Abstarct

There is a growing need for the production of a certain types of asphaltic materials having a good rheological properties compared with the non-modified a asphaltic materials can be using as a paving materials.In this research Rheological properties of Beije asphalt modified using oxidation process in the present of Sulphur and chlorides of (iron and zink).In this research we obtained asphaltic materials which can be used in paving and mastic according to the measuring of the (ductility, penetration and softening point.

Keywords

Export bibliographic record

Choose an application

• Reference Manager
• EndNote
• BibTex

Abstarct

It is clearly evident that the service sector, especially recently, requiring discussion and solution. Because this section involves the daily life of the citizen and is complex in nature and requires urgent consideration to determine points of weakness during implementation stage in Baghdad city (both sides). Road and highway are vital in Baghdad where roads maintenance having a great significance.Through observation of materials used and the performance of working standard involved, it has become operant where failure can be visible. This paper reflects evidence through observation of laboratory tests of asphalt mixtures and their failure and the repeat of divergence from. General specification for road and bridge. Department of planning and studies 2003, revised edition 2003. It also, covers operational performance of road and streets covered by this study by comparison of deviations between laboratory tests results for these roads andstreets and actual performance after certain period of time. The conclusion shows special divergence (through aggregate graduation of asphalt mixture, bitumen percentage, marshal stability, degree of compaction and asphalt layer thickness). These divergences are effective and commonly repeated which require certain action to a void failure by doing job mix formula according to the requiredspecification for the used layer course in addition to used the raw material that successful in laboratory tests with the implementation with the correct steps that giving the correct depth of layers. Consequently, better performance standards can be achieved.

Keywords

Export bibliographic record

Choose an application

• Reference Manager
• EndNote
• BibTex

Abstarct

AbstractThe main objective of this research study is to investigate the potential useof pyrolisis polypropylene as modifiers in hot mix asphalt paving mixtures. Sevendifferent blends including conventional mix were subjected to binder testing suchas rheological tests, as well as to some other tests related to the homogeneity ofthe system.Optimum asphalt content was obtained by Marshall method and used in allthe modified mixes. The engineering properties, including Marshall stability andindirect tensile strength were determined. Research results indicate that modifiedbinders showed higher softening point, keeping the vales of ductility at minimumrange of specification of (100cm), and caused a reduction in percent loss ofweight due to heat and air (i.e. increase durability of original asphalt). The resultsindicated that the inclusion of pyrolisis polypropylene with asphaltic concretemixtures gave a quite satisfactory result in terms of stability and other Marshallproperties, and increase in indirect tensile strength).Keywords: polypropylene, polymers, asphalt modifiers, Asphalt binders

Keywords

Export bibliographic record

Choose an application

• Reference Manager
• EndNote
• BibTex

Abstarct

Improving the ability of asphalt pavement to survive the heavily repeated axle loads and weathering challenges in Iraq has been the subject of research for many years. The critical need for such data in the design and construction of more durable flexible pavement in bridge deck material is paramount. One of new possible steps is the epoxy asphalt concrete, which is classified as a superior asphalt concrete in roads and greatly imparts the level of design and construction. This paper describes a study on 40-50 penetration graded asphalt cement mixed with epoxy to produce asphalt concrete mixtures. The tests carried out are the Marshall properties, permanent deformation, flexural fatigue cracking and moisture damage. Epoxy asphalt mixes performed better on resistance to fatigue and permanent deformation. They also performed significantly better on low-temperature properties and resistance to moisture damage. The addition of 30 percent of epoxy (by weight of asphalt cement) resulted in increase of Marshall stability by 39.8 percent, improve the tensile strength ratio by 22.9 percent, lowering both the rate of permanent deformation by 26.8 percent and the fatigue accumulation coefficient by 53.5 percent, in comparison with control HMA. Based on the above findings, it is recommended to use epoxy asphalt mixes as an optimal material for paving bridges deck in Iraq since it showed good prospects for this application due to the valuable performance and durability improvement.

Keywords

Export bibliographic record

Choose an application

• Reference Manager
• EndNote
• BibTex

Abstarct

There is a growing need for the production of certain types of asphaltic materials having good rheological properties compared with the unmodified asphaltic materials, thus many experiments were performed to prepare a modified asphalt that can be used in different fields. This study aims to modify asphalt with the addition of (spent lubricating oils) with different percentages and with air blowing oxidation.From this work we obtained the asphaltic materials which can be used in paving and mastic production according to the measuring of the (ductility, penetration, asphaltene and softening point)

Keywords

Export bibliographic record

Choose an application

• Reference Manager
• EndNote
• BibTex

Abstarct

Rutting is often responsible for premature maintenance and rehabilitation activities reducing service life of the pavement. Several finite element computer programs for analyzing flexible pavements have been developed over the years. Most of these programs (like ANSYS)did not take into consideration the effect of the aging factor on the behavior of viscoelastic asphalt concrete layer. The present work uses a displacement based finite element method to compute vertical compression strain and rutting depth for a flexible pavement system of three layers taking into consideration the aging (temperature) effect depending on Williams, Landel and Ferry (WLF) equation. Two popular tire/axle configurations with different tire pressure are investigated using the traditional approximate circular tire print.The results showed that the difference between the proposed technique and some other methods neglecting aging effect ranges from 5% to 15% while the difference between the proposed technique and linear elastic Pro-Engineer (version 4) program ranges from 10% to 17%.

Keywords

Export bibliographic record

Choose an application

• Reference Manager
• EndNote
• BibTex

Abstarct

In the present work a modification was made on three equations to represent the experiment data which results for Iraqi petroleum and natural asphalt. The equations have been developed for estimating the chemical composition and physical properties of asphalt cement at different temperature and aging time. The standard deviations of all equations were calculated. The modified correlation related to the aging time and temperature with penetration index and durability index of aged petroleum and natural asphalts were developed. The first equation represents the relationship between the durability index with aging time and temperature. The second equation represents the relationship between the penetration index with aging time and temperature. The third equation represents the relationship between the durability index with penetration index. The values of penetration index and durability index for all aged samples were compared with predicted values. These correlations give a percent of error in the range of 1.2 to 7.4%.

Keywords

Export bibliographic record

Choose an application

• Reference Manager
• EndNote
• BibTex

Abstarct

The increase in road traffic during the last two decades in combination with an insufficient degree of maintenance due to shortage in funds have caused an accelerated and continuous deterioration of the road network in Iraq. To alleviate this process, several types of measures may be effective, e.g., securing funds for maintenance, improved roadway design, use of better quality of materials and the use of more effective construction methods. In this research, waste plastic bags as one sort of polymers and polypropylene fiber are used to investigate the potential prospects to enhance asphalt mixture properties. The objectives also include determining which one of the two additives is better than the other to be used and its proportion. The two additives were introduced to the mixture in state of small pieces (2-4 mm). Marshall mix design was used, first to determine the optimum bitumen binder content and then further to test the modified mixture properties. In total, (51) samples were prepared (15 samples were used to determine the optimum binder content and the remaining samples were used to investigate the effect of modifying the asphalt mixtures). The optimum asphalt content was (5 %). Six proportions of each additive type and stated by weight of the optimum binder content were selected to be tested (2, 4, 6, 8, 10, and 12%). The tests include the determination of bulk density, stability and flow. Marshall Mix design requires the determination of the percentages of air voids and air voids of mineral aggregate. The results indicated that polypropylene fiber (PPF) modifier provides slightly better engineering properties. The recommended proportion of the polypropylene fiber (PPF) modifier is not more than (6%) by the weight of bitumen content, while it is not more than (8%) for recycled plastic bags (polyethylene). It is found to increase the stability, reduce the density and slightly increase the air voids and the voids of mineral aggregate, but no clear effect on the flow for both additives.

Keywords

Export bibliographic record

Choose an application

• Reference Manager
• EndNote
• BibTex

Abstarct

Asphalt durability is often linked to the thickness of the asphalt coating on the aggregate particles. In order for a pavement to have adequate film thickness, there must be sufficient space between the aggregate particles in the compacted pavement. This void space is referred to as Voids in the Mineral Aggregate (VMA). It must be sufficient to allow adequate effective asphalt (that which is not absorbed into the aggregate particles) and air voids.Marshall mix design was used, first to determine the optimum bitumen binder content and then further to test the mixtures properties of the various filler / asphalt ratio asphalt mixtures. In total, 75 samples were prepared to investigate the optimum asphalt content of the various mixes and to specify properties of them. Five proportions of asphalt cement binder were used for each mix type and state by weight of the total mix (4, 4.5, 5, 5.5, and 6). The tests include the determination of bulk specific gravity, maximum (theoretical) specific gravity, stability and flow. Marshall mix design requires the determination of the percentages of air voids, voids in mineral aggregate, and voids filled with asphalt.Due to the results, we found out that when the filler asphalt ratio is in the range between 1.2 and 1.5, the mixture's performance are better in all respects. If some aspects of mixture performance need to be modified, the filler asphalt ratio can adjusted on this basis.

Keywords

Export bibliographic record

Choose an application

• Reference Manager
• EndNote
• BibTex

Abstarct

This research investigates the influence of recycled mixture modified with styrene-butadienestyrene (SBS) polymer on rutting resistance. The reclaimed asphalt pavement (RAP) mixture percentages were used 10, 20 and 30% by weight of original mixture and one percentage of SBS polymer which was 5% by weight of asphalt cement. The moisture susceptibility and rutting were taken into consideration in this study. The results indicated that the recycled asphalt mixture containing on SBS polymer gives better moisture susceptibility and better rutting resistance. It is noted that indirect tensile strength ratio (ITSR) increases when adding SBS with 5% percentage polymer and reaching its maximum ratio 94.5% for 20% RAP and the rut depth decreases by 66.7% when adding SBS with 30% RAP content.

Keywords

Export bibliographic record

Choose an application

• Reference Manager
• EndNote
• BibTex