Research On Strength Properties Of Flowable Treated Soil

In the practical backfill engineering, traditional backfill material may not work well in some confined areas where the work face is restricted or the area is confined. This phenomenon not only affects the performance of structures, but also brings serious security risks. This papertries to take use of the abandoned excavation soil to prepare the flowable backfill material which we called flowable treated soil. Flowable treated soil is a kind of backfill material which can be self-filling, self-compacting,self-leveling. It can overcome the disadvantages which traditional backfill material cannot be compacted in thenarrow regions or underground trench or underground empty areas. So it has a good prospect in backfill engineering.This paper uses the uniform design method to design experiment. “Flow expansion” and unconfined compressive strength are used to separately evaluate the fluidity and compressive strength of flowable treated soil. Through the research on fluidity, shrinkage and strength properties of flowable treated soil, the following conclusions are summarized:(1) The fluidity of flowable treated soil increases with the increasing of unit water consumption, and it decreases with the increasing of clay consumption. The influence of cement consumption to the fluidity of flowable treated soil is very little.(2) The dry shrinkage of flowable treated soil mainly generate within 24 hours after poured. The reason is the volume of mixture contract which caused by loss large amount of water. The dry shrinkage of flowable treated soil increases with the increasing unit water content and cement content.(3) This paper emphasizes on the study of the strength properties of flowable treated soil. The unconfined compressive strength is set as its compressive strength index. According to the experiments, the compressive strength of flowable treated soil is mainly controlled by the water cement ratio. The larger water-cement ratio is, the smaller the compressive strength of flowable treated soil is, and vice versa.