SUMMARY
Through this paper, three main approaches were adopted to evaluate the effectiveness of waste paper ash (WPA) for stabilization on clay soil. First, the physical properties of mixing soil were studied. Furthermore, the swelling potential of mixing soil with different percentage was also discussed. Finally, the compressive strength using unconfined compressive strength (UCS) apparatus was evaluated. It was found that after mixing with waste paper ash (WPA), the percentage of soil passing sieving number 200 and plasticity index reduces by increasing of the waste paper ash (WPA) percentage. It might be attributed to the bonding of the chemical content of waste paper ash (WPA) to the soil particles. In addition, the swelling potential slightly reduces by increasing of waste paper ash (WPA) percentage. Furthermore, the compressive strength increases with waste paper ash (WPA) 5% and 10%.