| Phosphate with high quality,is very local characteristics of mineral resources in Guizhou Province.In recent years,with the continuous development of local phosphate fertilizer enterprises,especially the Kailin group in Kaiyang County and Wengfu Group in Fuquan City has resulted in more and more phosphogypsum,causing a large amount of accumulation and storage of industrial solid wastes,and the occupied land resources are increasing day by day,seriously polluting the natural environment.How to effectively dispose of phosphogypsum has become an urgent problem to be solved by phosphate mines.Therefore,it is of great practical significance to develop a phosphogypsum-based grouting material that can make extensive use of phosphogypsum and can be used for road construction and disease control.This paper relies on Guizhou Provincial Department of Transportation projects "the development and application of phosphogypsum-based(compound modified)grouting material in Guizhou Province " by the performance of Guizhou phosphorus gypsum-based grouting material experimental study.In this paper,the relationship between the components of the phosphogypsum-based grouting material in Guizhou area was studied by orthogonal test,and the law of its intensity was obtained.First,the basic physicochemical properties parameters of raw materials required for phosphogypsum-based grouting material were determined.Phosphogypsum as the main component,fly ash,cement,lime and other cementitious materials,get a new type of(highway engineering)grouting material,phosphogypsum-based grouting material: in order to find out the phosphogypsum-based grouting material,the optimal proportioning method was proposed for the initial proportioning design of phosphogypsum-based grouting material,and the corresponding unconfined compressive strength and softening coefficient were also determined through some related tests.Then,the proportioning scheme was optimized,an orthogonal design scheme for phosphogypsum-based grouting material was proposed,and a large number of experiments were conducted.The test results of the orthogonal ratio design scheme were analyzed,and the phosphogypsum-based grouting material was measured at the same time.Natural sedimentation height,velocity,fluidity,and other indicators,and ultimately obtained the optimal proportioning design of phosphogypsum-based grouting material:The first kind of scheme: 60% new Weng Phosphorus Gypsum +19% Fly Ash + 15%(32.5)Cement +6% Quicklime,the slurry concentration is 65% ~ 70%(the water to cement ratio is 0.3 ~ 0.35),in the standard wet under the curing conditions,the 28-day unconfined compressive strength can reach 3.13 MPa or more.The second option: 60% old Weng phosphogypsum +18% fly ash + 15%(32.5)cement + 7% quick lime,and the slurry concentration is 60%~65%(the water/cement ratio is 0.35~0.40).Under standard wet curing conditions,the 28-day uniaxial unconfined compressive strength can reach 4.80 MPa or more.The third option: 60% new Kai phosphogypsum + 20% fly ash + 13% ~ 14%(32.5)cement + 6% ~ 7% quicklime,slurry concentration of 60% ~ 65%(water to dust ratio 0.35~0.40),the uniaxial unconfined compressive strength can reach 4.47 MPa or more under standard wet curing conditions for 28 days.The fourth scheme: 60% of old Kai phosphogypsum +18% of fly ash + 15%(32.5)cement + 7% quicklime,and the slurry concentration is 60%~65%(the water/cement ratio is 0.35~0.40).Under standard wet curing conditions,the 28-day unconfined compressive strength can reach 3.89 MPa or more.In addition,the micro-hydration reaction mechanism of phosphogypsum-based grouting material was also analyzed,and the strength variation law was obtained.The environmental impact of phosphogypsum-based grouting material was evaluated.Finally,through the analysis of various diseases and causes of road embankment,the grouting mechanism,design and calculation method,construction technology and post-mortem quality test methods are also discussed. |
PDF Full Text Request