Author: Mohamed Ali Dhalaan
Publisher:
ISBN:
Category : Asphalt concrete
Languages : en
Pages : 311

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Author: E. Eustacchio
Publisher: CRC Press
ISBN: 1482267519
Category : Architecture
Languages : en
Pages : 672

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This book forms the Proceedings of an International RILEM Symposium, the fourth in the series, on Testing of Bituminous Mixes in Budapest, Hungary, October 1990. The aim of the Symposium is to promote tests for the characterization, design and quality control of bituminous mixes which combine the best features of traditional and modern approaches.

Author: Thomas William Kennedy
Publisher:
ISBN:
Category : Pavements, Asphalt
Languages : en
Pages : 74

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Author: Ilker Boz
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Characterization of asphalt concrete is of paramount importance for the sound structural design and analysis of flexible pavements. Of equal importance is the availability of test methods that can provide an accurate and reliable measure of the required engineering properties of the material. For routine applications in material characterization, selected test methods should be reliable, simple, quick, repeatable, and cost eective. The use of nondestructive test (NDT) methods has proven to provide such characterization capabilities. Among those methods, the impact resonance (IR) test is a vibration based NDT method, and has been increasingly used for asphalt concrete evaluation and characterization in the past two decades. The majority of studies regarding the IR test in asphalt concrete applications have been focused on comparison of the IR test moduli with the moduli obtained from conventional asphalt concrete dynamic modulus tests and the predictive equations. In this dissertation, the IR test was utilized to characterize the properties of asphalt concrete mixtures and recycled asphalt pavement (RAP) binder through mixture testing at a range of temperatures. To this eect, several independent studies were conducted.The second order equation of motion assumption in rheological modeling of the IR test response was evaluated for asphalt concrete testing. A set of asphalt concrete specimens was tested with the IR test, and the obtained signals at a range of temperatures were evaluated by means of the Hankel matrix method. The results showed that the assumption is violated for asphalt concrete testing, especially at high temperatures, mainly due to the presence of noise in the obtained response. However, the Hankel method was employed to filter out the noise. It was seen that the assumption could be employed for asphalt concrete at a range of temperatures including high temperatures, provided that the filtering is performed on the obtained signal. The results also showed that the employed filtering procedure produced improvements for the IR test material dependent responses, resonant frequency and especially damping ratio calculations.The IR test results are influenced by specimen size and testing configurations. A study was conducted to investigate the influence of aspect ratio (length/diameter) of laboratory specimens on the frequency response of asphalt concrete when tested with the IR. The IR test, performed in a longitudinal mode, demonstrated that the test is repeatable and reproducible. The test results indicated that the frequency response increased as the aspect ratio increased approximately up to 0.7, and then it decreased with a nonlinear trend as the aspect ratio increased beyond 0.7, indicating that the tendency of the frequency response reached a plateau as the aspect ratio increased. It was inferred from the test results that there was a threshold aspect ratio at which the fundamental longitudinal frequency mode was not the dominant frequency mode. Velocity calculations from measured resonant frequencies indicated that the true material properties for the longitudinal mode could be attained at an aspect ratio of as low as 1.In another study, the sensitivity of the resonant frequency response of the IR testing of asphalt concrete to asphalt concrete mixture parameters was investigated. The IR tests were performed on disk-shaped asphalt concrete specimens at the transverse (flexural) mode of vibration at a temperature range of approximately -10 to 50oC. Test results revealed that the relationship between the resonant frequency and temperature was described by a polynomial fit, and it was shown through statistical analysis that the slopes of the fit were significantly aected by mixture parameters such as air void content and binder content. Also, the statistical formulation (predictive model) between the resonant frequency and the asphalt concrete mixture parameters were established for a given aggregate gradation of nominal maximum size and an aggregate specific gravity. The prediction accuracy of the model was evaluated by independent data sets, and the test results indicated that the maximum error between the measured and predicted resonant frequencies was not more than 9 percent.In an eort to characterize the properties of recycled asphalt pavement (RAP) binder with the IR test through asphalt concrete mixture testing, two approaches were utilized. An approach is proposed for determination of binder properties through the IR testing of mixtures with RAP and binders with known engineering properties. The IR tests were performed in the longitudinal mode at a range of temperatures between 3 and 35oC. Also, RAP binder and virgin binders were tested using dynamic shear rheometer (DSR) at the same temperature range as the IR testing. It was seen that the IR test ranked the expected trend of binder stiness with respect to the resonant frequency of mixtures. The results indicate the potential of the proposed concept and feasibility of the approach in determining binder properties, including properties of the RAP binder. A practical method is proposed for determination of binder properties based on mixture testing.In the second approach, the IR test potential to characterize the low-temperature properties of an RAP binder that incorporated a rejuvenating agent was investigated. This approach included testing of mixes with virgin binders and pure RAP mixes treated with a rejuvenating agent at dierent levels using the IR, as well as testing of blends of recovered RAP binder, rejuvenator, and virgin binder using bending beam rheometer (BBR). The results showed that the IR test can properly rank the expected stiness of binders through mixture testing. The results also indicated high linear correlations between mixture properties obtained from the IR test (modulus and phase angle) and binder properties obtained from the BBR test (stiness and m-value, a relaxation index). The results clearly demonstrate the potential of IR to be used for grading and optimization for the asphalt binder of RAP and rejuvenator content in lieu of the binder recovery method.

Author: Manfred N. Partl
Publisher: Springer
ISBN: 3319710230
Category : Technology & Engineering
Languages : en
Pages : 320

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Book Description
This book presents the detailed results of five task groups of the RILEM technical committee TC 237-SIB on Testing and Characterization of Sustainable Innovative Bituminous Materials and Systems. It concentrates on specific new topics in asphalt binder and mixture testing, dealing with new developments in asphalt testing, in particular also in view of new innovative bituminous materials, such as hot and cold recycled mixtures, grid reinforced pavements and recycled Reclaimed Asphalt Pavements (RAP), where test methods developed for traditional asphalt concrete are not a priori applicable. The main objective is providing a basis for pre-standardization by comparing different test methods and showing ways for fundamental improvements. Thus, the book also points the way for a further advanced chemo-physical understanding of materials and their role in pavement systems relying on fundamental material properties and suitable models for describing and predicting the intrinsic mechanisms that determine the material behavior.

Author: Francesco Canestrari
Publisher: Springer
ISBN: 9401773424
Category : Technology & Engineering
Languages : en
Pages : 1024

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Book Description
This work presents the results of RILEM TC 237-SIB (Testing and characterization of sustainable innovative bituminous materials and systems). The papers have been selected for publication after a rigorous peer review process and will be an invaluable source to outline and clarify the main directions of present and future research and standardization for bituminous materials and pavements. The following topics are covered: - Characterization of binder-aggregate interaction - Innovative testing of bituminous binders, additives and modifiers - Durability and aging of asphalt pavements - Mixture design and compaction analysis - Environmentally sustainable materials and technologies - Advances in laboratory characterization of bituminous materials - Modeling of road materials and pavement performance prediction - Field measurement and in-situ characterization - Innovative materials for reinforcement and interlayer systems - Cracking and damage characterization of asphalt pavements - Recycling and re-use in road pavements This is the proceedings of the RILEM SIB2015 Symposium (Ancona, Italy, October 7-9, 2015).

Author: Donald W. Christensen
Publisher: Transportation Research Board
ISBN: 0309088089
Category : Pavements, Asphalt
Languages : en
Pages : 62

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Introduction and Research Approach -- Findings -- Interpretation, Appraisal, and Applications -- Conclusions and Recommendations -- References -- Appendixes.

Author: Pezhouhan Tavassoti Kheiry
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Asphalt concrete is a multiphase viscoelastic composite material; hence its mechanical properties change with frequency of the applied loads and the temperature. In many of the design tools such as the Mechanistic Empirical Pavement Design Guide (MEPDG), changes in dynamic modulus as a function of the loading frequency is the primary input. There are very limited testing devices that can directly measure the shear modulus of asphalt concrete. Most of the available devices for asphalt concrete testing are limited to a maximum loading frequency of 33 Hz. However, devices that are capable of exerting loads at higher frequencies are generally limited with respect to the maximum attainable strains. Treating an asphaltic mix as a thermo-rheologically simple material makes it possible to extrapolate its viscoelastic behavior from the low frequency to the high frequency ends through a modulus master-curve. However, such extrapolations are not always accurate and can result in significant errors in pavement design and performance prediction. In this dissertation, a conventional soils testing Resonant Column (RC) apparatus is retrofitted to test stiffer materials such as asphalt concrete at a range of temperatures and strains. Through the proposed RC test, the frequency dependent modulus of asphalt concrete at frequencies considerably higher than those attainable by the available devices, i.e. up to 300 Hz, and at strain levels comparable to the conventional modulus tests (about 100 microstrains) were measured. A set of dynamic modulus (DM) tests were performed on both the full-size and the proposed small-size specimens. It was confirmed that the small specimens exhibit the same properties as the full-size specimens. Non-destructiveness of the RC testing of asphalt concrete was also confirmed by investigating the repeatability of RC tests at each temperature, the reproducibility of the same results after one complete set of temperature-frequency sweep tests, and the modulus changes from Impact Resonance (IR) tests. Thus, the same specimen can be used for conducting multiple tests at different temperatures. Finally, RC technique was successfully used to characterize a wide range of asphalt concrete technologies including: conventional Hot Mix Asphalt (HMA), Warm Mix Asphalt (WMA), high Reclaimed Asphalt Pavements (RAP) content, and high Recycled Asphalt Shingles (RAS) mixes. Results indicate that the conventional modulus master curve underpredicts the actual modulus at higher frequencies. Therefore, the proposed power-form modulus-frequency functions are recommended in this dissertation to be used along with a variable Poissons ratio to achieve a better prediction, when an indirect calculation of shear modulus of asphalt concrete is needed. It was concluded that RC test can non-destructively characterize different asphalt concrete technologies at a wide range of temperatures. The RC test provides useful insights about the high frequency modulus and damping of asphalt concrete mixes.

Author: SA. Tan
Publisher:
ISBN:
Category : Asphalt mixtures
Languages : en
Pages : 14

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This paper reports the results of a research effort initiated in the early 1990s to develop a C-? (cohesion-angle of friction) characterization model for the design of asphalt mixtures and asphalt pavements. It is demonstrated that, since the model is based on the fundamental material properties represented by C and ?, it can derive analytically other asphalt mix design parameters such as Marshall stability and flow, and indirect tensile strength. The C-? characterization model therefore offers a useful basis for the development of a comprehensive design framework that integrates asphalt mix design with asphalt pavement structural design. To demonstrate this capability, the research developed an empirical-mechanistic rutting prediction model of asphalt pavement layer using the C-? characterization model. In addition, the model allows stresses and strains under design loading to be computed, which can be applied as input to structural analysis for asphalt material selection and pavement thickness design.

Author: Xuan Chen
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Cracking in asphalt pavements is a challenging problem and has been the subject of numerous research studies for decades. To properly address this problem, suitable tests must be conducted to capture material behavior in cracking, such testing must be accompanied by proper mechanistic and empirical modeling of the material behavior in cracking. For mixture design and material quality control/assurance purposes, there is not a commonly accepted protocol for testing asphalt mixtures for cracking resistance characterization, due to variability of test results, non-uniformity in test specimens, and overall complexities of the tests that prevent them from being adopted for daily uses. On the other hands, for the tests that are popular for research purposes, the validity and sensitivity of such tests have not been fully witnessed and proven, due to lack of data quantity. Addressing these problems will help improve mixture design procedures and advance quality control and quality assurance of asphalt mixes, especially when complicated components, such as recycled materials and performance enhancing additives, are commonly incorporated into asphalt concrete nowadays. The overall goal of this research is to characterize the cracking resistance of various types of asphalt concrete mixes via a suitable candidate test. An additional goal is to provide guidelines for performing balanced mixture design on asphalt concrete with virgin and recycled materials when using such a test. Throughout the research, the selected fracture test, namely the semi-circular bend (SCB) fracture test, was first evaluated by investigating the sensitivity of performance indicators under various test conditions and proposing the most appropriate test conditions using a solid theoretical background. Then, the test was used to study fracture behavior of a wide range of asphalt paving materials including, but not limited to, various virgin asphalt mixes, crumb rubber modified (CRM) asphalt mixes, asphalt mixes with recycled materials such as reclaimed asphalt pavement (RAP), and recycled asphalt shingles (RAS), together with asphalt mixes with recycling agents. Not only were these mixtures prepared in a single laboratory, specimens received from different laboratories and plants were also included in the test matrix to reduce bias and to investigate the variation of the performance indicators. Additionally, a method to conduct the performance-based balanced-design using only the SCB fracture test was explored. Finally, the effect of long-term aging on fracture behavior of asphalt mixes was investigated, in order to build foundations for performance prediction commonly used in asphalt pavement design procedures. The main contributions of this study are: 1) verification of the sensitivity of the SCB test using asphalt mixtures with controlled variables under the proposed test conditions that are suitable to the commonwealth of Pennsylvania, 2) investigation of the impacts of material variables and conditioning, namely aging process, on fracture behavior of asphalt concretes, 3) exploration of possibility of performing balanced mixture design on asphalt concrete using the SCB test as a stand-alone test. The SCB fracture test procedure is found to be suitable to qualify asphalt mixes to fulfill different traffic demands and pavement structural conditions. Reliable mix design and quality assurance of asphalt pavements with complicated rehabilitation histories and sophisticated material compositions can be performed with confidence using such a test.