LABORATORY AND FIELD EVALUATION OF A-6 LATERITIC SOIL TREATED WITH RECLAIMED ASPHALT PAVEMENT AND ORDINARY PORTLAND CEMENT

An A-6 lateritic soil was stabilized with Reclaimed Asphalt Pavement and 2% cement. The lateritic soil was mixed with 0, 20 to 140% RAP and each mixture compacted in the laboratory. The soil mixed with120% RAP gave the highest Maximum Dry Density of 2.252Mg/cm3. Laboratory California Bearing Ratio test was conducted on the soil, soil/120% RAP and soil/120% RAP/2% cement. A 15m section of untarred road was identified and demarcated into three sections (A, B and C) of 5.0m each. Materials on section A of the road composed of the lateritic soil/120% RAP/2% cement, section B contains lateritic soil/120% RAP, while section C composed of the lateritic soil only. The sections were compacted using smooth drum vibratory roller. In-situ density test and CBR test using Dynamic Cone Penetration test were carried out on the three sections of the road after 1, 7, 14, 28, 60 and 90days. The laboratory densities of materials used for the three sections are 2.254, 2.252 and 2.154g/cm3, while in-situ densities after 60 days were 2.249, 2.225 and 2.142Mg/cm3 for sections A, B and C respectively. The laboratory CBR values after 60 days were 118, 37 and 22%, while the field CBR values were 44.5, 49.0 and 112% for sections A, B and C respectively. It was concluded that in-situ and laboratory densities and CBR values closely agreed. However, the maximum densities were observed after 60days of field compaction. Also, only 90% of in-situ dry density was achieved immediately after the field compaction.