Marshall Properties Research Articles

EFFECT OF USING WASTE CEMENT DUST AS A MINERAL FILLER ON THE MECHANICAL PROPERTIES OF HOT MIX ASPHALT تأثير استخدام بودرة تراب الأسمنت على الخواص الميکانيکية للخلطات الأسفلتية

By pass cement dust is proposed within this research as an alternative to traditional limestone mineral filler in hot mix asphalt (HMA). The effect of using waste cement dust as a mineral filler on the mechanical properties of hot mix asphalt was investigated. The optimum cement dust content was determined. The studied mechanical properties include Marshall properties, indirect tensile strength, and unconfined compressive strength. Five asphalt concrete mixtures with various cement dust contents, namely; 0%, 25%, 50%, 75% and 100% by weight of the limestone mineral filler were studied. Laboratory testing has revealed an enhancement in Marshall and mechanical properties of asphalt concrete mixtures when cement dust was used. Marshall testing results have indicated an increase in the stability, unit weight and a decrease in the flow, voids ratio and voids in mineral aggregates when the percentage of cement dust content increases. The indirect tensile strength and unconfined compressive strength have also increased as the ratio of cement dust increased. The optimum cement dust ratio was found to be 100% of the used mineral filler. Hence, cement dust can totally replace lime stone mineral filler in asphalt paving mixtures.

Feasibility of Crumb Rubber Use for Asphalt Pavement Construction

There are two processes of adding crumb rubber modifier (CRM) to hot mix asphalt (HMA), that is, the wet process and the dry process; and different technologies are available for each process. On the basis of the results of the binder study and producer's practices, HMA specimens were prepared using two selected AR binders with Producer R and A CRMs for Rhode Island (RI) dense-graded and dense-graded friction course (DGFC) mixtures, respectively. Aggregates procured from four local asphalt contractors were used. In addition, gap-graded HMA specimens were prepared with 3 percent CRM and control AC-20 binder with two typical local aggregates using the dry process. Marshall mix design was performed on all mixtures to determine optimum binder content and Marshall properties. Mechanical properties were evaluated for the mixtures with and without CRM. Superpave Level I mix design was also performed for dense-graded, DGFC, and gap-graded mixtures with aggregates procured from Contractor C. Finally, the performan...

Feasibility of Crumb Rubber Use for Asphalt Pavement Construction

There are two processes of adding crumb rubber modifier (CRM) to hot mix asphalt (HMA), that is, the wet process and the dry process; and different technologies are available for each process. On the basis of the results of the binder study and producer's practices, HMA specimens were prepared using two selected AR binders with Producer R and A CRMs for Rhode Island (RI) dense-graded and dense-graded friction course (DGFC) mixtures, respectively. Aggregates procured from four local asphalt contractors were used. In addition, gap-graded HMA specimens were prepared with 3 percent CRM and control AC-20 binder with two typical local aggregates using the dry process. Marshall mix design was performed on all mixtures to determine optimum binder content and Marshall properties. Mechanical properties were evaluated for the mixtures with and without CRM. Superpave Level I mix design was also performed for dense-graded, DGFC, and gap-graded mixtures with aggregates procured from Contractor C. Finally, the performance of pavements with and without CRM was predicted using the computer program VESYS. Results of this study indicated that the use of CRM is feasible for RI dense-graded and DGFC mixtures utilizing the wet process.

Design of Polyvinyl Chloride Tar Mixes for Resistance to Permanent Deformation

Abstract The problem of shortages of normally acceptable materials can be alleviated by using low- and marginal-quality materials through selective use of stabilization. In areas where coal is prevalent coke-oven tar, modified with small quantities of polyvinyl chloride (PVC), can be mixed with sand to produce good paving material. Static and dynamic tests performed on PVC tar-sand mixtures show that the addition of PVC produces vast improvements in the Marshall properties and the resistance to permanent deformation, with only marginal influence on the compatibility. Mix design based on repeated loading tests at various temperatures suggests that the addition of PVC reduces the optimum binder content.