Evaluation of Asphalt Concrete Containing SBS and SBR Modified Binder PDF Download

Author: Donald W. Christensen
Publisher:
ISBN:
Category :
Languages : en
Pages : 16

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Author: Shad M. Sargand
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 188

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Book Description
The objectives of this study were to evaluate the effects of aggregate gradation and polymer modification on rutting and fatigue resistance of Superpave mixes. Asphalt mixes were prepared using three different gradations (above, through, and below the restricted zone) and three PG 70-22 binders (unmodified, SBS and SBR modified), and were evaluated using a triaxial repeated load test, a static creep, the Asphalt Pavement Analyzer, and the flexural beam fatigue test. When aggregates meeting Superpave angularity requirements was used, the effects of gradation on the rut and fatigue resistance of Superpave mixes were relatively small and the effects of the restricted zone was not significant. Even though binders used in this study had similar dynamic shear moduli, mixes containing polymer modified binders showed significantly lower resilient moduli than the unmodified mixes when measured in the indirect tensile and triaxial compressive modes. All laboratory test results indicated that the polymer modified mixes were significantly more rut resistant and fatigue resistant than the unmodified mixes with the same PG grading. Improvement in rut resistance due to polymer modification was shown to be most significant in the triaxial repeated load test, especially at a higher-temperature. Accelerated Pavement Load test results showed the similar trends regarding rutting performance. At higher test temperature or at a fast wheel speed, mixes with polymer modified binder performed better than mixes with an unmodified binder.

Author: Gajanan Suresh Natu
Publisher:
ISBN:
Category : Asphalt concrete
Languages : en
Pages : 338

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Author: Jose Luis Rivera Armenta
Publisher: BoD – Books on Demand
ISBN: 1789237262
Category : Technology & Engineering
Languages : en
Pages : 142

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Asphalt modification is an important area in the development of new road and pavement materials. There is an urgent demand for road materials that can minimize fracture at low temperatures and increase resistance to deformation at high temperatures. The function of asphalt is to bind aggregate to protect it from water and other harmful agents. In the beginning asphalt was ideal for this purpose, but recently traffic loads have increased and environmental factors have deteriorated more rapidly than before. Asphalt is a byproduct of crude oil in the refining process, and it is considered a complex heterogeneous mixture of hydrocarbons. Asphalt modification has become an important research area, using several methods and new materials as modifiers.

Author: Gaylon L. Baumgardner
Publisher:
ISBN:
Category :
Languages : en
Pages : 284

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Asphalt binder modification is a common method of improving Hot-mix Asphalt (HMA) performance by enhancing mix properties and reducing or delaying three general HMA distress types: deformation (rutting and shoving), cracking (from repeated loads and low temperatures) and general deterioration (raveling and stripping). Since the early 1960’s, a common modified asphalt alternative has employed reclaimed rubber as an economical and environmental friendly method of recycling waste tires while improving asphalt physical and mechanical properties. Pavement network deterioration combined with increasing material costs makes polymer modification of asphalt binder desirable, with reclaimed rubber from waste tires being an attractive alternative which addresses performance, economics and environmental issues. The primary objective of this dissertation is to demonstrate the importance of proper processing of all types of modified bituminous binders, whether they be virgin (e.g. styrene-butadiene-styrene (SBS) or styrene-butadiene rubber (SBR)), post-consumer polymers (e.g. ground tire rubber (GTR)) or a combination (GTR plus SBS). To achieve this four secondary objectives were identified: 1) characterize GTR using thermo-gravimetric analysis (TGA), 2) improve processing of GTR modified binders, 3) improve testing and specifications of GTR modified binders and 4) evaluate mixes containing GTR modified binders. A simple efficient instrumental, TGA, method to analyze polymers in binary rubber compounds was developed to quantify the functional polymer content available in GTR. TGA analysis provides a better understanding of the general chemical characteristics of GTR used in modification of asphalt binders for production of asphalt paving mixtures. Results are presented from efforts to optimize GTR modified binder formulations with respect to how GTR loading, GTR particle size, processing temperature and asphalt cement source affect modified binder properties and ability to meet performance graded binder specifications. These results are the basis to establish recommended processing parameters for formulation and preparation of GTR modified asphalt binders. GTR modified binders were used in: dense graded asphalt (DGA), stone matrix asphalt (SMA) and open graded friction courses (OGFC) and compared to conventional asphalt cement and styrene-butadiene-styrene (SBS) modified asphalt binders. Mixture performance evaluation with respect to binder effectiveness as it relates to the three general HMA distress types.

Author: David A. Anderson
Publisher: Strategic Highway Research Program (Shrp)
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 504

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Author: D. Y. Lee
Publisher:
ISBN:
Category : Asphalt cement
Languages : en
Pages : 178

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Book Description
Effects of polyolefins, neoprene, styrene-butadiene-styrene (SBS) block copolymers, styrene-butadiene rubber (SBR) latex, and hydrated lime on two asphalt cements were evaluated. Physical and chemical tests were performed on a total of 16 binder blends. Asphalt concrete mixes were prepared and tested with these modified binders and two aggregates (crushed limestone and gravel), each at three asphalt content levels. Properties evaluated on the modified binders (original and thin-film oven aged) included: viscosity at 25 deg C, 60 deg C and 135 deg C with capillary tube and cone-plate viscometer, penetration at 5 deg C and 25 deg C, softening point, force ductility, and elastic recovery at 10 deg C, dropping ball test, tensile strength, and toughness and tenacity tests at 25 deg C. From these the penetration index, the viscosity-temperature susceptibility, the penetration-viscosity number, the critical low-temperature, long loading-time stiffness, and the cracking temperature were calculated. In addition, the binders were studied with x-ray diffraction, reflected fluorescence microscopy, and high-performance liquid chromatography techniques. Engineering properties evaluated on the 72 asphalt concrete mixes containing additives included: Marshall stability and flow, Marshall stiffness, voids properties, resilient modulus, indirect tensile strength, permanent deformation (creep), and effects of moisture by vacuum-saturation and Lottman treatments. Pavement sections of varied asphalt concrete thicknesses and containing different additives were compared to control mixes in terms of structural responses and pavement lives for different subgrades. Although all of the additives tested improved at least one aspect of the binder/mixture properties, no additive was found to improve all the relevant binder/mixture properties at the same time. On the basis of overall considerations, the optimum beneficial effects can be expected when the additives are used in conjunction with softer grade asphalts.

Author: Ronald E. Reese
Publisher:
ISBN:
Category : Binders (Materials)
Languages : en
Pages : 66

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Author: Hussain Bahia
Publisher:
ISBN:
Category : Pavements, Asphalt
Languages : en
Pages : 92

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Author: Alekh S. Bhurke
Publisher:
ISBN:
Category : Asphalt concrete
Languages : en
Pages : 412

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