Reconstituted Coal Ash Stabilization of Reclaimed Asphalt Pavement

A laboratory evaluation of the characteristics of reconstituted coal ash stabilized reclaimed asphalt pavements (RAP) subjected to British Standard light, BSL (standard Proctor) compactive effort to determine the compaction characteristics and California bearing ratio (CBR) values was carried out. Test results show that the properties of RAP improved when treated with reconstituted coal ash, RA (coal fly ash, FA + coal bottom ash, BA). The particle size grading improved from 99.9% coarse aggregates and 0.1% fines for 100% RAP to 93 – 99% coarse aggregate with 1 – 7% fines for the various reconstituted coal ash-RAP mix proportions. The CBR values also improved from 13 and 9% for the unsoaked and soaked conditions respectively, for 100% RAP to 60% and 66% (soaked condition) for 10%RA(40%FA + 60%BA) + 90%RAP and 40%RA(20%FA + 80%BA) + 60%RAP mixes with corresponding unsoaked CBR values of 27 and 34%. Generally, soaked samples recorded higher CBR values than unsoaked samples. The reconstituted coal ash stabilized RAP proportion of 40%RA(20%FA + 80%BA) + 60%RAP and 10%RA(40%FA + 60%BA) + 90%RAP with CBR values of 66 and 60% (soaked for 24 hours) can be used as subbase or subgrade materials in road construction.