The Research On The Mechanism And Road Performance Of Secondary Steel Slag Disposing Subgrade

Steel is an important industrial material, steel industry is one of the most representative and growing industry in the process of industrialization in the world. However, with the growth of the steel industry, its by-product-the output of steel slag also increased. With the lack of effective use and long-term accumulation, steel slag has taken up a lot of farmland and pollute the environment. Also Steel slag is a material with good road performance, its safely and economically use for infrastructure construction has a significant meaning of improving the life of the construction works, reducing project cost and reducing the pollution to the environment. In this paper, the secondary steel slag is used which has been second cycle magnetic washed on the basis of the original and removing some heavy metals, iron and other materials that slag contains, at the same time eliminating the impact of expansion of steel slag (f-CaO). Through laboratory tests and experiment on the performance of different slag lime soil, hoping it can provide some reference for the technical evaluation system and practical engineering application.Firstly, the raw material used in the study was tested, including physical and chemical properties of experimental soil, steel slag and lime, focusing on the secondary steel slag composition, particle composition and stability.Secondly, compaction test, CBR test, USC test, bender element test were tested on secondary steel slag soil, lime soil, steel slag lime soil respectively. By comparing the different performance of various types of soil mechanics, taking research on the effect of steel slag and lime soil and mechanism of formation of slag lime intensity, and combining with various proportions of steel slag lime and mechanical properties of the mechanical parameters of the experimental data, considering the difference in performance of each general mechanics, it choose the best mix ratio of secondary slag, lime, soil is (50%,5%,45%).Thirdly,, taking research on the formation mechanism of the intensity a by taking X-ray diffraction test, SEM test and MIP test on the basis of the best mix ratio during the full age respectively. By taking XRD, SEM test, the mineral composition and quantity changes of secondary steel slag lime soli was counting out. The results showed that:as age growing, the C-S-H and Aft products structure becomes compact. Combining SEM with MIP test, Porosity rate has dropped from 40.7% to 35.3%, main pore becomes smaller which is accordant with mechanics experimental results.Fourthly, to meet the requirements of road performance, paving road test was tested to verify the feasibility of the steel slag lime soil. At the same time the result of bender element test matched the result of Rayleigh waves which established a bridge between indoor test and non-destructive test by observing the indoor and outdoor test. It also Provides a new basis for the non-destructive testing of the construction.Finally, according to the economy and utility of secondary steel slag, the corresponding construction technology and methods was proposed, and was applied to engineering.