A number of parameters,e.g.cement content,cement type,relative density,and grain size distribution,can influence the mechanical behaviors of cemented soils.In the present study,a series of conventional triaxial compre...A number of parameters,e.g.cement content,cement type,relative density,and grain size distribution,can influence the mechanical behaviors of cemented soils.In the present study,a series of conventional triaxial compression tests were conducted on a cemented poorly graded sandegravel mixture containing 30% gravel and 70% sand in both consolidated drained and undrained conditions.Portland cement used as the cementing agent was added to the soil at 0%,1%,2%,and 3%(dry weight) of sandegravel mixture.Samples were prepared at 70% relative density and tested at confining pressures of 50 kPa,100 kPa,and150 kPa.Comparison of the results with other studies on well graded gravely sands indicated more dilation or negative pore pressure in poorly graded samples.Undrained failure envelopes determined using zero Skempton’s pore pressure coefficient (= 0) criterion were consistent with the drained ones.Energy absorption potential was higher in drained condition than undrained condition,suggesting that more energy was required to induce deformation in cemented soil under drained state.Energy absorption increased with increase in cement content under both drained and undrained conditions.展开更多
The cementation reaction of copper on zinc metal in solutions of different concentrations ofcopper sulphate, at 25℃, has been studied and it is found to be a first order reaction. Moreover,the rates of this reaction ...The cementation reaction of copper on zinc metal in solutions of different concentrations ofcopper sulphate, at 25℃, has been studied and it is found to be a first order reaction. Moreover,the rates of this reaction at 0.15 mol'L-1 copper sulphate solution have been measured in a varietyof ethanol-water media at temperatures from 20℃ to 40℃. The correlation between the masstransfer coefficient and the dielectric constant has been investigated. Also, the thermodynamicparameters of activation have been calculated. The isokinetic relationship reveals the existenceof compensation effect, where the solute-solvent interactions play an important role.展开更多
文摘A number of parameters,e.g.cement content,cement type,relative density,and grain size distribution,can influence the mechanical behaviors of cemented soils.In the present study,a series of conventional triaxial compression tests were conducted on a cemented poorly graded sandegravel mixture containing 30% gravel and 70% sand in both consolidated drained and undrained conditions.Portland cement used as the cementing agent was added to the soil at 0%,1%,2%,and 3%(dry weight) of sandegravel mixture.Samples were prepared at 70% relative density and tested at confining pressures of 50 kPa,100 kPa,and150 kPa.Comparison of the results with other studies on well graded gravely sands indicated more dilation or negative pore pressure in poorly graded samples.Undrained failure envelopes determined using zero Skempton’s pore pressure coefficient (= 0) criterion were consistent with the drained ones.Energy absorption potential was higher in drained condition than undrained condition,suggesting that more energy was required to induce deformation in cemented soil under drained state.Energy absorption increased with increase in cement content under both drained and undrained conditions.
文摘The cementation reaction of copper on zinc metal in solutions of different concentrations ofcopper sulphate, at 25℃, has been studied and it is found to be a first order reaction. Moreover,the rates of this reaction at 0.15 mol'L-1 copper sulphate solution have been measured in a varietyof ethanol-water media at temperatures from 20℃ to 40℃. The correlation between the masstransfer coefficient and the dielectric constant has been investigated. Also, the thermodynamicparameters of activation have been calculated. The isokinetic relationship reveals the existenceof compensation effect, where the solute-solvent interactions play an important role.
