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Impact of Superpave Mix Design Method on Rutting Behaviour of Flexible Pavements

Thesis Info

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External Link

Author

Khan, Kamran Muzaffar

Program

PhD

Institute

University of Engineering and Technology

City

Taxila

Province

Punjab

Country

Pakistan

Thesis Completing Year

2008

Thesis Completion Status

Completed

Subject

Applied Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/1213

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726425039

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Effective communication is a key to national progress. Pakistan is located in a region where South-Asia converges with Central Asia and the Middle East. Blessed with extensive natural resources and rich agricultural land, it improves its economy particularly by exporting valuable items. In order to improve trade and economic activities and to materialize regional linkages with China, Afghanistan, Iran, Russia and other neighbouring Central Asian countries, the country is gearing up towards a large infrastructure network. Roads constitute a vital part of the infrastructure. In Pakistan most of the roads are constructed using flexible pavement concept, due to their comparatively low construction and maintenance cost. Pakistan has national highways with a length over 9555 Kilometers and motorways of 515 Kilometers. The drastic increase in traffic volume during the last few decades has resulted in premature pavement failures of almost the whole infrastructure of Pakistan. Premature rutting of flexible pavements is one of the major pavement distresses being faced by the country which is primarily due to uncontrolled axle load and high ambient temperatures. Rutting in asphaltic concrete depends on many factors, such as the composition of asphalt mixes, grading and quality of aggregates, type of binder, percentage of the bituminous binder, air void contents, degree of compaction, environmental conditions, load repetition, the substructure, and the bearing capacity of the subgrade. The objective of this research work was to compare the Superpave, Stone Mastic Asphalt (SMA) and Marshall methods of mix design of asphaltic concrete and to propose rut resisting asphalt mix suitable for local loading and environmental conditions. The mixes selected for the study were dense graded in case of Superpave and Marshall methods whereas gap graded for SMA. A comprehensive testing program was conducted on the samples prepared in the laboratory at the design asphalt contents and aggregate gradations. iiiPhysical properties of aggregates and asphalt were determined in the laboratory confirming to ASTM and AASHTO specifications. Mechanical Properties of Marshall, Superpave and Stone Mastic Asphalt (SMA) were evaluated by performing Indirect Tensile Modulus Test, Uniaxial Loading Strain Test (Creep Test), Dynamic Modulus Test and Wheel Tracking Test under prevailing load and environmental conditions of Pakistan in order to compare the performance of mixes. The study revealed that Superpave mixes performed better than Marshall and SMA mixes in terms of low induced permanent strains, high modulus of resilience, high dynamic modulus and better resistance against wheel rutting during wheel tracking test. Superpave technology can be adopted for the design of Hot Mix Asphalt (HMA) pavements in the country due to its superiority over the conventional mix design procedures. The guidelines for implementing Superpave mix design procedure in Pakistan have been proposed. In addition, a performance grading map has been proposed to be implemented in Pakistan by dividing it into seven zones according to the highest and lowest pavement temperatures. Keywords: Superpave, Rutting, Hot Mix Asphalt, Pavement
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ڈاکٹر شہزاد احمد کی شاعری کا فنی جائزہ

ڈاکٹرشہزاد احمد کی شاعری کا فنی جائزہ
سہل ممتنع
ڈاکٹرشہزاداحمد نعت خوانی سے نعت گوئی کی طرف مائل ہوئے ہیں۔ انھیں خیال آفرینی و مرصع کاری سے زیادہ ابلاغ کی فکر رہتی ہے۔ اس لیے وہ کلام میں سادگی کو اہمیت دیتے نظر آتے ہیں۔اُن کے کلام میں بھاری بھرکم تراکیب کی جگہ عام بول چال کے سادہ الفاظ ادائے مطلب کے لیے استعمال ہوئے ہیں۔ ان کی نعت کی مرکزی خصوصیت سہل ممتنع ہے جس کے بارے میں مولانا حسرت موہانی لکھتے ہیں :
’’سہل ممتنع سادگی وحسن بیان کی اُس صنف کا نام ہے جس کو دیکھ کر ہر شخص بظاہر یہ سمجھے کہ یہ بات میرے دل میں بھی تھی اور ایسا کہنا ہر شاعر کے لیے آسان ہے مگر جب کوشش کرکے ویسا لکھنا چاہے تو نہ لکھ سکے۔‘‘ (۲۴)
یہی سادہ اسلوب ہمیں ڈاکٹر شہزاد احمد کی نعت میں بڑے سلیقے سے برتا ہوا ملتا ہے۔ مثال میں دو شعر ملاحظہ ہوں:
آپ صرف اپنے محبوب کا
مجھ کو شیدا بنا دیجیے

پھر جہاں میں ہے تیرگی چھائی
اپنا جلوہ دکھائیے آقاؐ
غنائی لہجہ
شاعری میں موسیقیت نہ ہو تو کلام فصاحت سے کوسوں دُور رہتا ہے۔ موسیقیت کے لیے آواز کے زیرو بم کے استعمال سے واقفیت ضروری ہے۔ ڈاکٹر شہزاد احمد چوں کہ نعت خوانی سے بھی وابستہ ہیں۔ اس لیے اُن کے کلام میں غنائیت کا عنصر اوج پر ہے۔ پروفیسرنویدعاجز ؔ اس بارے میں یوں رقم طراز ہیں:
’’انھوں نے نعتیں محافل میں پڑھنے کے لیے لکھی ہیں، اس لیے اُن کی سب سے بڑی خوبی موسیقیت اور روانی ہے۔ ’’حبیبی یارسول اللہ، درودتم پر سلام تم پر اور بسم اللہ ‘‘ کی ردیف میں کہی گئی نعتیں مترنم لہجے کی حامل ہیں۔‘‘(۲۵)
ڈاکٹر شہزاداحمد کے کلام میں روانی اور مترنم لہجے کے اشعار کی کمی نہیں۔ چند مثالیں ملاحظہ ہوں:

الدر المختار کا سندھ میں مطالعہ: ایک تحقیقی جائزہ

A well Known book Durr al-Mukhtār has great importance in Ḥanafī School of thought. This is mainly due to its conciseness and comprehensiveness. This is why most of Ḥanafī Scholars has worked on it by editing the manuscripts and writing scholarly footnotes annotation which numbered more than sixty.   Al-Durr al-Mukhtār has remained law book in sub-continent. Sindhi scholars have also written commentaries and footnotes on this master piece of the latter Ḥanafī school of thought. This paper attempts to introduce these standard works in detail. 

Production and Molecular Characterization of Wide Cross Derivatives in Rice

Cultivated rice (Oryza sativa L.) is an important staple food for more than half of the people all around the world. Rice has a very narrow gene pool which can be broadened through transgression of genes from wild species for improving the cultivated rice. A comprehensive wide hybridization program was started at Department of Genetics, Hazara University, Mansehra, Pakistan. Four commercial varieties viz., Bas-385, JP-5, Fakhre Malakand, Swat-1 and two wild species of rice i.e. Oryza rufipogon and O. longistaminata were used in this endeavor. Seed viability of the germplasm was recorded and its dormancy was broken down for synchronized flowering. Interspecific crosses were made between commercial varieties and Oryza rufipogon. The pollinated spikelets were sprayed immediately with 75 ppm GA3 to enhance pollination. A mixture of growth regulators (100 ppm GA3, 25 ppm NAA and 5 ppm Kinetin) was applied twice a day for 7 days continuously to prevent embryo abortion. The F1 hybrids were confirmed through phenotypic markers such as color of the basal leaf sheath, stigma and awn color, pollen fertility, meiotic analyses, seed proteins, response to bacterial blight, phenotypic trait analysis in F2 and resistance pattern to bacterial blight in the F3 progeny. Total seed protein profile was also helpful in confirmation of the F1 hybrid. Results regarding the seed viability revealed significant results ranging from 78 - 92%, the lowest (78%) being recorded for the commercial variety Swat-1. Results of the seed dormancy, showed that O. rufipogon and O. longistaminata remained dormant and did not show any sign of germination at 32°C. The dry heat treatment of seed at 50°C, after remaining hull, improved the germination. The optimum temperature for germination was 35 ± 50 °C x and 40 ± 50 °C for the commercial varieties and wild species, respectively, in the lab. The quantitative traits also showed considerable diversity i.e., medium to high variance was recorded for culm length, culm diameter, culm number, peduncle length, leaf width, leaf area, flag leaf width, flag leaf area, ligule length, auricle length and anther length. Dendrogram analyses of the phenotypes sortout all genotypes into two main clusters A and B. Cluster A was comprised of commercial varieties along with their wild proginator O.rufipogon. Cluster A contained further two sub clusters A1 and A2. The sub cluster A1 consisted JP-5 and Fakhre Malakand that belong to O. sativa ssp. Japonica, whereas A2 consisted Indica type varieties along with O. rufipogon. The group B consisted O. longistaminata only. The total seed protein analyses showed 19 bands providing genetic distance estimates from 0–45%. Dendrogram constructed on the basis of total seed protein also sortedout all the genotypes into A and B main clusters. Where cluster A constituted the commercial varieties while cluster B consisted of wild species. Cluster A was further sub divided into two sub groups, A1 and A2. Sub cluster A1 was comprised of Japonica type varieties whereas A2 was comprised of Indica type varieties, the cluster B consisted of wild species only. Maximum genetic distance was observed between Bas-385 and O. longistaminata. Varities JP-5 and Fakhre Malakand showed 100% homology on the basis of total seed proteins. Cytogenetic analyses showed that all the genotypes had normal meiosis with remarkably high degree of chromosome pairing at M1. All the parents had a consistent chromosome number of 2n = 24, exhibiting one to one synapsis and one by one disjunction. Molecular analyses showed the presence of bacterial blight resistant gene Xa-21 in O. longistaminata. Oryza rufipogon, O. longistaminata, Bas-385 and Fakhre xi Malakand exhibited xa-13 gene. Varieties JP-5 and Fakhre Malakand showed the presence of xa-5 gene through PCR analysis. Resistance response to bacterial blight showed that the wild species were highly resistant to all the three local isolates of bacterial blight. Among the commercial varieties, Bas-385 proved moderately susceptible to Xoo-2 & Xoo-3, and moderately resistant to Xoo-1. Swat-1 proved to be highly susceptible to Xoo-2 and Xoo-3 and moderately susceptible to Xoo-1. The varieties JP-5 and Fakhre Malakand were moderately resistant to Xoo-1 and Xoo-2 and moderately susceptible to Xoo-3. Results of the interspecific crosses reveled that seed setting was generally very low ranging from 5.3 to 8.9% while its germination percentages ranged from 0–17.2%. Among the cultivated varieties only Bas-385 produced viable F1 hybrids when crossed with O. rufipogon. The F1 hybrids manifested heterosis for most of the quantitative traits. The syndatic behavior of chromosomal compliments of O. sativa and O. rufipogon, were analyzed in F1 hybrids. The frequently observed univalents, trivalents and laggards proved the hybrid nature of PMC’s. At metaphase I, all hybrids had more than 11.6 bivalents and 23.3 chiasma/PMC. Although on average all the hybrids showed normal meiosis, they produced 50-60% sterile pollen resulting in 85-95% spikelet sterility. Sixty three randomly selected F2 individual plants were evaluated on the basis of 14 quantitative traits. Basic statistics showed a considerable variability among the F2 genotypes for different traits. The response to bacterial blight showed that most of the F3 plants were resistant to bacterial blight isolates. Lines No, 1, 5, 10, 11, 12, 14, 20, 23, 24, 27, 29 and 30 proved highly resistant to all the three isolates of bacterial blight. Other lines showed differential responses to different Xoo isolates. The results showed that considerable xii variability with respect to the bacterial blight resistance was available in the F3 progeny, wherein the highly resistant germlines were selected as promosing lines for their potential use in genetic improvement of the cultivated rice.