The Potential Use of Crumb Rubber in Hot Asphalt Mixes in Egypt Using Dry Process”

Abstract

At the beginning of this research this thesis reviewed a literature of tires, different methods of tires processing, different methods to use crumb rubber as a modifier with hot asphalt mixtures and modification concept of dry mixed rubberized asphalt mixtures The second step was designing an experimental program for investigating the ability to use the crumb rubber as a modifier to the most frequently use hot asphalt mixture in Egypt (4-C);the used material used also was the comely used material in Egypt. This experimental program was divided to two parts; the first part was a set of validation tests to make sure that all materials can be used in pavement construction; these tests were designed for each material separately. The bitumen was tested for softening point, penetration, and rotational viscosity; aggregate were also tested for absorption, Los Angeles test and flakiness & elongation test. The second part was about designing the control mixture using Marshall Design method to be compared with other crumb rubber mixtures. A comparison between the control mixture and other crumb rubber mixtures was performed to study the effect of using the crumb rubber as a modifier with 4-C asphalt mixtures using a set of test like stability and flow test, indirect tensile strength test, dynamic modulus test and flow number.