Study On Preparation Technology Of Grouting Materials With Calcined Ginger Nuts As Main Agent In Earthen Sites

Due to the influence of construction craft and natural factors,there will be fissures of different forms and scales in the earthen sites.The development of fissures destroys the structure and reduces the stability of the earthen sites.At present,there are mainly PS series,SH series and traditional building materials in fracture grouting materials for earthen sites.There are also many researches on the grouting technology.However,the research on the agitation process of fracture grouting slurry is insufficient.The slurry mixing in the practical engineering mostly takes the experience of the field personnel as the main.There is no standardized scientific process of slurry mixing,which is disadvantageous for the fissure grouting project of the earthen site.In this paper,experiments were carried out with calcined ginger nuts and soil as the main slurry materials.The analysis and conclusion are as follows:(1)The problems in the slurry preparation process of the cracking grouting project in the earthen site were investigated,and the research results related to the fracture grouting in the earthen sites at home and abroad were teased out.The influencing factors in the slurry mixing process were analyzed.The water-cement ratio of the slurry,the initial moisture content of the test soil,the stirring speed of the slurry,the stirring time,the time of the second stirring,and the gradation of the soil were selected as the study objects.(2)For different types of prepared slurry,performance evaluation tests such as grouting pressure,fluidity,segregation,volumetric shrinkage,mechanical strength,freeze-thaw cycles,and water stability were conducted.The results show that the slurry was prepared by calcined ginger nuts and soil,with a ratio of 1:25,water-cement ratio of 0.45-0.5,stirring speed threshold of 3(132r/min),stirring time of about 11-14 min and secondary stirring interval of 6h.This kind of slurry material,which requires low pressure during the grouting process,has a strong flow ability,low segregation time at the same standing time,small shrinkage,high mechanical strength,and strong resistance to freezing,thawing and rain erosion;increasing the initial moisture content of the soil can improve the mechanical properties of the grouting stone but reduce the flow capacity of the slurry;the smaller the particle size is,the stronger its resistance to freezing,thawing and rain erosion are,but it will weaken the flow ability of the slurry and increase the grouting pressure.(3)In view of the lack of performance testing and evaluation method for fracture grouting slurry in suspension of the earthen sites,a grouting pressure tester and a free-flow test tray were developed to compare the grouting pressure,the free flowability and the segregation phenomenon of the slurry under the same conditions.The results obtained in this study have been relatively satisfactory and have verified the reliability of the equipment.It can be used to test the performance of fracture grouting slurry in earthen sites.Because of a short time and a large number of different tests having not been conducted,there are certain deficiencies that need to be continuously modified and improved.