Fracture Resistance Characterization of Superpave Mixtures Using the Semi-Circular Bending Test PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Fracture Resistance Characterization of Superpave Mixtures Using the Semi-Circular Bending Test PDF full book. Access full book title Fracture Resistance Characterization of Superpave Mixtures Using the Semi-Circular Bending Test by Z. Wu. Download full books in PDF and EPUB format.
Author: Z. Wu Publisher: ISBN: Category : Energy release rate Languages : en Pages : 15
Book Description
The fracture resistance of asphalt mixture is an important property directly related to pavement distresses, such as cracking. This paper reports the investigation of a newly-developed semicircular bending (SCB) test as a candidate test for the fracture resistance characterization of asphalt mixtures. Thirteen Superpave mixtures, designed with four different binder types (AC-30, PAC-40, PG70-22M, and PG76-22M) and four different compaction levels (Ndesign = 75, 97, 109, and 125), were considered in this study. The SCB tests were conducted at 25°C using a three-point bending fixture in a MTS testing system. The fracture resistance was analyzed based on an elasto-plastic fracture mechanics concept of critical strain energy release rate, also called the critical value of J-integral (Jc). Preliminary results indicate that the JC values were fairly sensitive to changes in binder type and nominal maximum aggregate size (NMAS) used in Superpave mixtures. This study suggests that the SCB test could be a valuable correlative tool in the evaluation of fracture resistance of asphalt mixtures.
Author: Z. Wu Publisher: ISBN: Category : Energy release rate Languages : en Pages : 15
Book Description
The fracture resistance of asphalt mixture is an important property directly related to pavement distresses, such as cracking. This paper reports the investigation of a newly-developed semicircular bending (SCB) test as a candidate test for the fracture resistance characterization of asphalt mixtures. Thirteen Superpave mixtures, designed with four different binder types (AC-30, PAC-40, PG70-22M, and PG76-22M) and four different compaction levels (Ndesign = 75, 97, 109, and 125), were considered in this study. The SCB tests were conducted at 25°C using a three-point bending fixture in a MTS testing system. The fracture resistance was analyzed based on an elasto-plastic fracture mechanics concept of critical strain energy release rate, also called the critical value of J-integral (Jc). Preliminary results indicate that the JC values were fairly sensitive to changes in binder type and nominal maximum aggregate size (NMAS) used in Superpave mixtures. This study suggests that the SCB test could be a valuable correlative tool in the evaluation of fracture resistance of asphalt mixtures.
Author: Imad L. Al-Qadi Publisher: CRC Press ISBN: 0203882199 Category : Technology & Engineering Languages : en Pages : 932
Book Description
Internationally, much attention is given to causes, prevention, and rehabilitation of cracking in concrete, flexible, and composite pavements. The Sixth RILEMInternational Conference on Cracking in Pavements (Chicago, June 16-18, 2008) provided a forum for discussion of recent developments and research results.This book is a collection of papers fr
Author: Xuan Chen Publisher: ISBN: Category : Languages : en Pages :
Book Description
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.
Author: Gabriel Nsengiyumva Publisher: ISBN: Category : Pavements, Asphalt concrete Languages : en Pages : 83
Book Description
Granted that most distresses in asphalt (flexible) concrete (AC) pavements are directly related to fracture, it becomes clear that identifying and characterizing fracture properties of AC mixtures is a critical step towards a better pavement design. This thesis examines the testing variables of a reliable and practical semicircular bending (SCB) test for evaluating the fracture characteristics of asphalt concrete mixtures at intermediate service temperature conditions. The first part of this thesis investigates the repeatability of the SCB fracture test method by integrating a statistical-experimental approach to identify testing variables of the SCB test that result in repeatable test results. Toward this end, five testing variables (the number of testing specimens, specimen thickness, notch length, loading rate, and testing temperature) of the SCB test were investigated due to their significant effects on mixture fracture characteristics. After statistical analysis of 18 specimens tested a typical testing variables, approximately, five to six specimens/replicates were found to be a reasonable sample size that could properly represent asphalt concrete fracture behavior using the SCB test method. The coefficient of variation (COV) of the mixture fracture energy was used to evaluate the effect of each variable on the repeatability of test results. A range of 1 mm/min. to 5 mm/min. for the loading rate, a notch length from 5 mm to 25 mm, and a specimen thickness of 40 mm to 60 mm and a testing temperature of 15-40°C showed the lowest variation of fracture energy. The second part of this work is to investigate the sensitivity of the SCB test using the previously determined testing variables. Fourteen different asphalt concrete (AC) mixtures collected from 12 field construction projects in Nebraska were used in this task. The ANOVA test showed statistically significant differences between mixtures at a 95% confidence level. Tukey's HSD multiple-comparison analysis found similarities within mixtures of same types and significant difference between mixtures types. In addition, the fracture energy of bituminous mixtures increased with increasing amount of virgin asphalt content in mixture. Overall, the SCB test method developed herein proved to be repeatable and sensitive to changes in mixtures, and thus a promising tool for evaluating the fatigue fracture resistance of AC mixtures.
Author: Prasanta Kumar Basu Publisher: CRC Press ISBN: 0415643317 Category : Technology & Engineering Languages : en Pages : 308
Book Description
This book provides the reader with a comprehensive background of semiconductor lasers. It covers their structure, materials, operating principles supported by proper theory, and light power output, as well as conversion efficiency and how frequently the devices can be switched on and off. It also discusses the different lasers working at different wavelengths, viz, ultraviolet, visible, infrared and mid and far infrared regions of electromagnetic spectrum along with proper structure, materials and theory.
Author: Shirley Dowdy Publisher: John Wiley & Sons ISBN: 0471477427 Category : Mathematics Languages : en Pages : 646
Book Description
Praise for the Second Edition "Statistics for Research has other fine qualities besides superior organization. The examples and the statistical methods are laid out with unusual clarity by the simple device of using special formats for each. The book was written with great care and is extremely user-friendly."—The UMAP Journal Although the goals and procedures of statistical research have changed little since the Second Edition of Statistics for Research was published, the almost universal availability of personal computers and statistical computing application packages have made it possible for today's statisticians to do more in less time than ever before. The Third Edition of this bestselling text reflects how the changes in the computing environment have transformed the way statistical analyses are performed today. Based on extensive input from university statistics departments throughout the country, the authors have made several important and timely revisions, including: Additional material on probability appears early in the text New sections on odds ratios, ratio and difference estimations, repeated measure analysis, and logistic regression New examples and exercises, many from the field of the health sciences Printouts of computer analyses on all complex procedures An accompanying Web site illustrating how to use SAS® and JMP® for all procedures The text features the most commonly used statistical techniques for the analysis of research data. As in the earlier editions, emphasis is placed on how to select the proper statistical procedure and how to interpret results. Whenever possible, to avoid using the computer as a "black box" that performs a mysterious process on the data, actual computational procedures are also given. A must for scientists who analyze data, professionals and researchers who need a self-teaching text, and graduate students in statistical methods, Statistics for Research, Third Edition brings the methodology up to date in a very practical and accessible way.
Author: Z. Wu
Author: Z. Wu
Author: Imad L. Al-Qadi
Author: Xue Li
Author: Xuan Chen
Author: Gabriel Nsengiyumva
Author: Louay Nadhim Mohammad
Author: 
Author: Prasanta Kumar Basu
Author: Shirley Dowdy
Author: C. Petit