One of the most significant problems in civil engineering application is unavailability of good soil for applications such as Highway, Railway Construction sites and Land filling. Specially; this problem arises while constructing the roads and in the construction sites.
Poor bearing capacity, low shear strength, and high compressibility are some of the many problems that can occurr in the road sector and in the construction sites due to the poor soil condition. Because of these problems, some issues might occur as follows;• Excessive settlement can occur due to low bearing capacity and the high compressibility• Shear strength might not be adequate for the slope stability of embankmentsetc.The common solution of this issue is removing the weak soil and refills it again with a new soil which has better characteristics. But this will be time consuming, it will be costly and not environmental friendly. Therefore, the best thing is improving the existing soil using appropriate material. Additions of other foreign materials can be used to improve the weak soil.
As an example; cement is a good mixing material to improve the characteristics of weak soil such as bearing capacity and shear strength. But this is very expensive. Therefore, many researches have been done for improving the soils using industrial wastages like Fly ash (wastages from the power plant at Norochchole), Copper Slag (Wastages from Port) etc. Therefore, it will be cost effective process to improve a soft soil using another industrial waste.
In this study, research was conducted to improve some weak soil, which is a very weak soft soil from the water treatment plants called sludge of such treatment plants and the additive material is fly ash, which is also an industrial wastage of the Norochchole power plant. Use of two different industrial by products wastes could be used in productive manner to improve a very soft soil and it will be a cost effective method. After improving such soil, it can be used for various development projects such as road projects, embankments, construction sites and land filling (playgrounds, recreational areas etc.) depending on the improvements achieved due to the addition of fly ash.