Study On Ecological Curing Of Straw Fiber Improvement Dredging Silt

In recent years,the dredging of inland rivers and the construction of marine ports have inevitably produced a large amount of dredged silt.How to efficiently use the discarded silt is a problem that needs to be solved urgently.Based on the "Research on the Strength Characteristics and Evolution Mechanism of Ecological Solidified Sludge Based on Straw Degradation Effect",this paper proposes a test method for improving solidified silt by using straw fiber.As well as the microscopic characteristics,a large number of experimental studies have been carried out to study the flow value and viscosity characteristics of the solidified sludge,analyze the compressive strength,shear strength,compression performance and permeability of the solidified sludge,and understand the chemical element changes in the solidified sludge.The change of composition and microscopic morphology,and the microscopic reasons for the change of the mechanical strength of solidified sludge are discussed.The experimental work of this paper is as follows:(1)Straw fiber improves the rheological properties of solidified sludge.Through fluidity test and viscosity test,the influencing factors of the rheological characteristics of the straw fiber improved solidified sludge are analyzed,and the influence of the amount of straw fiber blending on the flow value and viscosity is clarified,combined with the test of the sugar content of the straw filtrate.The influence mechanism of straw fibers on the rheological properties of solidified sludge.(2)Straw fiber improves the mechanical strength characteristics of solidified sludge.The stress-strain curve of the solidified sludge is obtained through the unconfined compressive strength test.The effect of the curing age and the amount of straw fiber on the compressive strength of the solidified sludge is clarified,and the deformation characteristics and the change law of the failure form of the solidified sludge are analyzed.;Through direct shear tests,the effects of curing age and straw fiber blending amount on the shear strength,internal friction angle,and cohesion of the solidified sludge are understood.(3)Straw fiber improves the compression and permeability characteristics of solidified sludge.Through the compression test,the yield stress of the solidified sludge is obtained,and the effect of the curing age and the amount of straw fiber blending on the yield stress is understood;through the flexible wall penetration test,the permeability coefficient of the solidified sludge is obtained,and the curing age and the straw fiber blending are determined.The influence of the input amount on the permeability of solidified sludge.(4)Chemical analysis and microscopic analysis of sludge modified by straw fiber.The pH value test is used to obtain the change in acidity and alkalinity of the solidified sludge;the loss on ignition test is used to obtain the organic matter change of the solidified sludge;the C,N,P,K trace element test is used to obtain the change of trace elements in the solidified sludge;Ray diffraction test and differential thermal analysis test to obtain the changes in the internal composition of the solidified sludge;through the SEM test,to understand the changes in the internal micro-morphology of the solidified sludge.Figure 79 Table 9 Reference 80...