This study was aimed to minimize the use of natural river sand which is being used for several years in construction, and to utilize bottom ash from thermal power station as a partial replacement (30%, 60%, 100%) for fine aggregate. An experimental investigation has been carried out to find the compressive strength of the replaced eco-friendly green concrete with different curing methods. An equation recommended by ACI committee for conventional concrete was used to predict 56, 90 and 180 days compressive strength from 28 days compressive strength of the eco-friendly green (bottom ash) concrete that resulted with the difference between the experimental and predicted compressive strength to ± 12%. To minimize the percentage of difference, an empirical relationship was developed between the compressive strength of accelerated curing and normal curing (28, 56, 90, 180 days). It is concluded that empirical relationship predicts later age compressive strength with the minimum percentage of difference. This study of predicting later age compressive strength from empirical relationship will ultimately save time, material and most importantly assessing the quality of the design of construction.