Stabilization of A-6 Lateritic Soil using Cold Reclaimed Asphalt Pavement

Abstract

Reclaimed Asphalt Pavement (RAP) was used for stabilization of a deficient lateritic soil, classified as A-6 and CL according to AASHTO and Unified Soil Classification System, respectively. The RAP, in a cold state, was mixed with the lateritic soil at varying percentages of 0, 5, 10, 15, to 100 %. California Bearing Ratio (CBR) and Unconfined Compressive Strength (UCS) were used as evaluation criteria for specimens of the soil-RAP mixtures, compacted at British Standard Heavy (BSH) energy level. The strength evaluation was carried out at 60 % RAP mixture which was found to be the optimum RAP content that gave the highest MDD. Extraction test result on the RAP gave 7.3 % bitumen content which is slightly higher than the 7.0 % maximum recommended. There was 12.7 % increase in MDD which occurred at 60 % RAP content. The Optimum Moisture Content (OMC) decreased by 31.3 %. The result of CBR on the soil and soil mixed with 60 % RAP showed slight increase of 7.2 %, while 9.9 % increase was recorded for the Unconfined Compressive Strength. The slight increase in strength was attributed to the cold state of the asphalt, which makes its adhesive (plastic) properties not pronounced.