مطلوب مهندسين شبكات وفنيين


النتائج 1 إلى 4 من 4
  1. [1]

    تاريخ التسجيل: May 2007
    المشاركات: 9
    Thumbs Up
    Received: 0
    Given: 0

    Polymer-Modified Asphalt (PMA)

    Polymer-Modified Asphalt (PMA)
    spurred transportation officials to look for new ways to add strength and durability to the pavement. One method that is rapidly gaining popularity is the use of polymer-modified asphalt binders. This product is particularly useful for road intersections and heavy truck traffic areas.
    To remain on the cutting edge of the asphalt technology, CITGO Asphalt joined forces with ERGON, Inc. to create a joint venture known as CITERCO. It's two new production facilities - one at CITGO Asphalt's Paulsboro, NJ refinery & the other at its Savannah, GA refinery - are producing polmer modified asphalts known as CITGOFLEX SP which have been specifically designed to meet SUPERPAVE binder specifications.
    This technology, combined with Venezuelan asphalts, results in truly outstanding binders of proven performance.
    For a complete listing of our CITGO Asphalt locations and contactse
    الترجمة للنص

    اسفلت معدل بالبولمير:
    إننا نحث المسؤولين عن الطرق ( المواصلات ) ليبحثوا عن طرق جديدة لتقوية ومتانة قوة إحتمال طبقات رصف الإسفلت , وهي بإستخدام الإسفلت المعدل بالبولميير .
    هذا المنتج هو مفيد خصوصاً للطرق الدولية ذات الحمولات العالية , ومناطق الإزدحام بالسيارات الثقيلة ,
    شركة CITGO قد إنضمت مع شركة ERGON لخلق مجموعة مشتركة بإسم CITERGO .
    مصفاة NG أنتجت هذا الصنف . ومنتجان جديدان إضافيان .
    شركة CITGO تنتج البولميير المعدل من مصفاة GA المعروف بإسم CITGOFLEX .
    والذي صمم خصيصاً لمواجهة متطلبات مواصفات , SUPER PAVE BINDER .

    Performance Grade Asphalt

    CITGO Asphalt has taken the lead in the production of performance based products, by installing state-of-the-art laboratory facilities at each of its asphalt refineries. The labs are fully capable of conducting the rheological testing needed to certify performance-grade asphalt binders as well as to characterize new materials for the company's growing product line.
    The new specifications for performance-grade asphalt binders reflect the expected performance of asphalt under actual climate and traffic conditions.
    To find out why you should consider a change to Performance Grade Asphalt, click here. You will need Adobe Acrobat to view this document.
    For a complete listing of our CITGO Asphalt locations and contacts, click here.

    ترجمة النص

    هذه التقنية ( مجموعة ومصحوبة ) مع VENEZUELAN للإسفلت وقد أنتجت BInDAR رائع كحقيقة إنجاز .
    درجة أداء الإسفلت
    CITGO للإسفلت قد أخذت القيادة والإدارة لإنتاج المواد الأساسية في انتاج الزفت المعدل بالبولميير , بتركيب ووضع مختبر للمواصفات في كل من مصافي الزفت .
    وهذا المختبر مجهز وقادر على ( القيادة والتحكم , الإدارة ) للفحص المطلوب للشهادة , على درجة أداء الإسفلت وأيضاً وضع المواصفات للمواد الجديدة لخط الإنتاج المتزايد للشركة .
    وهذه المواصفات الجديدة لدرجة أداء الإسفلت تعكس الأداء المتوقع للإسفلت تحت ظروف المناخ , ومرور الآليات .
    إنتهى .

  2. [2]
    عضو متميز
    الصورة الرمزية faiqmohmed

    تاريخ التسجيل: Jan 2006
    المشاركات: 273
    Thumbs Up
    Received: 15
    Given: 7
    السلام عليكم اني محمد الجنابي طالب للماجستير في جامعة بغداد بأختصاص المواصلات ارجو من جنابكم المساعدة وذلك بأرسال ما يتوفر لديكم من مواضيع وبحوث بأختصاص superpave ,pmp

    0 Not allowed!

  3. [3]

    تاريخ التسجيل: May 2007
    المشاركات: 9
    Thumbs Up
    Received: 0
    Given: 0
    السلام عليكم :رأيت من المفيد إطلاعكم عليها - مروان العش
    Superpave Models Update
    Gary L. Henderson
    The Federal Highway Administration (FHWA) has contracted with the University of Maryland at College Park for the management and refinement of the Superpave performance models, including supplemental efforts to support State highway agencies (SHA's) implementation of the Superpave system. The contract, which is divided into two phases, provides for continued improvement of all aspects of the Superpave system with emphasis on evaluation and further development of the pavement performance prediction models.
    A main effort of Phase I of this contract, was for the Models Contract Team to evaluate the Superpave performance prediction models that resulted from the SHRP research. A draft evaluation report on their findings was submitted to FHWA on September 30, 1996. The report documents the Team=s evaluation of the existing Superpave pavement performance prediction models and makes recommendations for corrections and enhancements to these models. The evaluation concludes that for the load associated distress models (fatigue and permanent deformation) substantial corrections and enhancements are considered mandatory to make the performance prediction models and analysis software reliable and suitable for general use by the industry. In addition to errors in the programming code, technical constraints, fundamental errors and restrictive assumptions were used in developing the load associated distress models. The existing nonload related models (thermal fracture) have been found to be in reasonably good shape. Revising and enhancing the load associated distress Superpave performance prediction models would require an additional effort to recalibrate and revalidate the resulting models, in order to provide the highway community with a credible product.
    The Superpave Models ETG met on October 22-23, 1996, in Washington, D.C. The ETG consists of representatives from States, industry, academia, and FHWA. The purpose of the meeting was to obtain the feedback of the ETG on the Draft Superpave Models Evaluation Report that has been written by the Models Contract Team. At the meeting, an overview of the report and followup questions were addressed by the Models Contract Team.
    Overall, the ETG was supportive of the many changes that are being proposed. Many members expressed the view that if the models are not enhanced to their fullest potential now, they never will be. There was also the consensus that mix design and structural design are interrelated and that taking this approach would give the Superpave models the broadest applicability within the highway community. They were in general agreement that the calibration and validation of the models is vital and that this should be performed by the existing Team, but there was some concern as to how this should be performed. Some issues are the proposed approach of using reconstituted specimens and whether GPS sites or specially constructed sites should be used. Some of the ETG members are concerned about the traffic data in the LTPP database and its effect on the calibration/validation.
    In the near term (3-5 years) most owner agencies and the industry will be fully involved in adapting to the Superpave volumetric mix design using the gyratory compactor. It was felt that the models would be used to analyze mixes on projects where performance is critical, but that these projects make up a relatively small percentage of the total hot mix asphalt produced. Considering the scope of the work proposed, the ETG advised FHWA not to hold to the current 5 year time line. Extending the time by a couple of years will not diminish the support for this effort.
    The ETG also agreed that review of the models work was important to avoid some of the problems discovered with the original models. They were supportive of frequent presentations to the ETG, and suggested the possibility of review by outside experts.
    The ETG members will be submitting their written comments to the COTR within the next week or two. A meeting is being coordinated whereby the original SHRP principal researchers will have an opportunity to comment on and discuss the Models Evaluation Report. This is to take place by the end of November. Once the input from the Models ETG and the SHRP researchers has been received, a written technical decision on the activities for Phase II of the Models Contract will be prepared. The technical decision will be reviewed by the Superpave Technology Delivery Team who will then forward a consensus position to the Pavement Management Coordinating Group (PMCG) and other management groups. It is anticipated that the final decision can be provided to the contractor by mid-January.
    You may wish to provide this update on the Models Contract to the State highway agency and others working to implement Superpave. When the technical decision for the Phase II work of the Models Contract has been concurred in, we will advise you of the scope of the future action and relative time line for further models refinement. Should you have questions, please feel free to direct them to Ms. Katherine Petros at 202-366-1340 or to any member of the Superpave Team.

    Return to
    Articles about Superpave
    Return to Superpave Home Page

    0 Not allowed!

  4. [4]

    تاريخ التسجيل: Jan 2015
    المشاركات: 2
    Thumbs Up
    Received: 0
    Given: 1
    اريد ان اعمل بحث يتعلق بالاسفلت
    وهو اضافة البلاستك في الاسفلت في الطرق الصحراويه

    0 Not allowed!

الكلمات الدلالية لهذا الموضوع

عرض سحابة الكلمة الدلالية