Performance of Indiana’s Superpave HMA Mixtures

This project followed the performance of a number of hot mix asphalt paving projects for seven to eight years in an attempt to relate laboratory test results to field performance. First, a small scale study compared sampling locations, specific gravity test procedures and compaction devices used on two samples from projects, one with volumetric acceptance and one with non-volumetric acceptance, to determine the best combination to use for Part 2 of the study. In Part 2, 12 projects constructed in 2001 and 2002 were sampled, tested and monitored. Laboratory testing involved determining maximum and bulk specific gravities, binder content, air voids and other properties of the mixes. Laboratory performance tests were also conducted, including Superpave shear tests at high and intermediate temperatures and indirect tensile tests at low temperatures. The Purwheel loaded wheel tester was used to test mixtures from four of the projects to examine the mixes’ tendencies to strip and rut. The laboratory testing results generally predicted that all of the mixtures would perform well in the field in terms of rutting. Results ranged from fair to excellent, with the vast majority of the results in the good to excellent categories. The indirect tensile testing results did not indicate any extreme problems would be expected with thermal cracking of these materials. While some of the mixes did have expected critical cracking temperatures warmer than the binder low temperature grade, all of them would be expected to perform well down to about -17°C. The single mix with a -28 grade binder, as opposed to the -22 grades for all of the other mixes, also had the lowest critical cracking temperature. Field performance of these projects was monitored through a condition survey and using videologs, rut depths and roughness measurements from the INDOT Pavement Management System. Through 2009, all 12 projects were performing well with rut depths generally less than 0.1 inch (2.5 mm) and roughness of less than about 100 in/mi. While there is some cracking on many of the projects, it is generally not severe and is likely reflective rather than thermal cracking. In general then, the laboratory results agree with the field performance. The lab tests suggested that the mixes would be resistant to rutting and fairly resistant to thermal cracking, and this was verified by the field performance in all cases. This study is limited somewhat by the fact that none of the mixes would be expected to perform poorly. Having mixes that “failed” a test would help to establish the boundaries between good and bad performance. The study is also subject to a common limitation of long-term performance studies – the fact that technology has evolved over the course of the project. Mix design parameters have changed somewhat and new test methods, particularly the dynamic modulus and flow number tests, have gained prominence. Nonetheless, this study does show that Superpave mixes from the early part of the century can be expected to perform well and that the laboratory performance tests used in this study generally can predict this good performance

Development of Indiana\u27s SPS9-A Site

The Superpave system for hot mix asphalt (HMA) design was introduced in 1995 and adopted throughout most of the USA by 2000. This system uses performance-oriented approach to materials selection and mix design, and takes into account the local environmental and traffic conditions. It recognizes that the behavior of HMA depends on the temperature, loading and aging conditions and provides tools (in the form of materials selection and performance-related tests) that should help to protect pavements against low-temperature cracking, rutting and fatigue cracking. This report summarizes the field and laboratory studies conducted to investigate the influence of asphalt binder grade on the field performance of HMA pavements. In particular, the effect of binder grade on low temperature cracking and on permanent deformation (rutting) of pavement was investigated. In addition, the validity of some of the existing low-temperature models for assessing the susceptibility of a given binder to low temperature cracking is also analyzed. The study involved construction and field evaluation of six test sections on the interstate I-70, east of Indianapolis, Indiana. Four of the six sections contained various SUPERPAVE binder grades, one of the sections was constructed using traditional Marshal mix design, and one of the sections contained 15% of recycled asphalt concrete (RAP). The monitoring of performance of the test sections involved periodical distress surveys and collection of field cores for laboratory testing of volumetric, binder and aggregate properties. In addition, the original binders and plant mix samples were also evaluated. The results of this test program indicate that, in general, the binder grade does influence the field performance of HMA and that susceptibility to failure of a given material can (in many cases) be predicted from the laboratory test results. Particularly good correlation between the laboratory-based data and field performance was observed for low-temperature binder tests, indicating that these tests can reliably predict the critical cracking temperature of the pavement. On the other hand, the test results also confirmed that low-temperature prediction algorithms proposed in the original Superpave specifications were too conservative, for the environmental conditions present at the test site

RESURGENCE OF RUSSIA AS A GREAT POWER AND ITS FOREIGN POLICY ORIENTATION TOWARDS SOUTH ASIA

Russia has re-emerged as an important global actor after the advent of the post-Soviet era. Kremlin’s repositioning in the global affairs under President Vladimir Putin has led to a geopolitical and geostrategic transformation of its foreign policy. It follows multilateralism with active outreach in different parts of the world. In contemporary Russian foreign policy, there are tangible determinants that call for multipolar world order including realignment of foreign relations and consolidation of great power status. This paper, therefore, examines Russian foreign policy in the post-Crimean annexation era, where Moscow launched various campaigns through active engagements with the world’s larger economies and strategically important countries, such as China, India, Pakistan, and Afghanistan. The paper also highlights Russia’s evolving bilateral relations with these countries, especially in economic, political, and military spheres. Following the current global geopolitical realities, it also attempts to mark clear adjustments in Moscow’s foreign policy with respect to its power, responsibility, and ambitions for international peace and stability.   Bibliography Entry Shah, Syed Taimoor, and Ayesha Afgun. 2020. "Resurgence of Russia as a Great Power and Its Foreign Policy Orientation towards South Asia." Margalla Papers 24 (2): 93-103

Investigation of Delta Tc for Implementation in Indiana

The current Superpave asphalt binder specifications do not address durability issues and do not adequately address fatigue. Several approaches have been proposed by different researchers to address both these durability issues. Some of the proposed refinements are quite complex, but one, ΔTc (delta Tc), is gaining favor because it is computationally simple and uses the existing BBR test method and data. This research explored the possible advantages and disadvantages of implementing a ΔTc limit in Indiana as one means to control binder-related durability cracking issues. This was accomplished by performing a detailed literature review, analyzing data for commonly used binders in the state as well as RAP stockpile data, and conducting laboratory testing on a range of asphalt binders with varying reclaimed asphalt pavement (RAP) and recycled asphalt shingle (RAS) contents. At this time, it is not recommended that INDOT implement ΔTc in its specifications. This recommendation is based in large part on several remaining issues. One primary consideration is the caution against using ΔTc for polymer modified binders. The results of testing unmodified binders seem to be more meaningful but would require identifying or assuming which binders are unmodified and handling them differently in the lab, which could be problematic. Another consideration is that the need for 40-h PAV aging is still being debated. INDOT could consider ΔTc a characterization or research tool for forensic studies, for certain applications like high recycled material contents, or other investigations. As research continues on a national level, future implementation in a purchase specification or quality acceptance process may become advisable

A Novel Color Image Encryption Scheme Based on Arnold’s Cat Map and 16-Byte S-box

The presented work sets out to subsidize to the general body of knowledge in the field of cryptography application by evolving color image encryption and decryption scheme based on the amalgamation of pixel shuffling and efficient substitution. Arnold’s cat map is applied to snap off the correlation in pixels of image and the shuffled image is encrypted by 16-byte S-box substitution. Computer simulations with a standard test image and the outcome is presented to scrutinize the competence of the projected system. Several image-quality measures and security analyses have been made out for the encrypted image to estimate the statistical and differential strength of the scheme. A comparison is presented by following out the scheme with 256-byte S-box and 16-nibble S-box to support for sturdiness of the idea. It is concluded from the results of analyses that the proposed scheme with 16-byte S-box can resist exhaustive attacks and is apt for practical applications

Tack Coat Installation Performance Guidelines

A tack coat is a thin application of asphalt (typically emulsified) used to bond pavement layers together so that they act monolithically. Lack of bonding can lead to fatigue cracking, delamination, slippage and other distresses. This study was undertaken to explore the impacts of various tack coat materials, application rates, and other variables on tack coat performance. The ultimate original goal was to develop a tack coat quality acceptance system. As the study progressed, some of the original objectives and tasks were modified or dropped. Laboratory testing of lab- and field-fabricated specimens using a monotonic direct shear test was used to evaluate the factors of interest. The findings showed that the most commonly used tack materials in Indiana, AE-NT and SS-1h, can perform, with the AE-NT exhibiting somewhat better performance overall. INDOT’s tack specifications could be clarified. The current applications rates are reasonable but could be refined to provide more guidance for use on different types of surfaces, as widely recommended nationally. The use of spray pavers and alternate tack materials should be further explored. Planned spray paver trial projects could provide the opportunity to expand on the results of this project, to explore other test methods, gain more experience with shear testing, and assess typical tack applications on non-experimental projects to assess the state of the practice. Additional implementation studies may help to refine a performance test and criteria for use to assess tack coat quality. The importance of tack coats should be emphasized to contractors and field personnel

Analysis of the Multiple Stress Creep Recovery Asphalt Binder Test and Specifications for Use in Indiana

The Superpave specifications and equipment, introduced in 1993, represented a major advancement with respect to offering a better understanding of the behavior and characteristics of asphalt binders based on their rheological properties. However, the Superpave high-temperature test protocol has been shown to be inadequate for characterizing the high-temperature behavior (rutting resistance) of asphalt binders, particularly polymer modified ones. Recently, a specification based on the Multiple Stress Creep Recovery (MSCR) test has been proposed to address the shortcomings of the Superpave high-temperature binder specifications. This study aims to investigate the merits of implementing the MSCR test and specification as a replacement for the conventional high-temperature testing in the Performance Graded (PG) system. A statistical analysis was conducted on a dataset from Indiana Department of Transportation (INDOT) to see how MSCR and PG procedures differ in grading different binders used in the state. In addition, an experimental study was conducted using seventeen different modified and unmodified binders. In addition to binder tests, seven of the binders were selected to conduct asphalt mixture tests such as dynamic modulus and flow number. The results confirm that the MSCR test is a suitable replacement for the current PG high temperature test since it provides a better tool to rank modified asphalt binders as well as unmodified ones. That is, creep compliance from the MSCR test more fundamentally represents binder behavior at high temperatures compared to the PG rutting parameter. In addition, the very simplified approach, known as grade-bumping, used in the current PG system to account for high traffic levels and low speed limits can be eliminated when using the MSCR test. The MSCR test also provides a better coefficient of correlation (at both stress levels) with flow number test results than the PG rutting parameter, again indicating that it more accurately reflects binder performance at high temperatures

Intellectual wellness awareness: a neglected area in medical universities of Pakistan

Abstract Objective: To compare the presence of intellectual wellness awareness in students of public and private sector medical colleges in a metropolitan city. Methods: The cross-sectional questionnaire-based survey was conducted from March to November 2011 at Bahria University Medical and Dental College, Karachi, and overall covered five private and 3 public sector medical colleges of the city. The study randomly selected 800 medical students. The responses -- never, sometimes, mostly and always (numbered 0-4) - were analysed in terms of frequency, proportion and percentages using Predictive Analysis Software version 18. Results: Of the 800 forms distributed, 736(92%) completed forms were analysed. Among the respondents, 526 (71.5%) were females. Besides, 450(61%) belonged to private medical colleges and 236(39) were from public medical colleges. The participants of private medical colleges had taken part in intellectual discussions actively compared to those from public colleges (p\u3c0.001). Habit of reading books to acquire knowledge was found in 126(44%) private college students compared to 149(33%) in public colleges (p\u3c0.004). The importance of creative mental activities (p=0.954) and current information about local and international affairs (p\u3c0.564) was deficient in both sets of students. Conclusion: Students of private medical colleges were better in terms of presence of intellectual wellness awareness, took active participation in class discussions, had good reading habits and carefully selected television programmes and movies

Lexical Richness, a reliable measure of Intermediate L2 Learners’ current status of acquisition of English language

This article aims to explore the utility of the relationship between lexical richness and size as an indicator of acquisition status of English language of L2 learners of intermediate level, having rural background on the basis of their self -written output. 126 students’ essays were used to measure the lexical richness (126 students of Sem-I and 63 students of Sem-II) Lexical Frequency Profile was used to sort it out.  Its values discriminated students of different proficiency level and displayed L2 Learners vocabulary size in use. LFP result’s consistency and legitimacy was obtained by comparing its result with an independent and separate measure of vocabulary size, VLT. The result showed that lexical richness has a direct link with vocabulary size (receptive vocabulary) of L2 learners. It discusses the utility of the inference based on the lexical richness of L2’s written text for monitoring purpose of language acquisition process of L2 learners and to determine appropriate strategies for the desired growth of vocabulary size