Asphalt Concrete Permanent Deformation

2013 ◽  
Vol 59 (3) ◽  
pp. 295-312
Author(s):  
M. Iwański ◽  
G. Mazurek
Keyword(s):  
Fatigue Life ◽  
Fatigue Test ◽  
Asphalt Concrete ◽  
Permanent Deformation ◽  
Positive Influence ◽  
Test Results ◽  
Fischer Tropsch ◽  
Stiffness Modulus ◽  
Tensile Fatigue ◽  
Indirect Tensile

Abstract The paper presents the results of the study of the effect of a Fischer-Tropsch (F-T) synthetic wax on the resistance to permanent deformation of the AC 11S asphalt concrete. The synthetic wax was dosed at 1.5%, 2.5% and 3.5% by weight of bitumen 35/50. The compaction temperatures were 115°C, 130°C and 145°C. The criteria adopted for measuring the resistance to permanent deformation included the following parameters: stiffness modulus at 2, 10 and 20°C, permanent deformation (RTS), fatigue life determined using the indirect tensile fatigue test (ITFT) and resistance to rutting (WTSAIR, PRDAIR). The test results confirmed the positive influence of F-T synthetic wax on enhancing the permanent deformation resistance of asphalt concrete placed at lower compaction temperatures compared to that of standard asphalt concrete compacted at 140°C.

scholarly journals A Machine Learning Approach to Determine Airport Asphalt Concrete Layer Moduli Using Heavy Weight Deflectometer Data

2021 ◽  
Vol 13 (16) ◽  
pp. 8831
Author(s):  
Nicola Baldo ◽  
Matteo Miani ◽  
Fabio Rondinella ◽  
Clara Celauro
Keyword(s):  
Machine Learning ◽  
Performance Evaluation ◽  
Asphalt Concrete ◽  
Data Augmentation ◽  
Integrated Approach ◽  
Pavement Management ◽  
Stiffness Modulus ◽  
Heavy Weight ◽  
Concrete Layer ◽  
Augmentation Techniques

An integrated approach based on machine learning and data augmentation techniques has been developed in order to predict the stiffness modulus of the asphalt concrete layer of an airport runway, from data acquired with a heavy weight deflectometer (HWD). The predictive model relies on a shallow neural network (SNN) trained with the results of a backcalculation, by means of a data augmentation method and can produce estimations of the stiffness modulus even at runway points not yet sampled. The Bayesian regularization algorithm was used for training of the feedforward backpropagation SNN, and a k-fold cross-validation procedure was implemented for a fair performance evaluation. The testing phase result concerning the stiffness modulus prediction was characterized by a coefficient of correlation equal to 0.9864 demonstrating that the proposed neural approach is fully reliable for performance evaluation of airfield pavements or any other paved area. Such a performance prediction model can play a crucial role in airport pavement management systems (APMS), allowing the maintenance budget to be optimized.

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