Properties Of Modified Binders Research Articles

Evaluating the Rheological Properties of Waste Natural Rubber Latex Modified Binder

Road surface is designed to be the durable surface material to sustain the traffic loading. However, due to physical and mechanical stress, pavement deterioration is accelerated. Thus, modifying conventional bitumen by improving its properties is seen as the best method to prolong pavement in-service life. The purpose of this paper is to study the effect of waste natural rubber (NR) latex on rheological properties of bitumen. Conventional bitumen PEN 80/100 was modified with different content of waste NR latex using a high shear mixer at temperature of 150°C. The modified binder properties were characterized by conducting physical test (i.e. softening point, penetration and penetration index) and rheological test (i.e. dynamic shear rheometer, DSR). Results showed that, the addition of waste NR latex improved the rheology properties, which indicates by improving of rutting factor (G*/sin δ). This properties improvement has also shows a potential to resist deformation on road surface despite of high traffic loading.

Structuring role of F-T synthetic wax in bitumen

Abstract The reduction in asphalt mixture production and placement temperatures can be achieved by modifying bitumen 35/50 with the Fischer-Tropsch synthetic wax. To identify the role this modifier plays in the bitumen 35/50, a series of tests has been performed. The experiment was carried out for wax doses from 1.5% to 4.0%. Analysis of the modified binder properties such as ductility at 5, 15 and 25◦C, complex modulus G* with the parameter G*/sinx and LSV, susceptibility according to MSCR procedure, morphology and group type analysis helped describe the structuring function of the F-T wax in the binder. The optimum F-T wax content of 2.5% has been identified to provide the desired parameters required for modified binders.

Performance Evaluation of Waste Polyethylene and PVC on Hot Asphalt Mixtures

Since the forefront invention of Polyethylene and Polyvinyl chloride (PVC), it has been spasmodically used in every possible purpose which is biologically non-degradable and has a blimp environmental problem leading astringent environmental impact. Nevertheless, for such property of sustainability the polyethylene and PVC have been reused in the field of transportation engineering for enhancing the property of asphalt binder, since for having a desirable binding property. At the same time the recycling of waste polyethylene and PVC can save disposal sites and reduce the amount of inert drawn from quarries. In this investigation, waste polyethylene and PVC as the sort of polymer is used to investigate the potential prospects to enhance asphalt mixture properties and to check the design criteria of asphalt mixture using this two modifier at optimum binder content. The investigation concentrated on the test of modified binder properties and Marshall mix design was used, first to determine the optimum binder content and then further to test the modified mixture properties. The tests include the determination of unit weight, stability, flow and voids characteristics. Some of the measured properties of asphalt mixture with the modifier used in this study were within the acceptable recommended limits. On the basis of experimental results, it is concluded that the asphalt mixtures with waste polyethylene modifier up to 10% and waste PVC modifier up to 7.5% can be used for flexible pavement construction in a warmer region from the standpoint of stability, stiffness and voids characteristics.

Laboratory Investigation of HMA Performance Using Hamburg Wheel Tracking and DSR Torsional Creep Tests

Abstract Lack of existing fundamental mechanistic tests to evaluate performance potential of HMA mixtures has given rise to a number of empirical and mechanical-empirical test procedures. In an effort to understand how one of these tests, the Hamburg rutting test, was impacted by differences in HMA mixture variables, the following experimental work was conducted. Three aggregate types consisting of a crushed granite, a crushed siliceous gravel, and a crushed limestone were evaluated at four design ESAL levels. These four ESAL levels were 300 000, 1 million, 3 million, and 10 million. For each of these aggregate types and ESAL levels, 5 PG graded binders were investigated. The binders were PG 58-28, PG 64-28C (chemically modified), PG 64-28P, PG 64-34, and PG 70-28; the latter 3 binders were polymer modified. For all mixtures, Hamburg Wheel Tracking tests were performed under water at 50°C. In addition, a DSR Creep Test developed at MTE was performed on each mixture at 58°C and 34 kPa stress to determine the dry strength characteristics. The Hamburg test showed consistently better results as the ESAL level of the mix increased and as the high temperature PG grade of the binder increased for a given base asphalt. In the Hamburg test, mixes produced with PG 64-34 did not perform as well as PG 70-28 or PG 64-28P, while in the DSR Creep Test, mixes produced with PG 64-34 performed significantly better than PG 64-28P. This leads to speculation that the modulus of the base asphalt plays a more significant role in stress applied moisture resistance tests and that dry high temperature permanent deformation tests are influenced by the modified binder properties.