Prediction Models for Modified Pavement Mixtures by Reclaimed Asphalt in Terms of Durability Indicators

The asphaltic pavement is often subjected to various types of distress during the service life caused by excessive load, construction practices, deficient materials, and environmental conditions. A lot of pavements may occur due to moisture damage because of the presence of water on the pavement's surface, which affects the pavement's service life. It needs periodic maintenance, which requires materials and money. So many countries take the economic side by reusing old, damaged pavement and mixed with new materials in addition to its sustainable benefits, the old material called reclaimed asphalt pavement (RAP). This study examines the effect of adding RAP on durability indicators, including tensile strength ratio, retained Marshall Stability, and durability Index, in addition to prediction statistical models for reclaimed asphalt pavement mixtures in terms of durability indicators. To achieve the goals of this study, the asphalt mixtures are designed according to the superpave system; the samples are compacted by a superpave gyratory compactor with a diameter of 100 mm and prepared with (6%, 13%, 19%, and 25%) RAP content with three conditioning periods of (1, 3, and 7) days and two aging periods (short term aging for loose mixture at 135˚C for 4 hours long term aging for 120 hours at 85˚C), and two testing temperature of 25˚C and 60˚C. The results indicated that stability increased as the RAP content increased compared to the control mix, and indirect tensile strength increased with RAP addition for both aging periods. Also, results illustrated that the tensile strength ratio for specimens tested at 25˚C is higher than that tested at 60˚C temperature

TENSILE STRENGTH FOR MIXTURE CONTENT RECLAIMED ASPHALT PAVEMENT

This paper is studying the effect of two different heating temperature of RAP on performance of water sensitivity tests, the Indirect Tensile Strength Ratio (TSR). the best gradation and optimum asphalt content was Selected according to Superpave method. Superpave Gyratory Compactor (SGC) used to compact mixture with 100-mm diameter. Four different percentages (20,30,40 and 50) of RAP used for preparation mixes to compared with virgin mixture. The test results indicated that addition RAP to mixes shows significant increase on resistance of moisture damage (TSR) for 110 cﹾ for all percent. For 140 cﹾ showed (TSR) increase to threshold (20%) of RAP while (TSR) decline for another percent but still above the standard limit of 80%