As we know day by day commercial vehicles are on hike and with this rate of increment our soil should be sustainable to take higher and increased stress without failure. In this work we will try to replace our conventional material with optimum content of incinerated sewage sludge ash. We have obtained the sludge ash by burning sludge at 800 ℃ for 2 h in electric furnace. Our intention of stabilization is to increase the bearing capacity of soil, reduce soil permeability, reduce cost of construction, reduce environmental waste and work on sustainable pavement construction approach. we havefocused mainly on changes in different properties of soilthat comes after addition of ISSA with our soil sample for that we have conducted several important tests like grain size distribution analysis, liquid limit, plastic limit, plastic index, proctor compaction test, California bearing Ratio test(soaked and un-soaked) test. All the tests were being performed according to guidelines given in IRC and I.S Codes. We have prepared samples with different Percentages of sludge ash i.e. 0, 2.5, 5, 7.5 and 10% and results were analysed. Based on the study of results we have seen that our soil is poorly graded sand. Our liquid limit has decreased from 27.69 at 0% replacement to 21.01 at 7.5% replacement and the maximum dry density values have increased from 1.81 to 2.02 gm/cm3 at 7.5% replacement of ISSA. The values of CBR have increased from 9.38 to 11.73% maximum at 7.5% replacement of ISSA. After getting all the values we have concludethat if we effectively use 7.5% of ISSA in our soil our C.B.R value will be greater and will see that the total thickness of pavement will decrease due to increased stability and strength value. From this we have stabilized the soil effectively by replacement of sewage sludge ash which will save cost of our project, and we have tried to reduce the environmental hazard that is associated with this material too.