الفهرس | Only 14 pages are availabe for public view |
Abstract The reclaimed asphalt pavement is one of the most recycled materials in the world. In Egypt, there are about 4 million tons per year of reclaimed asphalt materials are not used. Five dense grading mixtures of hot mix asphalt by using recycling asphalt pavement percentage of 0%, 25 %, 50 %, 75 %, and 100 % were designed by using Marshall method to study the effect of RAP on the mechanical and volumetric mix properties as a measure of mix acceptability. The investigated mechanical properties were such as Marshall quotient as a measure of stiffness resistance, rut depth as a measure of rutting resistance, indirect tensile strength and resilient modulus as a measure of resistance to shear stresses whereas the studied volumetric properties were included percentage air voids (Va), percentage volume of bitumen (Vb), percentage void in mineral aggregate (VMA) and percentage voids filled with bitumen (VFB). Loss of the integrity of a HMA mix through weakening of the bond between the aggregate and asphalt cement is known as stripping, when a weakening in the bond occurs, loss of strength of the HMA can be sudden, stripping causes rutting, shoving, corrugations, raveling, cracking and shoving .Thus, the effect of RAP addition ratio on the stripping tendency was also investigated to illustrate the moisture susceptibility of RAP. Finally, the benefits and saving in cost of materials was achieved by using the national asphalt pavement association (NAPA) method to evaluate the cost benefits for each RAP percentage used in hot mix asphalt mixtures. |